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Project Title:  NSCOR: Mechanisms underlying the risk of HZE particle-induced solid tumor development Reduce
Fiscal Year: FY 2016 
Division: Human Research 
Research Discipline/Element:
HRP SR:Space Radiation
Start Date: 01/01/2011  
End Date: 06/30/2016  
Task Last Updated: 09/10/2016 
Download report in PDF pdf
Principal Investigator/Affiliation:   Wang, Ya  M.D., Ph.D. / Emory University 
Address:  School of Medicine Radiation Oncology 
1365 Clifton Road NE 
Atlanta , GA 30322 
Email: ywang94@emory.edu 
Phone: (404) 778-1832   
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: Emory University 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Doetsch, Paul  Emory University 
Orloff, Gregg  Emory University 
Sun, Shi-Yong  Emory University 
Vertino, Paula  Emory University 
Wang, Huichen  Emory University 
Dynan, William  Emory University 
Key Personnel Changes / Previous PI: No change
Project Information: Grant/Contract No. NNX11AC30G 
Responsible Center: NASA JSC 
Grant Monitor: Simonsen, Lisa  
Center Contact:  
lisa.c.simonsen@nasa.gov 
Solicitation / Funding Source: 2010 Space Radiation NSCOR/Virtual NSCOR NNJ10ZSA002N 
Grant/Contract No.: NNX11AC30G 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:  
No. of Bachelor's Candidates: 17 
No. of PhD Degrees:
No. of Master's Degrees:  
No. of Bachelor's Degrees:
Human Research Program Elements: (1) SR:Space Radiation
Human Research Program Risks: (1) Cancer:Risk of Radiation Carcinogenesis
Human Research Program Gaps: (1) Cancer01:How can experimental models of tumor development for the major tissues (lung, colon, stomach, breast, liver, and leukemias) be developed to represent the major processes in radiation carcinogenesis and extrapolated to human risk and clinical outcome projections? (IRP Rev J)
(2) Cancer02:How can experimental models of tumor development for the other tissues (bladder, ovary, brain, esophagus, skin, etc.) be developed to represent the major processes in radiation carcinogenesis and extrapolated to human risk and clinical outcome projections? (IRP Rev J)
(3) Cancer03:How can experimental models of carcinogenesis be applied to reduce the uncertainties in radiation quality effects from SPEs and GCR, including effects on tumor spectrum, burden, latency and progression (e.g., tumor aggression and metastatic potential)? (IRP Rev F)
(4) Cancer04:How can models of cancer risk be applied to reduce the uncertainties in dose-rate dependence of risks from SPEs and GCR?
(5) Cancer07:How can systems biology approaches be used to integrate research on the molecular, cellular, and tissue mechanisms of radiation damage to improve the prediction of the risk of cancer and to evaluate the effectiveness of CMs? How can epidemiology data and scaling factors support this approach?
(6) Cancer08:What biological countermeasures should be used to reduce SPE and GCR cancer risks? What side effects should be tolerated vs. Mission risks?
Flight Assignment/Project Notes: NOTE: End date changed to 6/30/2016 per NSSC and S. Monk/LaRC (Ed., 12/31/15)

Task Description: Our NASA Specialized Center of Research (NSCOR) proposal entitled “Mechanisms underlying the risk of HZE particle-induced solid tumor development” (NNX11AC30G) was effective January 1, 2011 and completed June 30, 2016. There were two main goals of the Emory University NSCOR: (i). Evaluate how high of high charge and energy (HZE) particles (as a special component of space radiation) to induce lung tumorigenesis; (ii) Elucidate the mechanism underlying HZE particle-induced lung tumorigenesis.

Primary Goal (Risk Estimation): Emory NSCOR executed 8 beam exposures at Brookhaven National Laboratory (BNL) and NASA Space Radiation Research Laboratory (NSRL) (Fall 2011; Spring/Fall 2012, 2013, and 2014; Spring 2015) that included mice and cell irradiation. We have used 1340 in total mice and irradiated 1110 mice whole body to iron (600 MeV/n), silicon (300 MeV/n), oxygen (600 MeV/n), and x-ray (320 KeV) with either single dose (1 Gy) or fractionated doses (0.2 Gy x 5 at 24 h interval). At 1.5 years post irradiation, the incidents of lung tumorigenesis were analyzed and subsequently revealed that wild type C57BL/6J mice with an extremely low spontaneous lung tumorigenesis background induced more lung tumorigenesis at 1.5 years after exposure to high-LET (linear energy transfer) radiation (particularly to silicon) than low-LET radiation (such as x-rays). These results have been published (Radiat Res 2015, 183:233-239).

Secondary Goal (Mechanistic Studies): Four synergized scientific projects of our NSCOR investigated how HZE particle-induced lung tumorigenesis, studied the mechanism underlying how mammalians respond to HZE particle-induced DNA damage, which contributes to the development of lung tumor. HZE exposure elicits complex DNA damage that follows a broader cell/tissue stress response that likely includes changes in expression of tumor suppressor proteins, persistent elevation of reactive oxygen species, and alterations in the pattern of DNA methylation. HZE particle-induced broader stress response amplifies the carcinogenic risk from a primary DNA damage event, which served as the central hypothesis of the Emory NSCOR. The key investigators have used genetic, epigenetic, and biochemical approaches to address the stress responses in HZE particle-induced DNA damage and the nature of the damage linked to lung tumorigenesis. Our accomplishments pertaining to the mechanistic studies are reflected in our publications.

The administrative core executed the overall Emory NSCOR coordination. In conjunction with the NASA mid-term review, this core organized two Emory NSCOR retreats during 2013 February and 2015 January where the NSCOR team as well as our external consultants (experts in high-LET radiation field and other related cancer field) participated, which enabled fruitful discussions to ensure our NSCOR closely followed the NASA-NSCOR initiative. The Emory NSCOR had an education component that facilitated summer student involvement and public education. The education component was unique for our ESCOR, which was based on NASA encouragement and supported by the School of Medicine and the Winship Cancer Institute of Emory University ($50,000/ year, $250,000 total). Please see the Education Component achievement section for details. Together, 26 peer-reviewed publications and 53 published abstracts for proceedings resulted from the mechanistic studies and risk estimation experiments as described in the scientific projects and animal/radiation core.

Research Impact/Earth Benefits: Our NSCOR research impact on Earth is reflected as follows:

1. Contribution towards lung cancer prevention. Lung cancer is the leading cause of cancer death among men and women. Through studying the mechanism underlying space radiation-induced lung tumorigenesis, the Emory NSCOR research discovered new roles of some genes in lung tumorigenesis, which not only facilitated a better understanding of lung carcinogenesis but also provided strategies for improving lung cancer prevention. For example, we discovered a new mechanism to explain GPRC5A as a lung tumor suppressor by revealing that GPRC5A at the endoplasmic reticulum (ER) membrane suppresses synthesis of the secreted or membrane-bound proteins including a number of oncogenes, the most important one being Egfr. Our findings indicate that under-expressed GPRC5A during lung tumorigenesis enhances any transcriptional stimulation through an active translational status, which can be used to control oncogene expression and potentially resulting related disease. Since it is known that vitamin A can stimulate GPRC5A expression, our results suggest that taking vitamin A would help prevent radiation-induced lung tumorigenesis. This work was published in Nature Communication 2016.

2. Contribution to cancer radiotherapy. DNA damage, particularly DNA double strand breaks (DSB), is not only a severe threat to genomic stability but is also the major reason radiotherapy kills tumor cells. Therefore, understanding the mechanism underlying DNA DSB repair will benefit both cancer prevention and cancer treatment. Through studying the mechanism underlying the repair of space radiation-induced DNA DSB, our NSCOR research contributed to new discoveries to help better understand the nature of DNA DSB repair. One example, Ape1 (a base repair enzyme) plays an important role in generating small DNA double strand fragments by digesting the damaged base in cluster DNA damage sites, which contributes to high LET radiation-induced high relative biological effectiveness (RBE). This discovery does not only help us to reduce space radiation induced DNA damage by using an Ape1 inhibitor but also suggests that we can use an Ape1 activator to increase the efficiency of high-LET radiotherapy (such as carbon ion radiotherapy) on tumor killing. This work was published in JBC 2014.

Task Progress & Bibliography Information FY2016 
Task Progress: 2-1. Overall major achievements:

Major achievement 1: Our team demonstrated for the first time that wild type C57BL/6J mice with an extremely low spontaneous lung tumorigenesis background can induce more lung tumorigenesis at 1.5 years after whole body exposure to high-LET radiation (particularly to silicon) than low-LET radiation (such as x-rays).

Importance of this achievement: All previous studies (published and unpublished) including our initially planned experiments pertaining to radiation-induced lung tumorigenesis used mice with a highly spontaneous lung tumorigenesis background. Our results using the mice with a highly spontaneous lung tumorigenesis background revealed that these mice do not adequately resemble healthy astronauts or estimate the risk of space radiation-induced lung tumorigenesis. Fortunately, our wild type C57BL/6J control mice provided us with valuable data and demonstrated that high-LET radiation (particularly silicon) versus low-LET radiation (such as x-rays) have a higher risk of inducing lung tumorigenesis. Lung cancer is the most prevalent fatal cancer among men and women worldwide. Lung cancer is believed to be one of the major risks of HZE-particle exposure-induced carcinogenesis, although a quantitative and mechanistic understanding of this risk needs further study. Our published data (including positive and negative results) provide an important platform to continue studying the extent of the risk of existing space radiation-induced lung tumorigenesis. In addition, we can follow our studies to determine whether and how different qualities (LET) of radiation affects lung tumorigenesis. These results will not only provide important information that will aid in the facilitation of the NASA Mars project, but will also provide the public with useful information concerning lung carcinogenesis and the benefits of cancer prevention.

Major achievement 2: Our team has identified that Ape1 (a base repair enzyme) plays an important role in generating small DNA double strand fragments by digesting damaged base in cluster DNA damage sites, which contributes to high LET radiation-induced high relative biological effectiveness (RBE).

Importance of this achievement: Space radiation from HZE-particles with high-LET is different from terrestrial low-LET radiation. Understanding the mechanism by which mammalian cells respond to space radiation-induced DNA damage is a key issue for us to determine the risk of space radiation on astronauts’ health at any endpoint. Such results suggest that we can use this mechanism to identify a space radiation countermeasure by searching for an Ape1 enzyme inhibitor with low toxicity to reduce high-LET radiation-induced DNA damage and thereby reduce space radiation-induced health risks. These results have been published: JBC 2014, 289:30635-30644 (see Cumulative Bibliography hyperlink).

2-2. Major achievements per component

Project 1: Elucidate the mechanism underlying HZE particle-induced lung carcinogenesis by determining the nature of the damage and the roles of some key genes in lung carcinogenesis. We demonstrated how changed miRNA expression, such as miR-34a (a tumor suppressor) and miR-21 (an oncogene), after radiation contribute to lung tumorigenesis. Project 1 also demonstrated that miR-21 highly expresses in irradiated and human cells as well as different tissue from irradiated mice. In addition, Project 1 identified some new miR-21 targets linked to lung tumorigenesis. Furthermore, and most important, project 1 showed that the high levels of miR-21 in lung tumors from irradiated mice correlated with the miR-21 level in serum from the same mice. These results indicate that the miR-21 serum level might serve as a useful biomarker to predict the risk of space radiation-induced lung tumorigenesis, which is worthy of continued follow-up studies to confirm since, if proven, the miR-21 level in serum can be easily detected in astronauts to predict lung tumorigenesis risk. We demonstrated a new GPRC5A mechanism that serves as a lung tumor suppressor by revealing that GPRC5A at the endoplasmic reticulum (ER) membrane suppresses synthesis of the secreted or membrane-bound proteins including a number of oncogenes, the most important one being Egfr. The ER-located GPRC5A disturbs the assembly of the eIF4F-mediated translation initiation complex on the mRNA cap through directly binding to the eIF4F complex with its two middle extracellular loops. Particularly, suppression of EGFR by GPRC5A contributes significantly to preventing ionizing radiation (IR)-induced lung tumorigenesis. Thus, GPRC5A deletion enhances IR-promoted EGFR expression through an increased translation rate, thereby significantly increasing the lung tumor incidence in Gprc5a-/- mice. Our findings indicate that under-expressed GPRC5A during lung tumorigenesis enhances any transcriptional stimulation through an active translational status, which can be used to control oncogene expression and potentially resulting related disease. Since it is known that vitamin A could stimulate GPRC5A expression, our results suggest that taking vitamin A would help prevent radiation-induced lung tumorigenesis. This work has been published in Nature Communication 2016.

We demonstrated a new mechanism explaining why high-LET radiation induces chromosome translocation more efficiently than low-LET radiation. Previously, with the aid of NASA funding, we demonstrated that high-LET radiation compared to low-LET radiation generated more DNA double strand break (DSB) fragments (< 40 bp) that affect Ku/DNA-PKcs from properly binding and interfere with the efficiency of non-homologous end-joining (NHEJ) but do not affect homologous recombination repair (HRR) and, thus, result in high RBE for cell killing (DNA Repair, 2008, 7:725-733). Following this study, we further found that high-LET radiation-induced more DNA fragments are the major reason for high-LET radiation vs low-LET radiation to generate more chromosome translocations. In collaboration with project 2, we designed a series of reporters to demonstrate this important discovery and a manuscript will be submitted soon. This discovery will provide a mechanism to explain why high-LET radiation vs low-LET radiation more efficiently induces genomic instability and tumorigenesis since chromosome translocation is a key marker and a major reason for carcinogenesis.

Project 2: Determine whether HZE-particle radiation exposure results in hyper-reliance on error-prone DNA repair pathways and promotes lung-tumorigenesis. A history of exposure to HZE particle radiation compromises the ability to accurately repair future DNA damage, a phenomenon termed the mutagenic repair phenotype. This increases the risk of oncogenic chromosome rearrangements in a setting where occasional encounters with HZE particles occur in the context of ongoing exposure to low-LET components of the galactic cosmic ray field. However, because the mutagenic repair phenotype is a non-targeted effect attributable to cell-cell signaling, it might also be possible to suppress it through pharmacologic interventions as an HZE particle radiation countermeasure. Mutagenic repair phenotype observed following direct irradiation of a reporter cell line. The experimental approach is to test whether a history of HZE radiation exposure influences the fidelity (and not just the efficiency) of the response to future DNA damage. We term this effect the “mutagenic repair phenotype.” Work used a tumor cell line that had been engineered to report mutagenic repair of enzymatically-induced DNA double-strand breaks. We exposed replicate cultures to HZE particle radiation and challenged at intervals by expression of a rare-cutting nuclease that cuts within integrated reporter transgenes. In this system, deletion of a sequence within one of the reporter transgenes leads to green fluorescence, and translocation between two transgenes integrated into different chromosomes leads to red fluorescence. An increase in the frequency of nuclease-induced deletions and translocations indicates a breakdown in the fidelity of DNA double-strand break repair.

Using this system, we demonstrated that irradiation with 600 MeV/u 56Fe increases nuclease-induced translocations by up to 3-fold in a dose-dependent manner. It increases deletions by a more modest but nevertheless significant factor. The effect persists for up to two weeks and is associated with the presence of markers of chronic DNA damage. The effect is not seen with low-LET X or gamma-rays at any dose tested.

To further explore the influence of ion species and LET, we tested 1000 MeV/u 48Ti and 300 MeV/u 28Si. Irradiation with 48Ti increases the frequency of nuclease-induced translocations by 3-fold, although the duration of the effect is shorter than for 56Fe, and there is no change in the frequency of nuclease-induced deletions. Irradiation with 28Si does not affect the frequency of nuclease-induced translocations or deletions. Thus, induction of the mutagenic repair phenotype is dose and LET dependent.

Results are potentially significant for carcinogenesis in the space radiation environment, where occasional encounters with HZE particles occur in the context of more frequent encounters with energetic (low-LET) protons or helium nuclei. The findings indicate the existence of a mechanism whereby an initial encounter with an HZE particle degrades the ability to repair DNA double-strand breaks induced during subsequent encounters with low-LET particles, increasing cumulative risk of oncogenic chromosome rearrangements.

Mutagenic repair phenotype observed in bystander cells. We again performed experiments in which replicate cultures of reporter cells were exposed to HZE particle radiation. Rather than challenging them directly with rare-cutting nuclease, however, we co-cultured the irradiated cells at intervals with radiation-naïve reporter cells expressing the rare-cutting nuclease. We measured the relative frequency of nuclease translocations and deletions at predetermined sites within a reporter cassette. We performed experiments with two ions with different LET values (1000 MeV/u 48Ti and 600 MeV/u 56Fe) and with low-LET radiation as a reference. We observed increases in nuclease-induced translocations (up to 3-fold) and deletions (up to 1.5-fold) in the radiation-naïve reporter cells. No effect was seen when low-LET irradiated cells were co-cultured with the radiation-naïve bystanders. Results indicate that HZE-irradiated cells release a signal into the medium that results in a breakdown in the fidelity of DNA double-strand break repair in neighboring cells. In an attempt to identify the signal, we performed genome expression profiling. HZE irradiation of the reporter cells induces a characteristic set of mRNAs encoding secreted factors, including IL-1b, Il-6, and IL-8. However, these same mRNAs were also induced by low-LET radiation, which does not evoke the mutagenic repair phenotype. With separate NASA funding, we are currently exploring the hypothesis that extracellular vesicles, rather than secreted factors, serve as carriers of the mutagenic repair signal.

Results are again significant for carcinogenesis in the space radiation environment, where the HZE particle fluence is low. Because the mutagenic repair phenotype occurs as the results of a non-targeted effect, a single HZE particle has the potential to compromise the fidelity of repair not only in cells traversed by the radiation track, but also in nearby cells that are not directly traversed. In theory, it might be possible to suppress the mutagenic repair signal as a strategy to mitigate radiation risk. Further characterization of the signal will be required to establish the feasibility of such an approach.

Mutagenic repair phenotype observed for endogenous genes in near-normal lung epithelial cells. Experiments described thus far were performed using a tumor cell line bearing reporter transgenes, which permits facile and very accurate measurements of deletion and translocation frequencies. It was of prime importance to demonstrate whether the phenomenon is also seen in lung epithelial cells, which are the relevant target for lung carcinogenesis. It was also important to demonstrate whether it was seen, not only with artificial reporter genes, but also with endogenous, cancer-relevant proto-oncogenes. Such experiments had not been feasible at the start of the NSCOR project. However, they became feasible with the advent of CRISPR/Cas9 technology, which permits the introduction of targeted DNA double-strand breaks virtually anywhere in the genome.

We adopted an approach based on the introduction of simultaneous double strand breaks in the endogenous ALK and EML4 loci. Faithful DSB repair regenerates the original, unrearranged locus, whereas mutagenic DSB repair leads to a paracentric inversion, with overexpression of an oncogenic EML4-ALK fusion. This is the single most common chromosomal rearrangement in human nonsmall cell lung cancer and has previously been shown to act as a driver of lung carcinogenesis in a mouse model. We developed a Taqman PCR assay for precise quantification of inversion frequency in CRISPR/Cas9 expressing human bronchial epithelial cell populations.

Initial results indicate that exposure to 48Ti radiation leads to an increase in CRISPR/Cas9 nuclease-induced EML4-ALK rearrangements in derivatives of the near-normal human epithelial cell line, HBEC3-KT. We are continuing to characterize and optimize the system with support from an individual NASA award.

Project 3: Determine the nature of the HZE-particle induced ROS stress response, whether it contributes to HZE particle-induced lung carcinogenesis. This project focused on elucidating mechanisms underlying two prevalent phenotypes resulting from exposure to low and high LET radiation, namely reactive oxygen species (ROS) production and persistent genomic instability. Our initial studies in a non-cancerous human epithelial cell line (HBEC3KT) defined their temporal expression and LET dependence, determining that ROS levels and genomic instability persist within the progeny of irradiated cells proliferating in vitro for up to two weeks following exposure to 1 Gy x-rays (320 keV) or 1Gy 56Fe ions (600 MeV). While we did not observe radiation quality effects for ROS levels, micronuclei increased with an approximate RBE of 4 when these parameters were measured at day 7. We identified p38MAPK and ATM as molecules necessary to sustain these phenotypes. We further tested the role of pro-inflammatory responses in the ROS increases and genomic instability. We found that Fe induced IL-8 with an RBE of 4, by a mechanism dependent on IL-1alpha, which also induced the release of GM-CSF and GRO alpha. This IL-1alpha-dependent response however does not affect ROS production or genomic instability. ROS increases and genomic instability are elicited by multiple types of HZE ions, including Oxygen, Silicon, Iron as well as proton in a range of LET: 17 keV/µm, 70 keV/µm, and 175 keV/µm, respectively in in vitro exposed mouse and human bronchial epithelial cells and in the lungs of whole body irradiated mice. To further investigate the broader context of these phenotypes, we conducted a label-free global proteome analysis, which confirmed some of our previous findings from candidate-based approaches and revealed changes in novel pathways, implicating several nuclear proteins as potential mediators of genomic instability. These findings are of significance because such persistent phenotypes result from protracted biological responses to the initial exposure. Further mechanistic studies should allow identification of biomarkers to indicate individual responses to radiation exposure to assess risk and provide actionable targets to mitigate and/or prevent late effects.

Project 4: Determine the scope of HZE-particle radiation-induced alterations in DNA methylation patterns, whether these alterations contribute to lung carcinogenesis. We characterized the acute impact and long-term persistence of space radiation exposure on DNA methylation at 485,512 CpG sites using an array-based approach (Illumina Human Methylation 450K platform), and compared the effects of low LET (X-ray) vs. high LET (Ti, Fe, Si) radiation exposure. An in-house analytic pipeline was developed and used to identify DNA methylation changes significantly associated with dose, ion, and time. We showed for the first time that exposure of immortalized bronchial epithelial cells to HZE particle radiation induces stable and persistent changes to the epigenome, reflected in site-specific changes in DNA methylation. The radiation-induced changes to DNA methylation patterns are both LET- and quality-dependent; with each insult having a unique impact on the epigenome with regards to the direction, distribution, and specific CpG sites affected. Remarkably, the Fe-induced DNA methylation ‘signature’ uniquely reflects a cancer-specific DNA methylation pattern observed in primary human lung cancers. Taken together these data suggest that a stable imprint of prior space radiation exposure is reflected in the epigenome, and may prove useful as a biomarker of individual lung cancer risk.

Our work has also established a new paradigm for thinking about the influence of HZE particle exposure by probing the relationship between local chromatin environment and propensity towards space radiation-induced epigenome alterations. Using existing genome-wide histone modification profiles, RNA polymerase II binding profiles and other chromatin features from the ENCODE project, we determined the chromatin structure surrounding the radiation-sensitive CpG sites. This analysis revealed that the Fe-affected sites were more likely (OR=1.3-1.5 fold) to occur in areas with a more “open” chromatin structure, including promoters and distal regulatory elements (enhancers), but were depleted from the transcribed regions of genes. Consistent with a propensity for enhancers, Fe-affected sites were enriched in regions that are accessible to DNaseI and marked by acetylated histone H3 lysine 27 (H3K27ac), a mark of active enhancers. In contrast, Si -affected sites were depleted from genes altogether and were more likely to occur in the condensed chromatin environments found in the intergenic spaces. These data indicate that ions of different charge and LET impart a unique epigenetic imprint on the genome and further implicate local chromatin environment as a key determinant of the underlying susceptibility to, or persistence of, space radiation-induced DNA methylation changes.

Our data raise the exciting possibility that the long-term consequences of space radiation exposure are rooted in the epigenetic reprogramming at distal regulatory elements or enhancers, regions that influence gene expression from a distance and harbor the vast majority of allelic sequence variation associated with human cancer risk. Indeed, the majority of DNA sequence polymorphisms that have been linked to cancer risk in population-based studies are not within gene coding regions, but rather are enriched in known or suspected enhancer regions. DNA methylation status at distal enhancers is a far better indicator of the inter-tumor heterogeneity in gene expression than that of promoters and can be used as a surrogate to predict enhancer activity even in the absence of information about chromatin features. HZE particle induced changes at such regions could underlie the inter-individual variation in biological responses to HZE particle radiation exposure and ultimately in long-term disease risk. A better understanding of the epigenetic imprint left by the components of space radiation and the extent to which this reflects cancer risk sets the stage for the future use of epigenetic signatures to monitor the cumulative impact of space radiation exposure among astronauts in deep space.

Moving forward, our goal is to define HZE particle-specific epigenomic imprints manifest in enhancers and other non-genic parts of the genome. The Illumina 450K methylation array has been useful for our prior work in humans, and allows direct comparison to tumor tissue data in the TCGA project. However, it has limited coverage of non-genic regions and there is no corresponding array for the mouse. Thus, we have developed technology “reduced-representation bisulfite sequencing” (RRBS) that allows for the assessment of methylation at 2.7M (mouse) and 4.1M (human) CpGs (10-20% of the genome). This covers 98% of annotated human/mouse promoters and ~50% of enhancers, among other non-coding regions. Our team has developed a powerful new statistical approach, DSS, to identify differentially methylated CpG sites (DMSs) and regions (DMRs) between unexposed and exposed samples. Parallel RNAseq (TruSeq library preparation, paired-end sequencing) and differential expression analysis can be performed, allowing gene expression correlates. We have applied this approach to identify DMRs in mouse lung bronchial epithelial cells exposed to 1.0 Gy 28Si or 56Fe, and identified differentially methylated regions and correlated this with gene expression changes. We are thus poised to define HZE-particle induced epigenomic alterations at distal regulatory elements, as well to expand these studies to tissues from mice exposed to HZE ions.

Education component: The education component was unique for our ESCOR team, which was based on NASA encouragement and supported by School of Medicine and Winship Cancer Institute of Emory University ($50,000/ year, $250,000 total). The major goal of this component was to educate the student population as well as the public. The accomplished tasks were as follows:

(1) Public Outreach

A. Emory NSCOR Website. We developed a full website for the NASA Emory NSCOR project. The content contains information about the research done by the project leaders and general information about radiation and radiation biology. The website contains information about the research being done (and the researchers performing the work), educational materials for students and the public, and allows participants to keep up with events related to the Emory NSCOR.Video interviews with the project leaders are presented on the site. Relevant video clips (and additional links) have been placed on the CancerQuest website ( http://www.cancerquest.org ) to leverage the existing user base of CancerQuest.

B. Radiation Education Materials for Students and the Public. We developed and disseminated a radiation curricular unit designed for middle and high school. The unit includes a PowerPoint® presentation, vocabulary list, and more. All material is designed to meet the Georgia Science Standards. The PowerPoint® is also very well suited for education of the general public.

C. Facebook® Our Facebook® page has 32,000 fans and has been used to promote research related to the work of the Emory-NSCOR, our educational materials, Emory NSCOR events, and radiation biology research.

(2) Student Engagement: training of undergraduate researchers via the Summer Undergraduate Research at Emory (SURE) program

One goal of the education unit was to encourage students to pursue science technology and mathematics (STEM) careers. To achieve this, we worked with the Emory SURE Program. SURE is a 10-week long research program. The program is administered by the Emory College Center for Science Education. Participation of underrepresented minorities is strongly encouraged by the Emory SURE program and a minimum of 50% of SURE participants are members of these populations (including ethnic/racial groups, economically disadvantaged, first generation college students, and disabled students).

Emory NSCOR summer research students participate in all SURE activities and present their work via posters at the conclusion of the program. Emory NSCOR researchers hosted 17 different students in their laboratories. Two of those students worked for more than one summer.

(3) Internal Communication/Research Facilitation through Blackboard®

The Emory NSCOR utilized an Emory-sanctioned system, Blackboard®, to host pertinent grant-related documents including meeting agendas and minutes, and lists of shared reagents/cell lines. Access to the system was restricted to those individuals currently working on the project.

Administrative Core major achievements: Apart from coordinating the different components of Emory NSCOR through weekly email and monthly face-to-face meetings, the most important activities for this administrative core were to organize two successful retreats in February 2013 and January 2015. All internal advisory board (IAB) and external advisory board (EAB) members attended the Emory NSCOR retreats as well as all project-related personnel. EAB members included Carlo Croce, MD, Professor and Chair, Depts. of Human Cancer Genetics, Molecular Virology, Immunology and Medical Genetics; Director, Human Cancer Genetics Program, Ohio State University Medical Center (For Project 1). George Iliakis, PhD, Professor, Director, Institute of Medical Radiation Biology, University of Duisburg-Essen, Medical School, Essen, Germany (For Project 2). Peter O’Neill, PhD, Professor, Gray Institute for Radiation Oncology & Biology, Department of Oncology, University of Oxford, Oxford, UK (For Project 3). Marco Durante, PhD, Professor, GSI-Biophysik, Darmstadt – Germany (For Project 4).

The EAB/IAB members previewed their respective project materials and during these retreats, the Emory NSCOR project leaders reported their progress and EAB/IAB listened and provided valuable comments that greatly enhanced the team’s ability to follow the major track of the NASA Space Radiation Element requirements and to more efficiently carry out the designed experiments. Our NSCOR team benefitted significantly from the retreats and the retreats were institutionally supported.

Animal/Radiation Core major achievements: Apart from the major overall achievement 1 as described above (demonstrating for the first time that wild type C57BL/6J mice with an extremely low spontaneous lung tumorigenesis background can induce more lung tumorigenesis at 1.5 years after whole body exposure to high-LET radiation (particularly to silicon) than low-LET radiation), the animal/radiation core also served to facilitate a summary describing important lessons learned during our three-year animal experiments. The most important lesson being that mice with high spontaneous lung tumorigenesis: either over-expressed with oncogene or deficient in tumor suppressors are not good models for evaluating the risk of high-LET radiation-induced lung tumorigenesis. This summary is represented in detail in our publication (Life Science Space Research 2016, 9: 48-55). This publication provides NASA and affiliated scientists who study risk of space radiation-induced lung tumorigenesis with valuable lessons. This paper has been cited in the news section by the NASA supported online journal, “The Health Risks of Extraterrestrial Environments (THREE).”

Bibliography Type: Description: (Last Updated: 07/07/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Zhang X, Ng WL, Wang P, Tian L, Werner E, Wang H, Doetsch P, Wang Y. "MicroRNA-21 Modulates the Levels of Reactive Oxygen Species via Targeting SOD3 and TNFalpha." 22nd Annual Space Radiation Investigators' Workshop, League City, TX, September 18-21, 2011.

22nd Annual Space Radiation Investigators' Workshop, League City, TX, September 18-21, 2011. , Sep-2011

Abstracts for Journals and Proceedings Zheng X, Ding L, Hudson F, Dynan WS. "Long-term Effects of a Single Exposure of the Vertebrate Embryo to High Charge and Energy (HZE) Particle Radiation." Oral Presentation, 58th Annual Meeting of the Radiation Research Society, San Juan, Puerto Rico, September 30-October 3, 2012.

58th Annual Meeting of the Radiation Research Society, San Juan, Puerto Rico, September 30-October 3, 2012. S-1303. , Sep-2012

Abstracts for Journals and Proceedings Zheng X, Ding L, Hudson F, Dynan WS. "Long-term Effects of a Single Exposure of the Vertebrate Embryo to High Charge and Energy (HZE) Particle Radiation." 23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012.

23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012. Abstract #8078. , Jul-2012

Abstracts for Journals and Proceedings Li Z, Hudson FZ, Murnane JP, Dynan WS. "Effect of HZE Particle Radiation Exposure on Repair of Subsequent Enzyme-Induced DNA Double Strand Breaks." 23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012.

23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012. Abstract #7132. , Jul-2012

Abstracts for Journals and Proceedings Zheng X, Kuhne WW, Mitani H, Urushijara Y, Kakimoto T, Hudson F, Jaafar L, Dynan WS. "Long-term Effects of High Charge and Energy (HZE) Particle Exposure Measured in vivo Using the Japanese Medaka (Oryzias latipes)." 23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012.

23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012. Abstract #7133. , Jul-2012

Abstracts for Journals and Proceedings Doetsch P. "Effect of Space Radiation on Human Cells." Oral presentation, NASA Headquarters, Washington, DC, February 14, 2013.

Oral presentation, NASA Headquarters, Washington, DC February 14, 2013. , Feb-2013

Abstracts for Journals and Proceedings Doetsch P. "Acute and Chronic Genetic and Biological Effects of X-Rays Mediated by Reactive Oxygen Species." Oral presentation, University of Messina, Italy, April 10, 2013.

Oral presentation, University of Messina, Italy, April 10, 2013. , Apr-2013

Abstracts for Journals and Proceedings Pizzicato L, Wang J, Wang Y. "Investigating the effects of GPRC5A on metabolism." Summer Undergraduate Research at Emory (SURE) Symposium, Atlanta, GA, August 1, 2013.

Summer Undergraduate Research at Emory (SURE) Symposium, Atlanta, GA, August 1, 2013. , Aug-2013

Abstracts for Journals and Proceedings Corgiat E, Kandimalla R, Tang X, Wang H. "Effect of miR-155 on radiation induced DNA damage response." Summer Undergraduate Research at Emory (SURE) Symposium, Atlanta, GA, August 1, 2013.

Summer Undergraduate Research at Emory (SURE) Symposium, Atlanta, GA, August 1, 2013. , Aug-2013

Abstracts for Journals and Proceedings van Voorthuysen M, Abreu E, Patel P, Parsons ME, Kline E, Marcus AI, Vertino PM. "Altered cell cycle effects of TMS1." Summer Undergraduate Research at Emory (SURE) Symposium, Atlanta, GA, August 1, 2013.

Summer Undergraduate Research at Emory (SURE) Symposium, Atlanta, GA, August 1, 2013. , Aug-2013

Abstracts for Journals and Proceedings Li Z, Hudson FZ, Wang H, Wang Y, Murnane JP, Dynan WS. "Secretory protein phenotype accompanied by mutagenic joining of enzymatically-induced DNA double-strand breaks in a population of HZE-exposed human cells." 2014 NASA Human Research Program Investigators’ Workshop, Galveston, TX, February 12-13, 2014.

2014 NASA Human Research Program Investigators’ Workshop, Galveston, TX, February 12-13, 2014. , Feb-2014

Articles in Peer-reviewed Journals Ng WL, Chen G, Wang M, Wang H, Story M, Shay JW, Zhang X, Wang J, Amin AR, Hu B, Cucinotta FA, Wang Y. "OCT4 as a target of miR-34a stimulates p63 but inhibits p53 to promote human cell transformation." Cell Death Dis. 2014 Jan 23;5:e1024. https://doi.org/10.1038/cddis.2013.563 ; PubMed PMID: 24457968; PubMed Central PMCID: PMC4040665 , Jan-2014
Articles in Peer-reviewed Journals Li Z, Jella KK, Jaafar L, Li S, Park S, Story MD, Wang H, Wang Y, Dynan WS. "Exposure to galactic cosmic radiation compromises DNA repair and increases the potential for oncogenic chromosomal rearrangement in bronchial epithelial cells." Sci Rep. 2018 Jul 23;8(1):11038. https://doi.org/10.1038/s41598-018-29350-5 ; PubMed PMID: 30038404; PubMed Central PMCID: PMC6056477 , Jul-2018
Articles in Peer-reviewed Journals Zhang X, Wang P, Wang Y. "Radiation activated CHK1/MEPE pathway may contribute to microgravity-induced bone density loss." Life Sci Space Res. 2015 Nov;7:53-6. Epub 2015 Sep 14. https://doi.org/10.1016/j.lssr.2015.08.004 ; PubMed PMID: 26553637; PubMed Central PMCID: PMC4869895 , Nov-2015
Articles in Peer-reviewed Journals Werner E, Wang Y, Doetsch PW. "A single exposure to low- or high-LET radiation induces persistent genomic damage in mouse epithelial cells in vitro and in lung tissue." Radiat Res. 2017 Oct;188(4):373-80. Epub 2017 Jul 28. https://doi.org/10.1667/RR14685.1 ; PubMed PMID: 28753066 , Oct-2017
Articles in Peer-reviewed Journals Tang S, Liu B, Liu J, Wang J, Wang Y. "A protein-mRNA feedback exists in miR-21-associated E-selectin expression." Int J Radiat Biol. 2019 May;95(5):580-4. Epub 2019 Jan 28. https://doi.org/10.1080/09553002.2019.1564082 ; PMID: 30633612 , May-2019
Articles in Peer-reviewed Journals Tang S, Liu B, Liu M, Li Z, Liu J, Wang H, Wang J, Oh YT, Shen L, Wang Y. "Ionizing radiation-induced growth in soft agar is associated with miR-21 upregulation in wild-type and DNA double strand break repair deficient cells." DNA Repair (Amst). 2019 Mar 23;78:37-44. https://doi.org/10.1016/j.dnarep.2019.03.012 ; PMID: 30954901 , Mar-2019
Articles in Peer-reviewed Journals Werner E, Alter A, Deng Q, Dammer EB, Wang Y, Yu DS, Duong DM, Seyfried NT, Doetsch PW. "Ionizing radiation induction of cholesterol biosynthesis in lung tissue." Sci Rep. 2019 Aug 29;9(1):12546. https://doi.org/10.1038/s41598-019-48972-x ; PMID: 31467399; PMCID: PMC6715797 , Aug-2019
Articles in Peer-reviewed Journals Kennedy EM, Powell DR, Li Z, Bell JSK, Barwick BG, Feng H, McCrary MR, Dwivedi B, Kowalski J, Dynan WS, Conneely KN, Vertino PM. "Galactic cosmic radiation induces persistent epigenome alterations relevant to human lung cancer." Sci Rep. 2018 Apr 30;8(1):6709. https://doi.org/10.1038/s41598-018-24755-8 ; PubMed PMID: 29712937; PubMed Central PMCID: PMC5928241 , Apr-2018
Articles in Peer-reviewed Journals Wang J, Farris AB, Xu K, Wang P, Zhang X, Duong DM, Yi H, Shu HK, Sun SY, Wang Y. "GPRC5A suppresses protein translation at the endoplasmic reticulum to prevent radiation-induced lung tumorigenesis." Nature Communications. 2016 Jun 8;7:11795. http://dx.doi.org/10.1038/ncomms11795 ; PubMed PMID: 27273304; PubMed Central PMCID: PMC4899846 , Jun-2016
Articles in Peer-reviewed Journals Wang J, Zhang X, Wang P, Wang X, Farris AB 3rd, Wang Y. "Lessons learned using different mouse models during space radiation-induced lung tumorigenesis experiments." Life Sci Space Res. 2016 Jun;9:48-55. http://dx.doi.org/10.1016/j.lssr.2016.04.002 ; PMID: 27345200 , Jun-2016
Articles in Peer-reviewed Journals Sridharan DM, Asaithamby A, Blattnig SR, Costes SV, Doetsch PW, Dynan WS, Hahnfeldt P, Hlatky L, Kidane Y, Kronenberg A, Naidu MD, Peterson LE, Plante I, Ponomarev AL, Saha J, Snijders AM, Srinivasan K, Tang J, Werner E, Pluth JM. "Evaluating biomarkers to model cancer risk post cosmic ray exposure." Life Sci Space Res (Amst). 2016 Jun;9:19-47. Review. http://dx.doi.org/10.1016/j.lssr.2016.05.004 ; PMID: 27345199 , Jun-2016
Articles in Peer-reviewed Journals Werner E, Wang H, Doetsch PW. "Role of pro-inflammatory cytokines in radiation-induced genomic instability in human bronchial epithelial cells." Radiat Res. 2015 Dec;184(6):621-9. http://dx.doi.org/10.1667/RR14045.1 ; PubMed PMID: 26579942 , Dec-2015
Articles in Peer-reviewed Journals Li Z, Doho G, Zheng X, Jella KK, Li S, Wang Y, Dynan WS. "Co-culturing with high-charge and energy particle irradiated cells increases mutagenic joining of enzymatically induced DNA double-strand breaks in nonirradiated cells." Radiat Res. 2015 Sep;184(3):249-58. http://dx.doi.org/10.1667/RR14092.1 ; PubMed PMID: 26284422 , Sep-2015
Articles in Peer-reviewed Journals Liu M, Lee S, Liu B, Wang H, Dong L, Wang Y. "Ku-dependent non-homologous end-joining as the major pathway contributes to sublethal damage repair in mammalian cells." Int J Radiat Biol. 2015;91(11):867-71. Epub 2015 Aug 27. http://dx.doi.org/10.3109/09553002.2015.1075178 ; PubMed PMID: 26189733; PubMed Central PMCID: PMC4748373 , Sep-2015
Articles in Peer-reviewed Journals Barcellos-Hoff MH, Blakely EA, Burma S, Fornace AJ Jr, Gerson S, Hlatky L, Kirsch DG, Luderer U, Shay J, Wang Y, Weil MM. "Concepts and challenges in cancer risk prediction for the space radiation environment." Life Sci Space Res (Amst). 2015 Jul;6:92-103. Review. http://dx.doi.org/10.1016/j.lssr.2015.07.006 ; PubMed PMID: 26256633 , Jul-2015
Articles in Peer-reviewed Journals Deng C, Wang P, Zhang X, Wang Y. "Short-term, daily exposure to cold temperature may be an efficient way to prevent muscle atrophy and bone loss in a microgravity environment." Life Sci Space Res (Amst). 2015 Apr;5:1-5. https://dx.doi.org/10.1016/j.lssr.2015.02.001 ; PubMed PMID: 25821722; PubMed Central PMCID: PMC4374360 , Apr-2015
Articles in Peer-reviewed Journals Wang X, Farris AB 3rd, Wang P, Zhang X, Wang H, Wang Y. "Relative effectiveness at 1 gy after acute and fractionated exposures of heavy ions with different linear energy transfer for lung tumorigenesis." Radiat Res. 2015 Feb;183(2):233-9. http://dx.doi.org/10.1667/RR13884.1 ; PubMed PMID: 25635344 , Feb-2015
Articles in Peer-reviewed Journals Sridharan DM, Asaithamby A, Bailey SM, Costes SV, Doetsch PW, Dynan WS, Kronenberg A, Rithidech KN, Saha J, Snijders AM, Werner E, Wiese C, Cucinotta FA, Pluth JM. "Understanding cancer development processes after HZE-particle exposure: roles of ROS, DNA damage repair and inflammation." Radiation Research. 2015 Jan;183(1):1-26. http://dx.doi.org/10.1667/RR13804.1 ; PubMed PMID: 25564719 , Jan-2015
Articles in Peer-reviewed Journals Liu M, Wang H, Lee S, Liu B, Dong L, Wang Y. "DNA repair pathway choice at various conditions immediately post irradiation." Int J Radiat Biol. 2016 Dec;92(12):819-22. Epub 2016 Oct 13. http://dx.doi.org/10.1080/09553002.2016.1230243 ; PubMed PMID: 27622834 ; PubMed Central PMCID: PMC5183539 [Note: reported originally as Epub in Sept 2016] , Dec-2016
Project Title:  NSCOR: Mechanisms underlying the risk of HZE particle-induced solid tumor development Reduce
Fiscal Year: FY 2015 
Division: Human Research 
Research Discipline/Element:
HRP SR:Space Radiation
Start Date: 01/01/2011  
End Date: 06/30/2016  
Task Last Updated: 10/31/2014 
Download report in PDF pdf
Principal Investigator/Affiliation:   Wang, Ya  M.D., Ph.D. / Emory University 
Address:  School of Medicine Radiation Oncology 
1365 Clifton Road NE 
Atlanta , GA 30322 
Email: ywang94@emory.edu 
Phone: (404) 778-1832   
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: Emory University 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Doetsch, Paul  Emory University 
Orloff, Gregg  Emory University 
Sun, Shi-Yong  Emory University 
Vertino, Paula  Emory University 
Wang, Huichen  Emory University 
Dynan, William  Emory University 
Project Information: Grant/Contract No. NNX11AC30G 
Responsible Center: NASA JSC 
Grant Monitor: Simonsen, Lisa  
Center Contact:  
lisa.c.simonsen@nasa.gov 
Solicitation / Funding Source: 2010 Space Radiation NSCOR/Virtual NSCOR NNJ10ZSA002N 
Grant/Contract No.: NNX11AC30G 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:  
No. of Bachelor's Candidates:
No. of PhD Degrees:  
No. of Master's Degrees:  
No. of Bachelor's Degrees:
Human Research Program Elements: (1) SR:Space Radiation
Human Research Program Risks: (1) Cancer:Risk of Radiation Carcinogenesis
Human Research Program Gaps: (1) Cancer01:How can experimental models of tumor development for the major tissues (lung, colon, stomach, breast, liver, and leukemias) be developed to represent the major processes in radiation carcinogenesis and extrapolated to human risk and clinical outcome projections? (IRP Rev J)
(2) Cancer02:How can experimental models of tumor development for the other tissues (bladder, ovary, brain, esophagus, skin, etc.) be developed to represent the major processes in radiation carcinogenesis and extrapolated to human risk and clinical outcome projections? (IRP Rev J)
(3) Cancer03:How can experimental models of carcinogenesis be applied to reduce the uncertainties in radiation quality effects from SPEs and GCR, including effects on tumor spectrum, burden, latency and progression (e.g., tumor aggression and metastatic potential)? (IRP Rev F)
(4) Cancer04:How can models of cancer risk be applied to reduce the uncertainties in dose-rate dependence of risks from SPEs and GCR?
(5) Cancer07:How can systems biology approaches be used to integrate research on the molecular, cellular, and tissue mechanisms of radiation damage to improve the prediction of the risk of cancer and to evaluate the effectiveness of CMs? How can epidemiology data and scaling factors support this approach?
(6) Cancer08:What biological countermeasures should be used to reduce SPE and GCR cancer risks? What side effects should be tolerated vs. Mission risks?
Flight Assignment/Project Notes: NOTE: End date changed to 6/30/2016 per NSSC and S. Monk/LaRC (Ed., 12/31/15)

Task Description: The Emory University-Georgia Health Sciences University NSCOR will investigate the mechanisms by which high charge and energy (HZE) particles, a component of space radiation, induce lung cancer. HZE exposure elicits complex DNA damage, together with a broader cell/tissue stress response that likely includes changes in expression of tumor suppressor proteins, persistent elevation of reactive oxygen species, and alterations in the pattern of DNA methylation. The central hypothesis of this NSCOR is that this broader stress response amplifies the carcinogenic risk from a primary DNA damage event. Preliminary studies suggest that a small noncoding RNA, microRNA-21 (miR-21) plays a key role in coordinating the HZE particle-associated stress response. Center investigators will use genetic, epigenetic, and biochemical approaches to address the role of miR-21 dependent and independent stress responses in HZE particle-induced lung cancer. There are four projects:

1. Determine whether the lung cancer suppressor, Gprc5a, protects against HZE particle-induced lung carcinogenesis, and whether miR-21 overexpression blunts this protective effect.

2. Determine whether HZE-particle radiation exposure results in hyper-reliance on error-prone DNA repair pathways, whether miR21 mediates this effect, and whether dysregulation of DNA repair contributes to lung carcinogenesis.

3. Determine the nature of the HZE-particle induced ROS stress response, whether it contributes to HZE particle-induced lung carcinogenesis, and the role of miR-21 in this process.

4. Determine the scope of HZE-particle radiation-induced alterations in DNA methylation patterns, whether these alterations contribute to lung carcinogenesis, and the role of miR-21-dependent targeting of DNA methyltransferase 1 (DNMT1) in this process.

These four projects have a synergy through their collaboration on studying the mechanism underlying how mammalian respond to HZE particle-induced DNA damage, which contributes to tumor development.

Research Impact/Earth Benefits: Space radiation from HZE-particles with high-LET is different from radiation with low-LET on Earth. Understanding the mechanism by which mammalian cells respond to space radiation induced the DNA damage is a key issue for us to evaluate the risk of space radiation on astronauts’ health at any endpoint. Lung cancer is the most common fatal cancer among men and women worldwide. Lung cancer is believed to be one of the major risks of HZE-particle exposure-induced carcinogenesis, although a quantitative and mechanistic understanding of this risk is lacking. The Emory NSCOR will address this important knowledge gap. In addition, our NSCOR team will answer the question concerning whether and how different qualities (LET) of radiation affects lung tumorigenesis. These results will not only provide important information that will aid in the facilitation of the NASA Mars project, but will also provide the public with useful information concerning lung carcinogenesis and the benefits of cancer prevention.

Task Progress & Bibliography Information FY2015 
Task Progress: Overall Progress

The most important progress during the past year is reflected as follows:

1) We have discovered additional mechanism underlying the higher RBE of high-LET radiation when compared with low-LET radiation-induced cell killing: Ape1 in the clustered DNA damage site generated small DNA double strand breaks (DSBs) that contribute to the RBE. These results have been published: JBC 2014, 289:30635-30644. The importance of this work is to create an opportunity to consider about biological approaches that will reduce the risk of space radiation to astronauts.

2) We have found that heavy ions exposure induced higher incidents of lung tumors than x-ray exposure in whole body irradiated wild type mice. This is the first report to reveal that high-LET radiation can generate more lung tumors than low-LET radiation. These results have been resubmitted as a revised manuscript to Radiation Research. The importance of this work will enable us to further study the underlying mechanism and further estimate the risk of space radiation on lung tumorigenesis and reduce the risk.

Other progress: 1) We finished the mid-term evaluation that was organized by NASA’s radiation program on October 21, 2013 at NASA headquarters.

On October 21, 2013, the Emory NSCOR key personnel (the leaders of each project and the education component) reported our project progress to the review panel that included Drs. Colin Hill (USC Keck School of Medicine), Raymond Meyn (M.D. Anderson Cancer Center), Phuoc Tran (Johns Hopkins University), Janice Huff (USRA/NASA JSC), Noelle Metting (DOE), and Walter Schimmerling (USRA). We also answered questions raised by the panel members. We expect to obtain the final review report by December, 2013. Again, we believe that the mid-term evaluation will help our NSCOR team to better follow the major goal of NASA radiation program for estimating the risk of space radiation on astronauts’ health and exploring approaches to reduce the risk. 2) We have finished the animal radiation exposure for long-term tumorigenesis. In this NSCOR proposal, we used several mouse models to perform the radiation-induced tumorigenesis study. The mouse strains include wild type C57BL/6 mice, miR-21 knock-in mice, Gprc5a-/- mice, miR-21 knock-in, and Gprc5a-/- double mutant mice, miR-21-/- mice. X-ray exposure was performed in the Department of Radiation Oncology, Emory University and the HZE-particle exposure was performed at NASA Space Radiation Laboratory (NSRL), Brookhaven National Laboratory (BNL). We originally planned to sacrifice the mice at 8 months after irradiation; however, due to the fact that no significant tumorigenesis was observed at this time point from 3 irradiated miR-21 mice, we decided to extend the observation period from 8 months to 1.5 years to obtain the results of IR-induced tumorgenesis. Until now, we have finished all animal irradiation. We have obtained some valuable tumorigenesis data. The major discoveries are summarized as follows:

a. Wild C57BL/6 mice at 1.5 years after exposure to 1 Gy (single or fractionated dose) of different types of radiation with different LET (iron, silicon, oxygen and x-ray) showed that without radiation no lung tumorigenesis, low-LET exposure induced < 3% of lung tumorigenesis; however, all these tested HZE particles (iron, silicon, oxygen) induced a higher incidence of lung tumorigenesis than x-ray, the RBE was > 6 and silicon exposure induced more aggressive lung tumors. The manuscript is submitted.

b. MiR-21 knock-in mice without radiation showed a 30-40% lung tumorigenesis, suggesting that miR-21 is an oncogene. After radiation the lung tumor incidents in miR-21 knock-in mice reduced to half, which was related to the lower level of miR-21 in the irradiated lung tissues. These results confirm the oncogene characteristic of miR-21. We are working on this project and manuscript is expected to be finished by early next year.

c. Gprc5a-/- mice without radiation showed a 10% lung tumorigenesis, confirming that Gprc5a is a tumor supressor. After radiation the lung tumor incidents in Gprc5a-/- mice increased to 30%; however, no difference of lung tumorigenesis was observed between low and high-LET radiation. Combining these results with the data of lung tumorigenesis from miR-21 knock in mice, we conclude that artificial made gene mutation mice may not be good mouse model for observing lung tumorigenesis although these mice could be the good models to identify the real function of these genes in spontaneous carcinogenesis.

d. Gprc5a as a tumor suppressor was previously determined to only exist in lung tissue; however, we discovered that Gprc5a also exists in human and mice thyroid tissue. Therefore, we were interested in determining if Gprc5a plays any role in preventing thyroid tumorigenesis after exposure to low or high-LET radiation. To address this, we examined the incidence of thyroid tumorigenesis in wild and Gprc5a knockout C57BL/6 mice at 1.5 years after exposure to 1 Gy (single or fractionated dose) of different types of radiation with different LET (iron, silicon, oxygen, and x-rays). We found that radiation induced more thyroid tumors in Gprc5a knockout mice than wild type mice. We also found that high-LET radiation induced higher incidents of thyroid tumors than low-LET radiation (x-rays), and silicon ions in particular generated more thyroid tumors in Gprc5a knockout mice. These results indicate that high-LET radiation, particularly silicon ions, has a higher risk than low-LET radiation to generate thyroid tumors and Gprc5a as a tumor suppressor also plays an important role in preventing high-LET radiation-induced thyroid tumors. A manuscript is under preparation and is expected to finish by end of 2014.

Progress from each project: This proposal has four projects and one education component. The progresses from these projects are described as follows:

Project 1:

Major goal: The major goal of this project is to study how radiation-induced DNA double strand breaks (DSBs) contribute to carcinogenesis and how miR-21 dependent and independent miRNAs affect radiation-induced tumorigenesis.

Progress: During the past year, we have reported that miR-34a as a tumor suppressor inhibited high-LET radiation-induced oncogenic transformation. We also reported that different heavier ions with different LET spectrum use a same mechanism for killing cells (interfere with non-homologous end-joining). In addition, we collaborated with project 2 and 3 identified that Ape1 as a base excision repair enzyme contributes to the RBE of high-LET radiation-induced cell killing. We found that the decreased level of Gprc5a and increased EGFR is correlated with an increased frequency of radiation-induced tumorigenesis. These findings provide an important explanation for why DNA DSB repair deficient mice have a high frequency of spontaneous tumorigenesis, and also provides additional explanation concerning why radiation-induced DNA DSBs enhances tumorigenesis. In addition, we are collaborating with Dr. Vertino (project 4) as to how miR-21 affects cell response to HZE particles via targeting DNMT. We plan to complete these studies in the next year.

Next year plan: To study the mechanism underlying the high-LET radiation-induced lung tumorigenesis by analyzing the DNA and RNA changes in the high-LET radiation-induced lung tumors and studying the changed gene functions in tumorigenesis.

Project 2: The hypothesis underlying project 2 is, “exposure to HZE-particle radiation, or altered miR-21 expression status, results in hyper-reliance on error-prone repair pathways, which accounts for the excess relative risk of HZE-particle radiation in lung carcinogenesis.” The experimental approach is to test whether a history of HZE radiation exposure influences the fidelity (and not just the efficiency) of the response to future DNA damage. We term this effect the mutagenic repair phenotype. In prior publications supported by this award, we measured the fidelity of repair in an irradiated population. We have now extended the work to co-cultured bystander cells. We showed that co-culture of HZE-irradiated cells with naïve bystander cells increased the frequency of mutagenic repair in the bystanders. Results are significant because they provide the first evidence that the mutagenic repair phenotype is a non-targeted effect experienced at the population level.

Highlights of the past year include: • Completion of bystander experiments. We measured mutagenic repair by co-culturing directly irradiated and bystander cells, then challenging the bystander population at intervals with a rare-cutting nuclease and measuring the relative frequency of induced translocations and deletions at predetermined sites within a reporter cassette. We performed experiments with two ions with different LET values (1000 MeV/u 48Ti and 600 MeV/u 56Fe) and with low-LET radiation as a reference. Results with Si ions showed increases in both translocations (up to 3-fold) and deletions (up to 1.5-fold). No effect was seen with low-LET radiation. Each experiment was performed in triplicate during two different NSRL campaigns for a total of six independent biological replicates. We are now preparing the results for publication.

• Completion of gene expression experiments showing that 600 MeV/u 56Fe and 1000 MeV/u 48Ti induce a characteristic set of mRNAs encoding secreted factors, including IL-1b, Il-6, and IL-8. We performed additional replicates and tested higher doses of low-LET radiation to obtain a robust, complete data set.

• Development of new approaches to address whether the mutagenic repair phenomenon extends to near-normal human epithelial cells, which are the cells of interest for lung carcinogenesis. This work is in direct response to feedback received at the mid-term review. Initially, we contemplated an approach where we inserted a reporter cassette into a near-normal epithelial cell line. However, with the advent of facile CRISPR/Cas9 technology we decided to adopt an approach based on simultaneous, paired incisions at sites known to undergo rearrangement in human lung cancer (ALK/EML4 and CD74/ROS1). Initial results indicate that CRISPR pairs do stimulate rearrangements (an inversion and a translocation, respectively) under baseline conditions in the HBEC3KT line. We are continuing to characterize and optimize the system and are approved for experiments at NSRL in the Spring 2015 campaign.

Project 3:

Summary the past year progress and next year plan:

DNA damage inflicted by radiation or chemotherapeutic drugs induces a cellular stress response by as yet undefined mechanisms and consequences for cell survival, genomic stability, and carcinogenesis. The goals for Project 3 are to determine the nature of HZE particle induced stress response and the resulting DNA damage and genomic instability that contributes to HZE particle induced lung carcinogenesis. In the fourth year we have accumulated a critical mass of experimental results for a second publication (to be submitted to Radiation Research) examining the role of proinflammatory responses induced by Fe with an RBE of 6 on persisting genomic instability phenotypes. We found that Fe particle and proton irradiation as well as higher doses of X-ray induce IL-1a release, which drives the induction of cytokines including GM-CSF, GROa, IL-1a, IL-8. Using a competitive inhibitor for IL-1 activity, human recombinant IL-1 Receptor Antagonist (Anakinra), we show that this response does not influence genomic instability measured by micronucleus and DNA repair foci frequencies. Moreover, we found that in this model, genomic instability is a cell-autonomous phenotype, not modified by factors released into the media by irradiated cells. We started to address the recommendations of our mid-term review by evaluating the presence of these mechanisms in irradiated mouse models in collaboration with Project 1, with the goal of studying the role of the responses persisting beyond the repair of the initial DNA damage and putative intervention strategies we identify in vitro, for in vivo disease development and carcinogenesis. In parallel, we are using in vitro transformation assays to evaluate the potential role of the multiple components of the stress response on cell transformation. For the next year of support we will further characterize the protein expression phenotype of the cells with persisting genomic instability as these could function as biomarkers to identify and quantify the cells that were traversed by a particle at an earlier time as well as reveal further consequences of this phenotype.

Project 4:

Studies and Results: The primary goal of this project is to define the epigenetic “memory” of high LET radiation exposure. We hypothesize that alterations in DNA methylation and chromatin structure resulting from acute radiation exposure and local DNA damage have the potential to become ‘fixed’ if they are subsequently replicated, leading to permanent changes in DNA methylation and potentially new gene expression programs. To test this hypothesis, triplicate cultures of immortalized human bronchial epithelial cells (3KT) were exposed to low LET (X-ray) (onsite at Emory) or HLET radiation of various doses (0, 0.3, 1.0 Gy) and sources (Si, Fe, Ti) at the Brookhaven National Laboratory facility. Samples were collected from a fraction of the exposed population after 48 hrs and the remaining cells were maintained in continuous culture for an additional 20 population doublings (~3 months) with weekly collection for genomic DNA, RNA, and cellular protein. Unexposed cultures underwent the same handling procedures and were maintained in parallel. The methylation status of > 485,000 CpG residues across the human genome was analyzed using the Illumina Infinium Human Methylation 450K platform. Two independent experiments have been performed for the HLET Fe series. We have recently also completed a longitudinal study of Ti exposure at 1.0 Gy.

An analytical pipeline was developed to identify statistically significant changes in DNA methylation associated with dose, source, or time after exposure. A linear mixed-effects model was applied using an in-house tool (‘CpG assoc’) wherein Beta values (methylation level) were treated as the outcome (dependent variable), with various co-variates considered including dose, time elapsed, chip position, and a random effect for chip number. We considered the Ti, Fe, Si, and X-ray exposed cohorts separately in the analyses. Significance was assessed by the Holm, and Benjamini-Hochberg methods, and permutation analyses were incorporated to test for robustness of the results.

Our results indicate that the most significant association is with time; more than 100,000 CpG sites underwent a significant drift in methylation over time in culture, independently of the type or dose of radiation exposure. We estimate this to be an ~0.1 % change in methylation per day, that is, on average 1 in 1000 molecules of DNA switches its methylation status per day. Both hyper and hypomethylation events were observed, but CpG sites whose methylation patterns drift trend in the same direction over time, suggesting a cumulative effect.

We also identified methylation changes that were significantly associated with radiation dose, independent of time. We identified 934 sites whose methylation status was significantly associated with Fe dose (849 hyper; 86 hypo); 299 sites whose methylation status was associated with Si dose (158 hyper, 142 hypo) and 1150 that were associated with X-ray dose (252 hyper; 898 hypo).

Significantly, we find that the effects of radiation on genome-wide methylation patterns were dependent on both LET and on radiation quality. Exposure to Fe ions resulted in a genome-wide trend towards hypermethylation and tended to affect sites that start out with lower DNA methylation levels (mean=21.9%); whereas exposure to X-ray resulted in a genome-wide trend towards hypomethylation and affected sites that tended to start out with a higher methylation level (median=61.9%). Si had an intermediate effect and showed no particular trend in either direction. Importantly, radiation-induced methylation changes were observed early (48h after exposure) and persisted over time, indicating a stable and heritable change had occurred in the epigenome.

Through genome-wide comparative analyses, we also determined that high and low LET exposure tended to affect different genomic compartments, implying that they arise through distinct mechanisms, and have distinct cellular consequences. CpG sites whose methylation status was affected by Fe exposure tended to be enriched in CpG island ‘shores’, the regions surrounding CpG islands that harbor the most variable methylation in the genome, and underrepresented in gene bodies, whereas sites affected by X-ray exposure were enriched in gene bodies and intergenic regions. Sites affected by Si were overrepresented in heterochromatic regions. Interestingly, there was a 1.3 fold enrichment of Fe affected sites in regions with features of distal enhancer elements. Such regions are known to confer cell type specific transcriptional control and are also the source of significant genetic variation associated with diseases including cancer. Recent work suggests that the dynamic regulation of DNA methylation may also contribute to the regulation of gene expression at a distance through enhancer elements.

To probe the significance of our findings with respect to human cancer lung cancer, we compared our observed HLET methylation “signature” with the methylation patterns of primary human lung cancers of different genetic and pathologic backgrounds that have been analyzed as part of the NIH’s Cancer Genome Atlas (TCGA) project. Interestingly, we find that the methylation status of CpG sites affected by Fe exposure in our experimental model are capable of segregating lung cancer from normal adjacent tissue, both for a set of lung adenocarcinomas and a distinct dataset from squamous cell lung carcinomas, suggesting that they represent cancer-specific methylation changes in human lung cancer. Similar analysis showed no such relationship with the sites affected by either X-ray or by Si exposure. Thus, the HLET (Fe) radiation exposure methylation signature reflects a cancer-specific methylation in primary lung cancers. In addition, several Fe sites were identified whose methylation status reliably predicts patient outcomes.

Taken together these data suggest that both HLET and Low LET radiation exposure can induce stable and heritable changes in DNA methylation, but that these effects are distinct in mechanism, and may also have distinct biological consequences related to carcinogenesis. HLET radiation induced methylation changes may prove useful as biomarkers for long term risk assessment.

Plans for upcoming year

At this point all of our exposure and methylation analyses have been on lung cells in culture. While this has provided fundamental information regarding the role of HLET radiation-induced effects on the epigenome, our ultimate goal is to determine the impact of an altered epigenome on lung cancer risk, and over the long term, to identify methylation biomarkers that might be useful in biodosimetry and risk assessment. To this end, we are in the process of refining the methods to evaluate epithelial cells isolated from bronchial lavage from mice exposed to HLET radiation at the Brookhaven facility. This also requires a shift in technology to examine methylation patterns genome wide using Reduced Representation Bisulfite Sequencing RRBS) methods which provide information on ~1/10 of the genome (and 10x the coverage associated ic coverage (~2M CpG sites) across the mouse genome. These studies are being done in collaboration with Project 1 (Wang).

To determine whether HLET radiation induced DNA damage leaves an epigenetic ‘scar’ that is subsequently perpetuated, or more generally affects DNA methylation in random patterns (due to more global effects like increased cellular ROS), we will attempt clonal studies where individual cells will be isolated immediately after exposure and clonally expanded prior to methylation analysis. We also plan to work with Project 2 to assess DNA methylation and chromatin structural changes and around induced DSBs following the compromised repair observed in flow sorted HLET exposed cells.

Education Component: The main goal of the education and outreach plan is designed to maximize the immediate and long-term impact of the work performed by the NSCOR network (Network), which will greatly enhance the influence of the NASA education programs. For this purpose, the education component has the following activities:

Summary of Education Unit Activities November 2013-September 2014

1) Public Outreach

A. Emory NSCOR Website. This year we created video interviews with all of the Emory NSCOR project PIs and have placed them on the Emory NSCOR website ( http://nscor.emory.edu ). and in our YouTube channel. We are also placing relevant video clips (and additional links) on the CancerQuest website ( http://www.cancerquest.org ) to leverage the existing user base of CancerQuest.

We have worked to maintain and expand the Emory NSCOR website The website contains information about the research being done (and the researchers performing the work), educational materials for students and the public, and allows participants to keep up with events related to the Emory NSCOR.

B. Radiation Education for Students and the Public. 1. We are currently finalizing the new curricular unit on lung cancer. The topics covered include risks and prevention of lung cancer, including terrestrial radiation exposures (i.e. radon). The possible effects of space radiation, as researched by NASA NSCORs, will also be covered. 2. We continue to disseminate the radiation curricular unit. The unit includes a PowerPoint® presentation, vocabulary list, and more. All material is designed to meet the Georgia Science Standards. The PowerPoint® is also very well suited for education of the general public.

C. Facebook®. Our Facebook® page has 34,711 fans (up from ~9,500 last year at this time) and is actively used to promote research related to the work of the Emory-NSCOR, our educational materials, and Emory NSCOR events.

2) Student Engagement

A. Training of Undergraduate Researchers via the SURE program. One goal of the education unit is to encourage students to pursue science technology and mathematics (STEM) careers. To achieve this, we work with the Emory SURE Program. SURE is a 10-week long research program. The program is administered by the Emory College Center for Science Education.

Participation of underrepresented minorities is strongly encouraged by the Emory SURE program and a minimum of 50% of SURE participants are members of these populations (including ethnic/racial groups, economically disadvantaged, first generation college student, disabled).

Emory NSCOR summer research students participate in all SURE activities and present their work via posters at the conclusion of the program. Emory NSCOR researchers hosted two full-time SURE student researchers during the summer of 2014 and one half-time (education/outreach) student. Photographs of the Emory NSCOR students at the research symposium are posted on our website.

3) Internal Communication/Research Facilitation

A. Blackboard®. The Emory NSCOR Blackboard® site contains pertinent grant-related documents including meeting agendas and minutes, and lists of shared reagents/cell lines. Access is restricted to those individuals currently working on the project.

4) Administration

A. Participation in Monthly Meeting. Gregg routinely attends and actively participates in monthly Emory NSCOR meetings. The education products are presented and discussed along with the results/plans for the research projects.

B. Attendance/Presentation at NASA NSCOR Reviews. Education and outreach updates are presented at all internal and e external reviews of the Emory NSCOR. The Education unit provides multimedia equipment and support for events, as needed.

5) Future Plans

A. Student Researcher Interviews. We will videotape interviews with the students who worked in the Emory NSCOR laboratories to allow them to discuss their experiences with NASA-funded research. The videos will be placed on our websites and on YouTube. We hope to encourage participation in research by populations currently under-represented in the sciences.

B. Twitter® Integration. We will add Twitter® to our social media outlets by creating and connecting a Twitter® account to our Facebook® page. This will expand the reach of our posts and drive additional traffic to the Emory NSCOR website

C. Website Maintenance and Expansion. We will work to keep the research presented on the website reflective of the work done by our NSCOR and add additional sections to the site addressing advances in radiation and radiation therapy research.

Bibliography Type: Description: (Last Updated: 07/07/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Li Z, Hudson FZ, Wang H, Wang Y, Murnane JP, Dynan WS. "A genomic stress response as a novel mechanism leading to chromosomal instability in heavy particle-irradiated cell populations." 2014 NASA Human Research Program Investigators’ Workshop, Galveston, TX, February 12-13, 2014.

2014 NASA Human Research Program Investigators’ Workshop, Galveston, TX, February 12-13, 2014. http://www.hou.usra.edu/meetings/hrp2014/pdf/3138.pdf , Feb-2014

Abstracts for Journals and Proceedings Werner E, Tang KX, Wang H, Doetsch PW. "The role of persisting phenotypes on radiation-induced genomic instability." 2014 NASA Human Research Program Investigators’ Workshop, Galveston, TX, February 12-13, 2014.

2014 NASA Human Research Program Investigators’ Workshop, Galveston, TX, February 12-13, 2014. http://www.hou.usra.edu/meetings/hrp2014/pdf/3187.pdf , Feb-2014

Abstracts for Journals and Proceedings Li Z, Zheng X, Wang Y, Dynan WS. "Novel, non-targeted effect of HZE particle radiation on the DNA double strand repair machinery." 60th Annual Meeting of the Radiation Research Society, Las Vegas, Nevada, September 21-24, 2014.

60th Annual Meeting of the Radiation Research Society, Las Vegas, Nevada, September 21-24, 2014. , Sep-2014

Abstracts for Journals and Proceedings Werner E, Tang KX, Wang H, Doetsch PW. "The role of inflammation in radiation-induced genomic instability." 60th Annual Meeting of the Radiation Research Society, Las Vegas, Nevada, September 21-24, 2014.

60th Annual Meeting of the Radiation Research Society, Las Vegas, Nevada, September 21-24, 2014. , Sep-2014

Abstracts for Journals and Proceedings Vertino PM. "Islands, Shores, and Beyond: DNA Methylation in Space." Emory University Chromatin Club, Feb 22, 2014.

Emory University Chromatin Club, Feb 22, 2014. , Feb-2014

Articles in Other Journals or Periodicals Wang H, Wang X, Chen G, Zhang X, Tang X, Park D, Cucinotta FA, Yu DS, Deng X, Dynan WS, Doetsch PW, Wang Y. "Distinct roles of Ape1 protein, an enzyme involved in DNA repair, in high or low linear energy transfer ionizing radiation-induced cell killing." J Biol Chem. 2014 Oct 31;289(44):30635-44. http://dx.doi.org/10.1074/jbc.M114.604959 ; PubMed PMID: 25210033. ED. NOTE: Article re-categorized as "Other" since was WITHDRAWN May 2020, see PMID: 32358082; PMCID: PMC7196659 , Oct-2014
Articles in Peer-reviewed Journals Werner E, Wang H, Doetsch PW. "Opposite roles for p38MAPK-driven responses and reactive oxygen species in the persistence and resolution of radiation-induced genomic instability." PLoS One. 2014 Oct 1;9(10):e108234. eCollection 2014. http://dx.doi.org/10.1371/journal.pone.0108234 ; PubMed PMID: 25271419; PubMed Central PMCID: PMC4182705 , Oct-2014
Articles in Peer-reviewed Journals Zheng X, Zhang X, Ding L, Lee JR, Weinberger PM, Dynan WS. "Synergistic effect of high charge and energy particle radiation and chronological age on biomarkers of oxidative stress and tissue degeneration: a ground-based study using the vertebrate laboratory model organism Oryzias latipes." PLoS One. 2014 Nov 6;9(11):e111362. eCollection 2014. http://dx.doi.org/10.1371/journal.pone.0111362 ; PubMed PMID: 25375139; PubMed Central PMCID: PMC4222877 , Nov-2014
Articles in Peer-reviewed Journals Ng WL, Chen G, Wang M, Wang H, Story M, Shay JW, Zhang X, Wang J, Amin AR, Hu B, Cucinotta FA, Wang Y. "OCT4 as a target of miR-34a stimulates p63 but inhibits p53 to promote human cell transformation." Cell Death Dis. 2014 Jan 23;5:e1024. http://dx.doi.org/10.1038/cddis.2013.563 ; PubMed PMID: 24457968; PubMed Central PMCID: PMC4040665 , Jan-2014
Articles in Peer-reviewed Journals Wang Y. "The effects of space radiation-changed MiRNAs on tumorigenesis." The Health Risk of Extraterrestrial Environments (THREE) website, February 2014. http://three.usra.edu/articles/Ya-Wang-MiRNA.pdf ; accessed 11/11/14. , Feb-2014
Articles in Peer-reviewed Journals Li Z, Hudson FZ, Wang H, Wang Y, Murnane JP, Dynan WS. "Mutagenic joining of enzymatically induced DNA double-strand breaks, accompanied by persistent unrepaired DNA damage and a secretory protein phenotype, in HZE-exposed human cells." J Radiat Res. 2014 Mar 1;55(Suppl 1):i85-i86. (Proceedings of Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013.) http://dx.doi.org/10.1093/jrr/rrt169 , Mar-2014
Articles in Peer-reviewed Journals Werner E, Kandimalla R, Wang H, Doetsch PW. "A role for reactive oxygen species in the resolution of persistent genomic instability after exposure to radiation." J Radiat Res. 2014 Mar 1;55(Suppl 1):i14. (Proceedings of Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013.) PMCID: PMC3941489 ; http://dx.doi.org/10.1093/jrr/rrt183 , Mar-2014
Articles in Peer-reviewed Journals Kennedy EM, Conneely KN, Vertino PM. "Epigenetic Memory of Space Radiation Exposure." The Health Risks of Extraterrestrial Environments (THREE), 2014. https://three.jsc.nasa.gov/articles/Vertino.pdf , Jun-2014
Articles in Peer-reviewed Journals Li Z, Wang H, Wang Y, Murnane JP, Dynan WS. "Effect of radiation quality on mutagenic joining of enzymatically-induced DNA double strand breaks in previously irradiated human cells." Radiat Res. 2014 Nov;182(5):573-9. Epub 2014 Oct 20. http://dx.doi.org/10.1667/RR13723.1 ; PubMed PMID: 25329962 , Nov-2014
Articles in Peer-reviewed Journals Wang H, Wang Y. "Heavier ions with a different linear energy transfer spectrum kill more cells due to similar interference with the ku-dependent DNA repair pathway." Radiation Research. 2014 Oct;182(4):458-61. http://dx.doi.org/10.1667/RR13857.1 ; PMID: 25229976 , Oct-2014
Project Title:  NSCOR: Mechanisms underlying the risk of HZE particle-induced solid tumor development Reduce
Fiscal Year: FY 2014 
Division: Human Research 
Research Discipline/Element:
HRP SR:Space Radiation
Start Date: 01/01/2011  
End Date: 12/31/2015  
Task Last Updated: 10/29/2013 
Download report in PDF pdf
Principal Investigator/Affiliation:   Wang, Ya  M.D., Ph.D. / Emory University 
Address:  School of Medicine Radiation Oncology 
1365 Clifton Road NE 
Atlanta , GA 30322 
Email: ywang94@emory.edu 
Phone: (404) 778-1832   
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: Emory University 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Doetsch, Paul  Emory University 
Orloff, Gregg  Emory University 
Sun, Shi-Yong  Emory University 
Vertino, Paula  Emory University 
Wang, Huichen  Emory University 
Dynan, William  Emory University 
Project Information: Grant/Contract No. NNX11AC30G 
Responsible Center: NASA JSC 
Grant Monitor: Simonsen, Lisa  
Center Contact:  
lisa.c.simonsen@nasa.gov 
Solicitation / Funding Source: 2010 Space Radiation NSCOR/Virtual NSCOR NNJ10ZSA002N 
Grant/Contract No.: NNX11AC30G 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:  
No. of Bachelor's Candidates:
No. of PhD Degrees:  
No. of Master's Degrees:  
No. of Bachelor's Degrees:
Human Research Program Elements: (1) SR:Space Radiation
Human Research Program Risks: (1) Cancer:Risk of Radiation Carcinogenesis
Human Research Program Gaps: (1) Cancer01:How can experimental models of tumor development for the major tissues (lung, colon, stomach, breast, liver, and leukemias) be developed to represent the major processes in radiation carcinogenesis and extrapolated to human risk and clinical outcome projections? (IRP Rev J)
(2) Cancer02:How can experimental models of tumor development for the other tissues (bladder, ovary, brain, esophagus, skin, etc.) be developed to represent the major processes in radiation carcinogenesis and extrapolated to human risk and clinical outcome projections? (IRP Rev J)
(3) Cancer03:How can experimental models of carcinogenesis be applied to reduce the uncertainties in radiation quality effects from SPEs and GCR, including effects on tumor spectrum, burden, latency and progression (e.g., tumor aggression and metastatic potential)? (IRP Rev F)
(4) Cancer04:How can models of cancer risk be applied to reduce the uncertainties in dose-rate dependence of risks from SPEs and GCR?
(5) Cancer07:How can systems biology approaches be used to integrate research on the molecular, cellular, and tissue mechanisms of radiation damage to improve the prediction of the risk of cancer and to evaluate the effectiveness of CMs? How can epidemiology data and scaling factors support this approach?
(6) Cancer08:What biological countermeasures should be used to reduce SPE and GCR cancer risks? What side effects should be tolerated vs. Mission risks?
Task Description: The Emory University-Georgia Health Sciences University NSCOR will investigate the mechanisms by which high charge and energy (HZE) particles, a component of space radiation, induce lung cancer. HZE exposure elicits complex DNA damage, together with a broader cell/tissue stress response that likely includes changes in expression of tumor suppressor proteins, persistent elevation of reactive oxygen species, and alterations in the pattern of DNA methylation. The central hypothesis of this NSCOR is that this broader stress response amplifies the carcinogenic risk from a primary DNA damage event. Preliminary studies suggest that a small noncoding RNA, microRNA-21 (miR-21) plays a key role in coordinating the HZE particle-associated stress response. Center investigators will use genetic, epigenetic, and biochemical approaches to address the role of miR-21 dependent and independent stress responses in HZE particle-induced lung cancer. There are four projects:

1. Determine whether the lung cancer suppressor, Gprc5a, protects against HZE particle-induced lung carcinogenesis, and whether miR-21 overexpression blunts this protective effect.

2. Determine whether HZE-particle radiation exposure results in hyper-reliance on error-prone DNA repair pathways, whether miR21 mediates this effect, and whether dysregulation of DNA repair contributes to lung carcinogenesis.

3. Determine the nature of the HZE-particle induced ROS stress response, whether it contributes to HZE particle-induced lung carcinogenesis, and the role of miR-21 in this process.

4. Determine the scope of HZE-particle radiation-induced alterations in DNA methylation patterns, whether these alterations contribute to lung carcinogenesis, and the role of miR-21-dependent targeting of DNA methyltransferase 1 (DNMT1) in this process.

These four projects have a synergy through their collaboration on studying the mechanism underlying how mammalian respond to HZE particle-induced DNA damage, which contributes to tumor development.

Research Impact/Earth Benefits: Space radiation from HZE-particles with high-LET is different from radiation with low-LET on Earth. Understanding the mechanism by which mammalian cells respond to space radiation induced the DNA damage is a key issue for us to evaluate the risk of space radiation on astronauts’ health at any endpoint. Lung cancer is the most common fatal cancer among men and women worldwide. Lung cancer is believed to be one of the major risks of HZE-particle exposure-induced carcinogenesis, although a quantitative and mechanistic understanding of this risk is lacking. The Emory NSCOR will address this important knowledge gap. In addition, our NSCOR team will answer the question concerning whether and how different qualities (LET) of radiation affects lung tumorigenesis. These results will not only provide important information that will aid in the facilitation of the NASA Mars project, but will also provide the public with useful information concerning lung carcinogenesis and the benefits of cancer prevention.

Task Progress & Bibliography Information FY2014 
Task Progress: 1. Overview of the Emory NSCOR main achievements:

1) We successfully held a retreat during January 17-18, 2013 in Emory University. Besides the key personnel of our NSCOR team and related lab members, the following people attended the retreat:

Internal Executive Advisors: Walter Curran, MD, Executive Director, Winship Cancer Institute of Emory University, Associate Vice President of Cancer, Woodruff Health Sciences Center, Professor and Chair, Department of Radiation Oncology, Emory University School of Medicine; Fadlo Khuri, MD, FACP, Deputy Director, Winship Cancer Institute of Emory University, Professor and Chair, Department of Hematology and Medical Oncology, Emory University School of Medicine.

External Consultants: Carlo Croce, MD, Professor and Chair, Depts. of Human Cancer Genetics, Molecular Virology, Immunology and Medical Genetics; Director, Human Cancer Genetics Program, Ohio State University Medical Center (assigned for project 1) ; George Iliakis, PhD, Professor, Director, Institute of Medical Radiation Biology, University of Duisburg-Essen, Medical School, Essen, Germany (assigned for project 2) ; Peter O’Neill, PhD, Professor, Gray Institute for Radiation Oncology & Biology, Department of Oncology, University of Oxford, Oxford, UK (assigned for project 3) ; Marco Durante, PhD, Professor, GSI-Biophysik, Darmstadt – Germany (assigned for project 4).

NASA Executive Advisors: D. Marshall Porterfield, PhD, Division Director, NASA Life and Physical Sciences, Human Exploration and Operations Mission Directorate, NASA Headquarters, Washington, DC; Francis Cucinotta, PhD, Chief Scientist, Human Research Program Space Radiation Element, NASA Lyndon B. Johnson Space Center, Houston, Texas.

From this retreat, we obtained evaluations provided by the external consultants. We summarized the consultants’ main points as follows:

The consultants concurred in the goals of this NSCOR grant that were carefully selected and founded on promising hypotheses that are likely to generate valuable information towards the central aims of the NASA space radiation program. The consultants also believed that the progress made to date towards these goals was significant and the grant was very well managed and directed overall. The consultants noted that attention should be paid to the following aspects:

(1). Use the same cell lines that have been exposed to the same doses of HZE or X-ray among projects; (2). Study the global miRNA dysregulation in HZE particle-irradiated cells ; (3). Focus on study the mechanism of HZE-induced lung tumor.

These evaluations provide valuable information, which allows us to better follow the major goal of NASA radiation program for estimating the risk of space radiation on astronauts’ health and exploring approaches to reduce the risk. After this retreat, we submitted a report to NASA radiation program.

2) We finished the mid-term evaluation that is organized by NASA radiation program on October 21, 2013 at the NASA Headquarters.

On October 21, 2013, the Emory NSCOR key personnel (the leaders of each project and education component) reported our project progress to the review panel that includes Drs. Colin Hill (USC Keck School of Medicine), Raymond Meyn (M.D. Anderson Cancer Center), Phuoc Tran (Johns Hopkins University), Janice Huff (USRA/NASA JSC), Noelle Metting (DOE), and Walter Schimmerling (USRA). We also answered the questions raised by the panel members. We expect to obtain the final review report by December, 2013. Again, we believe that the mid-term evaluation will facilitate our NSCOR team to better follow the major goal of NASA radiation program for estimating the risk of space radiation on astronauts’ health and exploring approaches to reduce the risk. 3) We have finished the animal radiation exposure for long-term tumorigenesis. In this NSCOR proposal, we used several mouse models to perform the radiation-induced tumorigenesis study. The mouse strains include wild type C57BL/6 mice, miR-21 knock-in mice, Gprc5a-/- mice, miR-21 knock-in and Gprc5a-/- double mutant mice, miR-21-/- mice. X-ray exposure was performed in the Department of Radiation Oncology, Emory University and the HZE-particle exposure was performed at NASA Space Radiation Laboratory (NSRL), Brookhaven National Laboratory (BNL). We originally planned to sacrifice the mice at 8 months after irradiation; however, due to the fact that no significant tumorigenesis was observed at this time point from 3 irradiated miR-21 mice, we decided to extend the observation period from 8 months to 1.5 years to obtain the results of IR-induced tumorgenesis. Until now, we have obtained some tumorigenesis results from the irradiated mice. We expect to obtain the entire tumorigenesis results by end of 2014. 1,320 mice in total are used for the long-term project.

2. Progress from each project: This proposal has four projects and one education component. The progresses from these projects are described as follows:

Project 1: The main purpose of this project is to identify the targets of miR-21 and their regulation and effects on IR-induced carcinogenesis. Recently, we collaborated with Dr. Doetsch and H. Wang (project 3) to study the effects of miR-21 on the generation of radiation-induced reactive oxygen species (ROS); the results have been published (Cancer Res, 72:4707-4713, 2012). We found that miR-21 could directly target SOD3 and indirectly target SOD2 to enhance HZE particle-induced ROS and transformation in the human lung epithelial cells. We have finished this study and published the results. Also, we are collaborating with Dr. Dynan (project 2) and have found that the miR-21-EGFR loop is over-activated in the DNA double strand break (DSB) repair deficient cells and mice, which is stimulated by endogenous DNA DSB formation that occurs during DNA replication. We found that the increased level of miR-21 and EGFR is correlated with an increased frequency of radiation-induced tumorigenesis. These results demonstrate for the first time that DNA DSBs have a functional link with the up-regulation EGFR-miR-21 loop. These findings provide an important explanation for why DNA DSB repair deficient mice have a high frequency of spontaneous tumorigenesis, and also provides additional explanation concerning why radiation-induced DNA DSBs enhances tumorigenesis. In addition, we are collaborating with Dr. Vertino (project 4) as to how miR-21 affects cell response to HZE particles via targeting DNMT1. We plan to complete these studies in the next two years.

Project 2: The hypothesis underlying project 2 is, “exposure to HZE-particle radiation, or altered miR-21 expression status, results in hyper-reliance on error-prone repair pathways, which accounts for the excess relative risk of HZE-particle radiation in lung carcinogenesis.” The experimental approach is to test whether a history of HZE radiation exposure influences the fidelity (and not just the efficiency) of the response to future DNA damage. These experiments used a reporter cell line that has been engineered to report mutagenic repair of enzymatically-induced DNA double-strand breaks. We exposed replicate cultures to HZE particle radiation and challenged at intervals by expression of a rare-cutting nuclease that cuts within integrated reporter transgenes. In this system, deletion of a sequence within one of the reporter transgenes leads to green fluorescence, and translocation between two transgenes integrated into different chromosomes leads to red fluorescence. Highlights of the past year include:

• Publication of a manuscript showing that exposure to 1 Gy of 600 MeV/u 56Fe increases nuclease-induced translocations by 3-fold and deletions by a more modest but nevertheless significant amount. The effect persists for up to two weeks, is associated with presence of chronic DNA damage, and is not seen with low-LET radiation.

• Extension of findings to 1000 MeV/u 48Ti, which also increased the frequency of nuclease-induced translocations by 3-fold, although the duration of the effect is shorter.

• Demonstration that 600 MeV/u 56Fe, 1000 MeV/u 48Ti induce a characteristic set of mRNAs encoding secreted factors, including IL-1b, Il-6, IL-8. Preliminary data show that co-culture of HZE-irradiated cells with naïve bystander cells increased the frequency of mutagenic repair in the bystanders.

Together, results suggest a model depicted in the figure, where HZE exposure activates a biological stress response. Persistent DNA damage and the secretory response each contribute to activation of a mutagenic double-strand break repair pathway. This in turn leads to genomic instability and promotes tumor development. Results are of particular interest because they provide a new potential mechanism for the radiation bystander effect, based on dysregulation of DNA repair in bystander cells. For the past several months, we have been working to develop a new version of the reporter system in non-transformed bronchial epithelial cells, which are more representative of the target cells for lung carcinogenesis. We plan to test these in the coming year. We also plan further experiments to identify the mechanistic basis of the mutagenic repair phenotype.

Project 3: DNA damage inflicted by radiation or chemotherapeutic drugs induces a cellular stress response by as yet undefined mechanisms and consequences for cell survival and genomic stability. The goals for Project 3 are to determine the nature of HZE-particle induced stress response and the resulting DNA damage and genomic instability that contributes to HZE-particle induced lung carcinogenesis. In the third year we have accumulated a critical mass of experimental results for one publication (Oncogene, in revision) about the cellular context where elevated ROS levels persist, elevated up to two weeks following HZE particle exposure in the progeny of surviving cells. We found that elevated ROS co-exist with biomarkers of cellular senescence, genomic instability and nitric oxide (NO). We found that Fe particle irradiation, but not an equivalent X-rays dose, induced a senescence-like response, which increases genomic instability and can be abrogated by p38MAPK inhibition. We have initiated measuring nitric oxide production, which, following radiation exposure follows a temporal pattern overlapping with ROS, but does not appear to affect genomic instability or the senescence-like response. For the next year of support we will complete and publish studies about the ROS responses observed at earlier times following radiation exposure and effects on genomic instability. We will pursue our studies about the persisting effects of PARP-1 inhibition at early times following exposure to HZE. We will follow-up on the response leading to NO production as this is a potential, convenient biomarker that is easy to measure in exhaled air, reporting such persistent responses and signaling lung distress.

Project 4: Studies and Results: The primary goal of this project is to define the epigenetic determinants of HZE radiation exposure induced lung carcinogenesis and the extent to which this is mediated by miR-21. Our hypothesis is that there may be an epigenetic “memory” of high LET radiation exposure wherein alterations in DNA methylation resulting from acute radiation exposure and local DNA damage have the potential to become ‘fixed’ if they are subsequently replicated, leading to permanent changes in DNA methylation and new gene expression programs. To test this hypothesis, triplicate cultures of immortalized human bronchial epithelial cells (3KT) were exposed to low LET (X-ray) (onsite at Emory) or high LET of various doses (0, 0.3, 1.0 Gy) and sources (Si, Fe) at the Brookhaven National Laboratory facility. Samples were collected from a fraction of the exposed population after 48hrs and the remaining cells were maintained in continuous culture for an additional 20 population doublings (~3 months) with weekly collection for genomic DNA, RNA, and cellular protein. Unexposed cultures underwent the same handling procedures and were maintained in parallel. The methylation status of > 485,000 CpG residues across the human genome was analyzed using the Illumina Infinium Human Methylation 450K platform. Two independent experiments have been performed for the high LET Fe series, with a 0.1 Gy dose added to the second series.

An analytical pipeline was developed to identify statistically significant changes in DNA methylation associated with dose, source, or time after exposure. A linear mixed-effects model was applied using an in-house tool (‘CpG assoc’) wherein Beta values (methylation level) were treated as the outcome (dependent variable), with various co-variates considered including dose, time elapsed, chip position and a random effect for chip number. We considered the Fe, Si, and X-ray exposed cohorts separately in the analyses. Significance was assessed by the Holm, and Benjamini-Hochberg methods, and permutation analyses were incorporated to test for robustness of the results.

Our results indicate that the most significant association is with time; more than 100,000 CpG sites underwent a significant drift in methylation over time in culture, independently of the type or dose of radiation exposure. Nevertheless, high LET radiation exposure led to alterations in DNA methylation at a subset of these sites, with both hyper and hypomethylation events observed. In particular, we identified 124 CpG sites for which a change in methylation was significantly associated with Fe radiation dose (FDR<0.05).

We identified 934 sites whose methylation status was significantly associated with Fe dose (849 hyper; 86 hypo); 299 sites whose methylation status was associated with Si dose (158 hyper, 142 hypo) and 1150 that were associated with X-ray dose (252 hyper; 898 hypo). Interestingly, the effects of radiation on genome-wide methylation patterns were dependent on both LET and radiation quality. Exposure to Fe ions resulted in a genome-wide trend towards hypermethylation and tended to affect sites that start out with lower DNA methylation levels (mean=21.9%); whereas exposure to X-ray resulted in a genome-wide trend towards hypomethylation and affected sites that tended to start out with a higher methylation level (median=61.9%). Indeed, Fe and X-ray exposure tended to affect different genomic compartments; sites whose methylation status was affected by Fe exposure were enriched in CpG island promoters and ‘shores’ (44.3% obs vs. 39.3% exp) whereas sites affected by X-ray exposure were enriched in gene bodies and intergenic regions (64.4% obs vs 60.4% exp). Importantly, radiation-induced methylation changes were observed early (48h after exposure) and persisted over time, indicating a stable and heritable change had occurred in the epigenome.

Taken together these data suggest that both high and low LET radiation exposure can induce stable and heritable changes in DNA methylation, but that these effects are distinct in mechanism, and may also have distinct biological consequences related to carcinogenesis. Hypermethylation of CpG islands like that observed in Fe exposed cells is observed in human cancers and has been linked to the silencing of tumor suppressor and other genes. The genome-wide hypomethylation of gene bodies and intergenic regions seen with X-ray exposure is also observed in human cancers and is associated with in genome instability, large scale chromosomal aberrations, and reactivation of transposable elements. The above findings are currently in preparation for publication. Our goal is for submission of a manuscript before the end of 2013.

Plans for upcoming year: At this point all of our exposure and methylation analyses have been on cell populations. If the DNA methylation changes observed are consequent to localized DNA damage or ROS effects at the track site, then these effects would be randomly distributed in a cell population and thus the methylation effect diluted out across the ~10e6 cell equivalents analyzed. To determine whether HLET radiation induced DNA damage leaves an epigenetic ‘scar’ that is subsequently perpetuated, or more generally affects DNA methylation in random patterns (due to more global effects like increased cellular ROS), we will attempt clonal studies where individual cells will be isolated immediately after exposure and clonally expanded prior to methylation analysis. We also plan to work with Project 2 to assess DNA methylation and chromatin structural changes in and around an induced DSB following the compromised repair observed in flow sorted high LET exposed cells.

We also plan to do more analytic work to probe the significance of our findings with respect to human cancer. Planned are experiments to compare our observed high and low LET methylation “signature” with the methylation patterns of hundreds of primary human lung cancers of different genetic and pathologic backgrounds that have been analyzed as part of the NCI’s Cancer Genome Atlas project. Integrated analyses of DNA methylation with gene expression, mutation profiles and copy number alterations will allow for an assessment of the relationship between DNA methylation changes associated with radiation exposure and those associated with specific tumor classifications and subtypes, outcomes etc.

Education Component: The main goal of the education and outreach plan is designed to maximize the immediate and long-term impact of the work performed by the NSCOR network (Network), which will greatly enhance the influence of the NASA education programs. For this purpose, the education component has the following activities:

(1) Public Outreach. A. Emory NSCOR Website: We are now filming/editing/presenting interviews with Emory NSCOR project PIs and undergraduate student researchers. We plan to film additional interviews over the coming year. We have worked to maintain the Emory NSCOR website ( http://nscor.emory.edu ). The website contains information about the research being done (and the researchers performing the work), educational materials for students (see below), and allows participants to keep up with events related to the Emory NSCOR; B. Radiation Education for Students and the Public: We are currently developing a new curricular unit on lung cancer. The topics covered include risks and prevention of lung cancer, including terrestrial radiation exposures (i.e. radon). The possible effects of space radiation, as researched by NASA NSCORs, will also be covered. We continue to disseminate the radiation curricular unit. The unit includes a PowerPoint presentation, vocabulary list, and more. All material is designed to meet the Georgia Science Standards. The PowerPoint is also well suited for education of the general public; C. Facebook®: Our Facebook® page has over 9,500 fans (as of 10/23/13) and is actively used to promote research related to the work of the Emory-NSCOR, our educational materials, and Emory NSCOR events. To reach the widest possible audience, we are actively promoting the page via Facebook® advertising. In the future we hope to collaborate with other NSCORs and promote their work as well.

(2) Internal Communication/Research Facilitation. A. Virtual Bioinformatics Team: The purpose of the team is to facilitate the shared use of datasets created by NASA NSCOR researchers. Eventually, the standardized data will be made available to the greater research community; B. Blackboard®: The Emory NSCOR Blackboard® site contains pertinent grant-related documents including meeting agendas and minutes, and lists of shared reagents/cell lines. Access is restricted to those individuals currently working on the project.

(3) Student Engagement. A. Training of Undergraduate Researchers via the SURE program: One goal of the education unit is to encourage students to pursue science technology and mathematics (STEM) careers. To achieve this, we work with the Emory SURE Program. SURE is a 10-week long research program. The program is administered by the Emory College Center for Science Education. Our students participated in all SURE activities and presented their work via posters at the conclusion of the program. Emory NSCOR researchers hosted three SURE students during the summer of 2013.

(4) Administration. A. Participation in Monthly Meeting: The education products are presented and discussed along with the results/plans of the research projects. B. Attendance/Presentation at NASA NSCOR Review January 2013: The Education unit provided multimedia equipment and support for the two-day event.

Bibliography Type: Description: (Last Updated: 07/07/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Zhang X, Wang P, Shun S, Wang Y. "Investigate the LET effects of HZE particle radiation on lung tumorigenesis." Presented at the HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013.

Program & Abstracts, HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013. , May-2013

Abstracts for Journals and Proceedings Wang X, Wang P, Zhang X, Wang H, Kanna R, Chen B, Dynan, WS, Rudd K, Wang Y. "DNA-PK dependent NHEJ pathway plays a key role in preventing high-LET radiation-induced leukemia." Presented at the HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013. # 01-22

Program & Abstracts, HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013. , May-2013

Abstracts for Journals and Proceedings Wang H, Wang X, Wang P, Zhang X, Kanna R, Chen B, Dynan, WS, Wang Y. "DNA double strand breaks stimulate miR-21 expression and tumorigenesis." Presented at the HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013. # 09-15.

Program & Abstracts, HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013. , May-2013

Abstracts for Journals and Proceedings Werner E, Kandimalla R, Wang H, Doetsch P. "A role for Reactive Oxygen Species in the resolution of persistent genomic instability after exposure to radiation." Oral presentation at the HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013.

Program & Abstracts, HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013. , May-2013

Abstracts for Journals and Proceedings Werner E, Kandimalla R, Wang H, Doetsch P. "Early and persistent effects of PARP-1 inhibition after exposure to radiation." Presented at the HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013. # 09-16.

Program & Abstracts, HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013. , May-2013

Abstracts for Journals and Proceedings Li Z, Hudson FZ, Wang H, Wang Y, Murnane JP, Dynan WS. "Secretory protein phenotype accompanied by mutagenic joining of enzymatically-induced DNA double-strand breaks in a population of HZE-exposed human cells." Presented at the HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013.# 01-12,.

Program & Abstracts, HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013. , May-2013

Abstracts for Journals and Proceedings Tang X, Kandimalla R, Wang T, Wang H. "APP intracellular domain increases DNA damage response in hippocampal neuronal cells following exposure to high LET radiation." Presented at the HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013. # 03-09.

Program & Abstracts, HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013. , May-2013

Abstracts for Journals and Proceedings Kandimalla R, Tang X, Wang T, Wang H. "High LET radiation produces sustained DNA damage signaling and changes cellular homeostasis in hippocampal neuronal cells." Presented at the HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013. # 03-11.

Program & Abstracts, HITSRS2013--Heavy Ion in Therapy and Space Radiation Symposium 2013, Chiba, Japan, May 15-18, 2013. , May-2013

Abstracts for Journals and Proceedings Wang Y. "DNA Damage Response and MiR-RNA." Oral presentation at International Symposium on Radiation Science 2013 (Proton and heavy ion effects in relationship to risk and cancer treatment) and 24th Annual NASA Space Radiation Health Investigators’ workshop satellite meeting, Taipei, Taiwan, May 20-21, 2013.

International Symposium on Radiation Science 2013 (Proton and heavy ion effects in relationship to risk and cancer treatment) and 24th Annual NASA Space Radiation Health Investigators’ workshop satellite meeting, Taipei, Taiwan, May 20-21, 2013. , May-2013

Abstracts for Journals and Proceedings Ng WL, Chen G, Wang M, Wang H, Story M, Shay J, Zhang X, Wang J, Hu B, Cucinotta F, Wang Y. "OCT4 as a target of miR-34a stimulates p63 but inhibits p53 to promote human cell transformation." Oral presentation (Ya Wang) at 59th Annual Meeting of the Radiation Research Society, New Orleans, LA, September 14-18, 2013.

Proceedings of 59th Annual Meeting of the Radiation Research Society, New Orleans, LA, September 14-18, 2013. Presentation number: S-2402. http://www.abstractsonline.com/Plan/ViewAbstract.aspx?sKey=e509fe54-1e7f-4245-9c3d-793e3201b61a&cKey=99943add-73e4-49ec-9305-42090d5cc7c7&mKey={01C994CE-9545-4EC7-8580-D74360FA8373} ; accessed 10/30/13. , Sep-2013

Abstracts for Journals and Proceedings Zheng X, Ding LL, Dynan WS. "Persistent oxidative stress and degenerative tissue changes elicited by a single developmental exposure to low dose HZE particle radiation." 59th Radiation Research Society Annual Meeting, New Orleans LA, September 14-18, 2013.

Proceedings of of 59th Annual Meeting of the Radiation Research Society, New Orleans, LA, September 14-18, 2013. Presentation Number: PS3-38. http://www.abstractsonline.com/Plan/ViewAbstract.aspx?sKey=c2100182-c052-4560-b7d4-ba46257d214c&cKey=1d82e95b-2eb4-4a6f-a8b5-e31fad2ed6ad&mKey=01c994ce-9545-4ec7-8580-d74360fa8373 ; accessed 10/30/13. , Sep-2013

Articles in Other Journals or Periodicals Werner E, Kandimalla R, Wang H, Doetsch PW. "A role for Reactive Oxygen Species in the resolution of persistent genomic instability after exposure to radiation." Journal of Radiation Research. 2013, Accepted as of October 2013. , Oct-2013
Articles in Peer-reviewed Journals Zheng Z, Wang P, Wang H, Zhang X, Wang M, Cucinotta FA, Wang Y. "Combining heavy ion radiation and artificial miRNAs to target the homologous recombination repair gene efficiently kills human tumor cells." International Journal of Radiation Oncology*Biology*Physics. 2013 Feb;85(2):466-71. http://dx.doi.org/10.1016/j.ijrobp.2012.04.008 , Feb-2013
Articles in Peer-reviewed Journals Li Z, Hudson FZ, Wang H, Wang Y, Bian Z, Murnane JP, Dynan WS. "Increased mutagenic joining of enzymatically-induced DNA double-strand breaks in high-charge and energy particle irradiated human cells." Radiat Res. 2013 Jul;180(1):17-24. PMID: 23692479 , Jul-2013
Dissertations and Theses McCrary M. "The Epigenetic Effects of Radiation Exposure." Undergraduate Honors Biology Thesis, Emory University, May 2013. , May-2013
Project Title:  NSCOR: Mechanisms underlying the risk of HZE particle-induced solid tumor development Reduce
Fiscal Year: FY 2013 
Division: Human Research 
Research Discipline/Element:
HRP SR:Space Radiation
Start Date: 01/01/2011  
End Date: 12/31/2015  
Task Last Updated: 10/09/2012 
Download report in PDF pdf
Principal Investigator/Affiliation:   Wang, Ya  M.D., Ph.D. / Emory University 
Address:  School of Medicine Radiation Oncology 
1365 Clifton Road NE 
Atlanta , GA 30322 
Email: ywang94@emory.edu 
Phone: (404) 778-1832   
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: Emory University 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Doetsch, Paul  Emory University 
Orloff, Gregg  Emory University 
Sun, Shi-Yong  Emory University 
Vertino, Paula  Emory University 
Wang, Huichen  Emory University 
Dynan, William S. Emory University 
Key Personnel Changes / Previous PI: Oct 2012 report: Dr. William Dynan has now moved to Emory University, from Medical College Of Georgia Research Institute, Inc.
Project Information: Grant/Contract No. NNX11AC30G 
Responsible Center: NASA JSC 
Grant Monitor: Simonsen, Lisa  
Center Contact:  
lisa.c.simonsen@nasa.gov 
Solicitation / Funding Source: 2010 Space Radiation NSCOR/Virtual NSCOR NNJ10ZSA002N 
Grant/Contract No.: NNX11AC30G 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:  
No. of Bachelor's Candidates:
No. of PhD Degrees:  
No. of Master's Degrees:  
No. of Bachelor's Degrees:  
Human Research Program Elements: (1) SR:Space Radiation
Human Research Program Risks: (1) Cancer:Risk of Radiation Carcinogenesis
Human Research Program Gaps: (1) Cancer01:How can experimental models of tumor development for the major tissues (lung, colon, stomach, breast, liver, and leukemias) be developed to represent the major processes in radiation carcinogenesis and extrapolated to human risk and clinical outcome projections? (IRP Rev J)
(2) Cancer02:How can experimental models of tumor development for the other tissues (bladder, ovary, brain, esophagus, skin, etc.) be developed to represent the major processes in radiation carcinogenesis and extrapolated to human risk and clinical outcome projections? (IRP Rev J)
(3) Cancer03:How can experimental models of carcinogenesis be applied to reduce the uncertainties in radiation quality effects from SPEs and GCR, including effects on tumor spectrum, burden, latency and progression (e.g., tumor aggression and metastatic potential)? (IRP Rev F)
(4) Cancer04:How can models of cancer risk be applied to reduce the uncertainties in dose-rate dependence of risks from SPEs and GCR?
(5) Cancer07:How can systems biology approaches be used to integrate research on the molecular, cellular, and tissue mechanisms of radiation damage to improve the prediction of the risk of cancer and to evaluate the effectiveness of CMs? How can epidemiology data and scaling factors support this approach?
(6) Cancer08:What biological countermeasures should be used to reduce SPE and GCR cancer risks? What side effects should be tolerated vs. Mission risks?
Task Description: The Emory University-Georgia Health Sciences University NSCOR will investigate the mechanisms by which high charge and energy (HZE) particles, a component of space radiation, induce lung cancer. HZE exposure elicits complex DNA damage, together with a broader cell/tissue stress response that likely includes changes in expression of tumor suppressor proteins, persistent elevation of reactive oxygen species, and alterations in the pattern of DNA methylation. The central hypothesis of this NSCOR is that this broader stress response amplifies the carcinogenic risk from a primary DNA damage event. Preliminary studies suggest that a small noncoding RNA, microRNA-21 (miR-21) plays a key role in coordinating the HZE particle-associated stress response. Center investigators will use genetic, epigenetic, and biochemical approaches to address the role of miR-21 dependent and independent stress responses in HZE particle-induced lung cancer. There are four projects:

1. Determine whether the lung cancer suppressor, Gprc5a, protects against HZE particle-induced lung carcinogenesis, and whether miR-21 overexpression blunts this protective effect.

2. Determine whether HZE-particle radiation exposure results in hyper-reliance on error-prone DNA repair pathways, whether miR21 mediates this effect, and whether dysregulation of DNA repair contributes to lung carcinogenesis.

3. Determine the nature of the HZE-particle induced ROS stress response, whether it contributes to HZE particle-induced lung carcinogenesis, and the role of miR-21 in this process.

4. Determine the scope of HZE-particle radiation-induced alterations in DNA methylation patterns, whether these alterations contribute to lung carcinogenesis, and the role of miR-21-dependent targeting of DNA methyltransferase 1 (DNMT1) in this process.

Research Impact/Earth Benefits: Lung cancer is the most common fatal cancer among men and women worldwide. Lung cancer is believed to be one of the major risks of HZE-particle exposure, although quantitative and mechanistic understanding of this risk is lacking. The EU-GHSU NSCOR will address this important knowledge gap. In addition, our NSCOR team will answer the question concerning whether and how different qualities (LET) of radiation affects lung tumorigenesis. These results will not only provide important information that will aid in the facilitation of the NASA Mars project, but will also provide the public with useful information concerning lung carcinogenesis and the benefits of cancer prevention.

Task Progress & Bibliography Information FY2013 
Task Progress: 1. Radiation: this proposal includes two major categories: Animal and cell experiments. We have performed several types of studies, which are described as follows:

1). Cell studies: We carried out several experiments using human lung epithelial cells and cells over-expressing miR-21. We are currently preparing mouse lung epithelial cells from miR-21 knock-in or Gprc5a-/- mice. Exposure of those cells to X-ray or HZE- particles is planned for the next year of support.

2). Animal studies: We have irradiated 1120 mice and plan to finish additional miR-21-/- mice exposure in 2013.

X-ray exposure was performed at the Department of Radiation Oncology, Emory University and the HZE-particle exposure was performed at NASA Space Radiation Laboratory (NSRL), Brookhaven National Laboratory (BNL). We originally planned to sacrifice the mice at 8 months after irradiation; due to the fact that no significant tumorigenesis at this time point was observed from 3 irradiated miR-21 mice, we extend the observing period from 8 months to 1.5 year to secure obtaining the results of IR-induced tumorigenesis. During 2013, we will obtain some results of tumorigenesis from the irradiated mice. We expect to obtain the entire tumorigenesis results in 2014.

2. Each project: This proposal has four projects and project’s progress is described as follows:

Project 1: The main purpose of this project is to identify the targets of miR-21 and their regulation and effects on IR-induced carcinogenesis. Recently, we collaborated with Dr. Doetsch and H. Wang (project 3) to study the effects of miR-21 on the generation of radiation-induced reactive oxygen species (ROS), the results have been published (Cancer Res, In Press, 2012). We found that miR-21 could directly target SOD3 and indirectly target SOD2 to enhance HZE particle-induced ROS and transformation in the human lung epithelial cells. In addition, we collaborate with Dr. Dynan to have found that the miR-21-EGFR loop is over-activated in DNA double strand break (DSB) repair deficient cells and mice, which is stimulated by endogenous DNA DSB formation that occurs during DNA replication. In addition, we found that the increased level of miR-21 and EGFR is correlated with the increased frequency of radiation-induced tumorigenesis. These results demonstrate for the first time that DNA DSBs have a functional link with the up-regulation EGFR-miR-21 loop. These findings provide an important explanation for why DNA DSB repair deficient mice have a high frequency for spontaneous tumorigenesis, and also provides an additional explanation concerning why radiation-induced DNA DSBs enhance tumorigenesis. In next year, we will focus on completing the study.

Project 2: The hypothesis underlying project 2 is, “exposure to HZE-particle radiation, or altered miR-21 expression status, results in hyper-reliance on error-prone repair pathways, which accounts for the excess relative risk of HZE-particle radiation in lung carcinogenesis.” The hypothesis represents a new paradigm: that a past history of radiation exposure influences the fidelity (and not just the efficiency) of the response to future DNA damage. In what we term a “maladaptive response,” repair becomes more efficient but also more mutagenic. We are excited to report that we have experimental evidence to support the hypothesis, together with gene expression profiling data that suggests a potential mechanism.

The experimental models used in these studies are tumor cell lines that have been engineered to report mutagenic repair of enzymatically-induced DNA double-strand breaks. One line detects mutagenic nonhomologous end joining, resulting in deletions or translocations. The other detects mutagenic homologous recombination between tandem transgenes. In both cases the end result is to expression of a fluorescent transgene. The design of the experiment is to expose replicate cultures to HZE particle radiation, subculture, and challenge at intervals with I-SceI-expressing lentivirus. We expressed I-SceI as a fusion with infrared fluorescent protein fusion, which allowed gating on I-SceI expressing cells and correction for small differences in transduction efficiency over the month-long experiment. Our results showed the increase in precision deletions (mutagenic NHEJ in cis at 1 day (P<0.01), and 7 days (P<0.05), post-irradiation. Changes in mutagenic HR and changes with 300 MeV Si were nonsignificant.

To investigate mechanism, unexposed, 0.3 Gy, and 1.0 Gy groups were profiled in triplicate. Of some ~20,000 genes, only 234 mRNAs were significantly altered at 7 d post-irradiation. The gene set highly enriched for genes that participate in the senescence associated secretory phenotype (SASP). Our results showed the top 15 genes, of which 5 are part of the SASP and two are related. Results were surprising as SASP was initially defined in fibroblasts (not the epithelial tumor cells used here) and with high doses of gamma radiation (not the moderate doses of Fe used here). However, our reading of the literature suggests there may be a common mechanism, which is the presence of unrepaired DNA damage, possibly including telomere-associated repair foci, and consequent oxidative stress. These are testable hypotheses that we will address in the coming year.

Specifically, we hope to soon extend results to a second, non-transformed epithelial cell line (initial results were in tumor cells). We also suspect that our cultures may contain a mixture of population of responder and nonresponder cells, particularly after 7-14 days continuous passage, and we therefore hope to perform studies at the single-cell level. Specifically we hope to correlate unrepaired damage, SASP, and mutagenic NHEJ at the single-cell level.

Project 3: DNA damage inflicted by radiation or chemotherapeutic drugs induces a cellular stress response by still undefined mechanisms and consequences for cell survival and genomic stability. The goals for Project 3 are to determine the nature of the HZE-particle induced stress response and the resulting DNA damage and genomic instability that contributes to HZE-particle induced lung carcinogenesis and the role of miR-21 in this process. In this second year we have measured reactive oxygen species (ROS), DNA damage, and genomic instability in response to low and high LET radiation (1Gy X-rays or Fe particles). We have identified an acute increase in ROS within the first 30-60 minutes following exposure, which is mediated by a cellular NADPH oxidase (NOX) and induces oxidative damage on the DNA bases, while mediating signaling necessary for efficient double strand break repair. Between 4 and 6 hours following radiation exposure, cellular ROS levels increase again, but this time the induction is dependent on a mitochondrial function of respiratory chain activity. We found that ROS produced by this pathway promotes the formation of micronuclei during the first cell division following exposure to radiation. ROS levels remain elevated for up to two weeks in the progeny of surviving cells, co-existing with biomarkers of cellular senescence and genomic instability. Importantly, Fe particle irradiation induced a more robust senescence-like response compared to low-LET X-rays. Mir-21 expression reduced the expression of some of the phenotypes associated with senescence as well as genomic instability. For the next year of support we will complete these studies and publish these distinct ROS responses and effects on genomic instability. We will focus next on the mechanism involved in the induction of the response and molecular targets of ROS mediating genomic instability.

Project 4: The primary goal of this project is to define the epigenetic determinants of HZE radiation exposure induced lung carcinogenesis and the extent to which this is mediated by miR-21. Based on preliminary results showing that exposure of liver cells to a single dose of high (Fe) vs. low (gamma) LET ionizing radiation induced stable alterations in DNA methylation that could be observed weeks after the initial exposure, we proposed that there may be an epigenetic “memory” of high LET radiation exposure wherein alterations in DNA methylation resulting from acute radiation exposure and local DNA damage have the potential to become ‘fixed’ if they are subsequently replicated, leading to permanent changes in DNA methylation and new gene expression programs. To test this hypothesis, immortalized human bronchial epithelial cells (3KT) were exposed to varying doses (0.3, 1.0 Gy) and sources (Si, Fe) of high LET radiation at the Brookhaven National Laboratory facility. Samples were collected from a fraction of the exposed population after 48hrs and the remaining cells maintained in continuous culture for an additional 50 population doublings (~4 months) with weekly collection for genomic DNA, RNA, and cellular protein. Unexposed cultures underwent the same handling procedures and were maintained in parallel. The methylation status of > 485,000 CpG residues across the human genome was analyzed using the Illumina Infinium Human Methylation 450K platform. We compared acute DNA methylation patterns (eg. 48 hr after exposure) with that observed 2 weeks, 3 weeks and 2 months after high LET radiation exposure. An analytical pipeline was developed to identify statistically significant changes in DNA methylation associated with dose, source or time after exposure. A mixed-effects model was applied using an in-house tool (‘CpG assoc’) wherein Beta values (methylation level) were treated as the outcome (dependent variable), with various co-variates considered including dose, time elapsed, chip position and a random effect for chip number. We considered the Fe and Si exposed cohorts separately in the analyses. Significance was assessed by the Holm, and Benjamini-Hochberg methods, and permutation analyses were incorporated to test for robustness of the results.

Our results indicate that the most significant association is with time; more than 100,000 CpG sites underwent a significant drift in methylation over time in culture, independently of radiation exposure. Nevertheless, high LET radiation exposure led to alterations in DNA methylation at a subset of these sites, with both hyper and hypomethylation events observed. In particular, we identified 124 CpG sites for which a change in methylation was significantly associated with Fe radiation dose (FDR<0.05). Interestingly, in all cases the radiation-induced methylation changes were observed at baseline (48h after exposure) and persisted over time, exhibiting the same intrinsic direction and rate of epigenetic drift as observed at the same site in control cells. These data suggest that a single exposure to high LET radiation may ‘reset’ baseline methylation levels at a subset of sites that is then acted on by an age-dependent mechanism that is cell type and site intrinsic. This has important implications in that it implies that a single exposure to 1.0 Gy Fe hLET irradiation led to a permanent change in methylation that approximates 30-40 days in cell culture, effectively accelerating aging-related DNA methylation changes. There also appears to be an influence of radiation quality (ion source/dose rate/energy) in that there were no significant methylation changes associated with Si ion exposure (0 CpG sites associated with Si dose at FDR<0.05) at the same dose and over the same time frame.

In related studies, we have begun to characterize the epigenetic modulators that may be targets of miR-21. Given the methylation changes observed and the proposed relationship between radiation exposure and miR-21 levels, we determined the impact of miR-21 on DNMT1 levels. MiR target prediction algorithms suggest that the 3’ UTR of DNMT1 might be affected by miR-21*. We tested this directly in two models. First, we examined DNMT1 protein and mRNA levels in NL-20 cells stably overexpressing miR-21 comapared to a vector only control, and second, in a transient transfection system using miR-21 si-RNA mimics. While a known target of miR-21 PDCD4, was consistently downregulated in response to miR-21 overexpression, DNMT1 was unaffected. Further analysis revealed that DNMT1 sequence may be targeted by miR-21* strand. Few studies have investigated the role of miR-21* despite growing evidence of the primary miR-21 transcript (which would give rise to both miR-21 and miR21*) being upregulated by ionizing radiation and other cellular stresses. We are currently testing the role of miR-21* in the radiation response using miR mimics and anti-miRs. Our goal over the next year will be to validate the methylation changes observed and to determine the potential consequences of such changes on gene expression. We are also in the process of repeating the radiation exposures/ extended time frame experiments to determine the reproducibility of our DNA methylation findings. Planned are a direct repeat with exposure of 3KT bronchial epithelial cells at the Brookhaven facility in October 2012 (0.1, 0.3, 1.0 Gy Fe and Si) followed by extended culture; again taking both an acute measurements and extended time course after exposure to validate our above findings. As one component of these studies we will also be testing the possibility that these epigenetic changes underlie a persistent inflammatory state by testing for cytokine profiles in the culture medium over the same time course. Pending successful replication, our goal is for publication of these finding in early 2013.

Bibliography Type: Description: (Last Updated: 07/07/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Wang H, Wang P, Zhang X, Wang J. Wang Y. "Base Excision Repair of Ape1 Promotes Generation of DNA DSB in High Linear Energy Transfer Irradiated Cells." 23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012.

23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012. Abstract #8052. , Jul-2012

Abstracts for Journals and Proceedings Zhang X, Ng WL, Wang P, Tian L, Werner E, Wang H, Doetsch P, Wang Y. "MicroRNA-21 Modulates the Levels of Reactive Oxygen Species via Targeting SOD3 and TNF alpha." 23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012.

23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012. Abstract #8036. , Jul-2012

Abstracts for Journals and Proceedings Wang Y. "DNA Damage Response and MiR-RNA." 58th Annual Meeting of the Radiation Research Society, San Juan, Puerto Rico, September 30-October 3, 2012. Symposia presentation.

58th Annual Meeting of the Radiation Research Society, San Juan, Puerto Rico, September 30 – October 3, 2012. Symposia presentation S-1303. , Oct-2012

Abstracts for Journals and Proceedings Zheng X, Hudson F, Jaafar L, Dynan WS. "Long-term Effects of a Single Exposure of the Vertebrate Embry to High Charge and Energy (HZE) Particle Radiation." 23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012.

23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012. Abstract #8078. , Jul-2012

Abstracts for Journals and Proceedings Dynan WS. "Questions in Space Radiation: Lung Cancer." 58th Annual Meeting of the Radiation Research Society, San Juan, Puerto Rico, September 30-October 3, 2012. Workshop presentation.

58th Annual Meeting of the Radiation Research Society, San Juan, Puerto Rico, September 30-October 3, 2012. Workshop presentation WS-207. , Oct-2012

Abstracts for Journals and Proceedings Zheng X, Hudson F, Jaafar L, Dynan WS. "Long-term Effects of on Adult Organs following a Single Exposure to HZE Particle Radiation during Embryonic Exposure." 58th Annual Meeting of the Radiation Research Society, San Juan, Puerto Rico, September 30-October 3, 2012.

58th Annual Meeting of the Radiation Research Society, San Juan, Puerto Rico, September 30-October 3, 2012. PS5-22. , Oct-2012

Abstracts for Journals and Proceedings Werner E, Tang X, Wang H, Doetsch P. "Concurrent Delayed ROS Stress and Genomic Instability in Response to a Single Exposure to Ionizing Radiation." 23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012.

23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012. Abstract #8048. , Jul-2012

Abstracts for Journals and Proceedings Doetsch P, Wang H, Werner E. "Radiation-induced ROS Stress Response in Human Cells." 58th Annual Meeting of the Radiation Research Society, San Juan, Puerto Rico, September 30-October 3, 2012. Symposia presentation.

58th Annual Meeting of the Radiation Research Society, San Juan, Puerto Rico, September 30-October 3, 2012. Symposia presentation.S-1001. , Oct-2012

Abstracts for Journals and Proceedings Kandimalla R, Wang T, Tang X, Wang H. "Interaction of APP(swe) Mutant and GSK3 Modulates Radiation Response in Hippocampal Neuronal Cells." 23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012.

23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012. Abstract #8091. , Jul-2012

Abstracts for Journals and Proceedings Wang T, Tang X, Wang Y, Wang C, Wang H. "Homologous Recombination Mediates Persistent Clustered DNA Damage Processing." 23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012.

23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012. Abstract #8090. , Jul-2012

Abstracts for Journals and Proceedings Wang T, Tang X, Kandimalla R, Wang H. "Persistent DNA Damage Response Induces Long-Term Effects in Neuronal Cells Exposed to Low and High LET Radiation." 23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012.

23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012. Abstract #8101. , Jul-2012

Abstracts for Journals and Proceedings Wang T, Tang X, Wang Y, Kandimalla R, Wang H. "The Role of Homologous Recombination in Cluster DNA Damage Processing." 58th Annual Meeting of the Radiation Research Society, San Juan, Puerto Rico, September 30-October 3, 2012.

58th Annual Meeting of the Radiation Research Society, San Juan, Puerto Rico, September 30-October 3, 2012. PS2-40. , Oct-2012

Abstracts for Journals and Proceedings McCrary MR, Powell DR, Vertino PW. "Differential Methylation of the LIF Gene in Normal Versus Cancerous Human Lung Cells." Emory Department of Biology Undergraduate Research Symposium, Atlanta, GA, April 26, 2012.

Emory Department of Biology Undergraduate Research Symposium, Atlanta, GA, April 26, 2012. , Apr-2012

Abstracts for Journals and Proceedings McCrary MR, Powell DR, Vertino PW. "MicroRNA-21 May Target DNA Methyltransferase 1." 2012 Summer Undergraduate Research at Emory (SURE) Symposium, Atlanta, GA, August 3, 2012.

2012 Summer Undergraduate Research at Emory (SURE) Symposium, Atlanta, GA, August 3, 2012. , Aug-2012

Abstracts for Journals and Proceedings van Voorthuysen M, Abreu E, Patel P, Parsons ME, Kline E, Marcus AI, Vertino PM. "A novel role for ASC/TMS1 in primary cilia formation and cellular migration." Summer Undergraduate Research at Emory (SURE) Symposium, Atlanta, GA, August 2, 2012.

Summer Undergraduate Research at Emory (SURE) Symposium, Atlanta, GA, August 2, 2012. , Aug-2012

Abstracts for Journals and Proceedings Powell DR, McCrary MR, Conneely KN, Vertino PM. "Epigenetic Memory of High LET Radiation Exposure." 23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012.

23rd Annual NASA Space Radiation Investigators' Workshop, Durham, NC, July 8-11, 2012. Abstract #8117. , Jul-2012

Abstracts for Journals and Proceedings Zheng X, Kuhne WW, Mitani H, Urushijara Y, Kakimoto T, Hudson F, Jaafar L, Dynan WS. "Long-term Effects of High Charge and Energy (HZE) Particle Exposure Measured in vivo Using the Japanese Medaka (Oryzias latipes)." 22nd Annual Space Radiation Investigators' Workshop, League City, TX, September 18-21, 2011.

22nd Annual Space Radiation Investigators' Workshop, League City, TX, September 18-21, 2011. Abstract #7133. , Sep-2011

Articles in Peer-reviewed Journals Shi Y, Zhang X, Tang X, Wang P, Wang H, Wang Y. "MiR-21 is continually elevated long-term in the brain after exposure to ionizing radiation." Radiat Res. 2012 Jan;177(1):124-8. Epub 2011 Oct 28. PMID: 22034847 , Jan-2012
Articles in Peer-reviewed Journals Zheng Z, Ng WL, Zhang X, Olson JJ, Hao C, Curran WJ, Wang Y. "RNAi-mediated targeting of noncoding and coding sequences in DNA repair gene messages efficiently radiosensitizes human tumor cells." Cancer Res. 2012 Mar 1;72(5):1221-8. Epub 2012 Jan 11. PubMed PMID: 22237628 , Mar-2012
Articles in Peer-reviewed Journals Zheng Z, Wang P, Wang H, Zhang X, Wang M, Cucinotta FA, Wang Y. "Combining heavy ion radiation and artificial microRNAs to target the homologous recombination repair gene efficiently kills human tumor cells." Int J Radiat Oncol Biol Phys. 2012 Jun 1. [Epub ahead of print] PubMed PMID: 22658516 , Jun-2012
Articles in Peer-reviewed Journals Li Y, Qian H, Wang Y, Cucinotta FA. "A stochastic model of DNA fragments rejoining." PLoS One. 2012;7(9):e44293. http://dx.doi.org/10.1371/journal.pone.0044293 ; Epub 2012 Sep 13. PubMed PMID: 23028515 , Sep-2012
Articles in Peer-reviewed Journals Zhang X, Ng WL, Wang P, Tian L, Werner E, Wang H, Doetsch P, Wang Y. "MicroRNA-21 modulates the levels of reactive oxygen species levels by targeting SOD3 and TNF alpha." Cancer Res. 2012 Sep 15;72(18):4707-13. Epub 2012 Jul 25. PubMed PMID: 22836756 , Sep-2012
Project Title:  NSCOR: Mechanisms underlying the risk of HZE particle-induced solid tumor development Reduce
Fiscal Year: FY 2012 
Division: Human Research 
Research Discipline/Element:
HRP SR:Space Radiation
Start Date: 01/01/2011  
End Date: 12/31/2015  
Task Last Updated: 11/02/2011 
Download report in PDF pdf
Principal Investigator/Affiliation:   Wang, Ya  M.D., Ph.D. / Emory University 
Address:  School of Medicine Radiation Oncology 
1365 Clifton Road NE 
Atlanta , GA 30322 
Email: ywang94@emory.edu 
Phone: (404) 778-1832   
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: Emory University 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Doetsch, Paul  Emory University 
Dynan, William  Medical College Of Georgia Research Institute, Inc. 
Orloff, Gregg  Emory University 
Sun, Shi-Yong  Emory University 
Vertino, Paula  Emory University 
Wang, Huichen  Emory University 
Project Information: Grant/Contract No. NNX11AC30G 
Responsible Center: NASA JSC 
Grant Monitor: Cucinott1a, Francis  
Center Contact: 281-483-0968 
noaccess@nasa.gov 
Solicitation / Funding Source: 2010 Space Radiation NSCOR/Virtual NSCOR NNJ10ZSA002N 
Grant/Contract No.: NNX11AC30G 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:  
No. of PhD Candidates:
No. of Master's Candidates:  
No. of Bachelor's Candidates:
No. of PhD Degrees:  
No. of Master's Degrees:  
No. of Bachelor's Degrees:  
Human Research Program Elements: (1) SR:Space Radiation
Human Research Program Risks: (1) Cancer:Risk of Radiation Carcinogenesis
Human Research Program Gaps: (1) Cancer01:How can experimental models of tumor development for the major tissues (lung, colon, stomach, breast, liver, and leukemias) be developed to represent the major processes in radiation carcinogenesis and extrapolated to human risk and clinical outcome projections? (IRP Rev J)
(2) Cancer02:How can experimental models of tumor development for the other tissues (bladder, ovary, brain, esophagus, skin, etc.) be developed to represent the major processes in radiation carcinogenesis and extrapolated to human risk and clinical outcome projections? (IRP Rev J)
(3) Cancer03:How can experimental models of carcinogenesis be applied to reduce the uncertainties in radiation quality effects from SPEs and GCR, including effects on tumor spectrum, burden, latency and progression (e.g., tumor aggression and metastatic potential)? (IRP Rev F)
(4) Cancer04:How can models of cancer risk be applied to reduce the uncertainties in dose-rate dependence of risks from SPEs and GCR?
(5) Cancer07:How can systems biology approaches be used to integrate research on the molecular, cellular, and tissue mechanisms of radiation damage to improve the prediction of the risk of cancer and to evaluate the effectiveness of CMs? How can epidemiology data and scaling factors support this approach?
(6) Cancer08:What biological countermeasures should be used to reduce SPE and GCR cancer risks? What side effects should be tolerated vs. Mission risks?
Task Description: The Emory University-Georgia Health Sciences University NSCOR will investigate the mechanisms by which high charge and energy (HZE) particles, a component of space radiation, induce lung cancer. HZE exposure elicits complex DNA damage, together with a broader cell/tissue stress response that likely includes changes in expression of tumor suppressor proteins, persistent elevation of reactive oxygen species, and alterations in the pattern of DNA methylation. The central hypothesis of this NSCOR is that this broader stress response amplifies the carcinogenic risk from a primary DNA damage event. Preliminary studies suggest that a small noncoding RNA, microRNA-21 (miR-21) plays a key role in coordinating the HZE particle-associated stress response. Center investigators will use genetic, epigenetic, and biochemical approaches to address the role of miR-21 dependent and independent stress responses in HZE particle-induced lung cancer. There are four projects:

1. Determine whether the lung cancer suppressor, Gprc5a, protects against HZE particle-induced lung carcinogenesis, and whether miR-21 overexpression blunts this protective effect.

2. Determine whether HZE-particle radiation exposure results in hyper-reliance on error-prone DNA repair pathways, whether miR21 mediates this effect, and whether dysregulation of DNA repair contributes to lung carcinogenesis.

3. Determine the nature of the HZE-particle induced ROS stress response, whether it contributes to HZE particle-induced lung carcinogenesis, and the role of miR-21 in this process.

4. Determine the scope of HZE-particle radiation-induced alterations in DNA methylation patterns, whether these alterations contribute to lung carcinogenesis, and the role of miR-21-dependent targeting of DNA methyltransferase 1 (DNMT1) in this process.

Research Impact/Earth Benefits: Lung cancer is the most common fatal cancer among men and women worldwide. Lung cancer is believed to be one of the major risks of HZE-particle exposure, although quantitative and mechanistic understanding of this risk is lacking. The EU-GHSU NSCOR will address this important knowledge gap. In addition, our NSCOR team will answer the question concerning whether and how different qualities (LET) of radiation affects lung tumorigenesis. These results will not only provide important information that will aid in the facilitation of the NASA Mars project, but will also provide the public with useful information concerning lung carcinogenesis and the benefits of cancer prevention.

Task Progress & Bibliography Information FY2012 
Task Progress: Progress

1. Radiation: this proposal includes two major categories: Animal and cell experiments. We have performed several types of studies, which are described as follows:

1). Cell studies: We carried out several experiments using human lung epithelial cells and cells over-expressing miR-21. We are currently preparing mouse lung epithelial cells from miR-21 knock-in or Gprc5a-/- mice. Exposure of those cells to X-ray or HZE- particles is planned for the next year of support.

2). Animal studies are summarized as follows: We already exposed 620 mice (including wild type, miR-21 knock in and Gprc5a knock out) to HZE particle (iron or silicon) or X-ray at either single dose (1 Gy) or fractionation doses (0.2 Gy x 5). Next year we will exposure additional 560 mice ((including wild type, miR-21 knock out, Gprc5a knock out and combined miR-21 knock in and Gprc5a knock out) to HZE particle (iron or oxygen) or X-ray at either single dose (1 Gy) or fractionation doses (0.2 Gy x 5).

X-ray exposure was performed at the Department of Radiation Oncology, Emory University, and the HZE-particle exposure was performed at NASA Space Radiation Laboratory (NSRL), Brookhaven National Laboratory (BNL). The mice will be sacrificed at one year following radiation exposure for observing tumorigenesis, particularly in the lung tissue.

2. Each project: This proposal has four projects and project’s progress is described as follows:

Project 1: It is known that EGFR could promote miR-21 expression through stimulating Stat3, and miR-21 could in turn positively affect EGFR activity. However, it remains unclear how to link the miR-21-EGFR positive loop to radiation-induced tumorigenesis. Recently, we found that the miR-21-EGFR loop is over-activated in DNA double strand break (DSB) repair deficient cells and mice, which is stimulated by endogenous DNA DSB formation that occurs during DNA replication. In addition, we found that the increased level of miR-21 and EGFR is correlated with the increased frequency of radiation-induced tumorigenesis. These results demonstrate for the first time that DNA DSBs have a functional link with the up-regulation EGFR-miR-21 loop. These findings provide an important explanation for why DNA DSB repair deficient mice have a high frequency for spontaneous tumorigenesis, and also provides an additional explanation concerning why radiation-induced DNA DSBs enhance tumorigenesis. These data will further facilitate the experiments as described in project 2. At present, we are also collaborating with Dr. Doetsch and H. Wang (project 3) to study the effects of miR-21 on the generation of radiation-induced reactive oxygen species (ROS).

Project 2: It has been proposed that exposure to HZE particle radiation influences pathway choice and, in particular, that it may create an unfavorable intracellular environment for classical non-homologous end joining (C-NHEJ) by releasing small DNA fragments that interfere with the function of Ku protein, an essential participant in C-NHEJ. To further investigate the effect of HZE exposure on pathway choice, we examined its effect on repair of a subsequent I-SceI-induced DSB. We used four independent reporter cell lines. Two of them are designed to express eGFP when an I-SceI-induced DSB is repaired by homologous recombination (HR). The other two are designed to report end-joining events. Accurate joining of nearby I-SceI sites on the same chromosome results in eGFP expression, whereas joining of unlinked I-SceI sites results in dsRed expression. Sequencing of the joints allows discrimination between C-NHEJ and the less accurate process of alt-NHEJ. We exposed all four cell lines separately to 1 GeV/u Fe or 300 MeV/u Si particles during the spring and summer 2011 NSRL beam runs. We repeated the 1 GeV/u Fe exposures a third time during the fall 2011 beam run. We tested the capacity for HR and end-joining repair at intervals following recovery. Data analysis is in progress.

Project 3: DNA damage inflicted by radiation or chemotherapeutic drugs induces a cellular stress response by still undefined mechanisms and consequences for cell survival and genomic stability. The goals for Project 3 are to determine the nature of the HZE-particle induced stress response and the resulting DNA damage and genomic instability that contributes to HZE-particle induced lung carcinogenesis and the role of miR-21 in this process. In the first year we have focused on establishing methodologies and techniques proposed in Aim 1 to measure ROS, DNA damage and genomic instability in response to X-Ray and HZE-particles. Using flow cytometry, we have detected recurrent increases in superoxide and hydrogen peroxide levels in response to a single exposure to dosing as low as 1 Gy radiation. These elevations correlate with increased oxidative DNA damage detected with the alkaline comet assay and with chromosomal mis-segregation during the first mitosis measured by a micronucleus formation assay. ROS levels remain elevated, persisting up to several weeks in the progeny of surviving cells. Initial experiments show that cell exposure to 0.25Gy or 1Gy Fe particles increases the magnitude and the length of this chronic response. Our initial studies on the role of miR-21 show that transient expression at the moment of exposure increases the ROS response and micronucleus formation, pointing to a role in promoting genomic instability. For the next year of support we will analyze changes in gene expression associated with chronically elevated ROS levels to identify the mechanisms involved in their generation and the physiological consequences of a pro-oxidant status induced by both low and high-LET radiation.

Project 4: The primary goal of this project is to define the epigenetic determinants of HZE radiation exposure induced lung carcinogenesis and the extent to which this is mediated by miR-21. Our preliminary results had indicated that exposure of liver cells to high (Fe) vs. low (X-ray) LET ionizing radiation led to both unique and shared changes in DNA methylation. The fact that such changes were observed at several passages after the initial exposure led us to propose that there may be an epigenetic ‘memory’ of high LET radiation exposure wherein alterations in DNA methylation resulting from acute exposure and local DNA damage have the potential to become ‘fixed’ if they are subsequently replicated, leading to a now permanent change in DNA methylation and potentially gene expression. Over the last ten months, we have focused our efforts on testing this hypothesis. Immortalized human bronchial epithelial cells (3-KT) were exposed to varying doses (0.3 GY, 1 Gy) and sources (Si, Fe) of high LET radiation at the BNL facility in June 2011. After one day, a 24 hr exposure time point was collected, and the remaining cells shipped back to the lab in Georgia, where they were maintained in continuous culture for 50 population doublings (~4 months) with weekly collection of cells for genomic DNA, RNA, and protein isolation. Cultures that were not exposed underwent the same handling/ shipping procedures and were maintained in parallel. In preliminary studies we have examined the expression of ~10 genes in cells that have been maintained in continuous culture for 32 population doublings (~8 weeks) after exposure to 0.3 or 1.0 Gy Si particles. We found that DNMT1 and JunD expression show a persistent, dose-dependent, up-regulation (~2-fold) in the Si particle exposed cells, whereas several other genes (CHD1, VIM, DNMT3B, BRSK2, FAK) are unaffected. Interestingly, we identified IL-8 as a strongly, and persistently, upregulated gene; IL-8 expression was upregulated by >18-fold in cells that had been exposed to 1.0Gy Si even after 8 weeks in culture. These data suggest that the persistent activation cytokines, through genetic or epigenetic means, may be one consequence of high LET radiation exposure, and further, that the carcinogenic effects of prior exposure might occur by eliciting a chronic inflammatory state. IL-8 is known to be post-transcriptionally regulated by several miRNAs, several of which are controlled by CpG island containing promoters. One goal over the next funding period will be to determine whether epigenetic silencing of these pri-miRNAs might lead to persistent deregulation of IL-8 transcript levels. In addition, we are now poised to attack our primary goal which is to determine the scope of HZE particle induced DNA methylation changes genome-wide by subjecting DNA samples from acutely exposed and long-term ‘memory’ series to Illumina Infinium 450K Methylation analyses. We will be comparing the alterations in the DNA methylation profile induced by HZE particle exposure in an acute setting (24 hr after exposure) with those that survive many cell divisions, and their relationship to gene expression. Data generated from this platform will allow us to identify both global and site-specific DNA methylation changes that persist many months after the initial insult which may ultimately be useful as markers for risk assessment.

Bibliography Type: Description: (Last Updated: 07/07/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Shi Y, Yu X, Wang P, Wang H, Zhang X, Wang Y. "Ionizing radiation-induced tumorigenesis involves DNA double strand breaks-stimulated miR-21 over-expression." Presented at 22nd Annual NASA Space Radiation Investigators’ Workshop, League City, Texas, September 18-21, 2011.

22nd Annual NASA Space Radiation Investigators’ Workshop, League City, Texas, September 18-21, 2011. , Sep-2011

Abstracts for Journals and Proceedings Shi Y, Yu X, Zhang X, Wang P, Tang X, Wang H, Wang Y. "MiR-21 is a sensitive marker in the brain tissue from irradiated mice." Presented at 22nd Annual NASA Space Radiation Investigators’ Workshop, League City, Texas, September 18-21, 2011.

22nd Annual NASA Space Radiation Investigators’ Workshop, League City, Texas, September 18-21, 2011. , Sep-2011

Abstracts for Journals and Proceedings Li Z, Hudson FZ, Murnane JP, Dynan WS. "Effect of HZE particle radiation exposure on repair of subsequent enzyme-induced DNA double strand breaks." Presented at 22nd Annual NASA Space Radiation Investigators’ Workshop, League City, Texas, September 18-21, 2011.

22nd Annual NASA Space Radiation Investigators’ Workshop, League City, Texas, September 18-21, 2011. , Sep-2011

Abstracts for Journals and Proceedings Werner E, Limpose K, Tang X, Wang H, Doetsch PH. "Ionizing radiation-induced DNA damage causes ROS stress in human cells." Presented at 22nd Annual NASA Space Radiation Investigators’ Workshop, League City, Texas, September 18-21, 2011.

22nd Annual NASA Space Radiation Investigators’ Workshop, League City, Texas, September 18-21, 2011. , Sep-2011

Articles in Other Journals or Periodicals Shi Y, Zhang X, Wang P, Tang X, Wang H, Wang Y. "MiR-21 is continually elevated long-term in the brain following ionizing radiation." Radiation Research. In Press, October 2011. , Oct-2011
Project Title:  NSCOR: Mechanisms underlying the risk of HZE particle-induced solid tumor development Reduce
Fiscal Year: FY 2011 
Division: Human Research 
Research Discipline/Element:
HRP SR:Space Radiation
Start Date: 01/01/2011  
End Date: 12/31/2015  
Task Last Updated: 02/08/2011 
Download report in PDF pdf
Principal Investigator/Affiliation:   Wang, Ya  M.D., Ph.D. / Emory University 
Address:  School of Medicine Radiation Oncology 
1365 Clifton Road NE 
Atlanta , GA 30322 
Email: ywang94@emory.edu 
Phone: (404) 778-1832   
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: Emory University 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Doetsch, Paul  Emory University 
Dynan, William  Medical College Of Georgia Research Institute, Inc. 
Orloff, Gregg  Emory University 
Sun, Shi-Yong  Emory University 
Vertino, Paula  Emory University 
Wang, Huichen  Emory University 
Project Information: Grant/Contract No. NNX11AC30G 
Responsible Center: NASA JSC 
Grant Monitor: Cucinott1a, Francis  
Center Contact: 281-483-0968 
noaccess@nasa.gov 
Solicitation / Funding Source: 2010 Space Radiation NSCOR/Virtual NSCOR NNJ10ZSA002N 
Grant/Contract No.: NNX11AC30G 
Project Type: GROUND 
Flight Program:  
TechPort: No 
No. of Post Docs:  
No. of PhD Candidates:  
No. of Master's Candidates:  
No. of Bachelor's Candidates:  
No. of PhD Degrees:  
No. of Master's Degrees:  
No. of Bachelor's Degrees:  
Human Research Program Elements: (1) SR:Space Radiation
Human Research Program Risks: (1) Cancer:Risk of Radiation Carcinogenesis
Human Research Program Gaps: (1) Cancer01:How can experimental models of tumor development for the major tissues (lung, colon, stomach, breast, liver, and leukemias) be developed to represent the major processes in radiation carcinogenesis and extrapolated to human risk and clinical outcome projections? (IRP Rev J)
(2) Cancer02:How can experimental models of tumor development for the other tissues (bladder, ovary, brain, esophagus, skin, etc.) be developed to represent the major processes in radiation carcinogenesis and extrapolated to human risk and clinical outcome projections? (IRP Rev J)
(3) Cancer03:How can experimental models of carcinogenesis be applied to reduce the uncertainties in radiation quality effects from SPEs and GCR, including effects on tumor spectrum, burden, latency and progression (e.g., tumor aggression and metastatic potential)? (IRP Rev F)
(4) Cancer04:How can models of cancer risk be applied to reduce the uncertainties in dose-rate dependence of risks from SPEs and GCR?
(5) Cancer07:How can systems biology approaches be used to integrate research on the molecular, cellular, and tissue mechanisms of radiation damage to improve the prediction of the risk of cancer and to evaluate the effectiveness of CMs? How can epidemiology data and scaling factors support this approach?
(6) Cancer08:What biological countermeasures should be used to reduce SPE and GCR cancer risks? What side effects should be tolerated vs. Mission risks?
Task Description: The Emory University-Medical College of Georgia NSCOR will investigate the mechanisms by which high charge and energy (HZE) particles, a component of space radiation, induce lung cancer. HZE exposure elicits complex DNA damage, together with a broader cell/tissue stress response that likely includes changes in expression of tumor suppressor proteins, persistent elevation of reactive oxygen species, and alterations in the pattern of DNA methylation. The central hypothesis of this NSCOR is that this broader stress response amplifies the carcinogenic risk from a primary DNA damage event. Preliminary studies suggest that a small noncoding RNA, microRNA-21 (miR-21) plays a key role in coordinating the HZE particle-associated stress response. Center investigators will use genetic, epigenetic, and biochemical approaches to address the role of miR-21 dependent and independent stress responses in HZE particle-induced lung cancer. There are four projects:

1. Determine whether the lung cancer suppressors, Gprc5a and p53, protect against HZE particle-induced lung carcinogenesis, and whether miR-21 overexpression blunts this protective effect.

2. Determine whether HZE-particle radiation exposure results in hyper-reliance on error-prone DNA repair pathways, whether miR21 mediates this effect, and whether dysregulation of DNA repair contributes to lung carcinogenesis.

3. Determine the nature of the HZE-particle induced ROS stress response, whether it contributes to HZE particle-induced lung carcinogenesis, and the role of miR-21 in this process.

4. Determine the scope of HZE-particle radiation-induced alterations in DNA methylation patterns, whether these alterations contribute to lung carcinogenesis, and the role of miR-21-dependent targeting of DNA methyltransferase 1 (DNMT1) in this process.

Lung cancer is the most common fatal cancer among men and women worldwide. Lung cancer is believed to be one of the major risks of HZE-particle exposure, although quantitative and mechanistic understanding of this risk is lacking. The Emory-MCG NSCOR will address this important knowledge gap.

Research Impact/Earth Benefits: 0

Task Progress & Bibliography Information FY2011 
Task Progress: New project for FY2011.

Bibliography Type: Description: (Last Updated: 07/07/2021) 

Show Cumulative Bibliography Listing
 
 None in FY 2011