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Project Title:  NSCOR: Space Radiation and Gastrointestinal Cancer: A Comprehensive Strategy for Risk Assessment and Model Development Reduce
Images: icon  Fiscal Year: FY 2021 
Division: Human Research 
Research Discipline/Element:
HRP SR:Space Radiation
Start Date: 04/15/2015  
End Date: 09/30/2022  
Task Last Updated: 02/15/2021 
Download report in PDF pdf
Principal Investigator/Affiliation:   Fornace, Albert  M.D. / Georgetown University 
Address:  Dept. of Oncology, Lombardi Comprehensive Cancer Center 
Research Building, Room E504, 3970 Reservoir Rd., NW 
Washington , DC 20007-2126 
Email: af294@georgetown.edu 
Phone: 202 687-7843  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: Georgetown University 
Joint Agency:  
Comments: http://www9.georgetown.edu/gumc/lombardi/fornacelab/  
Co-Investigator(s)
Affiliation: 
Brenner, David  Ph.D. Columbia University 
Meltzer, Paul  M.D., Ph.D. National Cancer Institute, NIH 
Shay, Jerry  Ph.D. University of Texas Southwestern Medical Center at Dallas 
Suman, Shubhankar  Ph.D. Georgetown University 
Key Personnel Changes / Previous PI: February 2021 report: Kamal Datta moved to NIH; Shubhankar Suman added as Co-Investigator in the year-6 of this NASA Specialized Center of Research (NSCOR).
Project Information: Grant/Contract No. NNX15AI21G 
Responsible Center: NASA JSC 
Grant Monitor: Elgart, Robin  
Center Contact: 281-244-0596 (o)/832-221-4576 (m) 
shona.elgart@nasa.gov 
Solicitation / Funding Source: 2014-15 HERO NNJ14ZSA001N-NSCOR Radiation 
Grant/Contract No.: NNX15AI21G 
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) Cancer-103:Determine the effects of radiation quality on cancer initiation, promotion, and progression (IRP Rev M)
(2) Cancer-104:Determine the effects of radiation dose and dose-rate on cancer initiation, promotion and progression (IRP Rev M)
(3) Cancer-203:Evaluate the tissue-specific risks of space radiation exposure on cancer outcomes (IRP Rev M)
(4) Cancer-303:Identify early surrogate biomarkers that correlate with cancer, pre-malignancy, or the hallmarks of cancer (IRP Rev M)
Flight Assignment/Project Notes: NOTE: End date changed to 9/30/2022 per HRP Space Radiation (Ed., 8/3/21)

NOTE: End date changed to 9/30/2021 per PI and NSSC information (Ed., 3/4/21)

NOTE: End date changed to 4/14/2021 per NSSC information (Ed., 1/16/2020)

Task Description: Considering the high spontaneous incidence of gastrointestinal (GI) and lung cancer, and even a modest increase by space radiation exposure could have a significant effect on astronauts’ health risk estimates during and after long-duration manned space flights. However, there is substantial uncertainty for GI and lung cancer risk estimation from space radiation due to the lack of in vivo human data. Our overall goal is to specifically investigate cellular and molecular hypothesis-driven mechanisms in relevant mouse models that will contribute to carcinogenic risk estimates of GI and lung cancer after exposure to space radiation beams prioritized by NASA’s Human Research Program (HRP). Specifically, we seek to determine incidence, tumor frequency, and grade as well as identify molecular perturbations in the target cells associated GI and lung tumorigenesis through monitoring of changes in the tumor number, histology, and gene/protein expression of the proposed model system after exposure to space-radiation type beams. The overall hypothesis is that neutrons and mixed beam galactic cosmic radiation (GCR) type radiation are more carcinogenic due to important qualitative differences from gamma rays where human exposure data are available. Molecular events triggered by space radiation will be investigated in-depth and the mechanistic basis for persistent aberrant cell-signaling after space radiation will be dissected. Both quantitative and qualitative murine tumor data will contribute to the modeling of human risks for GI and lung cancer by space travel. We plan to test our hypothesis by pursuing the following specific aims:

Aim 1. Quantitatively assess GI tumorigenesis in mouse models of GI cancer and collect samples for qualitative analysis.

Aim 2. Dissection of the signaling events and consequences in GI cells of the persistent effects of space radiation.

Aim 3. Quantitatively assess lung tumorigenesis and test potential countermeasures in lung cancer susceptible mouse model.

Aim 4. Development of mathematical modeling for cancer risk assessment.

Research Impact/Earth Benefits: Gastrointestinal tumors are frequent in the U.S., and the American Cancer Society estimates that there will be 147,950 new cases of colorectal cancer (CRC) with 53,200 persons predicted to die of the disease in 2020. Overall, the lifetime risk of developing colorectal cancer is about 1 in 23 (4.4%) for men and 1 in 25 (4.1%) for women. Considering the high frequency of colorectal tumors in the American population, an even small increase by space radiation could have a major impact on risk estimates and planning of future crewed space missions. In addition to risk estimation, studies on the persistence of oxidative and inflammatory stress after HZE (high energy particle) radiation and its role in driving gastrointestinal tumorigenesis may provide insight into mutagenic processes affecting genome integrity and carcinogenesis. The significance and deliverable of this project are to improve the estimates of GI cancer risk in astronauts and to identify and test plausible targets for the development of mitigation strategies.

Task Progress & Bibliography Information FY2021 
Task Progress: Task Progress: Pointwise progress made for each aim/project is summarized below:

GI-tumorigenesis study (Project-1, Georgetown University): In the last six years of NSCOR funding, we have successfully applied mouse model approaches to acquire quantitative and qualitative GI tumorigenesis data to address prevailing uncertainties in risk modeling. Our overall goal is to determine the relative biological effectiveness (RBE) of various parameters for space radiation compared to terrestrial radiation. The risk estimates can then be extrapolated to space radiation using a RBE scaling factor. Our strategy is to i] quantitatively analyze tumor incidence and grade following space type radiation exposure. ii] Assess potential dose rate and gender variation. iii] Delineate cancer progression-specific biological signatures associated with space radiation exposure. Since low-linear energy transfer (LET) gamma radiation risk estimates are available for human populations from studies in atom bomb cohorts and like, we will then be able to combine our data to model the relative risk for space radiation. Pointwise details of progress made for GI tumorigenesis study are provided below:

1. Beam run participation in 2020: Georgetown University team participated in two-beam runs (NASA Space Radiation Laboratory (NSRL) 20B and 20C)), while planned experiments in the Spring-run (20A) were canceled due to COVID-19 restrictions at Brookhaven National Laboratory (BNL)/NSRL.

2. Dose-rate effect analysis using acute and chronic full GCR sim: In order to understand dose rate effects on GI-tumorigenesis after full-spectrum GCR sim exposures, we completed our initial study using 50 cGy dose of acute and chronic full-spectrum (33-ion) GCR beams during the NSRL 20B run. This initial study using a limited number of mice revealed a good signal after both acute and chronic full-spectrum GCR sim exposures, relative to controls. However, additional data from more mice are required; this initial study provided crucial insight and validated our mouse model for future experiments using lower doses of chronic full spectrum GCR beams.

3. Role of HZE in GCR-induced GI-tumorigenesis: Our previous study comparing quantitative tumor data obtained from the equivalent doses of a single HZE beam to the 4-ion mixed-field GCR-induced tumorigenesis revealed an association between higher intestinal tumor number and dose received from the HZE fraction of mixed-field GCR. Therefore, in order to understand the relative contributions of HZEs components in a full GCRsim induced tumorigenesis, we also exposed male Apc1638N/+ to p+He (45.7 cGy) and HZE only (4.3 cGy) during NSRL 20C run and quantitative tumorigenesis data will be obtained in early 2021. Once quantitative data from p+He (45.7 cGy) and HZE only (4.3 cGy) exposures are available, a comparison with 50 cGy full-GCRsim is planned to understand and model the relative role of HZE in GCR-induced tumorigenesis.

4. Role of non-targeted effects (NTEs) in HZE-induced tumorigenesis: In order to understand the role of non-targeted effects (NTEs) in HZE-induced tumorigenesis, male Apc1638N/+ mice (6-8 weeks) were whole-body exposed to sham-radiation, gamma-rays, and 28Si-ion at 10 cGy dose and mice were sacrificed at 60 d and 150 d after radiation exposure and intestinal tumor frequency were scored and analyzed. Our analysis of tumorigenesis rate data clearly indicated a remarkable acceleration in tumorigenesis rate at the late time point in 28Si exposed mice, relative to gamma-rays and control groups.

5. Addition of acute neutron beam to our range of single beam GI tumorigenesis data: Male Apc1638N/+ mice (6-8 weeks) were whole-body exposed to sham-radiation, gamma-rays, 4He, 12C, 16O, 28Si, and 56Fe-ion at 10 cGy dose at NSRL, while neutron (10 cGy) exposure was conducted at Radiological Research Accelerator Facility (RARAF) (Columbia University). Mice were sacrificed at 150 d after radiation exposure and intestinal tumor frequency was scored and analyzed. The highest number of tumors was observed after 28Si followed by 56Fe, neutron, 16O, 12C, and 4He radiation. No statistical difference in tumorigenesis count was evident between neutron, 16O, and 12C at 10 cGy dose.

Dissection of the signaling events and consequences in GI cells of the persistent effects of space radiation (Project-2, Georgetown University): Proliferative gastrointestinal (GI) tissue is radiation-sensitive, and heavy-ion space radiation with its high-linear energy transfer (high-LET) and higher damaging potential than low-LET gamma-rays is predicted to compromise astronauts' GI function. However, much uncertainty remains in our understanding of how heavy ions affect coordinated epithelial cell migration and extrusion, which are essential for GI homeostasis. The overall goal of this project is to understand the long-term effects of space radiation on normal gastrointestinal (GI) cells including stem cells. Coordinated epithelial cell migration is key to maintaining functional integrity and preventing pathological processes in gastrointestinal (GI) tissue and is essential for astronauts’ health and space mission success. Pointwise details of progress made for persistent effects of space radiation on GI-tissues are provided below:

1. We studied space radiation effects on intestinal stem cells (ISC) in male Lgr5 (Lgr5-EGFP-IRES-creERT2) mice in C57BL/6J background using 0.5 Gy of gamma-ray or 28Si ions. Lgr5 mice were exposed to 0.5 Gy of 28Si-ion and GFP+ Lgr5 cells were sorted from the isolated intestinal cells using flow-cytometry. Sorted cells were analyzed on flow cytometer for mitochondrial and cellular reactive oxygen species (ROS) using Mitosox or CellRox staining. Higher intracellular and mitochondrial ROS was observed in the 28Si exposed group, relative to gamma-ray and control GI stem cells.

2. We also demonstrated an increased level of beta-gal (senescence marker) positive intestinal stem cells in the 28Si exposed group, relative to gamma-ray. This suggests a higher number of stem cells were undergoing senescence after 28Si relative to gamma-ray or control group. This also correlated well with an increased number of gamma-H2AX foci in GI stem cells after 28Si compared to gamma ray or control group.

3. Emerging evidence indicates that senescent cells acquire a secretory phenotype (SASP) and production of inflammatory cytokines that lead to altered intestinal tissue homeostasis. A key pro-inflammatory secretory cytokine IL8 (SASP marker) was co-stained with p21 (senescent marker) and the data shows an increased level of IL8 expression in senescent cells (high p21 marker) indicating acquisition of the senescence-associated secretory phenotype (SASP) in a subset of senescent ISCs after 28Si exposure compared to gamma ray or control group.

4. A time-dependent analysis of persistent stress was conducted on samples collected at 2, 5, and 12-months post-exposure that indicated a progressive increase in DNA damage (gamma -H2AX), senescence (p16 and p21), and SASP (IL8) cells after 28Si exposure compared to gamma ray or control group.

5. Characterization of heavy ion-induced persistent oxidative modifications to DNA: We detected and quantified the spectrum of oxidative DNA base damage species using gas chromatography (GC)/mass spectrometry (MS) techniques two months after radiation exposure. Levels of damaged DNA base were significantly higher after 56Fe irradiation relative to sham-irradiated control as well as gamma-irradiated samples.

6. We also assessed the status of the repair pathways involved in repairing damaged DNA bases. Expression of BER (base excision repair) and NER (nucleotide excision repair) genes involved in the repair of identified DNA damage species was assessed in irradiated as well as in control samples. 56Fe exposure caused significant downregulation of many BER (Ogg1, Nth1, Neil1, Neil2, Neil3, Ape2, Xrcc1, and Lig3) and NER genes (Rbx1, ddb1, Ddb2, Xpc, Ercc8, Xpa, and Xpf). Additionally, immunoblot analysis of both BER (OGG1, NEIL1) and NER (DDB1, RBX1, CSB, NEIL1, and ERCC8) proteins showed significantly lower expression after 56Fe, relative to gamma radiation. We demonstrated a quantitatively higher accumulation of base damages that was associated with greater downregulation of BER and NER pathways after 56Fe, relative to gamma radiation.

Quantitatively and qualitatively compare effects of GCR-type irradiations on lung cancer initiation and progression in lung cancer susceptible mice. (Lead: Jerry W Shay) (Project-3, UTSW): The UTSW (University of Texas Southwestern) component of this project involves lung tissue from normal WT mice, and a mouse model of lung cancer (LA-1). The rationale for these models is that whole body exposure to space radiation will affect organ/tissues and cells in different ways. The lung only turns over cells with damage, while the colon turns over in humans every 7 days irrespective of damage. Thus, to model increased risks of more lethal cancers from space radiation exposure it is important to examine tissues with both a high rate of cellular turnover and tissues with a low rate of cell turnover. The inclusion of a lung model reflects the major solid tumor risk for astronauts traveling in space where the radiation-induced lung cancer incidence risk was estimated to be approximately 1% and 2.5% for male and female astronauts on a Mars mission, respectively, with upper 95% CIs extending well above 3% in both cases.

The overall hypothesis for this project is that space radiation induces molecular manifestations of a pro-inflammatory response as a function of radiation type, radiation doses, doses rates, LET value, and time that leads to increased risk of cancer initiation and progression. There remain uncertainties about cancer risks with single beam experiments and even simplified GCR simulations, but most experiments at the NSRL suggest late cancer effects are likely. It can be argued that we cannot predict what would happen in a mixed beam of fixed doses based on current data since most experiments were done in the acute setting with higher dose rates. While we recognize that there are issues of scaling from a mouse to human, and actually phenocopying the continuous low dose rates in the space environment, we have a large amount of legacy radiation carcinogenesis data and molecular baselines with mouse models using single beam experiments, a simplified 3 beam fast switching series of experiments, and now experiments with the 33-beam official full spectrum GCR simulation. We observed several hallmarks of cancer (even using a total dose of 30 cGy) in both our lung and colon cancer susceptible mouse models. Since our original NSCOR was focused on colon cancer, we had several mouse models of susceptibility to colon cancer and several papers have been published. However, the former space radiation element scientist recommended we add a lung cancer model for the GCR experiments in 2018 as part of our NSCOR.

We were the first team testing the NSRL-GCR 33 beam simulation with our lung cancer susceptible mouse model compared to WT mice starting in late 2018. Results from these studies were designed to evaluate the effects of both acute and chronic doses of the GCR simulator on radiation-induced health risks using a radiation-induced lung cancer in male and female wildtype and LA1 mutant (a lung cancer susceptible mouse) mice on a 129 background.

Each study included an acutely exposed group, a fractionated exposed group with consecutive doses of 20.8 mGy/day delivered over a four-week period, and sham controls. The simulator was baselined to 50 cGy for the first series of experiments. Acute exposures were delivered half-way through the fractionated exposure to support age-matching post irradiation During this initial experimental campaign approximately 300 mice received irradiations and ~200 mice treated as sham controls. The NSRL 18C (Fall 2018) run was a highly valuable experience in establishing concept of operations for future studies and providing a realistic determination of set-up and run times for future schedule planning.

Cancer risk modeling (Columbia University) (Project-4, CU): A trip to Mars and back, or another lengthy space exploration mission, will result in exposure of astronauts to a multi-component mixture of ionizing radiations which damage cells in multiple ways. Such damage mechanisms can be roughly classified into two categories: (1) Targeted effects (TE), involving the consequences of direct traversals of cells by ionizing tracks leading to DNA double strand breaks and other lesions. (2) Non-targeted effects (NTE, or “bystander” effects) caused by release of signals from cells directly hit by the tracks and the effects of these signals on other cells. The presence of both types of effects generates complex dose response shapes for space radiations, particularly in the low dose region relevant for space missions.

Here we used our mechanistically-motivated model formalism that includes both TE and NTE to analyze updated mouse tumorigenesis data from the current NSCOR. The updated data set now includes more detailed information on space-relevant doses of multiple radiation types. This new information and improved modeling approach allowed better estimation of dose response shapes and radiation effectiveness metrics in the space-relevant dose region. Specifically, relative biological effectiveness (RBE) and radiation effects ratio (RER) values at such doses of heavy ions and protons were estimated based on the most detailed data set version and improved methodology for describing variability in tumor numbers per mouse. These improvements provided updated and enhanced estimation of cancer risks in astronauts.

Bibliography Type: Description: (Last Updated: 12/03/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Xu L, Walker R, Zhu Y, Wang Y, Pineda M, Killian J, Suman S, Kumar S, Datta K, Shay J, Fornace A Jr, Meltzer P. "Genomic and epigenomic instability in gastrointestinal cancer developing after low dose space radiation." 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021.

Abstracts. 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021. [#1105-002104] , Feb-2021

Abstracts for Journals and Proceedings Siteni S, Luitel K, Barron S, Shay J. "CDDO & metformin as countermeasures for simulated space radiation on lung cancer progression." 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021.

Abstracts. 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021. [#1105-002157] , Feb-2021

Abstracts for Journals and Proceedings Suman S, Kumar S, Angdisen J, Moon B, Kallakury B, Datta K, Fornace A Jr. "Evaluation of aspirin as a chemopreventive agent against space radiation-induced gastrointestinal tumorigenesis." 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021.

Abstracts. 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021. [#1105-002278] , Feb-2021

Abstracts for Journals and Proceedings Shuryak I, Brenner D, Fornace A Jr, Suman S, Kallakury B, Slaba T, Blattnig S, Norman R, Plante I. "Mechanistically-based model development for space radiation risk assessment: modeling space radiation-induced carcinogenesis using targeted and non-targeted effects." 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021.

Abstracts. 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021. [#1105-002219] , Feb-2021

Abstracts for Journals and Proceedings Fornace A Jr, Suman S, Shay J, Meltzer P, Brenner D. "Space radiation-induced tumorigenesis, risk modeling, long-term injury responses, and mitigation strategy: NSCOR project update." 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021.

Abstracts. 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021. [#1105-002261] , Feb-2021

Abstracts for Journals and Proceedings Kumar S, Suman S, Fornace A Jr. "Long term space radiation exposure induces oxidative stress and accelerated aging in mouse intestinal stem cell." 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021.

Abstracts. 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021. [#1105-002189] , Feb-2021

Abstracts for Journals and Proceedings Kumar K, Datta K, Fornace A Jr, Suman S. "Radiation quality dependent increase in cellular senescence and altered bone marrow cell differentiation coincides with increased osteoclast activity and bone loss." 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021.

Abstracts. 2021 NASA Human Research Program Investigators’ Workshop, Virtual, February 1-4, 2021. [#1105-002288] , Feb-2021

Abstracts for Journals and Proceedings Kumar S, Suman S, Moon BH, Fornace A Jr. "Heavy ion radiation induces senescence, and triggers accelerated SASP phenotype in mouse intestinal stem cells." 66th Annual Meeting of Radiation Research Society, Virtual Meeting, October 18-21, 2020.

Abstracts. 66th Annual Meeting of Radiation Research Society, Virtual Meeting, October 18-21, 2020. (ps1151) , Oct-2020

Abstracts for Journals and Proceedings Suman S, Kumar S, Angdisen J, Moon B, Kallakury BVS, Datta K, Fornace A Jr. "Mixed field GCR-induced gastrointestinal tumorigenesis is dependent on doses received from constituent heavy-ions." 66th Annual Meeting of Radiation Research Society, Virtual Meeting, October 18-21, 2020.

Abstracts. 66th Annual Meeting of Radiation Research Society, Virtual Meeting, October 18-21, 2020. (PS12-09) , Oct-2020

Abstracts for Journals and Proceedings Kumar K, Datta K, Fornace A Jr, Suman S. "Proton and 56Fe-induced increased senescence, altered cell differentiation, and decreased osteocalcin is associated with higher osteoclast activity and bone loss." 66th Annual Meeting of Radiation Research Society, Virtual Meeting, October 18-21, 2020.

Abstracts. 66th Annual Meeting of Radiation Research Society, Virtual Meeting, October 18-21, 2020. (PS 12-10) , Feb-2020

Articles in Peer-reviewed Journals Suman S, Jaruga P, Dizdaroglu M, Fornace AJ Jr, Datta K. "Heavy ion space radiation triggers ongoing DNA base damage by downregulating DNA repair pathways." Life Sci Space Res. 2020 Nov 27:27-32. https://doi.org/10.1016/j.lssr.2020.07.001 , Nov-2020
Project Title:  NSCOR: Space Radiation and Gastrointestinal Cancer: A Comprehensive Strategy for Risk Assessment and Model Development Reduce
Images: icon  Fiscal Year: FY 2020 
Division: Human Research 
Research Discipline/Element:
HRP SR:Space Radiation
Start Date: 04/15/2015  
End Date: 04/14/2021  
Task Last Updated: 02/14/2020 
Download report in PDF pdf
Principal Investigator/Affiliation:   Fornace, Albert  M.D. / Georgetown University 
Address:  Dept. of Oncology, Lombardi Comprehensive Cancer Center 
Research Building, Room E504, 3970 Reservoir Rd., NW 
Washington , DC 20007-2126 
Email: af294@georgetown.edu 
Phone: 202 687-7843  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: Georgetown University 
Joint Agency:  
Comments: http://www9.georgetown.edu/gumc/lombardi/fornacelab/  
Co-Investigator(s)
Affiliation: 
Brenner, David  Ph.D. Columbia University 
Datta, Kamal  M.D. Georgetown University 
Meltzer, Paul  M.D., Ph.D. National Cancer Institute, NIH 
Shay, Jerry  Ph.D. University of Texas Southwestern Medical Center at Dallas 
Project Information: Grant/Contract No. NNX15AI21G 
Responsible Center: NASA JSC 
Grant Monitor: Simonsen, Lisa  
Center Contact:  
lisa.c.simonsen@nasa.gov 
Solicitation / Funding Source: 2014-15 HERO NNJ14ZSA001N-NSCOR Radiation 
Grant/Contract No.: NNX15AI21G 
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) Cancer-103:Determine the effects of radiation quality on cancer initiation, promotion, and progression (IRP Rev M)
(2) Cancer-104:Determine the effects of radiation dose and dose-rate on cancer initiation, promotion and progression (IRP Rev M)
(3) Cancer-203:Evaluate the tissue-specific risks of space radiation exposure on cancer outcomes (IRP Rev M)
(4) Cancer-303:Identify early surrogate biomarkers that correlate with cancer, pre-malignancy, or the hallmarks of cancer (IRP Rev M)
Flight Assignment/Project Notes: NOTE: End date changed to 4/14/2021 per NSSC information (Ed., 1/16/2020)

Task Description: The overall objective of this NASA Specialized Center of Research (NSCOR) is to model the relative risk of gastrointestinal (GI) tumorigenesis for high priority space radiation beams and compare with gamma radiation where human epidemiologic data are available. It will rely primarily on mouse models of gastrointestinal (GI) cancer, and human colonic epithelial cell (HCEC) culture approaches that have been optimized for low dose exposures. This will involve quantitative and qualitative analyses of tumors as well as normal GI epithelium after radiation in mouse models. Results will be further extrapolated to identify radiation-induced molecular signatures of carcinogenesis in both mouse models and state-of-the-art 2D and 3D cultured human colonocytes. While limited studies at select loci have shown high energy (HZE)-induced mutations including splicing errors, frameshifts, indels and complex changes, we will carry out genome-wide analysis using the power of modern next-gen sequencing (NGS) to assess the spectrum of mutations in radiation-induced tumors, and also persistent genome-wide epigenomic changes in normal cells after ionizing radiation (IR). These NGS and epigenomics findings will be integrated with transcriptomics (RNAseq and/or microarray) and metabolomics data as well as with the select events at the molecular level to develop a systems biology model for GI tumorigenesis. By assessing both quantitative in vivo tumorigenesis data and molecular events in mouse tissues and human colonocytes, space radiation-induced tumorigenesis will be compared to human epidemiologic data for low and high LET (linear energy transfer) radiation exposures, and approaches will be developed to model human risks for GI cancer by space radiation. In addition to obtaining quantitative tumorigenesis data we also seek to test potential GI-cancer prevention agents (such as metformin and CDDO) to achieve desired risk mitigation against space radiation-induced tumorigenesis.

We continue to employ two models of GI cancers: the APC1638N/+ model, which was generated by targeted modification of the Apc gene at a position corresponding to aa1638. These mice develop very few adenomas in the small as well as in the large intestine but post-radiation tumor numbers show marked increases. Radiation also induced substantial gastric tumorigenesis in this model. The second model is the CDX2P Apc flox/+ that has one APC allele inactivated almost exclusively in the colon leading to adenomas and subsequent low rate of adenocarcinomas in the colon that is increased post-irradiation. Data being collected from these two relevant mouse models will be used to calculate risk estimates for NASA. Since low-LET risk estimates are available for human populations, we will then be able to model the relative risk for space radiation. In particular, this ratio can then be extrapolated to human exposure to low-LET radiation to then make an estimate of risk for colorectal cancer (CRC) in humans exposed to space radiation compared to the standard risks based on atomic bomb survivors and other exposure populations.

In order to answer the critical question of risk for colonic tumorigenesis after acute and chronic space radiation exposures, in vitro human cell culture and animal models for CRC initiation and progression are needed. We are investigating the effects of high-LET particle and high-energy protons in colonic epithelial cells with respect to the nature of damage and consequent tumor induction using biological cancer-related endpoints and systems biology (genomics, proteomics, and metabolomics) approaches. In addition, we are comparing these results to the biological consequences of low dose rates and mixed fields of radiation which astronauts are likely to be continuously exposed. The studies of low- and high-LET radiation on colonocytes gain more relevance with increasing age when premalignant adenomas and other colonic lesions such as flat lesions and microscopic aberrant crypt foci become more prevalent. Pre-existing undetectable genetic or chromosomal aberrations in astronauts in addition to de novo mutations resulting from long-term irradiation may increase the chances of colonic stem cell malignant transformation.

Plans for this proposal build on our past accomplishments with GI tumorigenesis models and are focused on studies at low doses (5 to 50 cGy) with an expanded range of NASA’s high priority beams. This proposal is also focused on assessing the effects of gender, dose-rate, age, and genetic heterogeneity in mouse models. Molecular events triggered by space radiation will be investigated in-depth and the mechanistic basis for persistent aberrant cell signaling after HZE radiation will be dissected. Genome-wide NGS combined with other omics approaches will contribute to a systems biology understanding of the effects of space radiation in the intestines and stomach. Both quantitative murine tumor data and results for underlying molecular events in mouse and human GI cells will contribute to the modeling of human risks for GI cancer by space travel. The overall aims of this NSCOR are summarized below:

Aim 1 (Project 1). Quantitatively assess GI tumorigenesis in mouse models of GI cancer and collect samples for qualitative analysis.

Aim 2 (Project 2). Dissection of the signaling events and consequences in GI cells of the persistent effects of space radiation.

Aim 3 (Project 3): Characterization of IR-induced neoplastic events in normal diploid human colonocytes.

Aim 4 (Project 4). Development of systems biology (Project 4A) and mathematical modeling (Project 4B) approaches for GI cancer risk assessment.

Research Impact/Earth Benefits: Gastrointestinal tumors are frequent in the U.S, and the American Cancer Society estimates that there will be 147,950 new cases of colorectal cancer (CRC) with 53,200 persons predicted to die of the disease in 2020. Overall, the lifetime risk of developing colorectal cancer is: about 1 in 23 (4.4%) for men and 1 in 25 (4.1%) for women. Considering the high frequency of colorectal tumors in the American population, and an even small increase by space radiation could have a major impact on risk estimates and planning of future manned space missions. In addition to risk estimation, studies on the persistence of oxidative and inflammatory stress after HZE radiation and its role in driving gastrointestinal tumorigenesis may provide insight into mutagenic processes affecting genome integrity and carcinogenesis. The significance and deliverable of this project is to improve the estimates of GI cancer risk in astronauts, and to identify and test plausible targets for the development of mitigation strategies.

Task Progress & Bibliography Information FY2020 
Task Progress: In the case of APC1638N/+ mice, we are using this model to obtain quantitative and qualitative tumorigenesis data at space relevant doses and beams spanning a range of LET and energies as well as with mixed field beams. In 2019, we used the NASA Space Radiation Laboratory (NSRL) facility for two-beam runs in the summer (protons and 28Si-ion) and fall (28Si-ion) and we have exposed APC1638N/+, wild-type C57BL6/J, and Lgr5 (Lgr5-EGFP-IRES-creERT2) mice for GI-tumorigenesis, persistent stress signaling and risk mitigation studies. Our previous data in APC mutant mouse model demonstrated higher intestinal tumorigenesis after exposure to 12C, 28Si, and 56Fe radiation relative to gamma rays. We also observed important qualitative differences between heavy ions and gamma rays in both normal GI epithelial cells and tumors. Further additions to the quantitative data obtained until 2018 was done in 2019 using more mice, additional beam types (proton and mixed-field GCR), and doses (5 and 10 cGy) in male and female APC1638N/+ mice exposed to gamma-rays, proton (1000 MeV/n), 4He (250 MeV/n), 12C (290 MeV/n), 16O (325 MeV/n), 28Si (300 MeV/n), 56Fe (1000 MeV/n), and mixed-field GCR (60% proton, 20% 4He, 10% 16O and 10% 28Si –ions). Since APC1638N/+ mice are also a model of gastric tumorigenesis, we also compared gastric tumorigenesis after gamma-rays and 28Si-ion exposure, where we found a significant increase in gastric tumorigenesis after HZE exposure. Additionally, gastric tissues sections are being analyzed for histological signs of tumorigenesis to add more doses and beam types. Further, in consultation with NASA, we also carried out a pilot study to assess the potential protective effect of metformin (an anti-diabetic and anti-aging agent), which is also associated with decreased frequency of human CRC. While metformin has been reported to decrease aging phenotype and CRC risk in humans, the experimental approach was developed to test effectiveness of metformin in preventing/decreasing 28Si-induced GI-tumorigenesis in APC1638N/+ mice.

Task book accomplishments using APC1638N/+ and Lgr5 (Lgr5-EGFP-IRES-creERT2) mice:

1. Proton tumorigenesis study: In our earlier proton beam studies we have compared results of acute vs. fractionated exposure at high doses (1.2 Gy vs 0.4 Gy x3 fractions). Here, we exposed male and female APC1638N/+ to 50 cGy of proton radiation and tumors in the GI tract were counted after 150 days post-exposure. Further, proton tumorigenesis data was compared to the already acquired GI-tumorigenesis data after 50 cGy exposure of 4He, 12C, 16O, 28Si, and 56Fe –ions to understand radiation quality effects on GI-tumorigenesis.

2. Qualitative analysis of HZE-induced tumors: HZE-ion exposure led to higher carcinoma relative to gamma-rays. The highest % of carcinoma was observed after 56Fe radiation (25% were carcinoma) at 10 cGy dose. A similar trend of highest percentage pf carcinoma after 56Fe radiation was also observed after 50 cGy as well as after 2 Gy equitoxic doses of heavy-ion radiation.

3. Gastric tumorigenesis study: Male APC1638N/+ mice were whole-body exposed to sham-radiation, gamma-rays, and 28Si (300 MeV/n) in summer-2019 and mice were sacrificed150 days after irradiation, and gastric tumor-frequency was scored. A significant increase in gastric tumorigenesis after 10 cGy of 28Si (~3 fold higher) was observed compared to the same dose of gamma-rays.

4. Mixed-field GI tumorigenesis study in APC1638N/+ mice: Male and female APC1638N/+ mice were whole-body exposed to sham-radiation and mixed-field GCR type beam in fall of 2018 and mice were sacrificed 150 days after irradiation, and gastrointestinal tumor-frequency was scored. We compared quantitative tumor data obtained from the equivalent doses of single HZE beam to the mixed-field GCR-induced tumorigenesis that revealed a higher relative contributions of the dose received from HZE.

5. Persistent effects study: Lgr5+ mice (6 to 8 weeks) were exposed to 50 cGy of 28Si-ions and intestinal stem cells were isolated through flow-sorting and markers of persistent stress, senescence, and SASP are being analyzed. Additionally, these samples are also being used for next-gen transcriptomics (RNAseq) and epigenomic studies.

6. Metformin risk mitigation study: Tested risk mitigation efficacy of metformin (0.1% in diet). The male APC1638/+ mice were put on metformin diet at 4 weeks of age and continued on metformin to the end of the study. Mice were exposed to 28Si-ion (10 cGy) at 8 week of age and GI-tumorigenesis was estimated at 150 days post-exposure. Metformin administration led to a statistically significant reduction in HZE-induced GI-tumorigenesis.

In addition to our primary focus on GI-tumorigenesis using APC-based mouse models (APC1638N/+ and CDX2P Apc flox/+), in consultation with NASA, we also added a lung cancer mouse model (LA1) to study space radiation-induced lung tumorigenesis and mitigation study using CDDO.

Task book accomplishments using CDX2P Apc flox/+ and LA1 mice:

1. Simulated solar particle events (sSPE) radiation induces prolonged DNA damage, and senescence-associated inflammation in colon tissues.

2. sSPE increases colon cancer initiation and progression in CPC;APC mice. Increased p53 mutations in colon cancer after sSPE exposure was also observed.

3. SPE-irradiation results in a ~3-fold increased incidence of colon carcinoma in the CPC;APC mouse model while administration of CDDO diet during irradiation exhibit fewer polyps in comparison to mice on control diet.

4. CDDO provided 3 days prior to radiation exposure protected mice from sSPE induced colon cancer initiation and progression. The CPC;APC mice on CDDO diet during solar particle irradiation simulations exhibit a decreased incidence in invasive carcinoma in comparison to mice on control diet.

5. 5cGy (300 MeV/n) of a single dose exposure to Silicon does not increase cancer initiation or overall survival but 10 cGy results in a >2-fold cancer initiation and an overall decrease in lifespan.

6. LA1 mice on CDDO diet during fractionated 56Fe- irradiation exhibit a decreased incidence in invasive carcinoma in comparison to mice on control diet.

7. LA1 mice on CDDO diet during solar particle irradiation simulations exhibit a decreased incidence in invasive carcinoma in comparison to mice on control diet.

8. LA1 mice fed CDDO without irradiation show reduced tumor progression.

9. Mixed beam studies were also carried out in CDX2P Apc flox/+ mice using both acute and protracted GCR sim beans.

Task book accomplishments on genetic and epigenetic analysis of space radiation tumor and normal tissues: Using next-gen sequencing approaches, we defined the features of the tumor genomes arising in our murine models after gamma, proton, and HZE exposure. During 2019, efforts have focused on two primary areas described in detail below:

1. DNA sequence analysis of mouse colon tumor samples arising after radiation exposure: Using our well established next-generation sequencing pipeline, we first used a targeted approach to sequence the Apc and Trp53 regions. From targeted sequencing, there is evidence that the loss of the Apc region is the primary mechanism of tumor initiation. However, inactivating mutations in Apc without LOH have been identified in some tumors from Si irradiated mice. These results have been validated with the sensitive digital droplet PCR assay. At a whole-genome scale, we will have the potential to detect differences in the mutation signature between these groups including the presence of structural rearrangements as well as small mutations. We have now obtained whole-genome sequencing (WGS) on some samples and are in the process of obtaining WGS on a collection of tumors from control mice and those exposed to gamma or 28Si.

2. Development of a targeted bisulfite-seq platform for the epigenetic analysis of irradiated mouse tissue: It has now been firmly established that HZE radiation leads to a persistent disturbance in the architecture of the gut epithelium. To investigate the mechanistic basis of this apparently epigenetic phenomenon, we are utilizing the Lgr5-GFP model established in the Fornace lab in addition to the Apc cancer-prone models. However, there are limited commercial tools for large-scale analysis of DNA methylation in the mouse genome. While whole-genome bisulfite sequence is possible, it is prohibitively resource-intensive. Our solution is the implementation of a large-scale targeted bisulfite sequencing platform capturing 69.9 Mb with 128,614 oligonucleotides. This provides a reasonable sampling of the mouse genome. After validating this system with high molecular weight DNA, we have initiated the analysis of DNA samples extracted from fixed tissues harvested from experimental and control mice. Results are excellent with clear delineation of CpG methylation status at the nucleotide level. We are now processing 24 samples and beginning the search for differentially methylated regions that may be related to radiation exposure.

Task book accomplishments on risk modeling using mouse tumorigenesis data:

Astronauts embarking on a trip to Mars and back or on other lengthy space exploration missions will encounter a multi-component mixture of ionizing radiations. These radiations damage cells in multiple ways, which can be roughly classified into two categories:

1. Targeted effects (TE), involving the consequences of direct traversals of cells by ionizing tracks leading to DNA double-strand breaks and other lesions.

2. Non-targeted effects (NTE, also called “bystander” effects) caused by the release of signals from cells directly hit by the tracks and the effects of these signals on other cells.

The presence of both TE and NTE can produce complex dose response shapes for space radiations, particularly in the low dose region that is most relevant for space missions.

Mechanistically-motivated radiation carcinogenesis models serve as important tools to describe these dose responses and make estimates and predictions of cancer risks from space exploration. Here we used our model that includes both TE and NTE to analyze updated mouse tumorigenesis data from the current NSCOR. The updated data set now includes more detailed information on space-relevant doses of multiple radiation types. A more detailed modified model formalism that uses a weighted Negative Binomial distribution to better describe the data variability was developed and implemented on this data set. This new information and improved modeling approach allowed a better estimation of dose-response shapes in the space-relevant dose region. Specifically, NTE parameters and relative biological effectiveness (RBE) and radiation effects ratio (RER) values at such doses of heavy ions and protons were estimated with more information than previously possible. Ultimately, these improvements provided updated and enhanced estimation of gastrointestinal cancer risks in human astronauts.

Bibliography Type: Description: (Last Updated: 12/03/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Shuryak I, Cunha M, Brenner D. "Space radiation quality factors incorporating both targeted and non-targeted effects [#19321]. " Presented at 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019.

NASA HRP investigators workshop abstracts. 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019. , Jan-2019

Abstracts for Journals and Proceedings Brenner D, Shuryak I. "Understanding extrapolation of radiation risks from terrestrial to space exposures: are low-dose non-targeted effects from different HZE-ions additive? [#19161]." Presented at 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019.

NASA HRP investigators’ workshop abstracts. 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019. , Jan-2019

Abstracts for Journals and Proceedings Shay J, Luitel K. "Countermeasures for mouse models of space radiation-induced tumors." Presented at 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019.

NASA HRP investigators’ workshop abstracts. 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019. , Jan-2019

Abstracts for Journals and Proceedings Datta K, Kumar S, Suman S, Fornace A. "Long-term stress after heavy ion radiation-induces senescence and senescence associated secretory phenotype to decrease cell migration in mouse intestine." 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019.

Abstracts. 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019. , Jan-2019

Abstracts for Journals and Proceedings Suman S, Kumar S, Moon B, Angdisen J, Kallakury B, Fornace A J, Datta K. "HZE-induced gastrointestinal tumorigenesis in APC1638n/+mice is dependent on sex and radiation quality even if doses are extremely low." 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019.

Abstracts. 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019. , Jan-2019

Abstracts for Journals and Proceedings Xu L, Walker R, Zhu Y, Wang Y, Pineda M, Killian J, Kumar S, Suman S, Datta K, Shay J, Fornace A, Meltzer P. "Integrative genomics of space radiation-induced gastrointestinal tumors." 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019.

Abstracts. 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019. , Jan-2019

Abstracts for Journals and Proceedings Suman S, Datta K, Kumar S, Fornace AJ Jr. "Role of persistent DNA damage response in heavy-ion space radiation-induced carcinogenesis." Presented at 27th Annual Meeting of Council on Radiation Measurements and Standards (CIRMS), National Institute of Standards and Technology (NIST), Gaithersburg, MD, USA, April 8-12, 2019. (Invited talk)

CIRMS meeting proceedings. 27th Annual Meeting of Council on Radiation Measurements and Standards (CIRMS), National Institute of Standards and Technology (NIST), Gaithersburg, MD, USA, April 8-12, 2019. , Apr-2019

Abstracts for Journals and Proceedings Suman S, Kumar S, Moon BH, Angdisen J, Kallakury BVS, Fornace AJ, Datta K. "Heavy-ion space radiation exposure is a potential risk factor for gastrointestinal tumorigenesis even at extremely low doses." AACR Annual Meeting 2019, Atlanta, GA, March 29-April 3, 2019.

Cancer Res. 2019 Jul 1;79(13 Suppl):3729. https://doi.org/10.1158/1538-7445.AM2019-3729 , Jul-2019

Abstracts for Journals and Proceedings Kumar S, Suman S, Kallakury BVS, Moon BH, Fornace AJ, Datta K. "Inverse effect of 28Si and 56Fe radiation on intestinal tumorigenesis vs. carcinogenesis in APC1638N/+ mice." AACR Annual Meeting 2019, Atlanta, GA, March 29-April 3, 2019.

Cancer Res. 2019 Jul 1;79(13 Suppl):3728. https://doi.org/10.1158/1538-7445.AM2019-3728 , Jul-2019

Abstracts for Journals and Proceedings Suman S, Kumar S, Moon BH, Fornace AJ, Datta K. "Heavy ion radiation exposure compromises long-term intestinal nutrient absorption and barrier functions." 65th Annual Meeting of the Radiation Research Society, San Diego, CA, November 3-6, 2019.

Radiation Research Society meeting (RRS) abstracts. 65th Annual Meeting of the Radiation Research Society, San Diego, CA, November 3-6, 2019. , Nov-2019

Abstracts for Journals and Proceedings Kumar S, Suman S, Moon BH, Fornace AJ, Datta K. "Space radiation induces oxidative stress and senescence, and alters microenvironment in mouse intestinal stem cells." 65th Annual Meeting of the Radiation Research Society, San Diego, CA, November 3-6, 2019.

Radiation Research Society meeting abstracts. 65th Annual Meeting of the Radiation Research Society, San Diego, CA, November 3-6, 2019. , Nov-2019

Articles in Peer-reviewed Journals Suman S, Shuryak I, Kallakury B, Brenner DJ, Fornace AJ Jr, Johnson MD, Datta K. "Protons show greater relative biological effectiveness for mammary tumorigenesis with higher ERα and HER2 positive tumors relative to γ-rays in APCMin/+ mice." Int J Radiat Oncol Biol Phys. 2020 May 1;107(1):202-11. Epub 2020 Feb 6. https://doi.org/10.1016/j.ijrobp.2020.01.031 ; PubMed PMID: 32036005 , May-2020
Articles in Peer-reviewed Journals Suman S, Kallakury BVS, Fornace AJ Jr, Datta K. "Fractionated and acute proton radiation show differential intestinal tumorigenesis and DNA damage and repair pathway response in APCMin/+ mice." Int J Radiat Oncol Biol Phys. 2019 Nov 1;105(3):525-36. Epub 2019 Jul 2. https://doi.org/10.1016/j.ijrobp.2019.06.2532 ; PubMed PMID: 31271826 , Nov-2019
Articles in Peer-reviewed Journals Kumar S, Suman S, Fornace AJ, Datta K. "Intestinal stem cells acquire premature senescence and senescence-associated secretory phenotype concurrent with persistent DNA damage after heavy ion radiation in mice." Aging (Albany NY). 2019 Jun 25;11(12):4145-58. https://doi.org/10.18632/aging.102043 ; PubMed PMID: 31239406; PubMed Central PMCID: PMC6629005 , Jun-2019
Articles in Peer-reviewed Journals Luitel K, Kim SB, Barron S, Richardson JA, Shay JW. "Lung cancer progression using fast switching multiple ion beam radiation and countermeasure prevention." Life Sci Space Res (Amst). 2020 Feb;24:108-15. Epub 2019 Aug 1. https://doi.org/10.1016/j.lssr.2019.07.011 ; PubMed PMID: 31987474; PubMed Central PMCID: PMC6991460 , Feb-2020
Project Title:  NSCOR: Space Radiation and Gastrointestinal Cancer: A Comprehensive Strategy for Risk Assessment and Model Development Reduce
Images: icon  Fiscal Year: FY 2019 
Division: Human Research 
Research Discipline/Element:
HRP SR:Space Radiation
Start Date: 04/15/2015  
End Date: 04/14/2021  
Task Last Updated: 02/15/2019 
Download report in PDF pdf
Principal Investigator/Affiliation:   Fornace, Albert  M.D. / Georgetown University 
Address:  Dept. of Oncology, Lombardi Comprehensive Cancer Center 
Research Building, Room E504, 3970 Reservoir Rd., NW 
Washington , DC 20007-2126 
Email: af294@georgetown.edu 
Phone: 202 687-7843  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: Georgetown University 
Joint Agency:  
Comments: http://www9.georgetown.edu/gumc/lombardi/fornacelab/  
Co-Investigator(s)
Affiliation: 
Brenner, David  Ph.D. Columbia University 
Datta, Kamal  M.D. Georgetown University 
Meltzer, Paul  M.D., Ph.D. National Cancer Institute, NIH 
Shay, Jerry  Ph.D. University of Texas Southwestern Medical Center at Dallas 
Project Information: Grant/Contract No. NNX15AI21G 
Responsible Center: NASA JSC 
Grant Monitor: Simonsen, Lisa  
Center Contact:  
lisa.c.simonsen@nasa.gov 
Solicitation / Funding Source: 2014-15 HERO NNJ14ZSA001N-NSCOR Radiation 
Grant/Contract No.: NNX15AI21G 
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) Cancer-103:Determine the effects of radiation quality on cancer initiation, promotion, and progression (IRP Rev M)
(2) Cancer-104:Determine the effects of radiation dose and dose-rate on cancer initiation, promotion and progression (IRP Rev M)
(3) Cancer-203:Evaluate the tissue-specific risks of space radiation exposure on cancer outcomes (IRP Rev M)
(4) Cancer-303:Identify early surrogate biomarkers that correlate with cancer, pre-malignancy, or the hallmarks of cancer (IRP Rev M)
Flight Assignment/Project Notes: NOTE: End date changed to 4/14/2021 per NSSC information (Ed., 1/16/2020)

Task Description: This NASA Specialized Center of Research (NSCOR) aims to model the relative risk of colonic and stomach tumorigenesis for high priority space radiation beams and compare to gamma radiation where human epidemiologic data are available. It will rely primarily on mouse models of gastrointestinal (GI) cancer and human colonic epithelial cell (HCEC) approaches that have been optimized for low dose exposures. This will involve quantitative and qualitative analyses of tumors as well as normal GI epithelium after radiation. Results will be extrapolated to radiation-induced molecular changes in state-of-the-art 2D and 3D cultured human colonocytes. While limited studies at select loci, such as HRPT, have shown high energy (HZE)-induced mutations including splicing errors, frameshifts, and complex changes, we will carry out genome-wide analysis using the power of modern nextgen sequencing (NGS) to assess the spectrum of mutations in radiation-induced tumors, and also persistent genome-wide epigenomic changes in normal cells after radiation. These NGS omics findings will be integrated with transcriptomics and metabolomics results as well as events at the protein and cellular levels to develop a systems biology model for GI tumorigenesis. By assessing both quantitative in vivo tumorigenesis data and molecular events in mouse tissues and human colonocytes, space radiation-induced tumorigenesis will be compared to human epidemiologic data for low LET (linear energy transfer) radiation exposures, and approaches will be developed to model human risks for GI cancer by space radiation.

We continue to employ two models of GI cancers: the APC1638N/+ model, which was generated by a targeted modification of the Apc gene at a position corresponding to aa1638. These mice develop very few adenomas in the small as well as in the large intestine but post-radiation tumor numbers show marked increases. Radiation also induced substantial gastric tumorigenesis as well in this model. The second model is the CDX2P Apc flox/+ that has one APC allele inactivated almost exclusively in the colon leading to adenomas and subsequently a low rate of adenocarcinomas in the colon that is increased post-irradiation. Data being collected from these two relevant mouse models will be used to calculate risk estimates for NASA. Since low-LET risk estimates are available for human populations, we will then be able to model the relative risk for space radiation. In particular, this ratio can then be extrapolated to human exposure to low-LET radiation to then make an estimate of risk for colorectal cancer in humans exposed to space radiation compared to the standard risks based on atomic bomb survivors and other exposure populations.

In order to answer the critical question of risk for colonic tumorigenesis after acute and chronic space radiation exposures, in vitro human cell culture and animal models for colorectal cancer (CRC) initiation and progression are needed. We are investigating the effects of high-LET particle and high-energy protons in colonic epithelial cells with respect to the nature of damage and consequent tumor induction using biological cancer-related endpoints and systems biology (genomics, proteomics, and metabolomics) approaches. In addition, we propose to compare these results to the biological consequences of low dose rates and mixed fields of radiation which astronauts are likely to be continuously exposed. The studies of low- and high-LET radiation on colonocytes gain more relevance with increasing age when premalignant adenomas and other colonic lesions such as flat lesions and microscopic aberrant crypt foci become more prevalent. Pre-existing undetectable genetic or chromosomal aberrations in astronauts in addition to de novo mutations resulting from long-term irradiation may increase the chances of colonic stem cell transformation.

Plans for this proposal build on our past accomplishments with GI tumorigenesis models and are focused on studies at low doses with an expanded range of NASA's high priority beams. This proposal is also focused on assessing the effects of gender, dose-rate, age, and genetic heterogeneity in mouse models. Molecular events triggered by space radiation will be investigated in depth and the mechanistic basis for persistent aberrant cell-signaling after HZE radiation will be dissected. Genome-wide NGS combined with other omics approaches will contribute to a systems biology understanding of the effects of space radiation in the intestines and stomach. Both quantitative murine tumor data and results for underlying molecular events in mouse and human GI cells will contribute to modeling of human risks for GI cancer by space travel. The overall aims of this NSCOR are summarized below:

Aim 1 (Project 1). Quantitatively assess GI tumorigenesis in mouse models of GI cancer and collect samples for qualitative analysis

Aim 2 (Project 2). Dissection of the signaling events and consequences in GI cells of the persistent effects of space radiation

Aim 3 (Project 3): Characterization of IR(infrared)-induced neoplastic events in normal diploid human colonocytes

Aim 4 (Project 4). Development of systems biology (Project 4A) and mathematical modeling (Project 4B) approaches for GI cancer risk assessment.

Research Impact/Earth Benefits: Gastrointestinal tumors are frequent in the U.S., and American Cancer Society estimates that there will be 140,250 new cases of colorectal cancer (CRC) with 50,630 persons predicted to die of the disease in 2018. Colorectal cancer when considered in men and women is the second leading cancer killer in the United States ( http://www.cdc.gov/cancer/Colorectal ). Considering the high frequency of colorectal tumors in the American population, an even small increase by space radiation could have a major impact on risk estimates and planning of future manned space missions. The effect of complex DNA lesions, which are produced by HZE radiation, on intestinal tumorigenesis may provide insight into mutagenic processes affecting genome integrity and colorectal carcinogenesis.

Task Progress & Bibliography Information FY2019 
Task Progress: In 2018, we used NASA Space Radiation Laboratory (NSRL) facility for two beam runs in the spring and fall and currently, we have proposed beam time for the summer and fall of 2019. We are using the APC1638N/+ mice for quantitative and qualitative tumorigenesis data at lower doses of space radiation beams spanning a range of LET and energies as well as with mixed beam. During these beam runs, we have exposed additional mice for fulfilling statistically required numbers for different beams especially at low doses. Our previous data in APC mutant mouse model demonstrated higher intestinal tumorigenesis after exposure to 12-C, 28-Si, and 56-Fe radiation relative to gamma-rays. We also observed important qualitative differences between heavy ions and gamma-rays in both normal GI epithelial cells and tumors. While we exposed male and female mice to 5 cGy dose of gamma-rays, 16-O (325 MeV/n), 4-He (250 MeV/n), 28-Si (300 MeV/n), and 56-Fe (1000 MeV/n) as well as 10 cGy dose of 16-O (325 MeV/n) and 4-He (250 MeV/n) and presented data, we exposed additional mice and added to the data to enhance statistical power. While we started out tumorigenesis studies using 6 to 8 weeks old APC1638N/+ mice, we were also interested in comparing tumorigenesis in young vs aged mice. For aged mice, we used 20 to 24 weeks old mice which are equivalent to 30 to 50 years of human age and are within the astronauts’ age range. The comparative tumorigenesis study in young vs aged was undertaken in male as well as in female mice.

After consultation with NASA, we have also carried out pilot studies to assess the potential protective effect of aspirin, which is associated with decreased frequency of human CRC. While aspirin has been reported to decrease spontaneous tumorigenesis in APC mutant mice, the experimental approach was developed to test effectiveness of aspirin in preventing/decreasing 28-Si-induced intestinal tumorigenesis in APC1638N/+ mice. We used 50 and 10 cGy 300 MeV/n 28-Si ions (LET: 70 keV/micron). We chose these doses because these are the lowest doses that demonstrated significantly higher tumorigenesis relative to sham irradiation. We have chosen two doses because 50 cGy radiation induced higher tumor relative to 10 cGy and at 10 cGy due to lower tumor number signal to noise ratio for the aspirin effect on tumorigenesis could be problematic. Aspirin was administered in diet and three doses used were equivalent to human daily doses of 75, 150, or 300 mg aspirin tablet. We used three color-coded diets containing 61.5 mg, 123 mg, 246 mg aspirin, respectively, per kg of diet. We have chosen 3 human doses of aspirin because CRC chemoprevention studies in humans have reported aspirin dose range from 75 to 300 mg/day and this dose range was also effective in removing existing adenoma. We used daily aspirin administration schedule in 6 to 8 weeks old APC1638N/+ male mice and aspirin administration was started 1 month before irradiation and was continued until the end of the study. Mice were sacrificed 150 d after radiation and intestinal and colon tumors counted. Data show that aspirin did alter the course of space radiation-induced intestinal tumorigenesis.

Task book accomplishments 2018 using CDX2P Apc flox/+ mice: Completed 3 beam fast switching experiments (30 cGy total exposure) and demonstrated that the order of beams matter (e.g., protons, then helium followed by silcon) was the most carcinogenic

1. 5 cGy of silcon did not increase carcinogenesis, nor did 20-30 cGy of proton or 5 cGy of helium. Combining 20cGy of proton and 5 cGy of helium did not increase cancer progression.

2. Using fast beam switching, 30 cGy total IR proton-helium-silicon increased cancer progression as did 27 cGy total IR (e.g., 2 cGy silicon vs 5 cGy silicon). However, 25.5 cGy of total IR (20 cGy proton, 5 cGy helium and 0.5 cGy silicon did not increase cancer progression in mouse models of cancer.

3. Using the fast beam switching and treating mice with 20 cGy protons, then 5 cGy helium and then waiting 24 hours before exposing the same mice to 5 cGy of silicon did not result in increased carcinogenesis. This suggests repair of the proton and helium damage over 24 hours was sufficient to reduce the cancer progression.

4. Pretreating mice with the countermeasure CDDO in chow for 2 days prior to the 3 beam fast switching (30 cGy total IR) was sufficient to reduce cancer progression. However, similarly feeding mice with aspirin had no effect and cancer progression.

5. Official GCR (galactic cosmic radiation) simulation: We were the first group to treat mice with an acute 50 cGy IR with 5 proton energies, 5 helium energies, and 5 heavy ions (NSRL 18B). This was followed in NSRL 18C with a 4 week protracted exposure to 50 cGy GCR simulation.

Results are in progress but initial results 100 day post IR suggest acute and protracted are equivalent in regards to chronic and persistent oxidative damage as measure by increases in lipid peroxidation. The overall goal of this project is to understand long-term effects of space radiation on normal gastrointestinal (GI) cells including stem cells. Coordinated epithelial cell migration is key to maintaining functional integrity and preventing pathological processes in gastrointestinal (GI) tissue and is essential for astronauts’ health and space mission success. The GI tract with its high cell turnover is sensitive to radiation, and the effects of radiation are evident when the replacement process of cells lost during normal turnover are deregulated. In small intestine, considered a model system to study GI epithelial cell turnover, differentiated epithelial cells from crypt-base stem cells migrate along the crypt-villus axis to replace cells that shed into intestinal lumen via apoptosis at the villus tip. The current study irradiated wild type (Wt) mice (C57BL/6J; male; 6 to 8 weeks old; n=10) with 50 cGy 56-Fe (energy: 1000 MeV/nucleon; LET: 148 keV/micron) using simulated space radiation source at the NASA Space Radiation Laboratory (NSRL), Brookhaven National Laboratory (BNL). Mice were sacrificed either 7 d, 60 d, or 12 m after radiation exposure and cell migration in small intestine was assessed quantitatively and qualitatively. Iron radiation data were compared to an equal dose of gamma-rays data. We demonstrated that IEC migration along the crypt-villus axis is decreased up to 2 months after a low dose of heavy ion radiation relative to gamma-rays. Heavy ion radiation-induced decreased migration was associated with perturbation of molecular pathways involved in coordinated intestinal epithelial cell migration. We used also small intestine as a model system to delineate space radiation effects on GI stem cells. The intestine is a self-renewing tissue with an active crypt-base proliferative stem cell compartment and is sensitive to radiation exposures. We studied space radiation effects on intestinal stem cells (ISC) in male Lgr5 (Lgr5-EGFP-IRES-creERT2) mice in C57BL/6J background using low doses (<1 Gy) 56-Fe (1000 MeV/n) ions. Lgr5 mice were exposed to 0.5 Gy of 56-Fe and GFP+ Lgr5 cells were sorted from isolate intestinal cell using flow cytometry. Intracellular ROS was assessed in sorted intestinal stem cells (ISCs) using fluorescent probe CellROX and flow cytometry. Data show increased reactive oxygen species (ROS) and mitochondrial superoxide in ISCs 2-month after heavy ion radiation. We also show increased gammaH2AX and 53BP1 foci in iron irradiated samples suggesting continued presence of sub-lethal label of DNA DSB (double strand breaks) in these live sorted ISCs. We stained ISCs for PCNA, a known cell proliferation marker and showed increased PCNA staining supporting ISC proliferation in presence of chronic stress and DNA damage with potential for transformation. Future plan involves understanding whether stem cell stress is propagated to progeny and developing countermeasure strategy to block space radiation-induced persistent stem cell stress.

The goal of this project is to define the features of the tumor genomes arising in our murine models after gamma, proton, and HZE exposure. Using our well established next generation sequencing pipeline, we used a targeted to sequence the Apc and Trp53 regions to establish tumor purity and to identify the best samples for larger scale analysis. At the same time, we can identify any mutations occurring in these regions. Our data illustrate single nucleotide polymorphism analysis of the Apc region from a representative group of 12 tumors and 7 normal adjacent tissues. Allelic imbalance is observed in all tumors, but there is considerable variation in tumor purity. Over 50 tumors from the Fornace and Shay labs have been sequenced. In this fashion, we have identified the samples with the least dilution by normal DNA that are most suited to large scale sequencing. We are currently accessioning new samples in order to have sufficient material to test the hypothesis that HZE radiation has a recognizable mutation signature. From targeted sequencing, there is clear evidence that loss of the entire region is the primary mechanism of tumor initiation under all conditions. No single nucleotide mutations, small INDELS, or structural rearrangements in or flanking Apc have been identified. Excellent whole-genome copy number profiles can also be derived from this data. Our current analyses indicate at the dose levels used in this study, the tumor mutation burden from either chromosome rearrangements, aneuploidy, or small mutations (single nucleotide or small indels) is remarkably low. We have now initiated whole genome sequencing on selected samples to validate this conclusion at maximum resolution.

It has now been firmly established that HZE radiation leads to a persistent disturbance in the architecture of the gut epithelium. To investigate mechanistic basis of this apparently epigenetic phenomenon, we are utilizing the Lgr5-GFP model established in the Fornace lab in addition to the Apc cancer prone models. The Lgr5-GFP system presents the opportunity to carry out transcriptomic analysis of cells isolated from irradiated and control mice and flow sorted into groups which reflect stem cells (GFP high), proliferating cells (GFP low), and differentiated cells (GFP negative). Cells from control, gamma, and HZE irradiated mice were obtained in triplicate, sorted by GFP expression, and analyzed by RNA-Sequencing.

Analysis of the data suggests that distinct differences in gene expression are observed at 120 days post-irradiation within the stem cell (high GFP) samples. We are currently following up on this data with pathway gene set enrichment analyses and are preparing to validate and refine our results using single cell RNA-Seq techniques. To complement the transciptome studies, we plan to use DNA for targeted bisulfite sequencing of 850,000 CpG sites distributed across the mouse genome. Ultimately, the integration of transcriptional data with DNA methylation status could provide important insights into the mechanism and consequences of the persistent effects of HZE exposure. There may be potential to develop blood based assays to detect the signature of HZE DNA methylation.

Astronauts on long-duration space exploration missions such as a planned trip to Mars and back will be exposed to a complex mixture of radiations that is not encountered on Earth. This space radiation mixture includes heavy ions, which produce difficult to repair clustered damage in cells and can be much more carcinogenic than gamma rays. In such situations, non-targeted effects caused by release of signals from cells directly hit by heavy ion track cores are likely to be the dominant mechanism producing adverse health effects from heavy ion. Reliable estimates for the endpoint-specific dose-dependent weighting function, which take non-targeted effects into consideration, are needed to predict human cancer risks from heavy ion exposure during space missions, based on available data for gamma rays. We used a mechanistically-motivated mathematical model to analyze updated mouse tumorigenesis data from the current NSCOR and to generate convenient weighting function equations and estimates for several space-relevant heavy ion types, compared with gamma rays. The updated data set now includes two additional ion types and lower, more space-relevant, doses. The model-based weighting function estimates are dose-dependent and tend to be highest (>10) at low doses, where non-targeted effect terms dominate the radiation response.

Bibliography Type: Description: (Last Updated: 12/03/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Suman S, Kuman S, Moon BH, Angdisen J, Kallakury BVS, Fornace AJ, Datta K. "Heavy-ion radiation (HZE) has higher relative biological effectiveness for intestinal and colonic tumorigenesis at lower doses in APC1638N/+ mice." 64th Annual Meeting of the Radiation Research Society, Chicago, IL, September 23-26, 2018. Invited presentation.

64th Annual Meeting of the Radiation Research Society, Chicago, IL, September 23-26, 2018. , Sep-2018

Abstracts for Journals and Proceedings Kumar S, Suman S, Moon BH, Kallakury BVS, Fornace AJ, Datta K. "Linear energy transfer (LET)-dependent inverse effects of 28Si and 56Fe radiation on intestinal tumorigenesis vs. carcinogenesis in APC1638N/+ mice." 64th Annual Meeting of the Radiation Research Society, Chicago, IL, September 23-26, 2018.

64th Annual Meeting of the Radiation Research Society, Chicago, IL, September 23-26, 2018. , Sep-2018

Abstracts for Journals and Proceedings Suman S, Moon BH, Fornace AJ, Datta K. "Exposure to highly energetic charged (HZE) particle radiation is associated with higher colitis and colorectal cancer incidence in IL10-/- mice." AACR Annual Meeting 2018, Chicago, Illinois, April 14-18, 2018.

Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR. Cancer Res 2018 Jul;78(13 Suppl):Abstract nr 5057. https://doi.org/10.1158/1538-7445.AM2018-5057 , Jul-2018

Abstracts for Journals and Proceedings Kumar S, Suman S, Fornace AJ, Datta K. "Space radiation-induced persistent DNA damage and alterations in cytoskeletal remodeling pathways affect intestinal epithelial cell migration in mice." AACR Annual Meeting 2018, Chicago, Illinois, April 14-18, 2018.

Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR. Cancer Res 2018 Jul;78(13 Suppl):Abstract nr 4163. https://doi.org/10.1158/1538-7445.AM2018-4163 , Jul-2018

Abstracts for Journals and Proceedings Datta K, Suman S, Moon BH, Fornace AJ. "Acute and fractionated proton radiation-induced intestinal tumorigenesis In APCmin/+ mice." AACR Annual Meeting 2018, Chicago, Illinois, April 14-18, 2018.

AACR Annual Meeting 2018, Chicago, Illinois, April 14-18, 2018. , Apr-2018

Abstracts for Journals and Proceedings Xu L, Walker RL, Zhu YJ, Wang Y, Pineda M, Killian JK, Kumar S, Suman S, Datta K, Shay JW, Fornace AJ, Meltzer PS. "The genomes of space radiation induced gastrointestinal tumors." 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019.

2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019. , Jan-2019

Abstracts for Journals and Proceedings Suman S, Kumar S, Moon BH, Fornace AJ, Datta K. "Heavy ion radiation-induced intestinal and colonic tumorigenesis in APC1638N/+ mice is independent of dose rate." 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019.

2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019. , Jan-2019

Abstracts for Journals and Proceedings Suman S, Kumar S, Moon BH, Fornace AJ, Datta K. "Energetic heavy ion space radiation-induced long-term downregulation of autophagy and upregulation of proliferative pathways in normal mouse intestinal epithelium." 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019.

2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019. , Jan-2019

Abstracts for Journals and Proceedings Luitel K, Kim SB, Barron S, Shay JW. "Lung cancer progression using fast switch multiple ion beam exposure +/- cddo countermeasure." 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019.

2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019. , Jan-2019

Abstracts for Journals and Proceedings Luitel K, Shay JW. "NASA official GCR simulation: comparing acute to chronic exposure." 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019.

2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019. , Jan-2019

Abstracts for Journals and Proceedings Fornace AJ Jr, Datta K, Shay JW, Meltzer PS, Brenner DJ. "Gastrointestinal (GI) NSCOR for: cancer risk, development of risk mitigation strategies based on injury responses, and risk modeling." 2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019.

2019 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2019. , Jan-2019

Articles in Peer-reviewed Journals Shuryak I, Brenner DJ. "Mechanistic modeling predicts no significant dose rate effect on heavy-ion carcinogenesis at dose rates relevant for space exploration." Radiat Prot Dosimetry. 2019 May 1;183(1-2):203-12. Published: 11 December 2018. https://doi.org/10.1093/rpd/ncy223 ; PubMed PMID: 30535099 [Note: A correction has been published: Radiation Protection Dosimetry, Volume 183, Issue 3, May 2019, Page 403, https://doi.org/10.1093/rpd/ncz003 , correcting the funding statement.] , May-2019
Articles in Peer-reviewed Journals Kumar S, Suman S, Fornace AJ Jr, Datta K. "Space radiation triggers persistent stress response, increases senescent signaling, and decreases cell migration in mouse intestine." Proc Natl Acad Sci U S A. 2018 Oct 16;115(42):E9832-E9841. https://doi.org/10.1073/pnas.1807522115 ; PubMed PMID: 30275302; PubMed Central PMCID: PMC6196540 , Oct-2018
Articles in Peer-reviewed Journals Luitel K, Bozeman RG, Kaisani A, Kim SB, Barron S, Richardson JA, Shay JW. "Proton radiation-induced cancer progression." Life Sciences in Space Research. 2018 Nov;19:31-42. Epub 2018 Aug 18. https://doi.org/10.1016/j.lssr.2018.08.002 ; PubMed PMID: 30482279 , Nov-2018
Articles in Peer-reviewed Journals Zhang L, Kim SB, Lutiel K, Shay JW. "Cholesterol depletion by TASIN-1 induces apoptotic cell death through ER stress/ROS/JNK signaling in colon cancer cells." Mol Cancer Ther. 2018 May;17(5):943-51. Epub 2018 Feb 21. https://doi.org/10.1158/1535-7163.MCT-17-0887 ; PubMed PMID: 29467273 , May-2018
Articles in Peer-reviewed Journals Suman S, Kumar S, Fornace AJ Jr, Datta K. "The effect of carbon irradiation is associated with greater oxidative stress in mouse intestine and colon relative to gamma-rays." Free Radic Res. 2018 May;52(5):556-67. https://doi.org/10.1080/10715762.2018.1452204 ; PubMed PMID: 29544379 , May-2018
Project Title:  NSCOR: Space Radiation and Gastrointestinal Cancer: A Comprehensive Strategy for Risk Assessment and Model Development Reduce
Images: icon  Fiscal Year: FY 2018 
Division: Human Research 
Research Discipline/Element:
HRP SR:Space Radiation
Start Date: 04/15/2015  
End Date: 04/14/2020  
Task Last Updated: 02/14/2018 
Download report in PDF pdf
Principal Investigator/Affiliation:   Fornace, Albert  M.D. / Georgetown University 
Address:  Dept. of Oncology, Lombardi Comprehensive Cancer Center 
Research Building, Room E504, 3970 Reservoir Rd., NW 
Washington , DC 20007-2126 
Email: af294@georgetown.edu 
Phone: 202 687-7843  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: Georgetown University 
Joint Agency:  
Comments: http://www9.georgetown.edu/gumc/lombardi/fornacelab/  
Co-Investigator(s)
Affiliation: 
Brenner, David  Ph.D. Columbia University 
Datta, Kamal  M.D. Georgetown University 
Meltzer, Paul  Ph.D. National Cancer Institute, NIH 
Shay, Jerry  Ph.D. University of Texas Southwestern Medical Center at Dallas 
Project Information: Grant/Contract No. NNX15AI21G 
Responsible Center: NASA JSC 
Grant Monitor: Simonsen, Lisa  
Center Contact:  
lisa.c.simonsen@nasa.gov 
Solicitation / Funding Source: 2014-15 HERO NNJ14ZSA001N-NSCOR Radiation 
Grant/Contract No.: NNX15AI21G 
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) Cancer-103:Determine the effects of radiation quality on cancer initiation, promotion, and progression (IRP Rev M)
(2) Cancer-104:Determine the effects of radiation dose and dose-rate on cancer initiation, promotion and progression (IRP Rev M)
(3) Cancer-203:Evaluate the tissue-specific risks of space radiation exposure on cancer outcomes (IRP Rev M)
(4) Cancer-303:Identify early surrogate biomarkers that correlate with cancer, pre-malignancy, or the hallmarks of cancer (IRP Rev M)
Task Description: This NASA Specialized Center of Research (NSCOR) aims to model the relative risk of colonic and stomach tumorigenesis for high priority space radiation beams and compare to gamma radiation where human epidemiologic data are available. It will rely primarily on mouse models of gastrointestinal (GI) cancer and human colonic epithelial cell (HCEC) approaches that have been optimized for low dose exposures. This will involve quantitative and qualitative analyses of tumors as well as normal GI epithelium after radiation. Results will be extrapolated to radiation-induced molecular changes in state-of-the-art 2D and 3D cultured human colonocytes. While limited studies at select loci, such as HRPT, have shown high energy (HZE)-induced mutations including splicing errors, frameshifts, and complex changes, we will carry out genome-wide analysis using the power of modern nextgen sequencing (NGS) to assess the spectrum of mutations in radiation-induced tumors, and also persistent genome-wide epigenomic changes in normal cells after radiation. These NGS omics findings will be integrated with transcriptomics and metabolomics results as well as events at the protein and cellular levels to develop a systems biology model for GI tumorigenesis. By assessing both quantitative in vivo tumorigenesis data and molecular events in mouse tissues and human colonocytes, space radiation-induced tumorigenesis will be compared to human epidemiologic data for low LET (linear energy transfer) radiation exposures, and approaches will be developed to model human risks for GI cancer by space radiation.

We continue to employ two models of GI cancers: the APC1638N/+ model, which was generated by a targeted modification of the Apc gene at a position corresponding to aa1638. These mice develop very few adenomas in the small as well as in the large intestine but post-radiation tumor numbers show marked increases. Radiation also induced substantial gastric tumorigenesis as well in this model. The second model is the CDX2P Apc flox/+ that has one APC allele inactivated almost exclusively in the colon leading to adenomas and subsequently a low rate of adenocarcinomas in the colon that is increased post-irradiation. Data being collected from these two relevant mouse models will be used to calculate risk estimates for NASA. Since low-LET risk estimates are available for human populations, we will then be able to model the relative risk for space radiation. In particular, this ratio can then be extrapolated to human exposure to low-LET radiation to then make an estimate of risk for colorectal cancer in humans exposed to space radiation compared to the standard risks based on atomic bomb survivors and other exposure populations.

In order to answer the critical question of risk for colonic tumorigenesis after acute and chronic space radiation exposures, in vitro human cell culture and animal models for colorectal cancer (CRC) initiation and progression are needed. We are investigating the effects of high-LET particle and high-energy protons in colonic epithelial cells with respect to the nature of damage and consequent tumor induction using biological cancer-related endpoints and systems biology (genomics, proteomics, and metabolomics) approaches. In addition, we propose to compare these results to the biological consequences of low dose rates and mixed fields of radiation which astronauts are likely to be continuously exposed. The studies of low- and high-LET radiation on colonocytes gain more relevance with increasing age when premalignant adenomas and other colonic lesions such as flat lesions and microscopic aberrant crypt foci become more prevalent. Pre-existing undetectable genetic or chromosomal aberrations in astronauts in addition to de novo mutations resulting from long-term irradiation may increase the chances of colonic stem cell transformation.

Plans for this proposal build on our past accomplishments with GI tumorigenesis models and are focused on studies at low doses with an expanded range of NASA's high priority beams. This proposal is also focused on assessing the effects of gender, dose-rate, age, and genetic heterogeneity in mouse models. Molecular events triggered by space radiation will be investigated in depth and the mechanistic basis for persistent aberrant cell-signaling after HZE radiation will be dissected. Genome-wide NGS combined with other omics approaches will contribute to a systems biology understanding of the effects of space radiation in the intestines and stomach. Both quantitative murine tumor data and results for underlying molecular events in mouse and human GI cells will contribute to modeling of human risks for GI cancer by space travel. The overall aims of this NSCOR are summarized below:

Aim 1 (Project 1). Quantitatively assess GI tumorigenesis in mouse models of GI cancer and collect samples for qualitative analysis.

Aim 2 (Project 2). Dissection of the signaling events and consequences in GI cells of the persistent effects of space radiation

Aim 3 (Project 3): Characterization of IR-induced neoplastic events in normal diploid human colonocytes

Aim 4 (Project 4). Development of systems biology (Project 4A) and mathematical modeling (Project 4B) approaches for GI cancer risk assessment.

Research Impact/Earth Benefits: Gastrointestinal tumors are frequent in the U.S, and American Cancer Society estimates that there will be 140,250 new cases of colorectal cancer (CRC) with 50,630 persons predicted to die of the disease in 2018. Colorectal cancer when considered in men and women is the second leading cancer killer in the United States ( http://www.cdc.gov/cancer/Colorectal ). Considering the high frequency of colorectal tumors in the American population, an even small increase by space radiation could have a major impact on risk estimates and planning of future manned space missions. The effect of complex DNA lesions, which are produced by HZE radiation, on intestinal tumorigenesis may provide insight into mutagenic processes affecting genome integrity and colorectal carcinogenesis.

Task Progress & Bibliography Information FY2018 
Task Progress: The overall plan is to apply the well-characterized APC mouse models (APC1638N/+ and CDX2P Apcflox/+) of colorectal cancer (CRC) for development of risks estimates for various radiation exposures during manned space flight. We already know from studies in atomic bomb survivors that radiation is risk factor for CRC. Space radiation with its novel characteristics is expected to have greater risk relative to radiation on Earth. A standard approach in radiation biology towards risk estimation is to determine relative biologic effectiveness (RBE) of various parameters for space radiation compared to terrestrial radiation exposures. However, currently, there is much uncertainty in predicting risk of CRC in astronauts undertaking long duration space missions due to lack of sufficient in vivo mechanistic data in human or in animal models representing the human disease. Considering the limitation of acquiring human data, our study is focused on acquiring sufficient data in mouse models of human CRC with an aim to aid in risk model development for safe human space exploration. Therefore, qualitative and quantitative data on intestinal tumorigenesis in mice generated in this project will be used for quantitative dose response analyses. While such analyses will provide an estimate of risk in mouse models, our ultimate aim is to combine mouse model data from space radiation exposure and human epidemiological data from atomic bomb survivors to develop mathematical risk prediction models of CRC for astronauts.

We have continued irradiation of the APC1638N/+ mouse model to obtain quantitative and qualitative tumorigenesis data at lower doses of space radiation beams spanning a range of LET and energies. We participated in two beam runs in the spring and fall of 2017 and we are breeding and genotyping mice for the spring 2018 run at NASA Space Radiation Laboratory (NSRL). These beam runs have allowed us to irradiate mice for fulfilling statistically required numbers decided in consultation with our Project 4B lead Dr. Brenner at Columbia University. We are also assessing the effect of chronic aspirin administration on tumor frequency; there are human data indicating that low-dose aspirin can have a protective effect against CRC. Our previous data in APC mutant mouse model demonstrated higher intestinal tumorigenesis after exposure to 12C, 28Si, and 56Fe radiation relative to gamma rays. We also observed important qualitative differences between heavy ions and gamma rays in both normal GI epithelial cells and tumors. However, our lowest dose for these experiments was 10 cGy. This year we exposed APC1638N/+ male and female mice to 5 cGy of gamma-rays, 16O (325 MeV/n), 4He (250 MeV/n), 28Si (300 MeV/n), and 56Fe (1000 MeV/n) with an aim to assess tumorigenesis at doses lower than the previous ones with a broader range of ions. We also exposed mice to 10 cGy of 16O (325 MeV/n) and 4He (250 MeV/n), which are new beams proposed in the renewed NSCOR, to get statistically required numbers. In an effort to assess effects of genetic heterogeneity on space radiation-induced intestinal tumorigenesis, we performed backcrossing of APC1638N/+ in C57BL/6J background into C3H/HeN and BALB/c background. The backcrossing was done for 10 generations and Sequencing of the region spanning the APC gene locus after backcrossing for 10 generations indicate that much of the chromosomal DNA flanking this locus is now either from C3H/HeN or BALB/c and not from C57BL/6J. We have scheduled beam time in 2018 fall to irradiate APC1638N/+ mice in C3H/HeN and BALB/c background to compare tumorigenesis in these vs. C57BL/6J background.

We expanded our GCR simulations (GCRsim) using both colon and lung cancer susceptible mouse model in comparison to wild type mice. In our initial experiments we used the following beams: protons (1H), helium (4He) and silicon (28Si). We used fast switching of these beams at the NSRL using a dose rate of 0.5 cGy/min and the large 60 x 60 beam. The total dose mice were exposed to was either 30 or 27 cGy. We used 20 cGy of proton (120Mev/n), 5 cGy of helium (250 MeV/n) and either 2 or 5 cGy of silicon (300 MeV/n). We previously showed that 30 cGy of proton and 5 cGy of silicon as single beam exposures did not increase polyp size or number of polyps in the CPC;APC mouse model. However, we observed 100 days post-IR that the number and polyp sizes were increased in mice exposed to the GCRsim in comparison to protons alone or unirradiated mice. Initial results indicate differential expression in normal colonic tissue in the CPC;APC mice 100 days after GCRsim. These included increases in senescence-associated inflammatory response genes and an increase in senescence markers (such as p16INK4a). We also varied the order of the different ions. While the trend was similar irrespective of beam order, GCRsim that begin with protons and end with silicon showed higher expression of specific inflammatory genes and larger and more polyps compared to unirradiated or proton only irradiated mice. These inflammatory genes have been previously shown to correlate with poorer overall survival in humans with colon cancer. We are currently testing a model of why the order of irradiation matters. In addition, we have completed a small pilot series of experiments to test aspirin or CDDO (an anti-oxidant/anti-inflammatory agent that is orally available and currently in clinical development) as effective countermeasures of IR-induced gene expression changes and tumor progression. We are also comparing the results in the colon susceptible mice to a mouse model of lung cancer. Initial results indicate that mice irradiated with GCRsim at 100 days post-IR have higher levels of lipid peroxidation in the serum as well as an increased number of premalignant lung lesions.

Understanding molecular underpinning of space radiation-induced adverse effects in normal gastrointestinal (GI) tissue is a key factor for pathophysiologic risk assessment. This year we focused on assessing long-term effects of heavy ion radiation on autophagy in intestinal epithelial cells two months after exposure. Autophagy is a complex catabolic process involved in removing and recycling damaged or unwanted cellular constituents in autophagolysosomal vesicles. Reduced autophagy is known to promote cellular stress not only due to increased accumulation of damaged proteins but also due to decreased removal of damaged mitochondria (mitophagy). Our data in wild type C57BL/6J mice demonstrate that exposure to 1.6 Gy of 56Fe radiation led to decreased autophagy and increased oxidative stress suggesting that heavy ion radiation is propelling cells into persistent dysregulated homeostasis. Deregulation of intestinal homeostasis is further strengthened by the fact that there is increased PI3K/Akt signaling invariably linked to increased reactive oxygen species (ROS) production as well as Akt-mediated activation of mTOR, which is known to downregulate autophagy. The generated data is expected to contribute towards developing GI risk estimates of heavy ion radiation, which is qualitatively high linear energy transfer (high-LET) in outer space relative to gamma-rays, which are low-LET. Currently, the persistent effects studies have been expanded to additional priority beams at lower radiation doses and dose rates more relevant to the space environment. Additionally, we have focused on intestinal stem cell (ISC) studies in male Lgr5 (Lgr5-EGFP-IRES-creERT2) mice in C57BL/6J background using low doses (<1 Gy) 28Si (300 MeV/n) or 56Fe (1000 MeV/n) ions. Since we observed persistent stress in intestinal epithelial cells, we are investigating to determine if persistent stress is originating from stem cell and propagating to differentiated epithelial cells. Lgr5 mice were exposed to 0.5 Gy of 56Fe and GFP+ Lgr5 cells were sorted from isolated intestinal cell using flow cytometry. Sorted cells were pelleted by cytospin and the pellet was paraffin embedded for sectioning and immunostaining. Our stem cell data show that 56Fe radiation exposure was associated with increased oxidative stress and DNA damage in intestinal stem cells. We also show that at least some of the ISC are senescent (senescent marker Glb1 positive) suggesting the possibility of senescence associated secretory phenotype associated inflammatory stress. Future plan involves understanding whether stem cell stress is propagated to progeny and developing countermeasure strategy to block space radiation-induced persistent stem cell stress.

We have also isolated colonocytes from normal and colon cancer susceptible mice. In addition to determining the best methods to culture these cells in 2D monolayers, we have establish 3D organotypic cultures from normal colonocytes and those from colonic polyps. The cells expand in size and number in organotypic culture (Matrigel) over a week period and can be trypsinized and re-cultured in 2D or 3D again. In initial experiments we established 3D cultures from WT and from the CPC;APC mouse model and irradiated them with either low or high LET IR and then placed them back in 2D culture. In comparison we irradiated intact mice (WT and CPC;APC mice) with the same doses and then removed colonocytes and established them in 2D and 3D cultures. These cells are being passaged and tested for cancer associated changes. In other experiments we initiated experiments to compare the CPC;APC mouse model to other cancer susceptible models of cancer such as a lung cancer mouse model. Initial results indicate that human bronchial epithelial cells irradiated in 2D culture form more colonies in soft agar compared to 3D-irradiated cells. These results indicate that estimates of cancer progression based on 2D culture may overestimate the cancer risks. Going forward, we plan to test a biological countermeasure, CDDO, to determine if the changes observed can be reduced or prevented by either providing CDDO prior to or after a GCR simulation.

The goal of the genomics project is to define the features of the tumor genomes arising in our murine models after gamma, proton, and HZE exposure. Using our well established next generation sequencing pipeline, we used a targeted approach to sequence the Apc and Trp53 regions to establish tumor purity and to identify the best samples for larger scale analysis. At the same time, we can identify any mutations occurring in these regions. Single nucleotide polymorphism analysis of the Apc region from a representative group of 12 tumors and 7 normal adjacent tissues was performed. Allelic imbalance is observed in all tumors, but there is considerable variation in tumor purity. A total of 34 tumors from the Fornace and Shay labs were sequenced. In this fashion, we have identified tumors with the least dilution by normal DNA that are most suited to large scale sequencing. We are currently accessioning new samples in order to have sufficient material to test the hypothesis that HZE radiation has a recognizable mutation signature. From targeted sequencing, it appears that loss of the entire region is the primary mechanism of tumor initiation under all conditions. No single nucleotide mutations, small INDELS or structural rearrangements in or flanking Apc have been identified. Excellent, whole genome copy number profiles can also be derived from this data.

Astronauts performing space exploration missions will be exposed to heavy ion radiation, which can be considerably more carcinogenic per unit dose than terrestrial radiations such as gamma-rays or x-rays. Our project within the space radiation and gastrointestinal cancer NSCOR focuses on developing biologically based mathematical models to predict heavy ion induced cancer risks at doses and exposure durations relevant for space missions. Specifically, our modeling efforts are aimed at addressing the following important question: do the risks from protracted heavy ion exposures in space differ from the risks of such irradiation delivered over a short time in terrestrial experiments? We proposed a model of heavy ion carcinogenesis and fitted it to radiation lung carcinogenesis data in humans and rats. The model predicts that, at doses expected during astronaut missions, protraction of heavy ion exposure does not have a major effect on lung cancer risks. In other words, the risks from small doses of heavy ion irradiation delivered over a short time or a long time are likely to be similar. Overall, we plan to generate in vivo data on tumor frequency and mechanisms of tumor development using NASA mandated additional priority space radiation beams at lower doses relevant to space environment. These data will be used to reduce uncertainty in CRC risk prediction and develop reliable risk prediction model for humans.

Bibliography Type: Description: (Last Updated: 12/03/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Shay J. "Biological countermeasures to reduce space radiation-induced cancer progression." 5th International Symposium on Space Radiation and Particle Radiotherapy (ISSRPRT), Suzhou, China, May 24-26, 2017.

5th International Symposium on Space Radiation and Particle Radiotherapy (ISSRPRT), Suzhou, China, May 24-26, 2017. , May-2017

Abstracts for Journals and Proceedings Shay J. "Mouse models of cancer risk and prevention from GCR simulation." 2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018.

2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018. , Jan-2018

Abstracts for Journals and Proceedings Luitel K, Barron S, Shay JW. "Proton radiation-induced progression of cancer." 2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018.

2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018. , Jan-2018

Abstracts for Journals and Proceedings Kim SB, Luitel K, Shay JW. "Biological effects of GCR simuation on colon and lung cancer susceptible mouse models." 2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018.

2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018. , Jan-2018

Abstracts for Journals and Proceedings Xu L, Walker RL, Zhu YJ, Wang Y, Pineda M, Killian JK, Kumar S, Suman S, Datta K, Shay JW, Fornace AJ Jr, Meltzer PS. "The genomes of space radiation-induced gastrointestinal tumors." 2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018.

2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018. , Jan-2018

Abstracts for Journals and Proceedings Fornace AJ Jr, Datta K, Shay JW, Meltzer PS, Brenner D. "Assessing risk, developing risk prediction models, and testing risk mitigation strategies for space radiation-induced gastrointestinal carcinogenesis." 2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018.

2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018. , Jan-2018

Abstracts for Journals and Proceedings Suman S, Kumar S, Moon BM, Fornace AJ Jr, Datta K. "Heavy ion radiation-induced intestinal and colonic tumorigenesis in APC1638N/+ mice is independent of dose rate." 2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018.

2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018. , Jan-2018

Abstracts for Journals and Proceedings Suman S, Kumar S, Moon BM, Fornace AJ Jr, Datta K. "Energetic heavy ion space radiation-induced long-term downregulation of autophagy and upregulation of proliferative pathways in normal mouse intestinal epithelium." 2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018.

2018 NASA Human Research Program Investigators’ Workshop, Galveston, TX, January 22-25, 2018. , Jan-2018

Abstracts for Journals and Proceedings Suman S, Kumar S, Moon BM, Fornace AJ Jr, Datta K. "Low and high dose rate heavy ion radiation-induced intestinal and colonic tumorigenesis in APC1638N/+ mice." 63rd Annual Meeting of the Radiation Research Society, Grand Fiesta Americana Coral Beach, Cancun, Mexico, October 14-18, 2017.

63rd Annual Meeting of the Radiation Research Society, Grand Fiesta Americana Coral Beach, Cancun, Mexico, October 14-18, 2017. , Oct-2017

Abstracts for Journals and Proceedings Kumar S, Suman S, Moon BM, Fornace AJ Jr, Datta K. "Differential effects on murine intestinal epithelial cell migration is dependent on radiation quality. (Invited talk)." 63rd Annual Meeting of the Radiation Research Society, Grand Fiesta Americana Coral Beach, Cancun, Mexico, October 14-18, 2017.

63rd Annual Meeting of the Radiation Research Society, Grand Fiesta Americana Coral Beach, Cancun, Mexico, October 14-18, 2017. , Oct-2017

Abstracts for Journals and Proceedings Suman S, Kumar S, Moon BM, Fornace AJ Jr, Datta K. "Using IL10-/- mouse model to access heavy-ion radiation exposure associated colitis and colorectal cancer incidence." AACR (American Association of Cancer Research) special conference on 'Advances in Modeling Cancer in Mice: Technology, Biology, and Beyond,' Orlando, FL, September 24-27, 2017.

AACR (American Association of Cancer Research) special conference on 'Advances in Modeling Cancer in Mice: Technology, Biology, and Beyond,' Orlando, FL, September 24-27, 2017. , Sep-2017

Abstracts for Journals and Proceedings Suman S, Kumar S, Moon BM, Fornace AJ Jr, Datta K. "Intestinal Tumorigenesis In APCmin/+ Mice Is Higher After Acute Relative To Fractionated Proton Radiation: Implications For Space Radiation-induced Colorectal Carcinogenesis." AACR (American Association of Cancer Research) special conference on 'Advances in Modeling Cancer in Mice: Technology, Biology, and Beyond,' Orlando, FL, September 24-27, 2017.

AACR (American Association of Cancer Research) special conference on 'Advances in Modeling Cancer in Mice: Technology, Biology, and Beyond,' Orlando, FL, September 24-27, 2017. , Sep-2017

Articles in Peer-reviewed Journals Suman S, Kumar S, Moon BH, Fornace AJ Jr, Kallakury BVS, Datta K. "Increased transgenerational intestinal tumorigenesis in offspring of ionizing radiation exposed parent APC1638N/+ mice." J Cancer. 2017 Jul 1;8(10):1769-73. eCollection 2017. https://doi.org/10.7150/jca.17803 ; PubMed PMID: 28819373; PubMed Central PMCID: PMC5556639 , Jul-2017
Articles in Peer-reviewed Journals Suman S, Kumar S, Moon BH, Fornace AJ Jr, Datta K. "Low and high dose rate heavy ion radiation-induced intestinal and colonic tumorigenesis in APC1638N/+ mice." Life Sci Space Res (Amst). 2017 May;13:45-50. https://doi.org/10.1016/j.lssr.2017.04.003 ; PubMed PMID: 28554509 , May-2017
Articles in Peer-reviewed Journals Jafri MA, Al-Qahtani MH, Shay JW. "Role of miRNAs in human cancer metastasis: Implications for therapeutic intervention." Semin Cancer Biol. 2017 Jun;44:117-31. Epub 2017 Feb 8. Review. https://doi.org/10.1016/j.semcancer.2017.02.004 ; PubMed PMID: 28188828 , Jun-2017
Project Title:  NSCOR: Space Radiation and Gastrointestinal Cancer: A Comprehensive Strategy for Risk Assessment and Model Development Reduce
Images: icon  Fiscal Year: FY 2017 
Division: Human Research 
Research Discipline/Element:
HRP SR:Space Radiation
Start Date: 04/15/2015  
End Date: 04/14/2020  
Task Last Updated: 02/14/2017 
Download report in PDF pdf
Principal Investigator/Affiliation:   Fornace, Albert  M.D. / Georgetown University 
Address:  Dept. of Oncology, Lombardi Comprehensive Cancer Center 
Research Building, Room E504, 3970 Reservoir Rd., NW 
Washington , DC 20007-2126 
Email: af294@georgetown.edu 
Phone: 202 687-7843  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: Georgetown University 
Joint Agency:  
Comments: http://www9.georgetown.edu/gumc/lombardi/fornacelab/  
Co-Investigator(s)
Affiliation: 
Brenner, David  Ph.D. Columbia University 
Datta, Kamal  M.D. Georgetown University 
Meltzer, Paul  Ph.D. National Cancer Institute, NIH 
Shay, Jerry  Ph.D. University of Texas Southwestern Medical Center at Dallas 
Project Information: Grant/Contract No. NNX15AI21G 
Responsible Center: NASA JSC 
Grant Monitor: Simonsen, Lisa  
Center Contact:  
lisa.c.simonsen@nasa.gov 
Solicitation / Funding Source: 2014-15 HERO NNJ14ZSA001N-NSCOR Radiation 
Grant/Contract No.: NNX15AI21G 
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) Cancer-103:Determine the effects of radiation quality on cancer initiation, promotion, and progression (IRP Rev M)
(2) Cancer-104:Determine the effects of radiation dose and dose-rate on cancer initiation, promotion and progression (IRP Rev M)
(3) Cancer-203:Evaluate the tissue-specific risks of space radiation exposure on cancer outcomes (IRP Rev M)
(4) Cancer-303:Identify early surrogate biomarkers that correlate with cancer, pre-malignancy, or the hallmarks of cancer (IRP Rev M)
Task Description: The overall objective of this NASA Specialized Center of Research (NSCOR) is to model the relative risk of colonic and stomach tumorigenesis for high priority space radiation beams and compare to gamma radiation where human epidemiologic data are available. It will rely primarily on mouse models of gastrointestinal (GI) cancer and human colonic epithelial cell (HCEC) approaches that have been optimized for low dose exposures. This will involve quantitative and qualitative analyses of tumors as well as normal GI epithelium after radiation. Results will be extrapolated to radiation-induced molecular changes in state-of-the-art 2D and 3D cultured human colonocytes. While limited studies at select loci, such as HRPT (hypoxanthine phosphoribosyltransferase), have shown HZE (high energy particle)-induced mutations including splicing errors, frameshifts, and complex changes, we will carry out genome-wide analysis using the power of modern nextgen sequencing (NGS) to assess the spectrum of mutations in radiation-induced tumors, and also persistent genome-wide epigenomic changes in normal cells after ionizing radiation (IR). These NGS omics findings will be integrated with transcriptomics and metabolomics results as well as events at the protein and cellular levels to develop a systems biology model for GI tumorigenesis. By assessing both quantitative in vivo tumorigenesis data and molecular events in mouse tissues and human colonocytes, space radiation-induced tumorigenesis will be compared to human epidemiologic data for low LET (linear energy transfer) radiation exposures, and approaches will be developed to model human risks for GI cancer by space radiation.

We continue to employ two models of GI cancers: the APC1638N model, which was generated by a targeted modification of the Apc gene at a position corresponding to aa1638. These mice develop very few adenomas in the small as well as in the large intestine but post-radiation tumor numbers show marked increases. Radiation induced substantial gastric tumorigenesis as well in this model. The second model is the CDX2P Apc flox/+ that has one APC allele inactivated almost exclusively in the colon leading to adenomas and subsequent a low rate of adenocarcinomas in the colon that is increased post-irradiation. Data being collected from these two relevant mouse models will be used to calculate risk estimates for NASA. Since low-LET risk estimates are available for human populations, we will then be able to model the relative risk for space radiation. In particular, this ratio can then be extrapolated to human exposure to low-LET radiation to then make an estimate of risk for colorectal cancer in humans exposed to space radiation compared to the standard risks based on atomic bomb survivors and other exposure populations.

In order to answer the critical question of risk for colonic tumorigenesis after acute and chronic space radiation exposures, in vitro human cell culture and animal models for CRC initiation and progression are needed. We are investigating the effects of high-LET particle and high-energy protons in colonic epithelial cells with respect to the nature of damage and consequent tumor induction using biological cancer-related endpoints and systems biology (genomics, proteomics, and metabolomics) approaches. In addition, we propose to compare these results to the biological consequences of low dose rates and mixed fields of radiation which astronauts are likely to be continuously exposed. The studies of low- and high-LET radiation on colonocytes gain more relevance with increasing age when premalignant adenomas and other colonic lesions such as flat lesions and microscopic aberrant crypt foci become more prevalent. Pre-existing undetectable genetic or chromosomal aberrations in astronauts in addition to de novo mutations resulting from long-term irradiation may increase the chances of colonic stem cell transformation.

Plans for this proposal build on our past accomplishments with GI tumorigenesis models and are focused on studies at low doses with an expanded range of NASA’s high priority beams. This proposal is also focused on assessing the effects of gender, dose-rate, age, and genetic heterogeneity in mouse models. Molecular events triggered by space radiation will be investigated in depth and the mechanistic basis for persistent aberrant cell-signaling after HZE radiation will be dissected. Genome-wide NGS combined with other omics approaches will contribute to a systems biology understanding of the effects of space radiation in the intestines and stomach. Both quantitative murine tumor data and results for underlying molecular events in mouse and human GI cells will contribute to modeling of human risks for GI cancer by space travel. The overall aims of this NSCOR are summarized below.

Aim 1 (Project 1). Quantitatively assess GI tumorigenesis in mouse models of GI cancer and collect samples for qualitative analysis.

Aim 2 (Project 2). Dissection of the signaling events and consequences in GI cells of the persistent effects of space radiation.

Aim 3 (Project 3): Characterization of IR-induced neoplastic events in normal diploid human colonocytes.

Aim 4 (Project 4). Development of systems biology (Project 4A) and mathematical modeling (Project 4B) approaches for GI cancer risk assessment.

Research Impact/Earth Benefits: Gastrointestinal tumors are frequent in the U.S., and American Cancer Society estimates that there will be 132,700 new cases of colorectal cancer (CRC) with 49,700 persons predicted to die of the disease in 2015. Colorectal cancer when considered in men and women is the second leading cancer killer in the United States ( http://www.cdc.gov/cancer/Colorectal ). Considering the high frequency of colorectal tumors in the American population, an even small increase by space radiation could have a major impact on risk estimates and planning of future manned space missions. The effect of complex DNA lesions, which are produced by HZE radiation, on intestinal tumorigenesis may provide insight into mutagenic processes affecting genome integrity and colorectal carcinogenesis.

Task Progress & Bibliography Information FY2017 
Task Progress: The overall plan is to apply the well-characterized APC mouse models (APC1638N/+ and CDX2P Apcflox/+) of colorectal cancer (CRC) for development of risks estimates for various radiation exposures during manned space flight. We already know from studies in atomic bomb survivors that radiation is risk factor for CRC. Space radiation with its novel characteristics is expected to have greater risk relative to radiation on Earth. A standard approach in radiation biology towards risk estimation is to determine relative biologic effectiveness (RBE) of various parameters for space radiation compared to terrestrial radiation exposures. However, currently, there is much uncertainty in predicting risk of CRC in astronauts undertaking long duration space missions due to lack of sufficient in vivo mechanistic data in human or in animal models representing the human disease. Considering the limitation of acquiring human data, our study is focused on acquiring sufficient data in mouse models of human CRC with an aim to aid in risk model development for safe human space exploration. Therefore, qualitative and quantitative data on intestinal tumorigenesis in mice generated in this project will be used for quantitative dose response analyses. While such analyses will provide an estimate of risk in mouse model, our ultimate aim is to combine mouse model data from space radiation exposure and human epidemiological data from atomic bomb survivors to develop mathematical risk prediction model of CRC for astronauts.

Task progress on GI tumorigenesis (GU). We have participated in three beam runs at NASA Space Radiation Laboratory (NSRL) after our current NSCOR award in 2015 with an aim to assess tumorigenesis at doses lower than the previous ones with a broader range of ions. Greater tumorigenesis was observed with 28Si ions in our previous studies relative to other ions and gamma rays. This year we exposed APC1638N/+ mice to 5 cGy of 28-Si (300 MeV/n) and we used male mice due to higher tumor frequency in male relative to female mice. This year we have also started experiments with 16-O (325 MeV/n) and 4-He (250 MeV/n) ions, which are NASA prioritized ions of lower Z value proposed in the NSCOR. In 2017, we are also approved for proton, 28-Si, 56-Fe, and 4-He beam time and we will use the time to irradiated APC1638N/+ mice to fulfill statistical requirements. Importantly, we completed animal numbers required for our low dose rate (0.33 cGy/min) studies, data has been compiled, and tumor data from low and high (50 cGy/min) dose rate exposures were compared. We observed that differences in dose rate did not affect tumor frequency or size. An important aspect of our proposal was to study effects of genetic heterogeneity on space radiation-induced intestinal tumorigenesis. Our backcrossing of APC1638N/+ of C57BL/6J background into C3H/HeN and BALB/c background for the genetic heterogeneity study is near completion. The backcrossing was done for 10 generations and the plan is to sequence APC gene locus for detection of the mutation. We expect APC1638N/+ mice in C3H/HeN and BALB/c background to be ready for space radiation exposure during fall 2017 beam run.

We simulated a solar particle event (SPE) at the NSRL to characterize the biological effects of low dose rate protons in vivo. Using the colorectal cancer susceptible (CPC;Apc) mouse model, we studied colonic tumorigenesis after whole-body exposure to a simulated SPE with varying energies (50-150 MeV/n) using a total dose of 2 Gy over a 2 hour period (at an average dose rate of 1.67 cGy/min). We also exposed mice to 2 Gy at 20 cGy/min of acute (50 MeV/n) proton (91% of the sSPE was at 50 MeV/n) or X-ray (250 kVp, 1 mA, 1.65 mm Al filter) at a dose rate of 20 cGy/min as a reference radiation. We observed that whole-body irradiation with simulated SPE was more effective in inducing invasive adenocarcinoma incidence compared to unirradiated controls and x-rays. We started a pilot GCR simulation study in 2016 using protons, and helium and silicon ions. Using the large beam and large boxes to contain 2-3 mice each we were able to irradiate about 90 mice in about 90 minutes with the new fast switching capabilities at the NSRL. We reduced the dose rate to 0.5 cGy per minute (instead of the usual 10-20 cGy per minute) with a total dose of 30 cGy. For NRSL16C we used 20 cGy of proton, followed by 5 cGy of helium and then 5 cGy of silicon. Since 5 cGy of silicon did not increase polyp formation, these experiments were conducted to determine if adding both helium and protons to 5 cGy of silicon would increase polyp formation. We also reversed the order of ions in the GCRsim since it may affect carcinogenesis initiation and/or progression. Results from these experiments will require about 9 additional months. Going forward we will add more mice to this GCRsim for NSRL 17A.

This year we focused on assessing long-term effects of heavy ion radiation on GI epithelial cell migration up to two months after exposure and compare the results to gamma radiation. The generated data is expected to contribute towards developing GI risk estimates of heavy ion radiation, which is qualitatively high linear energy transfer (high-LET) in outer space relative to gamma-rays, which is low-LET. Mice (C57BL/6J) were exposed to sham, or 0.5 Gy of gamma or 56Fe radiation and small intestine, which is organized into well-defined crypts and villi and is considered a model system to study GI cell migration, and collected 7 and 60 d after exposure. Rate of IEC migration was assessed using BrdU pulse labeling 24 h prior to sacrificing the mice. We analyzed key signaling molecules involved in cell polarity, microtubule dynamics, and cell adhesion dynamics using immunoblots, immunofluorescence, immunohistochemistry. Our data from this study suggests that heavy ion radiation could impede GI epithelial cell migration persistently. Overall, these studies in normal GI tissues indicate a profound and persistent perturbation of normal GI physiology and cellular homeostasis, and has implications for space travel-related GI pathophysiological changes.

At the genomics level we are using laboratory and bioinformatics tools of systems genomics to identify the features of gastrointestinal tumors arising in our murine models. Using next generation sequencing (NGS) based methods we are determining the global mutation burden, and mutation types including small mutations and structural variations in these tumors. To further inform mechanistic interpretation of HZE effects, we are planning to use NGS technologies to examine transcriptomic and epigenomic changes in colonocytes recovered after space radiation. Our overarching goal is to utilize integrative genomics analyses to identify the signatures of space radiation exposure, tumorigenesis, and the mechanistic consequences of these disturbances so that this information can be utilized to support risk assessment and mitigation studies. We are using formalin fixed paraffin embedded (FFPE) tumor samples for sequencing. As an initial step, FFPE sections were H&E stained for pathology evaluation and areas representing adenoma or carcinoma are marked for dissection. DNA is extracted from the dissected tissue using our standard protocols. We have developed a methodology for molecular quality control that will allow an estimate of sample purity and comprehensive sequencing for space radiation genomic signature identification.

Analyses of mouse model data of simulated space radiation, using mechanistically-motivated mathematical models of carcinogenesis, are needed to better understand and potentially mitigate these risks. We have used data on heavy ions (12-C, 28-Si, and 56-Fe) and gamma-ray induced intestinal tumor frequency in APC1638N/+ mice. Our mathematical model includes: (1) targeted effects (TE), caused by ionizations within/close to nuclear DNA; (2) non-targeted effects (NTE), caused by radiation damage to other cell structures (e.g., mitochondria) and/or activation of stress signaling pathways; (3) cytotoxic effects. We used the model to estimate the NTE contribution to the dose response for each ion. According to our model, NTE cause the steep initial rise of the heavy ion dose responses observed between 0 and 0.1 Gy. Because at low fluences of heavy ions many cell nuclei will not be traversed by the cores of ion tracks, the contribution of NTE to the dose response at low doses is expected to be high. Model-based estimates of NTE contributions were consistent with this expectation: they dominated the dose response below 0.1 Gy. Non targeted effects may therefore play an important role in low-dose carcinogenesis from heavy ions. Overall, we plan to generate in vivo data on tumor frequency and mechanisms of tumor development using NASA mandated additional priority space radiation beams at lower doses relevant to space environment. These data will be used to reduce uncertainty in CRC risk prediction and develop reliable risk prediction model for human.

Bibliography Type: Description: (Last Updated: 12/03/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Shay JW. "Mouse models of cancer risk and prevention from space radiation." Presented at the 2017 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, January 23-26, 2017.

2017 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, January 23-26, 2017. , Jan-2017

Abstracts for Journals and Proceedings Kim SB, Bozeman R, Kim W, Zhang L, Richardson J, Wright WE, Fornace A, Shay JW. "Simulated solar particle events (SPE) promotes senescence-associated inflammatory responses in colorectal cancer susceptible mice." Presented at the 2017 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, January 23-26, 2017.

2017 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, January 23-26, 2017. , Jan-2017

Abstracts for Journals and Proceedings Suman S, Kumar S, Fornace AJ Jr, Datta K. "Persistent oxidative stress in mouse intestinal and colonic epithelial cells after exposure to 12C-ion exposure." To be presented in 2017 AACR (American Association of Cancer Research) Annual Meeting, Washington DC, April 1-5, 2017.

2017 AACR (American Association of Cancer Research) Annual Meeting, Washington DC, April 1-5, 2017. , Apr-2017

Abstracts for Journals and Proceedings Kumar S, Suman S, Moon B-H, Fornace AJ Jr, Datta K. "Low-dose ionizing radiation induces persistent activation of NADPH oxidase pathway in mouse colon." To be presented in 2017 AACR (American Association of Cancer Research) Annual Meeting, Washington DC, April 1-5, 2017.

2017 AACR (American Association of Cancer Research) Annual Meeting, Washington DC, April 1-5, 2017. , Apr-2017

Abstracts for Journals and Proceedings Suman S, Kumar S, Fornace AJ Jr, Datta K. "Space radiation exposure persistently increased leptin and IGF1 in serum and activated leptin-IGF1 signaling axis in mouse intestine." Presented at the 2017 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, January 23-26, 2017.

2017 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, January 23-26, 2017. , Jan-2017

Abstracts for Journals and Proceedings Kumar S, Suman S, Moon B-H, Fornace AJ Jr, Datta K. "Adverse effects of radiation on murine intestinal epithelial cell migration is dependent on radiation quality." Presented at the 2017 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, January 23-26, 2017.

2017 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, January 23-26, 2017. , Jan-2017

Abstracts for Journals and Proceedings Suman S, Kumar S, Moon B-H, Fornace AJ Jr, Datta K. "Parental exposure to ionizing radiation elicits gastrointestinal tumorigenesis in offspring with higher male preponderance." Presented at the 62nd Annual Meeting of the Radiation Research Society, Big Island, Hawaii, October 16-19, 2016.

62nd Annual Meeting of the Radiation Research Society, Big Island, Hawaii, October 16-19, 2016. , Oct-2016

Abstracts for Journals and Proceedings Suman S, Kumar S, Fornace AJ Jr, Datta K. "Exposure to gamma and 12-C radiation-induced differential long-term oxidative stress in mouse intestinal and colonic epithelial cells." Presented at the 62nd Annual Meeting of the Radiation Research Society, Big Island, Hawaii, October 16-19, 2016.

62nd Annual Meeting of the Radiation Research Society, Big Island, Hawaii, October 16-19, 2016. , Oct-2016

Abstracts for Journals and Proceedings Kumar S, Suman S, Moon B-H, Fornace AJ Jr, Datta K. "Low dose ionizing radiation induces persistent oxidative stress in mouse colon through the NADPH oxidase pathway." Presented at the 62nd Annual Meeting of the Radiation Research Society, Big Island, Hawaii, October 16-19, 2016.

62nd Annual Meeting of the Radiation Research Society, Big Island, Hawaii, October 16-19, 2016. , Oct-2016

Abstracts for Journals and Proceedings Shuryak I, Fornace AJ, Datta K, Suman S, Kumar S, Sachs RK, Brenner DJ. "Scaling human cancer risks from low LET to high LET when dose-effect relations are complex." Presented at the 2017 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, January 23-26, 2017.

2017 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, January 23-26, 2017. , Jan-2017

Abstracts for Journals and Proceedings Meltzer PS, Shay JW, Fornace AJ Jr. "Genome Abnormalities in Space Radiation Driven Gastrointestinal Carcinogenesis." Presented at the 2017 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, January 23-26, 2017.

2017 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, January 23-26, 2017. , Jan-2017

Articles in Peer-reviewed Journals Jafri MA, Al-Qahtani MH, Shay JW. "Role of miRNAs in human cancer metastasis: Implications for therapeutic intervention." Semin Cancer Biol. 2017 Feb 8. [Epub ahead of print] Review. http://dx.doi.org/10.1016/j.semcancer.2017.02.004 ; PubMed PMID: 28188828 , Feb-2017
Articles in Peer-reviewed Journals Norbury JW, Schimmerling W, Slaba TC, Azzam E, Badavi FF, Baiocco G, Benton E, Bindi V, Blakely EA, Blattnig SR, Boothman DA, Borak TB, Britten RA, Curtis S, Dingfelder M, Durante M, Dynan W, Eisch AJ, Robin Elgart S, Goodhead DT, Guida PM, Heilbronn LH, Hellweg CE, Huff JL, Kronenberg A, La Tessa C, Lowenstein D, Miller J, Morita T, Narici L, Nelson GA, Norman RB, Ottolenghi A, Patel ZS, Reitz G, Rusek A, Schreurs A-S, Scott-Carnell LA, Semones E, Shay JW, Shurshakov VA, Sihver L, Simonsen LC, Story M, Turker MS, Uchihori Y, Williams J, Zeitlin CJ. "Galactic cosmic ray simulation at the NASA Space Radiation Laboratory." Life Sci Space Res (Amst). 2016 Feb;8:38-51. http://dx.doi.org/10.1016/j.lssr.2016.02.001 ; PubMed PMID: 26948012 , Feb-2016
Articles in Peer-reviewed Journals Niwa O, Barcellos-Hoff MH, Globus RK, Harrison JD, Hendry JH, Jacob P, Martin MT, Seed TM, Shay JW, Story MD, Suzuki K, Yamashita S; ICRP. "ICRP Publication 131: Stem Cell Biology with Respect to Carcinogenesis Aspects of Radiological Protection." Annals of the ICRP (International Commission on Radiological Protection). 2015 Dec;44(3-4):7-357. Review. http://dx.doi.org/10.1177/0146645315595585 ; PubMed PMID: 26637346 , Dec-2015
Articles in Peer-reviewed Journals El-Ashmawy M, Coquelin M, Luitel K, Batten K, Shay JW. "Organotypic culture in three dimensions prevents radiation-induced transformation in human lung epithelial cells." Nature Scientific Reports. 2016 Aug 19;6:31669. http://dx.doi.org/10.1038/srep31669 ; PubMed PMID: 27539227; PubMed Central PMCID: PMC4990973 , Aug-2016
Articles in Peer-reviewed Journals Suman S, Kumar S, Fornace AJ, Datta K. "Space radiation exposure persistently increased leptin and IGF1 in serum and activated leptin-IGF1 signaling axis in mouse intestine." Sci Rep. 2016 Aug 25;6:31853. http://dx.doi.org/10.1038/srep31853 ; PubMed PMID: 27558773; PubMed Central PMCID: PMC4997262 , Aug-2016
Articles in Peer-reviewed Journals Suman S, Kumar S, Moon BH, Strawn SJ, Thakor H, Fan Z, Shay JW, Fornace AJ Jr, Datta K. "Relative biological effectiveness of energetic heavy ions for intestinal tumorigenesis shows male preponderance and radiation type and energy dependence in APC(1638N/+) mice." Int J Radiat Oncol Biol Phys. 2016 May 1;95(1):131-8. http://dx.doi.org/10.1016/j.ijrobp.2015.10.057 ; PubMed PMID: 26725728 (Was in press/advance online in 2016 report.). , May-2016
Articles in Peer-reviewed Journals Shuryak I, Fornace AJ, Datta K, Suman S, Kumar S, Sachs RK, Brenner DJ. "Scaling human cancer risks from low LET to high LET when dose-effect relationships are complex." Radiation Resarch. 2017 Apr;187(4):476-82. Epub 2017 Feb 20. http://dx.doi.org/10.1667/RR009CC.1 ; PubMed PMID: 28218889 , Apr-2017
Project Title:  NSCOR: Space Radiation and Gastrointestinal Cancer: A Comprehensive Strategy for Risk Assessment and Model Development Reduce
Images: icon  Fiscal Year: FY 2016 
Division: Human Research 
Research Discipline/Element:
HRP SR:Space Radiation
Start Date: 04/15/2015  
End Date: 04/14/2020  
Task Last Updated: 02/16/2016 
Download report in PDF pdf
Principal Investigator/Affiliation:   Fornace, Albert  M.D. / Georgetown University 
Address:  Dept. of Oncology, Lombardi Comprehensive Cancer Center 
Research Building, Room E504, 3970 Reservoir Rd., NW 
Washington , DC 20007-2126 
Email: af294@georgetown.edu 
Phone: 202 687-7843  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: Georgetown University 
Joint Agency:  
Comments: http://www9.georgetown.edu/gumc/lombardi/fornacelab/  
Co-Investigator(s)
Affiliation: 
Brenner, David  Ph.D. Columbia University 
Datta, Kamal  M.D. Georgetown University 
Meltzer, Paul  Ph.D. National Cancer Institute, NIH 
Shay, Jerry  Ph.D. University of Texas Southwestern Medical Center at Dallas 
Project Information: Grant/Contract No. NNX15AI21G 
Responsible Center: NASA JSC 
Grant Monitor: Simonsen, Lisa  
Center Contact:  
lisa.c.simonsen@nasa.gov 
Solicitation / Funding Source: 2014-15 HERO NNJ14ZSA001N-NSCOR Radiation 
Grant/Contract No.: NNX15AI21G 
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) Cancer-103:Determine the effects of radiation quality on cancer initiation, promotion, and progression (IRP Rev M)
(2) Cancer-104:Determine the effects of radiation dose and dose-rate on cancer initiation, promotion and progression (IRP Rev M)
(3) Cancer-203:Evaluate the tissue-specific risks of space radiation exposure on cancer outcomes (IRP Rev M)
(4) Cancer-303:Identify early surrogate biomarkers that correlate with cancer, pre-malignancy, or the hallmarks of cancer (IRP Rev M)
Task Description: The overall objective of this NASA Specialized Center of Research (NSCOR) is to model the relative risk of colonic and stomach tumorigenesis for high priority space radiation beams and compare to gamma radiation where human epidemiologic data are available. It will rely primarily on mouse models of gastrointestinal (GI) cancer and human colonic epithelial cell (HCEC) approaches that have been optimized for low dose exposures. This will involve quantitative and qualitative analyses of tumors as well as normal GI epithelium after radiation. Results will be extrapolated to radiation-induced molecular changes in state-of-the-art 2D and 3D cultured human colonocytes. While limited studies at select loci, such as HRPT, have shown HZE-induced mutations including splicing errors, frameshifts, and complex changes, we will carry out genome-wide analysis using the power of modern nextgen sequencing (NGS) to assess the spectrum of mutations in radiation-induced tumors, and also persistent genome-wide epigenomic changes in normal cells after ionizing radiation (IR). These NGS omics findings will be integrated with transcriptomics and metabolomics results as well as events at the protein and cellular levels to develop a systems biology model for GI tumorigenesis. By assessing both quantitative in vivo tumorigenesis data and molecular events in mouse tissues and human colonocytes, space radiation-induced tumorigenesis will be compared to human epidemiologic data for low LET (linear energy transfer) radiation exposures, and approaches will be developed to model human risks for GI cancer by space radiation.

We continue to employ two models of GI cancers: the APC1638N model, which was generated by a targeted modification of the Apc gene at a position corresponding to aa1638. These mice develop very few adenomas in the small as well as in the large intestine but post-radiation tumor numbers show marked increases. Radiation induced substantial gastric tumorigenesis as well in this model. The second model is the CDX2P Apc flox/+ that has one APC allele inactivated almost exclusively in the colon leading to adenomas and subsequent a low rate of adenocarcinomas in the colon that is increased post-irradiation. Data being collected from these two relevant mouse models will be used to calculate risk estimates for NASA. Since low-LET risk estimates are available for human populations, we will then be able to model the relative risk for space radiation. In particular, this ratio can then be extrapolated to human exposure to low-LET radiation to then make an estimate of risk for colorectal cancer in humans exposed to space radiation compared to the standard risks based on atomic bomb survivors and other exposure populations.

In order to answer the critical question of risk for colonic tumorigenesis after acute and chronic space radiation exposures, in vitro human cell culture and animal models for CRC initiation and progression are needed. We are investigating the effects of high-LET particle and high-energy protons in colonic epithelial cells with respect to the nature of damage and consequent tumor induction using biological cancer-related endpoints and systems biology (genomics, proteomics, and metabolomics) approaches. In addition, we propose to compare these results to the biological consequences of low dose rates and mixed fields of radiation which astronauts are likely to be continuously exposed. The studies of low- and high-LET radiation on colonocytes gain more relevance with increasing age when premalignant adenomas and other colonic lesions such as flat lesions and microscopic aberrant crypt foci become more prevalent. Pre-existing undetectable genetic or chromosomal aberrations in astronauts in addition to de novo mutations resulting from long-term irradiation may increase the chances of colonic stem cell transformation.

Plans for this proposal build on our past accomplishments with GI tumorigenesis models and are focused on studies at low doses with an expanded range of NASA’s high priority beams. This proposal is also focused on assessing the effects of gender, dose-rate, age, and genetic heterogeneity in mouse models. Molecular events triggered by space radiation will be investigated in depth and the mechanistic basis for persistent aberrant cell-signaling after HZE radiation will be dissected. Genome-wide NGS combined with other omics approaches will contribute to a systems biology understanding of the effects of space radiation in the intestines and stomach. Both quantitative murine tumor data and results for underlying molecular events in mouse and human GI cells will contribute to modeling of human risks for GI cancer by space travel. The overall aims of this NSCOR are summarized below.

Aim 1 (Project 1). Quantitatively assess GI tumorigenesis in mouse models of GI cancer and collect samples for qualitative analysis.

Aim 2 (Project 2). Dissection of the signaling events and consequences in GI cells of the persistent effects of space radiation.

Aim 3 (Project 3): Characterization of IR-induced neoplastic events in normal diploid human colonocytes.

Aim 4 (Project 4). Development of systems biology (Project 4A) and mathematical modeling (Project 4B) approaches for GI cancer risk assessment.

Research Impact/Earth Benefits: Gastrointestinal tumors are frequent in the U.S, and American Cancer Society estimates that there will be 132,700 new cases of colorectal cancer (CRC) with 49,700 persons predicted to die of the disease in 2015. Colorectal cancer when considered in men and women is the second leading cancer killer in the United States ( http://www.cdc.gov/cancer/Colorectal ). Considering the high frequency of colorectal tumors in the American population, an even small increase by space radiation could have a major impact on risk estimates and planning of future manned space missions. The effect of complex DNA lesions, which are produced by HZE radiation, on intestinal tumorigenesis may provide insight into mutagenic processes affecting genome integrity and colorectal carcinogenesis.

Task Progress & Bibliography Information FY2016 
Task Progress: Considering the increased colorectal cancer incidence in A-bomb survivors and the novel characteristics of space radiation, cancer causation by space radiation could potentially be even greater. One general approach for risk assessment is to determine the relative biologic effectiveness (RBE) of various parameters for space radiation compared to terrestrial radiation exposures. For HZE ions there is more uncertainty with RBE for cellular parameters, such as chromosome aberrations and cell lethality, where values obtained from in vitro studies typically ranges from 2 to 11-fold. However, we do not have sufficient in vivo mechanistic data in human or in animal models representing the human disease to develop reliable risk prediction models for space radiation-induced colorectal cancer (CRC). Considering the limitation of acquiring human data, our study is focused on acquiring sufficient data in mouse models of human CRC with an aim to aid in risk model development for safe human space exploration.

Task progress on GI tumorigenesis (GU). Since the award of the this NSCOR in April 2015, we have participated in one beam run (Fall 2015) at the NASA Space Radiation Laboratory (NSRL) and currently are scaling up APC1638N/+ mice breeding in preparation for our spring 2016 beam run. We have already demonstrated higher tumorigenesis with space radiation relative to gamma rays as well as important qualitative differences in the IR effects in both normal GI epithelial cells and GI tumors. The goals going forward are to assess tumorigenesis at more relevant lower doses and varied dose rates with a broader range of ions. Since maximal effects have been seen with 28-Si ions in our previous studies, we have continued experiments with 28-Si (300 MeV/n) albeit at new lower doses (5 and 1 cGy). We have also started studies using 16-O (325 MeV/n) and 4-He (250 MeV/n) ions, which are NASA prioritized ions of lower Z value proposed in this NSCOR. Additional mice will be irradiated in spring 2016 to fulfill statistical requirements. Apart from acute exposures (dose rate 10 to 50 cGy/min), we have also initiated studies using low dose rate (0.33 cGy/min) exposures and will continue in spring 2016. For comparison, we have exposed mice to gamma radiation at doses equal to HZE ions. Mice irradiated in 2016 fall will be ready for data collection 150 days after radiation exposure. Alongside, we have started backcrossing APC1638N/+ of C57BL/6J background into C3H/HeN and BALB/c background for the genetic heterogeneity study proposed in the project and is expected to take about a year to fully establish the model in these backgrounds.

Proton radiotherapy induces more precise DNA damage at the tumor site with reduced side effects to adjacent normal tissues. However, protons emerging from solar flares are considered to be one of the major acute risk factors for astronauts. Even though some shielding is possible, the long-term biological effects of proton irradiation in cancer initiation and progression compared with conventional photon irradiation remain poorly characterized. In this series of studies, using a human familial adenomatous polyposis syndrome susceptible mouse model, we show that whole-body irradiation with simulated solar particle event (SPE) protons are more effective in inducing senescence-associated inflammatory responses (SIRs), which are involved in colon cancer initiation and progression. After simulated SPE irradiation, a subset of SIR genes (Troy, Sox17, Opg, Faim2, Lpo, Tlr2, and Ptges) and a gene known to be involved in invasiveness (Plat), along with the senescence-associated gene (P19Arf) are markedly increased. Following these changes, loss of Casein kinase Ia (CKIa) and induction of chronic DNA damage and TP53 mutations are increased compared with the same doses of acute proton or x-ray irradiation. Simulated SPE irradiation (2 Gy, 92% 50 MeV/n, 8% 60-150 MeV/n) also increases the number of colonic polyps, and invasive adenocarcinomas compared to 2 Gy (50 MeV/n) single dose proton or 2 Gy (250 kVp) x-ray. Thus, exposure to SPE irradiation elicits significant changes in colorectal cancer initiation and progression

Considering that the responses were more pronounced after HZE irradiation relative to gamma radiation and 56-Fe and 28-Si were tested at moderately high doses in previous studies, the current project will expand persistent effect studies to additional priority beams, and lower radiation doses and dose rates more relevant to the space environment. To this end, we have irradiated male C57BL/6J and Lgr5-EGFP-IRES-creERT2 (Lgr5 mice) during 2015 fall run at 5 and 10 cGy and samples collected 2 months after exposure for molecular analysis, which is ongoing. Later, samples will also be collected 12 months after radiation to determine persistence of effects. The goal is to characterize persistent effects of space radiation at low doses and dose rates on GI epithelial and stem cells. Irradiation of mice is performed concurrently with the Project 1 mice. Work is also ongoing on human colonic epithelial cells (HCECs) with plans to irradiate these during the 2016 beam runs at NSRL. The work on the genomic project has been started with tumor samples from a moderate dose (1.6 Gy) of 56-Fe radiation archived from previous NSCOR. The goal is to standardize the methodology for signal detection using a relatively high dose of HZE radiation before analyzing lower doses (<1 Gy) of HZE radiation. Additionally, tumorigenesis data from the previous NSCOR is also used to calculate relative biological effectiveness (RBE) and develop modeling approach for colorectal cancer risk estimates in astronauts.

Bibliography Type: Description: (Last Updated: 12/03/2021) 

Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Suman S, Kumar S, Fornace AJ Jr, Datta K. "Persistent stress signaling in gastrointestinal tract after exposure to heavy ion space radiation." Presented at the 2016 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, February 8-11, 2016.

2016 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, February 8-11, 2016. , Feb-2016

Abstracts for Journals and Proceedings Kumar S, Suman S, Fornace AJ Jr, Datta K. "Effects of radiation quality on signaling pathways regulating intestinal cell migration in C57BL/6J mice." Presented at the 2016 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, February 8-11, 2016.

2016 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, February 8-11, 2016. , Feb-2016

Abstracts for Journals and Proceedings Suman S, Kallakury BVS, Fornace AJ Jr, Datta K. "Protracted upregulation of leptin and IGF1 is associated with activation of PI3K/Akt and JAK2 pathway in mouse intestine after ionizing radiation exposure." Presented at the 61st Annual Meeting of the Radiation Research Society, Weston, Florida, September 19-22, 2015.

61st Annual Meeting of the Radiation Research Society, Weston, Florida, September 19-22, 2015. , Sep-2015

Abstracts for Journals and Proceedings Kumar S, Suman S, Fornace AJ Jr, Datta K. "Differential effects of radiation quality on intestinal epithelial cell migration signaling pathways in C57BL/6J mice." Presented at the 61st Annual Meeting of the Radiation Research Society, Weston, Florida, September 19-22, 2015.

61st Annual Meeting of the Radiation Research Society, Weston, Florida, September 19-22, 2015. , Sep-2015

Abstracts for Journals and Proceedings Suman S, Kumar S, Moon B-H, Fan Z, Strawn SJ, Thakoor H, Fornace AJ Jr, Datta K. "Relative biological effectiveness for intestinal and colonic tumorigenesis showed heavy ion species, energy, and linear energy transfer dependency." Presented at the 61st Annual Meeting of the Radiation Research Society, Weston, Florida, September 19-22, 2015.

61st Annual Meeting of the Radiation Research Society, Weston, Florida, September 19-22, 2015. , Sep-2015

Abstracts for Journals and Proceedings Kim SB, Bozeman R, Kaisani A, Kim W, Zhang L, Richardson JA, Wright WE, Fornace AJ Jr, Shay JW. "Radiation promotes colorectal cancer initiation and progress by inducing senescence-associated inflammatory responses." Presented at the 2016 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, February 8-11, 2016.

2016 NASA Human Research Program Investigators’ Workshop, Galveston, Texas, February 8-11, 2016. , Feb-2016

Articles in Peer-reviewed Journals Barcellos-Hoff MH, Blakely EA, Burma S, Fornace AJ Jr, Gerson S, Hlatky L, Kirsch DG, Lederer U, Shay J, Wang Y, Weil MM. "Concepts and challenges in cancer risk prediction for the space radiation environment." Life Sciences in Space Research. 2015 Jul;6:92-103. http://dx.doi.org/10.1016/j.lssr.2015.07.006 , Jul-2015
Articles in Peer-reviewed Journals Jafri MA, Zaidi SK, Ansari SA, Al-Qahtani MH, Shay JW. "MicroRNAs as potential drug targets for therapeutic intervention in colorectal cancer." Expert Opin Ther Targets. 2015 Dec;19(12):1705-23. Epub 2015 Jul 18. http://dx.doi.org/10.1517/14728222.2015.1069816 ; PubMed PMID: 26189482 , Dec-2015
Articles in Peer-reviewed Journals Graillot V, Dormoy I, Dupuy J, Shay JW, Huc L, Mirey G, Vignard J. "Genotoxicity of cytolethal distending toxin (CDT) on isogenic human colorectal cell lines: Potential promoting effects for colorectal carcinogenesis." Front Cell Infect Microbiol. 2016 Mar 23;6:34. eCollection 2016. http://dx.doi.org/10.3389/fcimb.2016.00034 ; PubMed PMID: 27047802 ; PubMed Central PMCID: PMC4803749 , Mar-2016
Articles in Peer-reviewed Journals Datta K, Suman S, Kumar S, Fornace AJ Jr. "Colorectal carcinogenesis, radiation quality, and the ubiquitin-proteasome pathway." J Cancer. 2016 Jan 1;7(2):174-83. eCollection 2016. http://dx.doi.org/10.7150/jca.13387 ; PubMed PMID: 26819641; PubMed Central PMCID: PMC4716850 , Jan-2016
Articles in Peer-reviewed Journals Suman S, Kumar S, Moon BH, Strawn SJ, Thakor H, Fan Z, Shay JW, Fornace AJ Jr, Datta K. "Relative biological effectiveness of energetic heavy ions for intestinal tumorigenesis shows male preponderance and radiation type and energy dependence in APC1638N/+ mice." Int J Radiat Oncol Biol Phys. 2015 Oct 31. [Epub ahead of print] http://dx.doi.org/10.1016/j.ijrobp.2015.10.057 ; PubMed PMID: 26725728 , Oct-2015
Articles in Peer-reviewed Journals Suman S, Kumar S, Fornace AJ Jr, Datta K. "Decreased RXRalpha is associated with increased ß-catenin/TCF4 in (56)Fe-induced intestinal tumors." Front Oncol. 2015 Oct 8;5:218. eCollection 2015. http://dx.doi.org/10.3389/fonc.2015.00218 ; PubMed PMID: 26500891; PubMed Central PMCID: PMC4597120 , Oct-2015
Articles in Peer-reviewed Journals Kim SB, Bozeman RG, Kaisani A, Kim W, Zhang L, Richardson JA, Wright WE, Shay JW. "Radiation promotes colorectal cancer initiation and progression by inducing senescence-associated inflammatory responses." Oncogene. 2016 Jun 30;35(26):3365-75. [Epub 2015 Oct 19] http://dx.doi.org/10.1038/onc.2015.395 ; PubMed PMID: 26477319 ; PubMed Central PMCID: PMC483710 , Jun-2016
Project Title:  NSCOR: Space Radiation and Gastrointestinal Cancer: A Comprehensive Strategy for Risk Assessment and Model Development Reduce
Images: icon  Fiscal Year: FY 2015 
Division: Human Research 
Research Discipline/Element:
HRP SR:Space Radiation
Start Date: 04/15/2015  
End Date: 04/14/2020  
Task Last Updated: 06/19/2015 
Download report in PDF pdf
Principal Investigator/Affiliation:   Fornace, Albert  M.D. / Georgetown University 
Address:  Dept. of Oncology, Lombardi Comprehensive Cancer Center 
Research Building, Room E504, 3970 Reservoir Rd., NW 
Washington , DC 20007-2126 
Email: af294@georgetown.edu 
Phone: 202 687-7843  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: Georgetown University 
Joint Agency:  
Comments: http://www9.georgetown.edu/gumc/lombardi/fornacelab/  
Co-Investigator(s)
Affiliation: 
Brenner, David  Ph.D. Columbia University 
Datta, Kamal  M.D. Georgetown University 
Meltzer, Paul  Ph.D. National Cancer Institute, NIH 
Shay, Jerry  Ph.D. University of Texas Southwestern Medical Center at Dallas 
Project Information: Grant/Contract No. NNX15AI21G 
Responsible Center: NASA JSC 
Grant Monitor: Simonsen, Lisa  
Center Contact:  
lisa.c.simonsen@nasa.gov 
Solicitation / Funding Source: 2014-15 HERO NNJ14ZSA001N-NSCOR Radiation 
Grant/Contract No.: NNX15AI21G 
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) Cancer-103:Determine the effects of radiation quality on cancer initiation, promotion, and progression (IRP Rev M)
(2) Cancer-104:Determine the effects of radiation dose and dose-rate on cancer initiation, promotion and progression (IRP Rev M)
(3) Cancer-203:Evaluate the tissue-specific risks of space radiation exposure on cancer outcomes (IRP Rev M)
(4) Cancer-303:Identify early surrogate biomarkers that correlate with cancer, pre-malignancy, or the hallmarks of cancer (IRP Rev M)
Task Description: Considering the high spontaneous incidence of gastrointestinal (GI) cancer and higher incidence of premalignant colonic polyps, an even modest increase by space radiation exposure could have a significant effect on astronauts’ health risk estimates during and after long-duration manned space flights. However, there is substantial uncertainty for GI cancer risk estimation from space radiation due to the lack of in vivo human data. This proposal addresses the category in the current solicitation involving ‘new approaches’ towards ‘mechanistic understanding’ of GI cancer risk using ‘new biological models’ for ‘studies of radiation quality and dose-rate effects’ in relation to ‘individual radiation sensitivity’. The overarching goal of the current proposal is to specifically investigate cellular and molecular hypothesis driven mechanisms in relevant mouse models that will contribute to carcinogenic risk estimates of GI cancer after exposure to space radiation beams prioritized in the current solicitation. We have chosen high priority HZE beams. Since maximal effects have already been seen with 28Si ions, this will be a priority and we will extend to lower Z at similar energy using 16O and 4He ions. Having found modest effects in some studies with protons and considering the importance of assessing the effects of mixed beams, we will take advantage of the availability of the sequential field proton/56Fe (0.2/150 keV/µm) beam to start to represent the mixed particle radiation in space. We will consult with NASA on beam prioritization and consider the Galactic Cosmic Ray (GCR) Simulator as the study progresses. Specifically, this proposal seeks to determine incidence and grade as well as identify molecular perturbations and target cells associated with intestinal and gastric (stomach) tumors through monitoring of changes in the tumor number, histology, gene expression, metabolome, and in the genome of the proposed model system after exposure to these space-radiation beams. We are proposing four complementary Aims (and projects) that will have a common objective to develop a more reliable GI cancer risk prediction model. 1] Quantitatively assess GI tumorigenesis in mouse models of GI cancer and collect samples for qualitative analysis (Project 1), 2] Dissection of the signaling events and consequences in gastrointestinal cells of the persistent effects of space radiation (Project 2), 3] Characterization of radiation-induced neoplastic events in normal diploid human colonocytes (Project 3), 4] Development of systems biology (Project 4A) and mathematical modeling (Project 4B) approaches for GI cancer risk assessment.

Research Impact/Earth Benefits:

Task Progress & Bibliography Information FY2015 
Task Progress: New project for FY2015.

Bibliography Type: Description: (Last Updated: 12/03/2021) 

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 None in FY 2015