The goal of this proposal is to delineate the risk of CH for astronauts and other patients using improved, novel methods that map nucleic acids isolated from peripheral blood and urine. We hypothesize that radiation imparts a selective advantage, specifically in hematopoietic cells with DNA Damage Response mutations, and that spaceflight duration and radiation dose can drive and mediate this selection process.

We will use a cohort of >1,100 patients from Weill Cornell Medicine (WCM) with both blood and urine, where 11% already show CH, as well as existing data from healthy cohorts (n=20,000) from the Englander Institute for Precision Medicine (EIPM) and Memorial Sloan Kettering Cancer Center (MSKCC) (n=25,000). We will use established methods for purifying and extracting DNA, using protocols developed for the NASA Twins Study and our published EIPM PreCISE-1 test for CH. This includes 100+ genes involved in clonal hematopoiesis, cancer, and cardiovascular diseases (CVD), sequenced to a depth of >2000x coverage (with unique molecular barcodes), giving >95% sensitivity for variant allele frequencies (VAF) > 1% (about 1/50 cells).

The presence of CH can inform long-term CVD and cancer risk, and thus can serve as a useful metric for astronauts preparing for long-term missions. Also, CH confers a mutation-specific inflammatory risk, which can potentiate post-flight or post-radiation morbidity and be compared to other risk factors. Thus, identifying and managing CH represents a crucial unmet need for astronaut health, radiation risk stratification, and guiding oncology patients more broadly.

Specifically, in the I4 cohort (Garcia-Medina et al, 2024), we found no relationship between spaceflight and increased CHIP-related genetic abnormalities in the scale of three months after spaceflight. Telomere elongation occurred during spaceflight and shortened after return to Earth. Cell-free DNA analysis revealed increased immune cell signatures post-flight. While TET2 exhibited a missense mutation chr4:g.105275662G>T at a VAF ~ 0.3 in C003, no significant clonal hematopoiesis of indeterminate potential (CHIP) or whole-genome instability was observed. The long-term gene expression changes across immune cells suggested cellular adaptations to the space environment persisting months post-flight. However, putative mutations in CH-linked genes were not found at disproportionate allele frequencies post-flight, nor were de novo mutations seen in the post-flight samples.

Although our findings suggest that no pathological genomic alterations occurred as a function of spaceflight in the I4 cohort, further longitudinal tracking of the astronauts will help us discern the long-term effects, if any, of short-duration missions. Fortunately, one of the same crew members from I4 also flew on Polaris Dawn (PD), and we are now processing these samples with improved methods to delineate a long-term differential for CH changes. These data provide a unique opportunity to measure longitudinal changes in CH, which can be leveraged for a better understanding of long-term risk and clonal evolution. In terms of mentorship, publications supported by this grant led to one of our lab’s scientists (Dr. Eliah Overbey) getting a faculty position at the University of Austin in the fall of 2024 and another member of the lab (Dr. Jiwoon Park) getting a post-doctoral fellowship in the George Church lab at Harvard. This will extend the space medicine work to a new lab, which will continue to collaborate with our team and use these data, as part of the SOMA groups. Also, these funds helped several projects and informed best practices in the large Inspiration4/JAXA/NASA package in Nature, which is featured among a wide range of 22 publications across 2023-2025.

The goal of this proposal is to delineate the risk of CH for astronauts and other patients using improved, novel methods that map nucleic acids isolated from peripheral blood and urine. We hypothesize that radiation imparts a selective advantage, specifically in hematopoietic cells with DNA Damage Response mutations, and that spaceflight duration and radiation dose can drive and mediate this selection process.

We will use a cohort of >1,100 patients from Weill Cornell Medicine (WCM) with both blood and urine, where 11% already show CH, as well as existing data from healthy cohorts (n=20,000) from the Englander Institute for Precision Medicine (EIPM) and Memorial Sloan Kettering Cancer Center (MSKCC) (n=25,000). We will use established methods for purifying and extracting DNA, using protocols developed for the NASA Twins Study and our published EIPM PreCISE-1 test for CH. This includes 100+ genes involved in clonal hematopoiesis, cancer, and cardiovascular diseases (CVD), sequenced to a depth of >2000x coverage (with unique molecular barcodes), giving >95% sensitivity for variant allele frequencies (VAF) > 1% (about 1/50 cells).

The presence of CH can inform long-term CVD and cancer risk, and thus can serve as a useful metric for astronauts preparing for long-term missions. Also, CH confers a mutation-specific inflammatory risk, which can potentiate post-flight or post-radiation morbidity and be compared to other risk factors. Thus, identifying and managing CH represents a crucial unmet need for astronaut health, radiation risk stratification, and guiding oncology patients more broadly.

1) The first deep-sequencing study of Clonal Hematopoiesis of Indeterminate Potential (CHIP) in a short duration civilian spaceflight mission;

2) The longest follow-up of CHIP-related clonal dynamics from the NASA Twins Study mission and the first comparison of clonal burden between career astronauts and civilian first-time fliers;

3) The first multi-omic study to date to integrate cell-free DNA cell signatures from immune cells with gene expression changes in immune cell populations in astronauts;

4) The deepest coverage of plasma cfDNA genomics in a spaceflight study to date;

5) The first study to date to denote long and short-term mitochondrial, ribosomal, and immune function gene expression changes, at a single cell resolution, associated to short duration spaceflight;

6) The first study of genome stability, through comprehensive sequencing approaches, in civilians as a function of short duration spaceflight;

7) In-depth omics profiles of American astronauts.

The goal of this proposal is to delineate the risk of CH for astronauts and other patients using improved, novel methods that map nucleic acids isolated from peripheral blood and urine. We hypothesize that radiation imparts a selective advantage, specifically in hematopoietic cells with DNA Damage Response mutations, and that spaceflight duration and radiation dose can drive and mediate this selection process.

We will use a cohort of >1,100 patients from Weill Cornell Medicine (WCM) with both blood and urine, where 11% already show CH, as well as existing data from healthy cohorts (n=20,000) from the Englander Institute for Precision Medicine (EIPM) and Memorial Sloan Kettering Cancer Center (MSKCC) (n=25,000). We will use established methods for purifying and extracting DNA, using protocols developed for the NASA Twins Study and our published EIPM PreCISE-1 test for CH. This includes 100+ genes involved in clonal hematopoiesis, cancer, and cardiovascular diseases (CVD), sequenced to a depth of >2000x coverage (with unique molecular barcodes), giving >95% sensitivity for variant allele frequencies (VAF) > 1% (about 1/50 cells).

The presence of CH can inform long-term CVD and cancer risk, and thus can serve as a useful metric for astronauts preparing for long-term missions. Also, CH confers a mutation-specific inflammatory risk, which can potentiate post-flight or post-radiation morbidity and be compared to other risk factors. Thus, identifying and managing CH represents a crucial unmet need for astronaut health, radiation risk stratification, and guiding oncology patients more broadly.