Effect of Radiation Quality and Galactic Cosmic Radiation Simulation on the Risk of Carcinogenesis in an Outbred Mouse Model (HS/Npt)

1. Background Astronauts on long-duration space missions are exposed to galactic cosmic rays (GCR) and solar particle events (SPE), creating elevated risks of carcinogenesis, cardiovascular disease (CVD), and central nervous system (CNS) decrements. Traditional inbred animal models have limitations due to genetic uniformity, potentially leading to overestimation of relative biological effectiveness (RBE). Outbred mouse models (HS/Npt) provide a genetically diverse system that better mirrors human populations and may yield more accurate assessments of radiation-induced cancer and related health risks.

2. Objectives The objectives of this study are to:

1. Determine the effects of radiation quality, dose, and dose rate on cancer initiation, promotion, and progression in HS/Npt outbred mice.

2. Establish RBEs and quality factor estimates for space-relevant radiation exposures.

3. Provide biobanked tissue and comprehensive metadata to support future NASA investigations.

4. (Optional) Assess cardiovascular and CNS outcomes, as well as sex-specific responses, within budget constraints. 3. Scope of Work The Principal Investigator (PI) shall design and execute experiments utilizing outbred HS/Npt mice supplied by NASA. Work shall include:

- Radiation exposures at technically acceptable laboratory (See attached laboratory technical acceptability requirements sheet), including gamma irradiation, full GCR simulation (acute and fractionated), and single-ion exposures (e.g., 56Fe) where justified. - Dose coverage relevant to Mars design reference missions (300–450 mGy). - Survival, tumor incidence, and tumor spectrum analyses. - Comprehensive tissue collection, preservation, and metadata management. - Biobanking of required samples per NASA specifications. - Preparation of interim and final reports. This is stricly a request for information. The Government has no obligation for award. If interested please provide a capabilities statement.