Visualization of In Vivo DNA damage responses to galactic cosmic radiation

Galactic Cosmic Rays (GCR) include various high energy charged particles (HZE) in addition to photons (UV and gamma rays). The complex space radiation environment is an important factor that makes space different from the environment on earth. Increasing risk of delayed radiation effects such as carcinogenesis have been reported and concerned people who will stay for extended periods of time in this vast realm of space. It has been hypothesized that cancers are mechanistically caused by the accumulation of mutations within several distinct genes (TP53, ATM, BRCA1/2, etc.) which normally guard cellular genomic integrity from any internal and external genomic stresses (i.e. DNA damage by ionizing radiation). In animal tissue exposed to GCR, those mutations can be generated by immediate repair of on-site DNA lesions in those genes (“targeting” effects), and also can be induced indirectly by “non-targeting” effects through unknown epigenetic mechanisms. In the present project, we are investigating the process of IR-induced mutation in various tissues in mice irradiated with heavy ion particles using a novel animal model system in order to understand how “non-targeting” radiation effects contribute to the mutagenesis of the mammalian life “in Space”.ISSRPRT 201