Effects of ionizing radiation on DNA-mediated gene transfer

The process of DNA-mediated gene transfer is a powerful genetic tool that involves the cellular uptake, genomic integration and expression of exogenous DNA sequences. This process can also be used to examine the effects of radiation at the molecular level. There have been a few reported describing the enhancement of the gene transfer process by a number of DNA damaging agents. The agents tested included UV light, x-rays and accelerated argon particles. One hypothesis to explain this phenomenon is that these DNA damaging agents themselves, or subsequent DNA repair processes, introduce strand breaks into the cellular DNA of recipient cells. These DNA breaks then serve as possible sites of integration for the exogenous DNA sequences. The authors are continuing these studies by determining what effect neutrons have on the transfection of DNA. The gene transfer system we plan to employ involves the transfection of the chimeric plasmid pSV2-GPT into recipient hamster cell lines. This plasmid contains the Escherichia coli ecogpt gene, which codes for the enzyme xanthine-guanine phosphoribosyltransferase (XGPRT), along with simian virus 40 (SV40) sequences which allow for expression of the bacterial gene in mammalian cells