MODIFICATION OF THE RADIOSENSITIVITY OF HUMAN-CELLS TO WHICH SIMIAN-VIRUS-40 T-ANTIGEN WAS TRANSFECTED

Effects of the introduction of the Simian virus 40 T-antigen (SV40 T-A g) gene to cultured human cells were examined in relation to radiosens itivity. Two relatively radioresistant tumor cell lines (T98 and G361) became significantly radiosensitive after the introduction of SV40 T- Ag, whereas radiosensitive tumor cell lines did not show a change in r adiosensitivity. In contrast, a human fibroblast cell line became radi oresistant after SV40 T-Ag introduction. T98 cells which have a mutati on at codon 237 in the p53 gene were unable to form a complex between p53 protein and SV40 T-Ag, whereas G361, which became radiosensitive b y a SV40 T-Ag introduction, formed the complex. This indicates that th e status of p53 is independent of the change in radiosensitivity in th e cell lines studied.