α粒子对叙利亚地鼠胚胎细胞H－ras和p53基因的影响

Effects of α-irradiation on H-ras and p53 genes in Syrian hamster embryo cells

观察了２Ｇｙα粒子（５．３４ＭｅＶ）照射诱发叙利亚地鼠胚胎细胞转化后Ｈ－ｒａｓ和ｐ５３基因的变化．结果表明，转化细胞Ｈ－ｒａｓ基因处于激活和ｐ５３基因失活状态，以逆转录聚合酶链反应和单链构象多态性分析方法进一步分析，证明Ｈ－ｒａｓ基因发生突变和ｐ５３基因部分缺失．本实验结果提示，Ｈ－ｒａｓ基因突变与ｐ５３基因突变的偶联可能是α粒子诱发叙利亚胚胎细胞转化的重要分子机理．

The expression of H-ras and p53 genes in transformed Syrian hamster embryo(SHE) cells, induced by 2Gy 5.34 MeV α particles from plutonium-238, were in the state of activation, although pattern of restriction fragment length polymorphism (RFLP) of H-ras did not change. Furthermore, mutation occurred in the H-ras of transformed cells was confirmed by using reverse transcriptional polymerase chain reaction (RT-PCR) followed by single strand conformation polymorphism (SSCP). About 800 to 900 base pairs were deleted in p53 cDNA of transformed SHE cells and no p53 protein was detected in cells derived from tumor grown in nude mice injected with transformed SHE cells. These results suggest the cooperation of H-ras gene mutation with inactivation of p53 gene might be an alternative mechanism for α particles induced SHE cell transformation.