人食道癌细胞系CaEs-17放射敏感性与H-ras的扩增

HETEROGENEITY IN RADIOSENSITIVITY WITHIN ESOPHAGEAL CELL LINE CaEs-17 AND AMPLIFICATION OF H-ras GENE

从我国自行建株的人食道癌细胞系CaEs－17野生型中分离出两株放射抗拒的亚系克隆7和克隆10，其SF2值分别为0．41、0．58和0．61。存活曲线的分析表明，与野生型比较，克隆7及克隆10的Do值差异不大，但DQ与N值有较大的差别。野生型细胞系DQ为1．07Gy，而克隆7的DQ为1．85Gy，克隆10的DQ值为2．04Gy；野生型细胞的N值为1．96，克隆7亚系的N值为3．07，克隆10亚系的N值为3．63。用SouthernBlot杂交检测了H－ras基因的扩增，结果发现克隆10亚系在照射2Gy后H－ras显著扩增，可能克隆10的放射抗拒与H－ras的扩增有一定关系，但未发现两者之间有恒定的关系。

Ten clones were picked from cultured colonies of CaEs-17 cell line and developed to a subcell line. The values of SF2 were measured for each subcell line.Two radioresistant subcell lines, clone 7 and clone 10 were established.According to survival curve assay,for wild type, the value of Do was 1. 57 Gy, DQ was 1.07Gy,N was 1. 96, SF, was 0. 41. For clone 7,the value of D, was 1.64 Gy, DQ was 1.85Gy, N was 3.07, SF2 was 0.53. For clone 10, the value of Do was 1.58 Gy,DQ was 2.04 Gy, N was 3.63, SF2 was 0.61. Clone 7 and clone 10 have much higher values of DQ and N than those of wild type. there was amplification of H-ras gene in clone 10 after 2 Gy irradiation. The amplification of H-ras gene in clone 10 after 2 Gy irradiation might be involved in hetero geneity of CaEs-17 cell line.