Jaffe D R, Haraf D, Schwartz J L, Weichselbaum R R, Diamond A M
Department of Radiation and Cellular Oncology, University of Chicago Medical Center, IL 60637.
Carcinogenesis. 1990 Aug;11(8):1265-9. doi: 10.1093/carcin/11.8.1265.
X-ray-resistant clones of the xrs-5 radiosensitive derivative of the CHO-K1 cell line were generated by transfecting cosmid library DNAs into the X-ray-sensitive cells. Transfectants were selected for both a dominant drug resistance marker present in the vector sequences and return to wild-type survival. Three cell lines were isolated which show X-ray survival characteristics similar to parental K1 cells. These revertant lines were examined for their cross-sensitivity to cis-diamminedichloroplatinum(II) (cisplatin) and bleomycin. Although these cell lines reverted with regard to X-ray sensitivity, they retained their sensitivity to cisplatin. Furthermore, changes in bleomycin and X-ray sensitivity did not correlate. There was a positive correlation between return to wild-type radiosensitivity and an increase in the rate of DNA double-strand break rejoining.
通过将黏粒文库DNA转染到X射线敏感的细胞中，获得了CHO-K1细胞系的X射线敏感衍生物xrs-5的抗X射线克隆。针对载体序列中存在的显性耐药标记以及恢复到野生型存活率来选择转染子。分离出三个细胞系，它们显示出与亲本K1细胞相似的X射线存活特征。检测了这些回复系对顺二氨二氯铂（II）（顺铂）和博来霉素的交叉敏感性。尽管这些细胞系在X射线敏感性方面发生了回复，但它们对顺铂仍保持敏感。此外，博来霉素和X射线敏感性的变化并不相关。恢复到野生型放射敏感性与DNA双链断裂重新连接速率的增加之间存在正相关。
