Lipskaia L A, Grinchuk T M, Efimova E V, Artsybasheva I V, Sorokina E A, Vasiukhin V I, Ignatova T N
Tsitologiia. 1994;36(12):1236-44.
Stable mutant cells Cebr-1 and Cebr-2, resistant to ethidium bromide (EB) in concentration of 2 micrograms/ml, have been isolated by a multistep selection in Chinese hamster ovary cells. It was shown that Cebr-1 and Cebr-2 cells acquired a cross-resistance to unrelated drugs. Stable changes in the structure of chromosomes 1, 2, 5 and 8 were revealed by karyological analysis. Overexpression and amplification of mdr genes were detected in Cebr-2 cells using Northern RNA and Southern DNA blot hybridization. Two independent hybrids Hybr-1 and Hybr-2 were obtained by fusion of Cebr-2 cells with Chinese hamster lung V-79 RJK cells, sensitive to EB. Hybr-2 cells were characterized by the same level of EB-resistance as Cebr-2 cells. Hybr-1 cells have a lower level of EB-resistance than Cebr-2 cells. Hybr-2 cells have demonstrated amplification and overexpression of mdr gene, the same as in Cebr-2 cells, whereas in Hybr-1 cells no mdr gene amplification was observed, but the level of mdr gene expression was higher than in sensitive cells. The data suggest that resistance of Chinese hamster cells to EB is mediated by amplification and overexpression of mdr genes.
通过在中国仓鼠卵巢细胞中进行多步筛选，分离出了对浓度为2微克/毫升的溴化乙锭（EB）具有抗性的稳定突变细胞Cebr-1和Cebr-2。结果表明，Cebr-1和Cebr-2细胞对不相关药物产生了交叉抗性。通过核型分析揭示了1号、2号、5号和8号染色体结构的稳定变化。使用Northern RNA和Southern DNA印迹杂交法在Cebr-2细胞中检测到了mdr基因的过表达和扩增。通过将Cebr-2细胞与对EB敏感的中国仓鼠肺V-79 RJK细胞融合，获得了两个独立的杂种Hybr-1和Hybr-2。Hybr-2细胞具有与Cebr-2细胞相同水平的EB抗性。Hybr-1细胞的EB抗性水平低于Cebr-2细胞。Hybr-2细胞表现出与Cebr-2细胞相同的mdr基因扩增和过表达，而在Hybr-1细胞中未观察到mdr基因扩增，但mdr基因表达水平高于敏感细胞。数据表明，中国仓鼠细胞对EB的抗性是由mdr基因的扩增和过表达介导的。
