title: Isolation and preliminary characterization of bleomycin-resistant mutants from Chinese hamster ovary cells.
abstract: Stable mutants resistant to an anticancer antibiotic, bleomycin-A2, were selected in Chinese hamster ovary (CHO) cell either spontaneously or after ethylmethane sulfonate mutagenesis. Fluctuation analysis showed that bleomycin resistance occurs in CHO at a rate of 6.50--6.58 x 10(-7) mutations per cell per generation. Bleomycin-A2-resistant cell lines exhibited increased resistance to bleomycin analogs--bleomycin-A5, -B2, -B4, and pepleomycin. Colchicine, mitomycin C, and ultraviolet light irradiation inhibited colony formation equally in CHO cells and in bleomycin-resistant mutants. Cell-cell hybridization tests showed that bleomycin-resistance behaves as a dominant trait. Bleomycin-inactivating activity in the mutant cell extracts was three to fourfold higher than that in extracts of the parental CHO cell.
mesh_terms: D000818:Animals; D001761:Bleomycin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D002460:Cell Line / Q000502:physiology; D002469:Cell Separation; D002477:Cells / Q000145:classification* / Q000201:enzymology; D002999:Clone Cells / Q000502:physiology; D006224:Cricetinae; D003412:Cricetulus; D004351:Drug Resistance; D005260:Female; D014644:Genetic Variation / Q000187:drug effects; D009154:Mutation; D010053:Ovary / Q000166:cytology
chemical_list: D001761:Bleomycin