title: Effect of 12-O-tetradecanoylphorbol-13-acetate on selection of drug-resistant phenotypes in rodent cells.
abstract: The effect of the tumour promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) on the selection of drug-resistant phenotypes in hamster and mouse cells has been studied. TPA increased considerably the incidence of methotrexate (MTX)-, N-(phosphonacetyl)-L-aspartate- and cadmium-resistant 3T6 and 3T3 mouse cell clones, but it had little effect on V79 and CHO hamster cells. The MTX-resistant V79 hamster cell clones, selected with or without TPA, lost their resistance within 15 cell cycles, however, 50% of the 3T6 mouse cell clones selected and maintained in the presence of TPA preserved their resistance for more than 15 cell cycles. A number of the MTX-resistant 3T6 clones overproduced dihydrofolate reductase enzyme; however, their frequency was lower among the clones selected in the presence of TPA.
mesh_terms: D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D002104:Cadmium / Q000494:pharmacology; D002460:Cell Line; D002478:Cells, Cultured; D002999:Clone Cells; D006224:Cricetinae; D003412:Cricetulus; D004351:Drug Resistance; D008168:Lung; D008727:Methotrexate / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D010641:Phenotype; D010704:Phorbols / Q000494:pharmacology*; D010746:Phosphonoacetic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D013762:Tetrahydrofolate Dehydrogenase / Q000378:metabolism
chemical_list: D000964:Antimetabolites, Antineoplastic; D010704:Phorbols; D002104:Cadmium; D001224:Aspartic Acid; C013195:sparfosic acid; D013762:Tetrahydrofolate Dehydrogenase; D010746:Phosphonoacetic Acid; D013755:Tetradecanoylphorbol Acetate; D008727:Methotrexate