Adaptive resistance of Saccharomyces cerevisiae to chronic treatment with genotoxic and nongenotoxic carcinogens.
The exposure of mammalian cells or tumors for weeks or months to low nonlethal doses of cytostatic drugs may induce multidrug resistance, which can be enhanced by a variety of DNA-damaging agents. Multidrug resistance to a variety of drugs has been observed. But in yeast, DNA-damaging agents have not yet been tested. As the appearance of resistance is the result of longterm exposure, we decided to extend the application of test substances to a period of up to 400 days. In such long-term experiments S. cerevisiae MP1 adapted to treatment with low doses of mutagens. Consistent results were obtained for both genotoxic and nongenotoxic carcinogenic substances, which implies that there may be a single pathway for carcinogens with different modes of action.
Department of Genetics, Fraunhofer Institute of Toxicology and Aerosol Research, Hannover, Germany.
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D000081:Acetamides / Q000633:toxicity; D002273:Carcinogens / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D026141:Drug Resistance, Multiple, Fungal / Q000235:genetics*; D005557:Formaldehyde / Q000633:toxicity; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity*; D011995:Recombination, Genetic / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics*; D014265:Triethylenemelamine / Q000633:toxicity
D000081:Acetamides; D002273:Carcinogens; D009153:Mutagens; D005557:Formaldehyde; C030686:acetamide; D014265:Triethylenemelamine