Overcoming of vincristine resistance in L1210/VCR cells by several corticosteroids. Collateral sensitivity of resistant cells

Abstract

Five corticosteroids were tested to determine whether they are able to overcome the multidrug resistance of vincristine resistant mouse leukemia cells L1210/VCR. The most effective in reversing multidrug resistance were cortisone and dexamethasone, less effective as reversing agents were 11-deoxycorticosterone, 1-dehydrocortisone and hydrocortisone. By testing of collateral sensitivity of vincristine resistant cell line to these corticosteroids it was found that only 11-deoxycorticosterone and dexamethasone were toxic to multidrug resistant cells at doses much lower than required for toxicity to the drug-sensitive L1210/S cells. Using thin layer chromatography the polarity of tested corticosteroids was estimated, and good correlation was found between polarity of corticosteroids and their increased toxicity to vincristine resistant cells.