The Effects of Development of the MDR1 Phenotype on Cell Susceptibility to Undergoing Lipid Peroxidation and Ionizing Radiation.
Resistance to anticancer drugs is frequently observed in cancer treatment. Cancer cells expressing the multiple drug resistant (MDR1) phenotype may be resistant to ionizing radiation used in radiotherapy as well as to cells with cytotoxic effect. We postulated that the common mechanism to explain these three different types of cell resistance to damaging agents is mediated by resistance to the toxic effect of free radicals. Experiments made to address this point showed that the MDR1 phenotype is not invariably associated with resistance to free radicals measured as susceptibility to undergoing lipid peroxidation or dying of ionizing radiation. Cancer cells can be resistant to free radical effects independently from the expression of the MDR1 phenotype. The induction of this phenotype by the transfection of the MDR1 gene in non transformed cells actually increases susceptibility to ionizing radiation and undergoing lipid peroxidation.
KeywordsHuman Hepatocellular Carcinoma Cell Line Drug Resistant Cell MDR1 Phenotype Drug Resistant Phenotype Confer Drug Resistance
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