INVOLVEMENT OF ANTIOXIDANT ENZYMES IN MULTIPLE-DRUG RESISTANCE IN A HUMAN T-LYMPHOBLASTIC LEUKEMIA-CELL LINE WHICH OVER-EXPRESSES P-GLYCOPROTEIN
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- Published online on: July 1, 1993 https://doi.org/10.3892/ijo.3.1.99
- Pages: 99-104
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Abstract
We have compared the specific activities of Cu/Zn superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in a vinblastine sensitive human T-lymphoblastic cell line (CCRF-CEM) and its multiple drug resistant (MDR) counterpart cell line (CEM/VLB100), which over-expresses P-glycoprotein (PGP). We have found that the specific activity Cu/Zn SOD was consistently 38% increased in CEM/VLB100 cells compared with CCRF-CEM cells. In contrast, the activities of CAT and GSH-Px were similar in the two cell lines. These results suggest that MDR in CEM/VLB100 is a complicated phenotype which not only involves a PGP mechanism, but also a SOD protection mechanism against drug-mediated O2.- cytotoxicity.