CORRELATION BETWEEN PERMEABILITY-RELATED GLYCOPROTEIN EXPRESSION AND SUSCEPTIBILITY TO OXYGEN RADICALS IN VINCRISTINE-RESISTANT HEMATOLOGICCELL-LINES

This study was designed to test the correlation between the expression of permeability-related glycoprotein (P-GP) and susceptibility to oxy gen radicals derived from the reaction of hypoxanthine (HX)-xanthine o xidase (XO) in wild type and vincristine (VCR)-resistant hematologic c ell lines. A marked correlation between P-GP expression and susceptibi lity to oxygen radicals was found in VCR-resistant cells, while it was weak in wild cell lines. In contrast, there was neither correlation b etween sensitivity to VCR and oxygen radicals nor between sensitivity to VCR and P-GP expression in both wild type and VCR-resistant cells. No correlation between sensitivity to adriamycin or oxygen radicals an d P-GP expression were observed in both cells tested. These results ma y suggest a new mechanism of drug resistance in cells expressing P-GP. (C) 1997 Elsevier Science Ireland Ltd.