Expression of the P-glycoprotein gene in multidrug-resistant Chinese hamster ovary cells.
A series of multidrug-resistant (MDR) Chinese hamster ovary (CHO) cells was established to survive in stepwise increasing concentrations of vincristine. These MDR cells contained amplified P-glycoprotein (mdr) genes. Using monoclonal antibody against the P-glycoprotein, we present here results showing that the levels of P-glycoprotein and its phosphorylation and glycosylation did not correlate with those of drug resistance. Our results suggest that overproduction of the P-glycoprotein cannot account for the differences in drug resistance in these MDR cells, and that multiple modalities are involved in multiple drug resistance in mammalian cells.
Mukhopadhyay
T
T
Department of Molecular Pathology, University of Texas M.D. Anderson Cancer Center, Houston 77030.
Kuo
M T
MT
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D004351:Drug Resistance; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D009369:Neoplasms / Q000188:drug therapy; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000032:analysis
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D008562:Membrane Glycoproteins; D012333:RNA, Messenger