title: Expression of the multidrug transporter, P-glycoprotein, in chronic myelogenous leukaemia cells in blast crisis.
abstract: The overexpression of a cell-surface glycoprotein termed P-glycoprotein (P-gp) is frequently associated with multidrug resistance (MDR) in cell lines in vitro. To evaluate the implications of P-gp expression in clinical drug-resistance, we examined the expression of P-gp in fresh leukaemia cells from chronic myelogenous leukaemia (CML) patients in blast crisis. By using immunoblotting with a monoclonal antibody against P-gp, C219, we showed that leukaemia cells from three CML patients in blast crisis were P-gp negative at the stage when these patients were in complete remission, and that the cells showed high levels of P-gp expression at times when the same patients had relapsed and had not responded to chemotherapy. Six out of 11 patients (nine in the refractory state) were P-gp positive and they rarely responded to chemotherapy. These data suggest that the expression of P-gp is closely associated with drug-resistance in CML.
authors.affiliation: Cancer Research Institute, Faculty of Medicine, Kagoshima University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kuwazuru
authors.forename: A
authors.initials: A
authors.lastname: Yoshimura
authors.forename: S
authors.initials: S
authors.lastname: Hanada
authors.forename: M
authors.initials: M
authors.lastname: Ichikawa
authors.forename: T
authors.initials: T
authors.lastname: Saito
authors.forename: K
authors.initials: K
authors.lastname: Uozumi
authors.forename: A
authors.initials: A
authors.lastname: Utsunomiya
authors.forename: T
authors.initials: T
authors.lastname: Arima
authors.forename: S
authors.initials: S
authors.lastname: Akiyama
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001752:Blast Crisis / Q000188:drug therapy / Q000378:metabolism*; D004351:Drug Resistance / Q000502:physiology*; D005260:Female; D006801:Humans; D015151:Immunoblotting; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis*; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis*; D014407:Tumor Cells, Cultured / Q000378:metabolism
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins