title: [The clinical significance of the expression of the multiple-drug resistance protein P-glycoprotein in chronic myeloleukemia].
abstract: Cell resistance to pharmaceutical agents arises among other causes because of multiple drug resistance induced by P-glycoprotein (P-gp). The analysis of expression of P-gp and differentiation antigens of hemopoietic cells has been made on myeloid cells from 14 patients in CML chronic phase and 25 with CML acceleration and in blast crisis. Surface antigen expression was evaluated at flow cytofluorimetry (FACScan unit). Fluorescent dye rodomin (Rh123) helped examine P-gp functional activity. A close relationship is shown between P-gp expression and CD34 (r = 0.69. p = 0.0004), this giving evidence of these antigens expression on the same cells. In chronic phase P-gp is expressed on a few cells in some patients, its activity being low or absent. The appearance of UIC-2+ cells was unrelated to previous chemotherapy and brought no resistance to treatment. In terminal stage P-gp is expressed in 50% of cases. Functional tests identified the active protein in blast populations with a large number of UIC-2+ cells and in some patients with a small number of cells expressing P-gp. Therefore, comprehensive clinical investigations are needed of multiple drug resistance, though in half of the resistant patients in AML blast crisis P-gp+ cells were not identified suggesting the existence of other mechanisms responsible for resistance to treatment.
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000097:blood / Q000235:genetics*; D000328:Adult; D000368:Aged; D018952:Antigens, CD34 / Q000097:blood; D014408:Biomarkers, Tumor / Q000097:blood; D002469:Cell Separation; D018432:Drug Resistance, Multiple / Q000235:genetics*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005260:Female; D005434:Flow Cytometry; D015973:Gene Expression Regulation, Leukemic / Q000235:genetics*; D005819:Genetic Markers; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000097:blood / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D008875:Middle Aged
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018952:Antigens, CD34; D014408:Biomarkers, Tumor; D005819:Genetic Markers
vernacular_title: Klinicheskoe znachenie ékspressii belka mnozhestvennoĭ lekarstvennoĭ ustoĭchivosti P-glikoproteina pri khronicheskom mieloleĭkoze.