Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P33527 (ABCC1)
 1,164 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We analyzed P glycoprotein (PGP) expression and its correlation with hematological parameters and outcome in 50 cases of newly diagnosed adult acute lymphoblastic leukemia (ALL). PGP expression was evaluated by flow cytometry using MRK16 monoclonal antibody (MoAb) and/or immunocytochemistry on marrow slides, using JSB1 MoAb. Thirty-two of the 50 patients (64%) were PGP positive by at least one of the two methods, which gave concordant results in 15 of the 18 cases in which they were both used. No correlation between PGP expression and clinical and hematological parameters including WBC counts, immunophenotype and karyotype was seen, although there was a trend for more frequent CD34 expression in PGP-positive cases. All patients were treated with intensive chemotherapy. We found no difference in complete remission (CR) rate, actuarial disease-free survival and survival in PGP-positive and PGP-negative cases. Our findings suggest that the clinical significance of PGP expression is less clear in ALL than in AML. Wider use of functional techniques of evaluation of mdr1 gene expression, which assess the 'pumping' activity of PGP, and their correlation with quantitative analysis of mdr1 mRNA and protein, would probably improve knowledge of the role of PGP in ALL. Analysis of other mechanisms of drug resistance, especially multidrug resistance-associated protein (MRP) expression, would also be useful.
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PMID:Expression of the multidrug resistance P glycoprotein in newly diagnosed adult acute lymphoblastic leukemia: absence of correlation with response to treatment. 747 77

P-glycoprotein (P-gp), lung resistance-related protein (LRP) and multidrug resistance-associated protein (MRP) expression, and blast cell intracellular daunorubicin accumulation (IDA) were evaluated in 95 previously untreated cases of adult acute lymphoblastic leukaemia (ALL) using flow cytometry. Forty-five out of 95 (47%) patients were P-gp positive (+), 12/66 (18%) were LRP+ and 11/66 (17%) were MRP+. Eighteen out of 66 (28%) patients showed a simultaneous multidrug resistance (MDR)-related protein expression higher than controls for more than one protein, while 24/66 (36%) cases did not overexpress any protein. Twenty-one out of 24 (87%) cases overexpressing at least one MDR-related protein had a defect in accumulating daunorubicin into their blast cells, while only 4/24 (16%) cases who did not overexpress any protein had similar features. The complete remission rates were similar in MDR-positive and -negative (-) patients but relapses within 6 months were more frequent in P-gp+ cases, and therefore the disease-free survival duration was shorter in P-gp+ than in P-gp- patients (P = 0.01). The number of MRP+ and/or LRP+ cases was too small to be able to draw any conclusion on their role in affecting or predicting therapy outcome. In conclusion, P-gp overexpression associated with a defect in daunorubicin accumulation is a frequent feature in adult ALL at onset and seems to be related to poorer therapy outcome and, consequently, a shorter disease-free survival. LRP and MRP overexpression seems to be a rare event and no conclusion can be drawn on its prognostic role.
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PMID:P-glycoprotein, lung resistance-related protein and multidrug resistance-associated protein in de novo adult acute lymphoblastic leukaemia. 1184 7