In the subgroup analysis, according to the type of leukemia, significant association was found between MDR1G2677T polymorphism and myeloid leukemia but not lymphoblastic leukemia (TT vs. GG: OR = 0.66, 95% CI = 0.46-0.95, P = 0.026; TT vs.
Activation of the MDR1 upstream promoter (USP) has been described previously in four lymphoblastic leukemia patients, where it is the major MDR1 promoter associated with P-glycoprotein overexpression.
In order to identify genomic changes associated with drug-resistance acquisition, we performed R-banding karyotyping, fluorescence in situ hybridization, and comparative genomic hybridization to compare a human T-cell lymphoblastic leukemia cell line, CEM-wild type, and a subline with resistance to vinblastine (CEM-VLB) and overexpressing P-glycoprotein.
The aim of the present study was to investigate the relationship between mdr1 RNA levels and P-glycoprotein (Pgp) content of leukemic cells from patients with acute myelogenous or lymphocytic leukemia.
To evaluate the frequency and the prognostic value of different mechanisms of drug resistance in acute leukemias, we investigated the expression of mdr1 by immunocytochemistry, mRNA slot blot or RT-PCR in 182 cases of adult acute myeloid and 37 cases of adult lymphoblastic leukemia.