XIAP and P-glycoprotein co-expression is related to imatinib resistance in chronic myeloid leukemia cells

Abstract

P-glycoprotein (Pgp) and XIAP co-expression has been discussed in the process of the acquisition of multidrug resistance (MDR) in cancer. Here, we evaluated XIAP and Pgp expression in chronic myeloid leukemia (CML) samples, showing a positive correlation between them. Furthermore, we evaluated the effects of imatinib in XIAP and Pgp expression using CML cell lines K562 (Pgp(-)) and K562-Lucena (Pgp(+)). Imatinib increased XIAP and Pgp expression in K562-Lucena cells, while in K562 cells a downregulation of these proteins was observed, suggesting that imatinib induces an increment of MDR phenotype of CML cells that previously exhibit high levels of Pgp/XIAP co-expression.

Keywords: CML; CSA; Chronic myeloid leukemia; IAPs; IC(50); Imatinib; MDR; MFI; Multidrug resistance; P-glycoprotein; Pgp; RFI; Rho-123; Survivin; VRP; XIAP; chronic myeloid leukemia; concentration achieving 50% inhibition of cell growth; cyclosporin A; inhibitor of apoptosis proteins; mean of fluorescence intensity; multidrug resistance; ratio of mean of fluorescence intensity; rhodamine-123; verapamil.