This study aims to investigate the effects and mechanism of pantoprazole on multidrug resistant leukemia K562/A02 and K562/ADM cell lines. K562/A02 and K562/ADM cells at logarithmic growth phase were pre-treated with different concentration of pantoprazole (0, 50, 100, 200 μg/mL) for 24 h. Flow cytometry was used to measure the cell growth cycle and apoptosis. RT-PCR and Western blot were used to measure the expression of p-PI3K, p-AKT, p-mTOR, P-glycoprotein (P-gp) and multidrug resistance-associated protein-1 (MRP1). Pantoprazole pretreatment significantly increased the ratio of G0/G1 phase but decreased the S phase of K562/A02 and K562/ADM cells in dose-dependent manner (p < 0.05). Flow cytometry analysis indicated that pretreatment of leukemic cells with pantoprazole induced apoptosis in a dose-dependent manner. RT-PCR and Western blot analysis indicated that pantoprazole pretreatment inhibited the mRNA and protein expression of p-PI3K, p-Akt, p-mTOR, P-gp and MRP1 in K562/A02 and K562/ADM cells in a dose-dependent manner (p < 0.05). Pantoprazole arrested cell cycle and induced apoptosis of multidrug resistant leukemic cells by inhibiting the expression of P-gp and MRP1 through PI3K/Akt/mTOR signaling pathway.
Keywords: Leukemia; Multidrug resistance-associated protein-1; P-glycoprotein; PI3K/AKT/mTOR signaling; Pantoprazole; Proton pump inhibitor.