NVP-BEZ235 inhibits proliferation and colony-forming capability of CD34(+)CD38(-) human acute myeloid leukemia stem cells

Abstract

This study was aimed to explore the effect of NVP-BEZ235, a dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor, on proliferation, cell cycle and colony forming capability of CD34(+)CD38(-) human acute myeloid leukemia (AML) KG1a cells. Flow cytometry was used to detect expression of CD34 and CD38 on the surface of human AML KG1a cells; Trypan blue assay was used to analyze the effect of NVP-BEZ235 at various concentrations on proliferation of KG1a cells; flow cytometry was performed to examine the cell cycle of KG1a cells after NVP-BEZ235 treatment; Soft agar colony-forming experiment was used to detect the colony forming ability of KG1a cells treated with NVP-BEZ235 at various concentrations. The results indicated that the percentage of CD34(+)CD38(-) AML KG1a cells was (98.02 ± 0.72)%. NVP-BEZ235 (0.125 - 1 µmol/L) inhibited the proliferation of KG1a cells in a time-and dose-dependent manner (P < 0.05) and the 50% inhibition concentrations (IC50) at 24 h and 48 h were 0.597 µmol/L and 0.102 µmol/L, respectively. KG1a cells were arrested at G0/G1 phase after treating with 0.5 µmol/L NVP-BEZ235 for 24 h, it was significantly higher than that of control group (83.2 ± 3.80)% vs (43.47 ± 9.60)% (P < 0.05). KG1a cells treated with NVP-BEZ235 (0 - 1 µmol/L) for 14 d and 21 d, the number of colony decreased respectively from (375.67 ± 21.46) per 2500 KG1a cells and (706.33 ± 87.31) per 2500 KG1a cells to 0, with statistical significance (P < 0.05). It is concluded that NVP-BEZ235 can inhibit proliferation and colony-forming capability of CD34(+)CD38(-) human AML KG1a cells.