Effect of nicotinamide phosphoribosyltransferase on proliferation and apoptosis of human multiple myeloma U266 cells and its mechanism / 白血病·淋巴瘤

ABSTRACT

Objective:To investigate the effect of small interfering RNA (siRNA) silencing nicotinamide phosphoribosyltransferase (NAMPT) gene expression on proliferation and apoptosis of human multiple myeloma U266 cells and its mechanism.Methods:In vitro, NAMPT gene-specific siRNA was synthesized to transfect U266 cells. The experiment was divided into si-NAMPT group (transfected siRNA-NAMPT U266 cells) and si-NC group (transfected negative control siRNA U266 cells). The proliferation of U266 cells after transfection was detected by the methyl thiazolyl tetrazolium (MTT) method, and the apoptosis was detected by flow cytometry. Western blot was used to detect the expression levels of NAMPT, protein kinase B (AKT), phosphorylation-AKT (p-AKT), glycogen synthase kinase-3β (GSK-3β), phosphorylation-GSK-3β (p-GSK-3β), and β-catenin proteins in each group after transfection.Results:Compared with the si-NC group, the proliferation inhibition of U266 cells (absorbance value at 570 nm) increased after transfection for 48 h and 72 h in the si-NAMPT group (48 h 0.78±0.06 vs. 1.62±0.11; 72 h 1.23±0.14 vs. 2.37±0.18), and the differences were statistically significant ( t = 3.54, P = 0.034; t = 4.72, P < 0.01). The early apoptotic rate of cells in the si-NAMPT group increased compared with si-NC group [(53.42±0.25)% vs. (25.98±3.18)%], and the difference was statistically significant ( t = 4.41, P < 0.01). Compared with the si-NC group, the levels of p-AKT, p-GSK-3β, NAMPT and β-catenin proteins were significantly reduced in the si-NAMPT group (all P < 0.05). Conclusion:Silence of NAMPT gene can significantly inhibit U266 cell proliferation and induce cell apoptosis, and it may play a role by inhibiting the AKT-GSK-3β-β-catenin signaling pathway.