Effect of gambogic acid on the apoptosis of multiple myeloma U266 cell line and its mechanism

Objective This study was aimed to investigate the effect of gambogic acid(GA) on the apoptosis of multiple myeloma U266 cell line and its mechanism.Methods The U266 cells were treated with GA at different concentration,the inhibition rates were detected by MTT assay.Apoptosis induced by GA was observed by Annexin Ⅴ/PI doubling staining assay.Mitochondrial membrane potential was measured by JC assay.Activated Caspase 3,Caspase 8 and Caspase 9 in living U266 cells were measured by caspGLOWTM fluorescein staining kit.Results U266 cell growth was inhibited in a concentration-dependent manner.GA decreased the mitochondrial membrane potential of U266 cell.GA induced apoptosis of U266 cells and increased activated Caspase 3,Caspase 8,Caspase 9 positive cell number for 24.9%,31.7%,32.4% in 24 h and 57.0%,64.5%,63.5% in 48 h.Conclusions GA inhibits the growth of U266 cell by the effect of apoptosis,GA triggers U266 cell apoptosis through both intrinsic and extrinsic pathways.