[Effects of simvastatin on proliferation and apoptosis of acute monocytic leukemia cell line SHI-1].

The purpose of this study was to investigate the effect of simvastatin (SIM) on proliferation and apoptosis of acute monocytic leukemia cell line SHI-1 and its mechanism. Experiments were divided into control and test groups (5 µmol/L, 10 µmol/L, 20 µmol/L SIM groups). The growth inhibitory rate of SHI-1 cells was detected using methyl thiazolyl tetrazolium (MTT) method. The cell cycle distribution and apoptotic rate were measured by using flow cytometry. The expression of BCL-2, caspase-3 mRNA were determined by reverse transcription polymerase chain reaction (RT-PCR). The expression of BCL-2, caspase-3 protein levels were analyzed by Western blot. The results demonstrated that SIM inhibited the growth of SHI-1 cells in time- and does-dependent manners. Cell cycle analysis showed that SHI-1 cells significantly arrested in S phase (p < 0.05) after treating with SIM for 48 hours, as compared with control group. 5 µmol/L SIM in test group significantly blocked cell cycle progression, but can not induce apoptosis. The expressions of BCL-2 mRNA and protein were down-regulated and caspase-3 mRNA and protein were up-regulated along with the increase of SIM concentration (p < 0.05). It is concluded that SIM is able to inhibit proliferation and induce apoptosis of SHI-1 cells, the mechanism may be associated with downregulating the expression of apoptosis-related gene BCL-2, upregulating the expression of caspase-3.