LY294002对多药耐药急性白血病细胞株HL60/VCR的凋亡及细胞周期的影响研究

Effect of LY294002 on Cell Cycle and Apoptosis of Multidrug Resistant HL60/VCR Cell Line

目的:研究磷脂酰肌醇-3-激酶(PI3K)抑制剂LY294002对多药耐药急性白血病细胞株HL60/VCR凋亡与细胞周期的影响及可能机制。方法:取耐长春新碱(VCR)的HL60/VCR多药耐药急性白血病细胞株分为未加药的对照组及加入不同浓度的LY294002(其终浓度为1.0、2.5、5.0、10μmol.L-1)组,MTT法检测2种细胞的半数抑制浓度(IC50),流式细胞仪检测细胞凋亡及细胞周期分布,半定量逆转录-聚合酶链反应(RT-PCR)检测抗凋亡蛋白Bcl-2、细胞周期调控分子CyclinD1mRNA表达。结果:与对照组比较,LY294002可明显降低HL60/VCR对VCR的IC50(P<0.05),且与剂量相关;LY294002可显著增加HL60/VCR细胞凋亡率,阻滞细胞于G0/G1期,降低HL60/VCR细胞的Bcl-2、CyclinD1mRNA的表达(P均<0.05)。结论:LY294002可能是通过影响Bcl-2及CyclinD1基因的表达,从而促进HL60/VCR细胞凋亡及抑制细胞增殖。

OBJECTIVE： To explore the effect of the specific inhibitor - LY294002 of the signaling pathway PI3K/AKT on cell cycle and apoptosis of HL60/VCR cells and its mechanism. METHODS： Vincristine （VCR） resistant HL60/VCR were treated with LY294002 （final concentration at 1.0, 2.5, 5.0, or 10 μmol·L^-1） or without LY294002 （control） . IC50 was detected by MTT; flow cytometry was used to evaluate apoptosis and cell cycle distribution, and changes of Bcl- 2, CyclinD1 gene mRNA levels were detected by reverse transcription polymerase chain reaction. RESULTS： As compared with control, LY294002 significantly reduced the IC50 value in HL60/VCR to vincristine in a concentration dependent manner （P 〈 0.05） . LY294002 significantly increased the rate of apoptosis, arrested cells in G0/G1 phase and reduced the levels of Bcl - 2 and CyclinD1 mRNA （all P 〈 0.05）. CONCLUSION： The underlying mechanism for LY 294002 to promote apoptosis of HL60/VCR and suppress cell Droliferation lies in its imoact on Bcl - 2 level and CycllinD1 gene expression .