苦参碱诱导U937细胞凋亡及其对Bcl-2表达的影响

U937 cell apoptosis-inducing effects of matrine and its effect on Bcl-2 expression

目的:探讨苦参碱(Mat)抑制人淋巴瘤细胞(U937)增殖及诱导其凋亡的机制.方法:四甲基偶氮唑蓝(MTT)比色法观察Mat对U937细胞增殖的影响;流式细胞术(FCM)检测细胞周期变化;Annexin V双标记染色结合FCM检测凋亡率;RT-PCR方法检测Bcl-2 mRNA表达.结果:Mat(0.2～0.5g/L)作用24,48,72h后对U937细胞均有增殖抑制作用(P<0.05或P<0.01),在该浓度范围内呈剂量和时间依赖性,其半数抑制浓度(IC50)为0.4g/L;Mat0.2～0.5g/L组作用U937细胞72h后,S期细胞比例均增加,细胞发生S期阻滞(P<0.01);细胞凋亡率分别为3.25%,5.32%,8.17%,11.20%,与U937细胞对照组(1.84%)及Mat0.1g/L组(1.95%)相比较差异具有统计学意义(P<0.05或P<0.01).RT-PCR显示Bcl-2 mRNA表达明显减弱,且随剂量增加越明显.结论:Mat在一定浓度和时间对U937细胞具有增殖抑制作用,其机制可能是使细胞发生S期阻滞;Mat可以下调U937细胞Bcl-2表达,促进细胞凋亡.

AIM： To explore the proliferation inhibition and apoptosis inducing effects of matrine （Mat） on U937 cells and its mechanism. METHODS： The proliferation inhibition rate of U937 cells was assayed by MTF analysis; cell cycle was evaluated by flow cytometry （FCM） ; cell apoptosis rate was calculated by Annexin/PI double staining method. The Bcl-2 mRNA expression of U937 cells treated with Mat was assayed by RT-PCR. RESULTS ： After U937 cells were treated with Mat （ 0.2 - 0.5 g/L） for 24, 48 and 72 h, the cell proliferation was markedly inhibited in a dose-dependent and time-dependent manner （P 〈 0.05 or P 〈0.01 ） , and the 5% inhibiting concentration （ ICs0 ） was 0.4 g/L. Cell cycle analysis showed that it was arrested in the S phase after 72 h. When the U937 cells were treated by Mat （0.2- 0.5 g/L） for 72 h, the corresponding apoptosis rate （3.25%, 5.32%, 8.17%, 11.20%） indicated by AnnexinV- FITC double staining, had statistical significance compared with the control group （ 1.84% ） and the 0. 1 g/L Mat-treated group （ 1.95% , P 〈 0.05 or P 〈 0.01 ）. The Bcl-2 mRNA expression in U937 cells was decreased 72 h after treated by Mat （0.2 - 0.5 g/L） with a concentration-effect relationship. CONCLUSION： Mat can suppress the U937 cell proliferation in a concentrationdependent and time-dependent manner. The effect has a relation with the U937 cell cycle arrested in the S phase. Mat can downregulate the expression of Bel-2 and induce the apoptosis.