槲皮素对BGC-823胃癌细胞caspase-3、Bcl-2表达影响与抑癌作用研究

Influence of quercetin on proliferation of gastric cancer line BGC 823 and the expression of caspase-3,Bcl-2

目的：研究槲皮素（quercetin，QUE）抑制人胃癌BGC-823细胞增殖和诱导凋亡的作用。方法：采用四甲基噻唑氮蓝（methyl thiazolyl tetrazolium，MTT）比色法检测不同终浓度的QUE对BGC-823细胞增殖的影响及其细胞毒活性，流式细胞术（FCM）对不同浓度的QUE作用24h的BGC-823细胞进行凋亡检测及其周期分析．用免疫组化法测定Bcl-2、caspase-3的表达率。结果：QUE对体外培养的BGC-823细胞具有明显的增殖抑制作用，在30～120μmol／L范围内可显著抑制BGC-823细胞增殖，且呈剂量-时间依赖性。FCM检测后，BGC-823细胞周期阻滞于S期，药物浓度呈正相关。经QUE处理后BGC-823细胞株caspase-3蛋白表达明显增加，Bcl-2蛋白表达降低。免疫组化检测表明，用药组Bcl-2蛋白的表达下降，easpase-3蛋白的表达率增强，与对照组相比差异有统计学意义（P〈0．01）。结论：QUE诱导BGC-823细胞发生凋亡，使细胞周期阻滞于S期，抑制增生与诱导凋亡的机制可能与下调Bcl-2、上调caspase-3蛋白的表达有关。

Objective：To study the influence of quercetin （QUE） on the growth and apoptosis of human gastric carcinoma cell line BGC-823. Methods：Methyl thiazolyl tetrazolium （MTT） assay was used to determine the influence of different concentrations of QUE on the cell proliferation of BGC-823 ;the change of cell cycle and apoptosis was observed by flow cytometry （FCM） after the cells were treated with different concentrations of QUE for 24 h ; the positive expression rate of Bcl-2 and caspase-3 were detected by immunocytochemieal staining. Results： QUE at concentrations ranging from 30μmol/L to 120μmol/L significantly inhibited the proliferation of BGC-823 cells in a dose-and-time-dependent manner（P 〈 0.01 ）. FCM analyses showed that QUE arrested BGC-823 cells at the S phase. Expression of Bcl-2 protein decreased following QUE induction in a dose-dependent manner, whereas easpase-3 expression increased significantly compared with that of the control group （ P 〈 0.01 ）. Conclusions ： QUE can inhibit the growth and induce apoptosis of BGC-823 cells,keeping the cell cycle at S phase. Its mechanisms may be relevant to the down- regulation of Bcl-2 protein expression as well as the up-regulation of caspase-3 expression.