槲皮素对人结肠癌细胞HT29的增殖抑制及诱导凋亡的体外实验研究

研究槲皮素(quercetin,Que)对人结肠癌细胞株HT29的增殖抑制作用及凋亡诱导效应,并通过Fas、Caspase-3蛋白的表达变化对其分子作用机制进行探讨。方法常规培养结肠癌HT29细胞,分别用40、80、120μmol.L-1 Que(Que1、Que2、Que3组)、4.02mmol.L-1苦参碱(Mat组,为阳性对照)作用于细胞,以未加药组为对照组。采用MTT法检测细胞的增殖抑制率,透射电镜观察细胞的超微结构,流式细胞仪(FCM)检测细胞凋亡率,Western Blot法检测细胞Fas和Caspase-3蛋白的表达。结果 Que能显著增加细胞增殖的抑制率(P<0.01),并呈剂量依赖关系;且Que2、Que3组的抑制率随着培养时间的延长而升高,呈时间依赖关系。电镜下Que各组均呈现不同程度的凋亡特征形态变化:核固缩、染色质边集、并见核碎裂,凋亡小体出现。Que能明显增加细胞的凋亡率(P<0.01)、能显著增加Fas和Caspase-3的表达(P<0.01),并均呈剂量依赖关系。结论 Que对HT29细胞具有增殖抑制作用,并能诱导其凋亡,其作用机制可能与激活死亡受体Fas介导的Fas-Caspase-3凋亡信号通路有关。

Quercetin Induces Apoptosis and Inhibits Proliferation in Human Colon Carcinoma Cell Line HT-29 in Vitro

Objective To investigate the effects of quercetin(Que)on cell proliferation and apoptosis in human colon carcinoma cell line HT29,and to explore the molecular mechanism through examining the changes in Fas and Caspase-3 protein expression.Methods HT29 cells were treated with Que at concentrations of 40μmol.L-1(Que1group),80μmol.L-1(Que2 group)and 120μmol.L-1(Que3 group).Positive control group was challenged with matrine(4.02mmol.L-1).Control cells received the vehicle only.Cell growth,apoptosis,ultrastructure and expression of Fas and caspase-3 protein were measured by MTT,flow cytometry,transmission electron microscope and Western Blot,respectively.Results Que treatment significantly inhibited cell growth in a dose-ependent manner(P<0.01),and the inhibition rates increased in a time-dependent manner in Que2 and Que3 groups.Examination with the electron microscope showed nuclear condensation,chromatin margination,nuclear fragmentation and apoptotic body formation in cells treated with Que.Furthermore,Que treatment significantly increased cell apoptosis and protein expression of Fas and Caspase-3 in a dose-dependent manner(P<0.01).Conclusion Que can inhibit proliferation and induce apoptosis in HT29 cells through an apoptotic pathway involving Fas-mediated activation of Caspase-3.