茶多酚对人结肠癌细胞株Caco-2凋亡及RhoA蛋白活性的影响

Influence of tea polyphenols on the apoptosis of human colon cancer cell line Caco-2 and RhoA protein activity

目的探讨茶多酚对人结肠癌细胞株Caco-2凋亡及RhoA蛋白活性的影响。方法将传代后的人结肠癌细胞株Caco-2细胞分为实验组和对照组,实验组加入不同浓度的茶多酚(25、50、100和200μmol/L),对照组加入等量RPMI-1640培养液,采用四甲基偶氮唑盐(MTT)法测定茶多酚对Caco-2增殖抑制的影响,流式细胞术(FCM)检测细胞凋亡指数,Pull-down法检测人结肠癌细胞株Caco-2细胞内的RhoA蛋白活性。结果不同浓度的茶多酚对人结肠癌细胞株Caco-2有明显的抑制作用,且呈剂量及时间依赖性;Pull-down法检测结果显示,茶多酚可以降低人结肠癌细胞株Caco-2细胞内的RhoA蛋白活性,且随浓度增加其蛋白活性降低。结论茶多酚可促进人结肠癌细胞株Caco-2的凋亡,其可能通过降低RhoA蛋白活性来实现。

Objective To explore the influence of tea polyphenols （TP） on the apoptosis of human colon cancer cell line Caco-2 and RhoA protein activity. Methods The passage human colon cancer cell line Caco-2 ceils were divided into experimental group and control group. The experimental was added with different concentrations of TP （25, 50, 100 and 200 μmol/L） , while the control group was added with equal amount of culture fluid RPMI-1640. Inhibition of Caco-2 proliferation, ap- optosis indexes and RhoA protein activity within human colon cancer cell line Caco-2 cells were re- spectively detected by methyl thiazolyl tetrazolium （MTT）, flow cytometry （FCM） and Pull-down method. Results Different concentrations of TP showed significant inhibitory effects on human colon cancer cell line Caco-2. Pull-down test results showed that TP could reduce the activity of RhoA pro- tein in human colon cancer cell line Caco-2 cells, and with the increasing of concentration, its protein activity decreased. Conclusion TP can promote the apoptosis of human colon cancer cell line Caco-2, which may be achieved by reducing the activity of RhoA protein.