表没食子儿茶素没食子酸酯对人胃癌细胞株MKN45诱导凋亡作用的研究

The apoptotic effects of epigallocatechin-3 gallate on human gastric cancer cell line MKN45

目的了解表没食子儿茶素没食子酸酯(EGCG)是否诱导人胃癌细胞株 MKN45凋亡及其凋亡信号传导途径,为其临床应用提供进一步的理论依据。方法用四甲基偶氮唑蓝(MTT)比色法检测 EGCG 对 MKN45细胞生长的抑制作用;膜连蛋白 V-异硫氰基荧光素(Annexin V-FTTC)+碘化丙啶(PI)方法测定 EGCG 作用后 MKN45细胞的凋亡率;酶联免疫吸附测定(ELISA)检测 EGCG 对 MKN45细胞内caspase-3活性的影响;Rhodamine123染色检测 EGCG 作用后 MKN45细胞内线粒体膜电位的改变情况。结果 EGCG 作用后 MKN45细胞发生凋亡,随着 EGCG 作用时间的延长及浓度的增加,凋亡率增加。在EGCG 作用8h 后 MKN45细胞内的 caspase-3的活性开始升高,并于作用12h 后活性明显升高。线粒体的膜电位于 EGCG 作用4h 后就开始明显下降,并与时间和浓度正相关。结论 EGCG 可以诱导人胃癌细胞株 MKN45细胞凋亡,且与作用时间及浓度正相关。EGCG 对 MKN45细胞凋亡的诱导是通过线粒体途径发生的。

Objective To investigate the apoptotic effect of epigallocatechin-3-gallate（EGCG） on gastric cancer cell line MKN45 and its apoptotic pathway, and to provide further evidence for its chnical application. Methods The inhibitory effect of EGCG against MKN45 cells was detected by methyl thiazolyl tetrazohum（MAT）. The apoptotic rate of MKN45 cells after EGCG treatment was evaluated by Annexin V-FITC ＋ PI. The influence of EGCG on the activity of caspase-3 in the MILN45 was determined by enzyme hnked immunosorbent assay（ELISA）. By Rhodamine123 staining, the membrane potential change of mitochondrion was investigated. Results EGCG can induce apoptosis of MKN45 cells, and the apoptotic rates were in a time-and dose-dependent manner. Eight hours after treatment of EGCG, the activity of caspase-3 in the MKN45 was increased, which was further induced 12 h after treatment. The membrane potential of mitochondrion was significantly weakened 4 h after being treated with EGCG, which was positively correlated with time and dose. Conclusion EGCG can induce apoptosis of human gastric cancer cell line MKN45 in a time-and dose-dependent manner. The apoptotic pathway triggered by EGCG in MKN45 was mitochondrial dependent.