表没食子儿茶素没食子酸酯对结肠癌细胞株HCT-8和HT29的抑制作用及影响机制

Inhibitory effect and mechanism of （-）-epigallocatechin-3-gallate on HT29 and HCT-8 colorectal cancer cell lines and expression of HES1 and JAG1

目的探讨绿茶提取物表没食子儿茶素没食子酸酯（EGCG）对结肠癌细胞株HCT－8细胞和HT29细胞增殖的抑制作用，研究其对HESl与JAGl基因表达的影响。方法体外培养HCT-8细胞和HT29细胞，采用不同浓度的EGCG（10、20、35mg／L）对其进行干预，MTT法检测EGCG对HCT-8细胞和HT29细胞增殖的抑制作用：用流式细胞仪检测EGCG对HCT-8细胞和HT29细胞细胞凋亡和细胞周期的影响。实时荧光定量PCR检测EGCG干预后的HCT-8细胞和HT29细胞的HESl与JAGl基因的表达情况。结果EGCG对HCT-8细胞和HT29细胞增殖及凋亡均有影响，3个EGCG浓度对HCT-8增殖抑制率分别为（28．894±5．076）％，（34．903±1．794）％和（39．028±0．105）％；对HT29的增殖抑制率分别为（14．682±4．244）％、（22．429±3．847）％和（29．840±5．076）％。EGCG能将HCT-8细胞阻滞在G／M期，阻碍其向M期转换，将HT29细胞阻滞在S期，阻碍其向G2期转换，抑制其细胞增殖。EGCG可下调两株细胞HESl的基因表达，但差异均无统计学意义（P〉0．05）：EGCG能上调两株细胞JAGl的基因表达，但只有HCT．8细胞的基因表达差异有统计学意义（O．201±0．018比0．440±0．077．P=0．029）。结论EGCG对体外培养的HCT-8细胞和HT29细胞的增殖有明显抑制作用．且能诱导细胞凋亡和影响细胞周期。其作用机制可能与上调JAGl的基因表达有关。

Objective To study the inhibitory effect of （-）-epigallocatechin-3-gallate （EGCG） on cancer cells line HCT-8 and HT29 and its influence on the expression of HES1 and JAG1. Methods Colorectal cancer cells line HCT-8 and HT29 were cultured in vitro and treated with different concentrations of EGCG （10 mg/L,20 rag/L,35 mg/L）. The inhibition of proliferation was tested by MTT analysis. Influence of EGCG on the cell apoptosis and cell cycle of HCT-8 and HT29 were detected with flow cytometry, and gene expression of HCT-8 and HT29 after EGCG treatment with real-time polymerase chain reaction. Results EGCG affected the proliferation and apoptosis of HCT-8 and HT29. The inhibition rates of the three different concentrations of EGCG were （28.894±5.076）%, （ 34.903±1.794） %, and （39.028±0.105） % on HCT-8, and （14.682±4.244） %, （22.429±3.847） %, and （29.840±5.076）% on HT29. EGCG caused G2/M phase arrest and M phase transition in HCT-8 cell line, and S phase arrest and G2 phase transition in HT29 cell line. EGCG down-regulated HES1 gene expression in both cell lines, however, the differences were not statistically significant （both P〉0.05）.EGCG upregulated JAG1 gene expression in both cell lines, however only the difference in HCT-8 was statistically significant （0.201±0.018 vs. 0.440±0.077, P=0.029）. Conclusions EGCG can significantly inhibit the proliferation of HT29 cells and HCT-8 cells by changing cell cycle and inducing cell apoptosis. The mechanism may be related to the upregulation of JAG1 gene expression.