摘要
目的探讨表没食子儿茶素没食子酸酯（EGCG）对大肠癌细胞系HT-29细胞增殖和凋亡的影响及可能的作用机制。方法体外培养的HT-29细胞,分为对照组和实验组,实验组和对照组加入同等体积的培养基,实验组用不同浓度（15-120μg/ml）EGCG分别处理24、48、72 h,MTT比色法测定其对HT-29细胞增殖的影响;EGCG（浓度分别为0、15、30、60μg/ml）处理HT-29细胞48 h后,流式细胞仪检测细胞凋亡,分光光度计检测Casepase-9相对活性,Rho123探针染色流式细胞仪检测线粒体膜电位变化,Western blot法检测Bax、Bcl-2、Akt、p-Akt、pGSK-3β的表达。结果 EGCG能有效抑制HT-29细胞增殖,且呈剂量和时间依赖性;EGCG（15、30、60μg/ml）作用于HT-29细胞48 h后,细胞凋亡率分别为11.6%、23.4%、34.5%;Bax表达量上调,而Bcl-2表达量下调;Casepase-9相对活性显著增加;线粒体膜电位显著降低;此外,EGCG可抑制p-Akt及其下游蛋白p-GSK-3β的表达。结论 EGCG可通过抑制HT-29细胞增殖并促进其凋亡,其作用机制可能与抑制Akt信号通路,继而激活线粒体凋亡途径相关。
Objective To investigate the effect of epigallocatechingallate （EGCG） on cell proliferation and apoptosis in colorectal cancer line HT-29 cells and to explore the possible mechanisms. Methods HT-29 cells were cultured in vitro, and were divided into two groups, control group and drug-treated group. The control group received only the culture medium. After treatment by EGCG at different concentrations respectively at different time, the cell survival was de- termined by MTF method. Apoptosis was detected by flow cytometry. The relative activity of caspase-9 was monitored by spectrophotometer. The mitochondrial membrane potential was evaluated by flow cytometry analysis after Rho123 probe staining. Western blot was used for Bcl-2, Bax, Akt, p-Akt and p-GSK-3β protein analysis. Results From the data of MTF, the cell proliferation of HT-29 cells was inhibited by EGCG at a dose-dependent and time-dependent manner. Flow cytometry analysis showed that EGCG significantly induced cell apoptosis. After treatment with EGCG（ 15,30,60 μg/ml） , the apoptosis rate of HT-29 cells was 11.6%, 23.4%, 34. 5%, which showed an obvious concentration-effect relationship. The treatment with EGCG promoted the expression of pro-apoptotic factor Bax, and suppressed the expression of anti-apoptotic factor Bel-2. The relative activity of caspase-9 of EGCG group was increased. Furthermore, the mitochondrial membrane potential was reduced. The data of western blot showed that EGCG decreased the expression of p-AKT and down-stream effector of Akt, p-GSK-3β at a dose-dependent manner. Conclusions EGCG inhibits the cell proliferation and in- duces cell apoptosis of HT-29 cells, and the effects of antitumor may be associated with inhibition of the Akt signaling path- way, thus activating mitochondria apoptosis pathway.
出处
《实用老年医学》
CAS
2015年第7期583-586,589,共5页
Practical Geriatrics
基金
湖北省自然科学基金课题(302-131854)
