细胞凋亡相关基因在二甲双胍抑制结肠癌细胞增殖中的作用

The effect of apoptosis-related genes in apoptosis of HT-29 cells induced by metformin

目的：探讨二甲双胍对人结肠癌HT-29细胞增殖、凋亡及裸鼠皮下瘤生长的影响。方法噻唑蓝（MTT）比色法分别检测二甲双胍作用于结肠癌细胞后其细胞活力及生长抑制率；流式细胞仪检测二甲双胍对结肠癌HT-29细胞周期时相、凋亡率的影响；免疫印迹法（Western blot）检测凋亡相关蛋白的表达；将结肠癌HT-29细胞接种于裸鼠，观察不同浓度二甲双胍对裸鼠皮下瘤生长的影响。结果5 mmol/L二甲双胍作用细胞48 h，细胞生长周期阻滞于G0/G1期,细胞凋亡率为（22.46±2.19）%；Western blot检测显示抗凋亡蛋白Bcl-2、Bcl-xl的表达随着药物浓度的增加而减少，而促凋亡蛋白Bid的表达随着药物浓度增加而增加。高剂量二甲双胍组及联合用药组裸鼠皮下瘤体积显著小于对照组裸鼠瘤的体积，20 d时两组抑瘤率分别为38.4%、67.7%。结论二甲双胍通过线粒体介导的凋亡通路途径来诱导人结肠癌细胞发生凋亡，并抑制结肠癌细胞裸鼠瘤生长。

ObjectiveTo investigate the effect of metformin on proliferation, apoptosis of HT-29 cells and tumor growth in nude mice.Methods HT-29 cells were treated with metformin at different concentrations,cell viability was assayed using MTT methods.Cell cycle,apoptosis rate were assayed by flow cytometry.Nude mice were transplanted with HT-29 cells,and tumor growth inhibition rate was detected. Results After HT-29 cells were treated with 5 mM metformin for 48 h,the growth cycle was arrested in Go/Gl phase,the apoptosis rate was （22.46±2.19）%,The expressions of Bcl-2,Bcl-xl protein was down-regulated after metformin treatment,while the bid protein was significantly increased,Tumor size in the high-dose metformin group,cisplatin combined with metformin group were significantly smaller than the control group, and the inhibition rates were 38.4%、67.7% respectively.Conclusion Metformin inhibits proliferation of HT-29 cells,and induces apoptosis in vitro and significantly inhibits the growth of colon cancer in nude mice.