二甲双胍调控 AKT／MDR －1增强人结肠癌细胞 HT －29对5－FU 药物敏感性机制探讨

摘要

Objective:To explore the mechanism of that metformin enhances the cytotoxicity of 5 -fluorouracil(5-FU)to human colon cancer cell line HT -29.Methods:Treating the HT -29 cells with 5 -FU with or without metformin.MTT assay to analyze the cell proliferation,flow cytometry to detect apoptosis.Lipofectmin 2000 transfected AKT plasmid.RT -PCR to detect the nucleic acid expression level of AKT,MDR -1.Western Blot to check the pro-tein expression level of AKT,p -AKT and MDR -1.Results:Compared with the single -agent 5 -FU,metformin can enhance 5 -FU on inhibiting the proliferation of HT -29 cells.The apoptosis rates for single -agent and double -agent were (50.12 ±5.96)% and (78.00 ±3.39)%,respectively(P <0.05).Metformin may down -regulate the p -AKT and MDR -1 levels in both nucleic acid and protein levels.While overexpressed of AKT,for the 5 -FU sin-gle -agent,apoptotic rate was decreased (19.72 ±2.23)% than negative control plasmid,and for combination,it also decreased (20.30 ±3.15)%(P <0.05).Conclusion:By regulating AKT/MDR -1 pathway,metformin enhances the drug sensitivity of 5 -FU to human colon cancer cell line HT -29.%目的：探究二甲双胍增强化疗药物5－氟尿嘧啶（5－FU）对人结肠癌细胞株 HT －29细胞毒的相关机制。方法：体外培养人结肠癌细胞株 HT －29，以5－FU 联合或不联合二甲双胍干预细胞，MTT 法检测细胞增殖情况；流式细胞仪检测细胞凋亡；Lipofectmin 2000转染 AKT 质粒；RT －PCR 法检测 AKT、MDR －1核酸表达；Western Blot 法检测 AKT、p －AKT、MDR －1蛋白表达。结果：二甲双胍能够增强5－FU 对 HT －29细胞增殖的抑制作用，单用5－FU 与5－FU 联合二甲双胍干预的细胞早期及晚期凋亡率分别为（50．12±5．96）％和（78．00±3．39）％，差异具有统计学意义（P ＜0．05）。二甲双胍可以在核酸及蛋白的水平上下调 AKT、p －AKT 及 MDR －1水平；过表达 AKT 单独5－FU 处理较空白质粒组凋亡率降低（19．72±2．23）％，过表达联合用药组凋亡率较空白质粒组降低（20．30±3．15）％，差异具有统计学意义（P ＜0．05）。结论：二甲双胍通过调节 AKT／MDR －1增强人结肠癌细胞 HT －29对5－FU 的药物敏感性。