二甲双胍抑制乳腺癌MCF-7细胞作用的研究

Inhibitory effects of metformin on breast cancer cell line MCF-7

目的初步探讨二甲双胍对乳腺癌MCF-7细胞的抑制作用。方法将乳腺癌MCF-7细胞分为实验组和对照组,实验组用终浓度为16.56g/L的二甲双胍培养,对照组不用二甲双胍干预。两组MCF-7细胞在相同条件下培养48h后分别提取细胞总蛋白,应用Western blot法检测乳腺癌MCF-7细胞中NF-κBp65、Lin28B的表达情况。以RT-PCR法检测MCF-7细胞中microRNA let-7下游基因HMGA2、H-Ras的转录水平。结果药物干预48h后,乳腺癌MCF-7细胞中NF-κBp65、Lin28B的表达水平下降,差异有统计学意义(P<0.05)。实验组乳腺癌MCF-7细胞中自我复制和多向分化的相关基因HMGA2、H-Ras的转录水平明显下降,2-△△Ct测得两种基因的表达分别下降85%和96%(P均<0.05)。结论 16.56g/L的二甲双胍能够有效地降低乳腺癌MCF-7细胞中NF-κBp65、Lin28B的表达,进一步抑制乳腺癌MCF-7细胞多向分化和自我复制相关基因HMGA2和H-Ras的表达,从而为二甲双胍抑制乳腺癌的复发和转移提供实验依据。

Objective To explore the mechanism of metformin in inhibiting breast cancer cell line MCF-7. Methods MCF-7 cells were cultured for 48 h in the presence or absence of 16.56 g/L metformin,total protein was extracted from cells and expression of nu- clear factor-kappa B（NF-KB） p65 and Lin28B were detected by Western blot. Furthermore, transcription levels of HMGA2 and H-Ras, which are regulated by microRNA let-7,were determined by RT-PCR. Results NF-KB p65 and Lin28B expression declined signifi- cantly after 48-h drug treatment（t=23.44, t= 14.24;P〈0.05 ）.Transcription levels of HMGA2 and H-Ras,which are related to self-renewal and multipotent differentiation of tumor cells,decreased 85%（P〈0.05） and 96%（P〈0.05）, respectively, based on 2-△△Ct measurements. Conclusions Metformin at 16.56 g/L can effectively reduce NF-KB and Lin28B expression and inhibit HMGA2 and H-Ras transcrip- tion in MCF-7 cells.These findings suggest that metformin inhibits breast cancer at the cellular level.