二甲双胍通过NF-κB对乳腺癌细胞MDA-MB-435S的抑制作用

目的探讨二甲双胍对乳腺癌细胞MDA-MB-435S的抑制作用。方法将细胞分为四组:A组(对照组),B组(TNF-α组),C组(TNF-α+10mM二甲双胍组),D组(10mM二甲双胍组)。培养48h后,运用Western Blot检测各组乳腺癌细胞MDA-MB-435S中NF-κ B、Lin28B的表达情况,RT-PCR检测A组、D组乳腺癌细胞MDA-MB-435S中microRNA let-7下游基因HMGA2、H-Ras的转录水平。结果药物干预48h后,与A组相比,B组乳腺癌细胞中NF-κB和Lin28B的表达均明显上调(P<0.01),而D组细胞中NF-κ B(P<0.01)和Lin28B(P<0.01)表达明显下降。与B组相比,C组乳腺癌细胞中NF-κ B(P<0.05)和Lin28B(P<0.01)表达下调。D组乳腺癌细胞中与肿瘤细胞自我复制和多向分化潜能相关的基因HMGA2和H-Ras转录分别下降83%(t=6.2;P<0.05)和94%(t=34.5;P<0.01)。结论 10mM浓度的二甲双胍能够有效的降低NF-κB、Lin28B的表达,进一步抑制乳腺癌细胞中自我复制和多向分化潜能相关基因HMGA2和H-Ras的转录。

Objective To explore the mechanism that metformin inhibit breast cancer cell line MDA-MB-435 S. Methods We divided MDA- MB-435 S cells into four groups： A （control group）, B （TNF-α group）, C （TNF-α＋10 mM metformin group）, D （10 mM metformin group）. Four groups cells were cultivated with 48 h,we extract total protein from cells and detect the expression level of nuclear factor-kappa B（NF-κB） and Lin28 B by Western Blot, we also detect transcription level of HMGA2 and H-Ras which are regulated by microRNA let -7 in MDA-MB-435 S cells. Results After drug intervention 48 h cells, compared with group A,the expression level of NF-rd3（P〈0.01） and Lin28 B（P〈0.01） significantly decline in group D, while the expression level of NF-r,B（P〈0.01） and Lin28 B（P〈0.01） significantly remarkable rise in group B.Compared with group B,the expression level of NF-κB（P〈0.05） and Lin28 B（P〈 0.01） decline in group C. In group D, the transcription level of HMGA2 and H-Ras which are related with self-renewal and multipotential differentiation of breast cancer cells were down 83% （t=6.2;/）〈0.05） and 94%（t=-34.5; P〈0.05）. Conclusion The findings of the current study suggest that 10 mM metformin can effectively reduce the expression level of NF-κB and Lin28 B, further inhibit expression level of NF-rd3 which is actived by TNF-α. While metformin could inhibit transcription level of HMGA2 and H-Ras which are related to self-renewal and multipotential differentiation of breast cancer cells.