miR-18b增强乳腺癌MDA-MB-231细胞对顺铂化疗敏感性的作用及其机制

目的:探讨miR-18b在三阴性乳腺癌MDA-MB-231细胞对顺铂(DDP)化疗敏感性中的作用,阐明其可能的机制。方法:乳腺癌MDA-MB-231细胞根据转染条件分为MDA-MB-231组、MDA-MB-231+DDP组、MDA-MB-231-NC组、MDA-MB-231-NC+DDP组、MDA-MB-231 mimic组和MDA-MB-231 mimic+DDP组。采用生物信息学方法预测的miR-18b的靶基因;荧光素酶报告基因分析验证miR-18b与靶基因3'UTR的结合;应用qRT-PCR法检测各组MDA-MB-231细胞中miR-18b的表达水平;Western blotting法检测MDA-MB-231细胞中ATM蛋白表达水平;CCK-8法检测各组细胞的生长抑制率。结果:荧光素酶实验报告验证ATM为miR-18b的靶基因,并与ATM 3'UTR序列部分结合;与MDA-MB-231-NC组比较,MDA-MB-231 mimic组和MDA-MB-231 mimic+DDP组细胞中miR-18b的表达水平升高(P<0.05);Western blotting法检测,与MDA-MB-231组比较,MDA-MB-231+DDP组细胞中ATM蛋白表达水平升高(P<0.05);与MDA-MB-231-NC组比较,MDA-MB-231 mimic组细胞中ATM蛋白表达水平降低(P<0.05);与MDA-MB-231-NC+DDP组比较,MDA-MB-231 mimic+DDP组细胞中ATM蛋白表达水平降低(P<0.05);CCK-8法检测,与MDA-MB-231 NC组比较,经不同浓度DDP作用后,MDA-MB-231 mimic组细胞生长抑制率均升高。结论:miR-18b通过靶向调控ATM蛋白增强乳腺癌MDA-MB-231细胞对DDP的化疗敏感性。

Enhancement effect of miR-18b on chemosensitivity of human breast cancer MDA-MB-231 cells to DDP and its mechanism

Objective To investigate the effect of miR-18b on the chemosensitivity of human breast cancer MDA-MB-231 cells,and to elucidate its possible mechanism.Methods The breast cancer MDA-MB-231 cells were divided into MDA-MB-231 group,MDA-MB-231+DDP group,MDA-MB-231-NC group,MDA-MB-231-NC+DDP group,MDA-MB-231 mimic group,and MDA-MB-231 mimic+DDP group.The target gene of miR-18b was predicted by bioinformatics method;Dual-luciferase Reporter Assay was used to demonstrate the binding of miR-18b 3' UTR of targets;Western blotting method was used to analyze the expression levels of ATM protein;qRT-PCR method was used to detect the expression levels of miR-18b in MDA-MB-231 cells;CCK-8 method was used to detect the inhibitory rate of growth of MDA-MB-231 cells.Results The Luciferase results showed that the ATM was the target gene of miR-18b-MB-231,which combined with the ATM 3'UTR sequence part;compared with MDA-MB-231 group, the expression levels of miR-18b in the MDA-MB-231 cells in MDA-MB-231 mimic group and MDA-MB-231 mimic+DDP group were increased(P<0.05).The Western blotting results showed that comared with MDA-MB-231 group,the expression level of ATM protein in MDA-MB-231 group was increased(P<0.05).Compared with MDA-MB-231-NC group,the expression level of ATM protein of the cells in MDA-MB-231 mimic group was decreased(P<0.05);compared with MDA-MB-231-NC+DDP group,the expression level of ATM protein of the cells in MDA-MB-231 mimic+DDP group was decreased(P<0.05).The CCK-8 results showed that compared with MDA-MB-231-NC group,after treated with different concentrations of DDP,the inhibitory rates of the proliferation of the cells in MDA-MB-231 mimic group were increased.Conclusion miR-18b can enhance the chemosensitivity of human breast cancer MDA-MB-231 cells to DDP through target-regulating ATM protein.