miR-137通过TWIST1调控乳腺癌MDA-MB-231细胞侵袭、迁移及凋亡

miR-137 regulates invasion, migration and apoptosis of breast cancer MDA-MB-231 cells through TWIST1

目的:探讨微小RNA-137(miR-137)对乳腺癌细胞侵袭、迁移及凋亡的影响和分子机制。方法:在乳腺癌MDA-MB-231细胞中转染miR-137模拟物(miR-137 mimics),RT-qPCR检测miR-137表达量,流式细胞术检测细胞凋亡,Transwell小室检测侵袭和迁移,Western blot检测基质金属蛋白酶9(MMP-9)、cleaved caspase-3(C-caspase-3)和Bax的蛋白水平。生物信息学软件预测TWIST1可能是miR-137的靶基因后用萤光素酶报告基因鉴定。Western blot检测miR-137 mimics对TWIST1蛋白表达影响。在乳腺癌细胞中共转染TWIST1过表达载体和miR-137 mimics,测定细胞凋亡、侵袭、迁移及MMP-9、C-caspase-3、Bax蛋白水平的变化。结果:转染miR-137 mimics后的乳腺癌细胞中miR-137水平升高,细胞凋亡率升高,细胞侵袭和迁移能力降低,C-caspase-3和Bax的蛋白水平增高,MMP-9蛋白表达减少(P<0.05)。萤光素酶报告载体鉴定显示miR-137靶向调控TWIST1,并且miR-137 mimics能够抑制乳腺癌细胞中TWIST1表达。与共转染阴性对照载体和miR-137 mimics的细胞比较,TWIST1过表达载体和miR-137 mimics共转染后的乳腺癌细胞TWIST1和MMP-9蛋白表达水平升高,C-caspase-3和Bax蛋白水平减少,细胞凋亡率降低,细胞侵袭和迁移能力增强(P<0.05)。结论:miR-137靶向TWIST1抑制乳腺癌细胞侵袭迁移并诱导细胞凋亡。

AIM:To investigate the effect and its molecular mechanism of microRNA-137(miR-137)on the invasion,migration abilities and apoptosis of breast cancer cells.METHODS:miR-137 mimimics were transfected into the breast cancer MDA-MB-231 cells.The expression of miR-137 was detected by RT-qPCR.Apoptosis was analyzed by flow cytometry.The invasion and migration abilities were detected by Transwell assays.The protein levels of matrix metalloproteinase 9(MMP-9),cleaved caspase-3(C-caspase-3)and Bax were determined by Western blot.Bioinformatics software was used to predict that TWIST1 might be the target gene of miR-137 and then it was conformed by luciferase reporter gene identification.The effect of miR-137 mimics on TWIST1 protein expression was evaluated by Western blot.TWIST1 over-expression vector and miR-137 mimics were co-transfected into the MDA-MB-231 cells,and then the apoptosis,invasion,migration abilities and the protein levels of MMP-9,C-caspase-3 and Bax were determined.RESULTS:In the miR-137 mimics transfected MDA-MB-231 cells,the expression level of miR-137 and the apoptosis rate were increased,the cell invasion and migration abilities were decreased,the protein levels of C-caspase-3 and Bax were increased,the protein expression of MMP-9 was decreased(P<0.05).In addition,the target regulation of TWIST1 by miR-137 was identified by luciferase reporter assay.Moreover,the expression of TWIST1 in the MDA-MB-231 cells was inhibited by miR-137 mimics.Compared with the MDA-MB-231 cells co-transfected with negative control vector and miR-137 mimics,the protein expression levels of TWIST1 and MMP-9 in the MDA-MB-231 cells co-transfected with TWIST1 over-expression vector and miR-137 mimics were increased,the protein levels of C-caspase-3 and Bax and the apoptosis rate were decreased,the cell invasion and migration abilities were increased.CONCLUSION:miR-137 inhibits the invasion,migration abilities and induces apoptosis of breast cancer cells through targeting TWIST1.