miR-130a靶向G3BP2促进乳腺癌侵袭

miR-130a promotes breast cancer invasion by targeting G3BP2

目的探讨基因预测软件Targetscan预测到的微小RNA-130a如何调节GTP酶激活蛋白SH3功能区结合蛋白2(GTPase activating protein SH3 binding protein 2,G3BP2)的表达,进而影响乳腺癌细胞的侵袭。方法应用实时荧光定量PCR(qRT-PCR)检测正常乳腺上皮及乳腺癌细胞系中miR-130a的表达水平;蛋白质印迹法(Western blot)检测改变miR-130a表达水平对乳腺癌细胞株MCF-7和MDA-MB-231中G3BP2及上皮间质转化(epithelial-to-mesenchymal transition,EMT)相关蛋白的影响;双荧光素酶报告基因实验检测miR-130a是否能与G3BP2靶向结合,以及Transwell侵袭实验检测miR-130a表达水平与MCF-7和MDA-MB-231细胞侵袭能力的关系。结果qRT-PCR显示miR-130a表达量在高侵袭乳腺癌细胞株明显高于低侵袭乳腺癌细胞株MCF-7及正常乳腺上皮细胞;Western blot检测显示,miR-130a负向调控G3BP2的表达并促进乳腺癌细胞发生EMT;qRT-PCR显示改变乳腺癌细胞内miR-130a表达后G3BP2 mRNA基本没有变化;双荧光素酶报告基因结果显示,miR-130a能与G3BP2 mRNA的3’UTR结合;Transwell侵袭实验显示,miR-130a促进乳腺癌细胞的体外侵袭。结论miR-130a通过靶向结合G3BP2 mRNA的3’UTR区,在翻译水平抑制G3BP2表达后促进乳腺癌细胞发生EMT,从而促进乳腺癌细胞的侵袭。

Objective To investigate how Targetscan predicted miR-130a regulates GTPase activating protein SH3 binding protein 2(G3BP2)expression and further affects the invasion of breast cancer cells.Methods Quantitative real-time PCR(qRT-PCR)was used to detect the expression of miR-130a in normal breast epithelial cells and breast cancer cells;miR-130a and its inhibitor plasmids were transfected into breast cancer cell lines MCF-7 and MDA-MB-231,and the expression of G3BP2 and epithelial-to-mesenchymal transition(EMT)related proteins in each group of cells was detected by Western blot;whether miR-130a could bind to G3BP2 was detected by dual-luciferase reporter gene test;and the invasion ability of each group was detected by Transwell invasion test.Results qRT-PCR showed that the expression of miR-130a in high invasive breast cancer cells was significantly higher than that in weak invasive MCF-7 cells and normal breast epithelial cells.MiR-130a negatively regulated the expression of G3BP2 protein and promoted the production of EMT related proteins.qRT-PCR showed that there was no change in G3BP2 mRNA after altering miR-130a level in breast cancer cells.The results of dual-luciferase reporter gene test showed that miR-130a could bind to the 3’UTR of G3BP2 mRNA and inhibit its luciferase activity.This inhibition effect disappeared when the 3’UTR of G3BP2 was mutated.Transwell invasion assay showed that miR-130a promoted the invasion ability of breast cancer cells in vitro.Conclusion miR-130a can promote EMT and the invasion ability of breast cancer cells by targeting the 3’UTR region of G3BP2 mRNA.