miR-520a调控RAB22A表达并抑制结肠癌细胞的增殖和侵袭

miR-520a inhibits cells proliferation and invasion through regulating RAB22A expression in colon cancer

目的:探讨miR-520a对结肠癌生物学行为的影响及其对RAB22A表达的调控。方法:应用分子生物学技术构建miR-520a的表达质粒(miR-520a)及抑制剂(anti-miR-520a),应用MTT和Transwell探讨miR-520a对结肠癌细胞株增殖和侵袭的影响。实时荧光定量PCR和蛋白印迹检测转染miR-520a对RAB22A的mRNA和蛋白表达水平的影响,构建RAB22A的野生型及突变型3’-UTR报告基因,报告基因分析miR-520a对RAB22A的调控。结果:miR-520a可以显著抑制结肠癌细胞的增殖和侵袭。蛋白印迹显示miR-520a可以显著抑制RAB22A的蛋白表达水平,而对mRNA表达无显著影响。报告基因分析显示miR-520a能够下调RAB22A的野生型3’-UTR报告基因的荧光表达,而对突变型报告基因的荧光表达影响不大。结论:miR-520a可能通过转录后调控癌基因RAB22A的表达抑制结肠癌细胞的增殖和侵袭,在结肠癌中发挥抑癌基因功能。

Objective:To investigate the effect of miR-520 a on behavior of colon cancer and its post-transcriptional regulation of RAB22 A expression.Methods:After construction of miR-520 a expression vector(miR-520 a) and miR-520 a inhibitor(anti-miR-520 a),the effect of miR-520 a on proliferation and invasion of colon cancer cell line SW480 was detected by MTT and Transwell respectively.Regulation of miR-520 a on expression of RAB22 A was investigated by real time PCR,Western blot and luciferase reporter assay system.Results:miR-520 a inhibited proliferation and invasion in SW480.Moreover,real time PCR and Western blot revealed that miR-520 a down-regulated the expression of RAB22 A protein,but had no effect on RAB22 A mRNA expression in vitro.Luciferase reporter assay confirmed that miR-520 a regulated RAB22 A expression through certain sequence in 3’-UTR.Conclusion:miR-520 a inhibits proliferation and invasion possibly through post-transcriptionally regulating expression of RAB22 A oncogene,suggesting miR-520 a functions as a tumor suppressor in colon cancer.