过表达miR-18a靶向ATM对结肠癌细胞增殖和迁移的影响

Study on the Effect of Overexpression of miR-18a on Cellular Proliferation and Migration by Targeting ATM in Human Colorectal Cancer Cells

目的研究miR-18a通过靶基因共济失调-毛细血管扩张突变基因(ataxia telangiectasia mutated gene,ATM)调控结肠癌细胞的生物学特性。方法通过软件预测miR-18a其中一个靶基因。设计合成miR-18a的模拟剂(mimics)和抑制剂(inhibitor),通过转染不同组分上调或下调内源性miR-18a在结肠癌细胞株HCT116中的表达。采用实时荧光定量(qRT)-PCR、Western blot、MTT法、克隆形成实验、Transwell等方法,检测过表达miR-18a调控ATM基因的表达对体外结肠癌细胞增殖及迁移能力的影响。结果软件预测发现miR-18a的其中一个靶基因是ATM。通过瞬时转染,过表达内源性miR-18a,可降低HCT116细胞内靶基因ATM蛋白的表达水平。转染miR-18amimics后能够下调HCT116细胞的增殖活力,同时显著降低HCT116细胞的克隆形成能力、横向迁移能力及纵向侵袭能力,以上各项改变均与miR-18a过表达有关。结论证实了miR-18a通过负向调控ATM的表达,抑制结肠癌细胞HCT116的增殖和迁移能力。

Objective To study the regulation to colon cancer cellular biological properties through miR-18 a targeting ataxia-telangiectasia mutated gene（ATM）.Methods A target of miR-18 a was predicted by using bioinformatics tools.The miR-18 a mimics and inhibitors were designed and synthesized.The expression of endogenous miR-18 ain colon cancer cell line HCT116 was up-regulated or down-regulated by transfection.The effect of overexpression of miR-18 aon cellular proliferation,invasion and migration via regulation of ATM gene expression was confirmed in vitro by using qRT-PCR, Western blot, MTT assay,clone forming assay and Transwell method,respectively.Results ATM was identified as a potential target gene of miR-18 ain the bioinformatics analysis.In addition,through transient transfection leading to the overexpression of miR-18 ain HCT116cell,the expression level of ATM was decreased.Down-regulation of HCT116 cell proliferation activity while significantly reducing HCT116 cell clone forming ability,lateral migration ability and longitudinal invasion ability were observed after transfected with miR-18 amimics.All of the changes were related to the overexpression of miR-18 a.Conclusion miR-18 ainhibited the proliferation and migration of colon cance cell HCT116 through negative regulation of ATM expression.