过表达miR-18a靶向ATM对结肠癌细胞增殖和迁移的影响

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-18a mimics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。

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

Objective To study the regulation to colon cancer cellular biological properties through miR-18a targeting ataxia-telangiectasia mutated gene (ATM). Methods A target of miR-18a was predicted by using bioinformatics tools. The miR-18a mimics and inhibitors were designed and synthesized. The expression of endogenous miR-18a in colon cancer cell line HCT116 was up-regulated or down-regulated by transfection. The effect of overexpression of miR-18a on 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-18a in the bioinformatics analysis. In addition, through transient transfection leading to the overexpression of miR-18a in HCT116 cell, 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-18a mimics. All of the changes were related to the overexpression of miR-18a. Conclusion miR-18a inhibited the proliferation and migration of colon cance cell HCT116 through negative regulation of ATM expression.