MicroRNA-4465对结肠癌细胞凋亡和侵袭的影响

目的探讨microRNA-4465(miR-4465)在结肠癌细胞中的生物学作用及其潜在的调控机制。方法qPCR检测SW480、HT-29和HCT-116三种结肠癌细胞中的miR-4465水平,然后在HCT-116细胞中过表达miR-4465,MTT法和流式细胞仪分别检测细胞活性和细胞凋亡,试剂盒检测Caspase-3活性,Transwell实验检测细胞侵袭,荧光素酶报告基因检测分别测定miR-4465与HMGA1、HMGA2或EZH2的靶向关系。Westernblot和qPCR分别检测HMGA1、HMGA2、EZH2的蛋白和mRNA表达水平。结果在SW480、HT-29和HCT-116三种结肠癌细胞中,miR-4465表达均显著下调(P<0.05)。过表达miR-4465能够降低结肠癌HCT-116细胞活性,提高细胞凋亡率,增强Caspase-3活性,抑制细胞侵袭(均P<0.05)。miR-4465直接靶向HMGA1、HMGA2或EZH2的3'-非翻译区(3'-UTR),进而负向调控其表达。结论miR-4465过表达能够降低结肠癌细胞活性,促进细胞凋亡并抑制细胞侵袭,这可能与负向调控HMGA1、HMGA2或EZH2基因有关。

Effects of MicroRNA-4465 on Apoptosis and Invasion of Colon Cancer Cells

Objective To investigate the biological roles and potential regulatory mechanisms of microRNA-4465 (miR-4465) in colon cancer cells. Methods qPCR was used to detect the miR-4465 levels in SW480, HT-29 and HCT-116 cells; then miR-4465 was overexpressed in HCT-116 cells, and cell viability and apoptosis were detected by MTT assay and flow cytometry, respectively; the Caspase-3 activity was measured by a kit; the cell invasion was detected by Transwell assay; the targeting relation between miR-4465 and HMGA1, HMGA2, EZH2 were determined by the luciferase reporter gene assay. The protein and mRNA expression levels of HMGA1, HMGA2 and EZH2 were detected by Western blot and qPCR, respectively. Results The expression of miR-4465 was significantly down-regulated in SW480, HT-29 and HCT-116 cells (P<0.05). Overexpression of miR-4465 reduced the viability of HCT-116 cells, increased cell apoptosis, enhanced Caspase-3 activity and suppressed cell invasion (all P<0.05). MiR-4465 directly targeted 3’-UTR of HMGA1, HMGA2 or EZH2, thereby regulating their expression negatively. Conclusion MiR-4465 overexpression could reduce the viability of colon cancer cells, promote cell apoptosis and suppress cell invasion, which may be related to the negative regulation of HMGA1, HMGA2 or EZH2.