Zhang Xianxiang, Xu Ji, Jiang Tao, Liu Guangwei, Wang Dongsheng, Lu Yun
Department of General Surgery, The Affiliated Hospital of Qingdao University Qingdao 266555, China.
Air Force AM Evaluation and Training Center of Qingdao Qingdao 266071, China.
Am J Cancer Res. 2016 Nov 1;6(11):2631-2640. eCollection 2016.
Colorectal cancer (CRC) is a prevalent cancer with high mortality worldwide. This study was aimed to explore the functional effects of microRNA-195 (miR-195) on CRC cells and the underling mechanism involved. quantitative PCR (qPCR) was performed to monitor the expression of miR-195 in CRC tissues and cell lines. SW480 and SW620 cells were transfected with either miR-195 mimic or antisense oligonucleotides (ASO) of miR-195. Then cell viability, cell cycle and the expressions of CyclinB1, CyclinD1 and Cyclin-Dependent Kinase 2 (CDK2) were respectively detected by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyltetrazolium bromide (MTT), flow cytometry, qPCR and Western blot. A target of miR-195 was predicted and verified by using TargetScan and microRNA database, Dual-Luciferase reporter assay, qPCR and Western blot. Further, the functions of the target on cell viability and cell cycle were detected by transfection with its expression vector. Moreover, the expressions of Wnt/β-catenin pathway proteins were detected by qPCR and Western blot. Results show that MiR-195 was decreased during CRC, and miR-195 overexpression inhibited cell viability, arrested cells in G2/M phase, and down-regulated CyclinB1, CyclinD1 and CDK2 ( < 0.05 or < 0.01). Fibroblast growth factor 2 (FGF2) was a direct target of miR-195 and alleviated the inhibitive effects of miR-195 on cell viability and cell cycle progression ( < 0.05 or < 0.01). Further, miR-195 specifically regulated Wnt/β-catenin pathway proteins ( < 0.01). All these findings suggest that miR-195 suppressed CRC cells proliferation via targeting FGF2 and blocking Wnt/β-catenin pathway.
结直肠癌(CRC)是一种在全球范围内普遍存在且死亡率很高的癌症。本研究旨在探讨微小RNA-195(miR-195)对结直肠癌细胞的功能影响及其潜在机制。采用定量聚合酶链反应(qPCR)监测miR-195在结直肠癌组织和细胞系中的表达。用miR-195模拟物或miR-195反义寡核苷酸(ASO)转染SW480和SW620细胞。然后分别通过3-(4,5-二甲基-2-噻唑基)-2,5-二苯基四氮唑溴盐(MTT)法、流式细胞术、qPCR和蛋白质免疫印迹法检测细胞活力、细胞周期以及细胞周期蛋白B1(CyclinB1)、细胞周期蛋白D1(CyclinD1)和细胞周期蛋白依赖性激酶2(CDK2)的表达。利用TargetScan和微小RNA数据库、双荧光素酶报告基因检测、qPCR和蛋白质免疫印迹法预测并验证miR-195的一个靶标。此外,通过转染其表达载体检测该靶标对细胞活力和细胞周期的作用。而且,通过qPCR和蛋白质免疫印迹法检测Wnt/β-连环蛋白信号通路相关蛋白的表达。结果显示,在结直肠癌中miR-195表达降低,miR-195过表达抑制细胞活力,使细胞停滞于G2/M期,并下调CyclinB1、CyclinD1和CDK2的表达(P<0.05或P<0.01)。成纤维细胞生长因子2(FGF2)是miR-195的直接靶标,可减轻miR-195对细胞活力和细胞周期进程的抑制作用(P<0.05或P<0.01)。此外,miR-195特异性调节Wnt/β-连环蛋白信号通路相关蛋白的表达(P<0.01)。所有这些发现表明,miR-195通过靶向FGF2并阻断Wnt/β-连环蛋白信号通路抑制结直肠癌细胞增殖。