miRNA-381 对胃癌细胞增殖和侵袭的影响及机制

目的 观察miRNA-381 对胃癌细胞增殖和侵袭的影响，并探讨其作用机制。方法 应用实时荧光定量聚合酶链反应（qRT-PCR）检测胃癌细胞系AGS、MGC-803、Hs746T 及BSG823 和正常胃黏膜上皮细胞系RGM-1 中miRNA-381 的表达；将AGS 细胞系分成两组，阴性对照组和miRNA-381 模拟物组，采用Lipofectamine TM 2000 分别转染miRNA-381 scramble 及mimics，采用CCK-8、Transwell 实验测定两组细胞增殖和侵袭的影响，Western blot 检测两组细胞肝受体类似物1（LRH-1）和扭曲相关蛋白1（Twist1）表达水平。结果 胃癌细胞系AGS、MGC-803、Hs746T 及BSG823 中miRNA-381 相对表达量较正常胃黏膜上皮细胞系RGM-1 为低。miRNA-381 模拟物组在转染后72 和96 h OD 450 nm 值低于阴性对照组（P <0.05）；阴性对照组侵袭细胞数为（79.6±7.2）个，miRNA-381 模拟物组侵袭细胞数为（31.70±4.2）个，miRNA-381 模拟物组侵袭细胞数少于阴性对照组（P <0.01）；miRNA-381 模拟物组LRH-1 蛋白相对表达量为（0.39±0.04），阴性对照组为1.0，miRNA-381 模拟物组LRH-1 蛋白相对表达量低于阴性对照组（P <0.01）；miRNA-381 模拟物组Twist1蛋白相对表达量为（0.51±0.05），阴性对照组为1.0，miRNA-381 模拟物组Twist 1 蛋白相对表达量低于阴性对照组（P <0.01）。结论 miRNA-381 低表达于胃癌细胞系，miRNA-381 过表达可抑制胃癌细胞增殖和侵袭能力，其机制可能与下调LRH-1 和Twist1 的表达有关。

Role of miR-381 on cell proliferation and invasion of gastric cancer

Objective To investigate the role of miR-381 on proliferation and invasion of gastric carcinoma cells and its potential mechanism. Methods The expression of miR-381 in normal and gastric cell lines were determined by qRT-PCR. The AGS cell line was divided into two groups including negative control group which was transfected with miR-381 vehicle, and miR-381 mimics group which was transfected with miR-381 mimics through Lipofectamine 2000. Proliferation and invasion rate were evaluated with CCK8 and Transwell assay, respectively.LRH-1 and Twist1 protein levels were measured by Western blot. Results Substantially reduction of miR-381 was found in gastric cancer cell line when compared with normal gastric cell line (P < 0.05). The number of invasive cell in miR-381 mimics group was decreased significantly compared with negative control group (31.70 ± 4.2) vs (79.6 ± 7.2), P < 0.01]. Expression levels of LRH-1 and Twist1 significantly dropped in miR-381 mimics group in comparison with those in negative control group (0.39 ± 0.04) vs (1.0 ± 0.0), (0.51 ± 0.05) vs (1.0 ± 0.05), P < 0.01,respectively]. Conclusions Low expression of miR-38 is identified in gastric cell line. Up-regulated expression of miR-381 contributes to inhibition of cellular proliferation and invasion activity through LRH-1and Twist signal pathway.