miR-141表达异常对人肝癌细胞恶性生物学表型的影响

 目的: 研究微小RNA-141(miR-141)在人肝癌细胞和正常胎肝细胞中的表达,同时分析miR-141表达异常对人肝癌细胞恶性生物学表型的影响。方法: 分别提取人肝癌细胞SMMC-7721和正常肝细胞HL-7702的总RNA,采用实时荧光定量PCR法检测miR-141的表达。采用脂质体介导的转染方法分别将miR-141 mimic转染SMMC-7721细胞,将miR-141 inhibitor转染HL-7702细胞;MTS试剂盒和BrdU-ELISA检测细胞增殖能力,流式细胞术检测转染前后细胞周期和凋亡率的变化。Transwell实验检测miR-141表达变化对细胞体外迁移能力的影响。结果: miR-141在SMMC-7721细胞中的表达较HL-7702细胞明显下降。与空白组、脂质体组和阴性对照组相比,转染25 nmol/L miR-141 mimic的SMMC-7721细胞中,细胞增殖速度减慢,S期细胞比例降低,凋亡细胞比例上升,细胞体外迁移能力下降;转染50 nmol/L miR-141 inhibitor的HL-7702细胞中,细胞增殖速度加快,S期细胞比例上升,凋亡细胞比例下降,细胞体外迁移能力增强。结论: miR-141在人肝癌细胞中表达下降,上调miR-141表达可抑制肝癌细胞体外增殖活性和迁移能力,影响细胞周期和凋亡。在肝癌发病进程中,miR-141可能扮演抑癌基因的角色。

Effect of abnormal expression of miR-141 on malignant biological behaviors of human hepatocarcinoma cells

AIM: To investigate the expression of microRNA-141 (miR-141) in human hepatocellular carcinoma (HCC) cell line SMMC-7721 and normal hepatocyte line HL-7702, and to analyze the effect of abnormal expression of miR-141 on the malignant biological behaviors of human hepatocarcinoma cells. METHODS: The RNA from SMMC-7721 cells and HL-7702 cells was extracted. SYBR Green real-time PCR was performed to detect the expression of miR-141. Synthetic miR-141 mimic and its negative control were transfected into the SMMC-7721 cells, and miR-141 inhibitor and its negative control were transfected into the HL-7702 cells by the method of Lipofectamine. After transfection, MTS assay and BrdU-ELISA were employed to evaluate the effect of miR-141 on the cell proliferation. Flow cytometry was used to detect cell cycle and apoptosis. The changes of migration ability were investigated by Transwell invasion assay. RESULTS: The expression of miR-141 in the SMMC-7721 cells was significantly lower than that in the HL-7702 cells (P < 0.05). Compared with blank group, Lipofectamine group and negative control group, the proliferation of the SMMC-7721 cells transfected with 25 nmol/L miR-141 mimic was significantly inhibited in a time-dependent manner (P < 0.05). The percentages of G₁ phase cells and early apoptotic rate were significantly increased when miR-141 was up-regulated, but the migration ability was inhibited (P < 0.05). Compared with blank group, Lipofectamine group and negative control group, the proliferation of HL-7702 cells transfected with 50 nmol/L miR-141 inhibitor was significantly increased in a time-dependent manner (P < 0.05). When miR-141 was down-regulated, the percentages of G₁ phase cells and early apoptotic rate were significantly decreased, but the migration ability was enhanced (P < 0.05). CONCLUSION: miR-141 is down-regulated in human hepatocarcinoma cell line. Up-regulation of miR-141 will not only inhibit cell proliferation and migration ability, but also affect the cell cycle and apoptosis of SMMC-7721 cells. miR-141 may function as a tumor suppressor gene during HCC development.