[摘要] 目的：寻找用于肝癌诊断的miRNA分子靶标，探讨其在肝癌细胞增殖及细胞周期中的作用及其机制。方法：通过对TCGA数据库中377 例肝癌样本和37 例癌旁样本的miRNAs 表达数据资料进行统计分析，得到一组包含33 个差异表达的miRNA。对差异表达的miRNA采用受试者工作特征曲线（ROC曲线）和Kaplan-Meier 生存分析进行进一步的筛选，同时结合现有文献最终选择miR-451 作为研究目标。向人肝癌细胞株HepG2 转染pLVX-shRNA2-miR-451，使之过表达miR-451，通过CCK-8 细胞增殖实验检测其对HepG2 细胞增殖能力的影响，用流式细胞术观察对HepG2 细胞细胞周期的影响。结果：miR-451 在肝癌组织中的表达水平明显低于癌旁组织[ （473.40±390.24) vs (1 990.47±2 118.04)，P<0.05]，且可以作为肝癌诊断的标志物，ROC值为0.91（敏感度0.89，特异性0.87）。体外实验结果表明，过表达miR-451 后肝癌HepG2 细胞增殖能力明显降低[48 h：(0.69±0.04) vs(1.08±0.05)；72 h：(0.76±0.07) vs (1.52±0.02)；均P<0.01]，大量细胞被阻滞于S 期（P<0.05）。结论：miR-451 不但可以作为诊断肝癌和指示预后的生物标志物，还具有抑制肝癌细胞增殖的作用。

[Abstract] Objective: To explore the mRNA molecular targets for diagnosis of hepatic carcionoma and to investigate their functional roles in proliferation and cell cycle of hepatic cancer cells. Methods: Based on the statistical analysis of miRNA expression data from 377 hepatic carcionoma samples and 37 adjacent non-cancerous samples in TCGA database, a group of 33 differentially expressed miRNAs were identified. A further screen of these differentially expressed miRNAs was performed using the receiver operating characteristic curve (ROC curve) and Kaplan-Meier survival analysis; and with referring to the current publications, miR-451 was screened as the study subject. HepG2 cells were transfected with pLVX-shRNA2-miR-451 to over-express miR-451. The effect of miR-451 over-expression on the proliferation of HepG2 cell was determined by CCK-8 assay; while the effect on cell cycles was detected by flow cytometry.Results: The expression of miR-451 in the adjacent non-cancerous tissues was significantly lower than that in cancer tissues ([473.40±390.24] vs [1 990.47±2 118.04], P<0.05). MiR-451 could be used as an early diagnostic biomarker of hepatic carcionoma,with a high ROC value of 0.91 (sensitivity 0.89, specificity 0.87). The results of in vitro experiments showed that the proliferation of HepG2 cells was significantly decreased after miR-451 over-expression (48 h: [0.69±0.04] vs [1.08±0.05]; 72 h: [0.76±0.07] vs [1.52±0.02]; all P<0.01), and a large number of cells were blocked in S phase(P<0.05). Conclusion: miR-451 has the potential to be used as a biomarker for hepatic carcionoma diagnosis and prognosis; moreover, it also exhibits the inhibitory effect on proliferation of hepatic cancer cells.

国家自然科学基金资助项目（No. 81572782）