Zhu Weiyou, Qian Jing, Ma Ling, Ma Pei, Yang Fengming, Shu Yongqian
Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, P.R. China.
Oncology Center, Shengze Hospital of Nanjing Medical University, Wujiang, Jiangsu Province, P.R. China.
Oncotarget. 2017 May 22;8(39):65218-65229. doi: 10.18632/oncotarget.18060. eCollection 2017 Sep 12.
BACKGROUND & AIMS: The miRNAs are demonstrated to be involved in the carcinogenesis of hepatocellular carcinoma (HCC) and some exhibit potential value for oncotherapy. This study was designed to explore the role of miR-346 in the pathogenesis of hepatocellular carcinoma.
High throughput screening was employed following with Real time-PCR to investigate the candidate miRNAs. 5-ethynyl-2-deoxyuridine (EdU) assay, CCK-8, transwell assay, cell cycle assay, luciferase reporter assay, western blot and mice xenotransplantation model were performed in the present study.
We found miR-346 was significantly down-regulated in the HCC tissues compared with the non-tumor controls and was associated with the tumor size and TNM grade. Additionally, the and assays confirmed that miR-346 suppressed the proliferation of HCC. Then, bioinformatic algorithms and luciferase reporter assays proved that miR-346 directly targeted SET and MYND domain containing 3(SMYD3). We also performed the rescue experiments by inhibiting the expression of SMYD3 and found the down-regulation of SMYD3 could neutralize the inhibitory effects of miR-346 on HCC. At last, the cox proportional hazards analysis showed that low expression of miR-346 was an an independent prognostic factor for HCC.
Our findings illuminated miR-346 targeting SMYD3 to inhibit the proliferation of HCC and its down-regulation predicts a poor prognosis.
微小RNA（miRNA）已被证明参与肝细胞癌（HCC）的致癌过程，一些miRNA在肿瘤治疗中显示出潜在价值。本研究旨在探讨miR-346在肝细胞癌发病机制中的作用。
采用高通量筛选结合实时定量聚合酶链反应（Real time-PCR）来研究候选miRNA。本研究进行了5-乙炔基-2'-脱氧尿苷（EdU）检测、细胞计数试剂盒-8（CCK-8）检测、Transwell检测、细胞周期检测、荧光素酶报告基因检测、蛋白质免疫印迹法（western blot）以及小鼠异种移植模型实验。
我们发现与非肿瘤对照相比，miR-346在HCC组织中显著下调，且与肿瘤大小和TNM分级相关。此外，EdU检测和CCK-8检测证实miR-346抑制HCC的增殖。然后，生物信息学算法和荧光素酶报告基因检测证明miR-346直接靶向含SET和MYND结构域蛋白3（SMYD3）。我们还通过抑制SMYD3的表达进行了挽救实验，发现下调SMYD3可抵消miR-346对HCC的抑制作用。最后，Cox比例风险分析表明miR-346低表达是HCC的独立预后因素。
我们的研究结果表明miR-346通过靶向SMYD3抑制HCC的增殖，其下调预示着预后不良。
