Jia Pengbo, Wei Guangbing, Zhou Cancan, Gao Qi, Wu Yunhua, Sun Xuejun, Li Xuqi
1 Department of General Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
2 Department of General Surgery, The First People's Hospital of Xianyang City, Xianyang, China.
Technol Cancer Res Treat. 2018 Jan 1;17:1533034618765221. doi: 10.1177/1533034618765221.
MicroRNAs are involved in hepatocellular carcinoma metastasis, a principal cause of hepatocellular carcinoma-related death in patients worldwide. MiR-212 is a microRNA that has been identified in several types of cancers and is postulated to influence cell signaling and subsequent malignant pathogenesis. Despite emerging reports suggesting that miR-212 plays a significant role in the onset, progression, and migration of these types of malignant tumors, its involvement in the development of hepatocellular carcinoma has not been fully elucidated.
Quantitative reverse transcription polymerase chain reaction, wound healing, transwell migration and invasion assays, Western blotting, and xenograft tumor growth models were performed to test the expression levels and functions of miR-212 in hepatocellular carcinoma. Luciferase reporter assay, quantitative reverse transcription polymerase chain reaction, Western blotting, and immunohistochemistry were used to identify and verify the target of miR-212.
In this study, we identify significant repression of miR-212 in hepatocellular carcinoma and demonstrate that overexpression of miR-212 inhibits the migration of hepatocellular carcinoma cells in vitro and in vivo. Furthermore, we identify forkhead box M1, whose expression is inversely related to that of miR-212, as a direct target of miR-212. Additionally, reexpression of forkhead box M1 rescues the miR-212-mediated inhibition of cell migration. We observed that inhibition of miR-212 activates forkhead box M1 but inhibits the Wnt/β-catenin pathway by suppressing Wnt, LEF-1, c-Myc, and nuclear β-catenin. Finally, in vivo studies confirmed the inhibitory effect of miR-212 on hepatocellular carcinoma growth.
Our present findings indicate that miR-212 is a potential prognostic biomarker of hepatocellular carcinoma and that the miR-212/forkhead box M1 regulatory axis may represent a new therapeutic objective for hepatocellular carcinoma treatment.
微小RNA参与肝细胞癌转移，这是全球范围内肝细胞癌相关死亡的主要原因。MiR-212是一种在多种癌症中已被鉴定出的微小RNA，据推测其可影响细胞信号传导及后续的恶性发病机制。尽管越来越多的报道表明MiR-212在这些类型恶性肿瘤的发生、发展和迁移中发挥重要作用，但其在肝细胞癌发生发展中的作用尚未完全阐明。
采用定量逆转录聚合酶链反应、伤口愈合实验、Transwell迁移和侵袭实验、蛋白质免疫印迹法以及异种移植瘤生长模型来检测MiR-212在肝细胞癌中的表达水平及功能。利用荧光素酶报告基因实验、定量逆转录聚合酶链反应、蛋白质免疫印迹法和免疫组织化学来鉴定并验证MiR-212的靶标。
在本研究中，我们发现肝细胞癌中MiR-212显著下调，并证明MiR-212过表达在体外和体内均可抑制肝癌细胞迁移。此外，我们鉴定出叉头框M1（FOXM1）是MiR-212的直接靶标，其表达与MiR-212呈负相关。另外，叉头框M1的重新表达可挽救MiR-212介导的细胞迁移抑制作用。我们观察到抑制MiR-212可激活叉头框M1，但通过抑制Wnt、淋巴样增强因子1（LEF-1）、原癌基因c-Myc和核β-连环蛋白来抑制Wnt/β-连环蛋白信号通路。最后，体内研究证实了MiR-212对肝细胞癌生长的抑制作用。
我们目前的研究结果表明，MiR-212是肝细胞癌潜在的预后生物标志物，且MiR-212/叉头框M1调控轴可能是肝细胞癌治疗的新靶点。
