Basic Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 21, 2016; 22(23): 5364-5373
Published online Jun 21, 2016. doi: 10.3748/wjg.v22.i23.5364
MicroRNA-548a-5p promotes proliferation and inhibits apoptosis in hepatocellular carcinoma cells by targeting Tg737
Ge Zhao, Ting Wang, Qi-Ke Huang, Meng Pu, Wei Sun, Zhuo-Chao Zhang, Rui Ling, Kai-Shan Tao
Ge Zhao, Qi-Ke Huang, Meng Pu, Wei Sun, Zhuo-Chao Zhang, Kai-Shan Tao, Department of Hepatobiliary Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an 710032, Shaanxi Province, China
Ting Wang, Rui Ling, Department of Thyroid, Breast and Vascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an 710032, Shaanxi Province, China
Author contributions: Zhao G, Wang T and Huang QK performed the majority of experiments; Zhao G, Pu M, Sun W and Zhang ZC provided technical supports and were also involved in editing the manuscript; Zhao G and Tao KS collected all the human materials and provided financial support for this work; Ling R and Tao KS designed the study and wrote the manuscript.
Supported by National Natural Science Foundation of China, No. 81272648.
Institutional review board statement: All procedures were performed in accordance with a protocol approved by Institutional Medical Ethics Committee (No. XJYYLL-2012475).
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Institutional Animal Care and Use Committee of the Fourth Military Medical University (No. 20120211121). All the patients provided written informed consent for the use of specimens included in the study.
Conflict-of-interest statement: Tao KS has received research funding from the National Natural Science Foundation of China. The authors have no conflicts of interest to disclose.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at taoks2015@sina.com. Participants gave informed consent for data sharing. No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Kai-Shan Tao, MD, PhD, Department of Hepatobiliary Surgery, Xijing Hospital, Fourth Military Medical University, 17 Changle West Road, Xi’an 710032, Shaanxi Province, China. taoks2015@sina.com
Telephone: +86-29-84775259 Fax: +86-29-84775259
Received: February 14, 2016
Peer-review started: February 15, 2016
First decision: March 7, 2016
Revised: April 4, 2016
Accepted: May 4, 2016
Article in press: May 4, 2016
Published online: June 21, 2016
Abstract

AIM: To investigate whether Tg737 is regulated by microRNA-548a-5p (miR-548a-5p), and correlates with hepatocellular carcinoma (HCC) cell proliferation and apoptosis.

METHODS: Assays of loss of function of Tg737 were performed by the colony formation assay, CCK assay and cell cycle assay in HCC cell lines. The interaction between miR-548a-5p and its downstream target, Tg737, was evaluated by a dual-luciferase reporter assay and quantitative real-time polymerase chain reaction. Tg737 was then up-regulated in HCC cells to evaluate its effect on miR-548a-5p regulation. HepG2 cells stably overexpressing miR-548a-5p or miR-control were also subcutaneously inoculated into nude mice to evaluate the effect of miR-548a-5p up-regulation on in vivo tumor growth. As the final step, the effect of miR-548a-5p on the apoptosis induced by cisplatin was evaluated by flow cytometry.

RESULTS: Down-regulation of Tg737, which is a target gene of miR-548a-5p, accelerated HCC cell proliferation, and miR-548a-5p promoted HCC cell proliferation in vitro and in vivo. Like the down-regulation of Tg737, overexpression of miR-548a-5p in HCC cell lines promoted cell proliferation, increased colony forming ability and hampered cell apoptosis. In addition, miR-548a-5p overexpression increased HCC cell growth in vivo. MiR-548a-5p down-regulated Tg737 expression through direct contact with its 3’ untranslated region (UTR), and miR-548a-5p expression was negatively correlated with Tg737 levels in HCC specimens. Restoring Tg737 (without the 3’UTR) significantly hampered miR-548a-5p induced cell proliferation, and rescued the miR-548a-5p induced cell proliferation inhibition and apoptosis induced by cisplatin.

CONCLUSION: MiR-548a-5p negatively regulates the tumor inhibitor gene Tg737 and promotes tumorigenesis in vitro and in vivo, indicating its potential as a novel therapeutic target for HCC.

Keywords: microRNA-548a-5p, Tg737, Proliferation, Apoptosis, Hepatocellular carcinoma cells

Core tip: Tg737 gene functions as a tumor suppresser in hepatocellular carcinoma (HCC). However, studies based on regulation of Tg737 were rare. MiR-548a-5p is a novel miRNA which negatively regulates Tg737 and promotes tumorigenesis in vitro and in vivo, indicating its potential as a novel therapeutic target for HCC.