Retrospective Cohort Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 28, 2016; 22(24): 5589-5597
Published online Jun 28, 2016. doi: 10.3748/wjg.v22.i24.5589
miR-422a is an independent prognostic factor and functions as a potential tumor suppressor in colorectal cancer
Gui-Xi Zheng, Ai-Lin Qu, Yong-Mei Yang, Xin Zhang, Shou-Cai Zhang, Chuan-Xin Wang
Gui-Xi Zheng, Ai-Lin Qu, Yong-Mei Yang, Xin Zhang, Shou-Cai Zhang, Chuan-Xin Wang, Department of Clinical Laboratory, Qilu Hospital of Shandong University, Jinan 250012, Shandong Province, China
Author contributions: Zheng GX and Wang CX conceived the study, participated in its design and coordination and helped draft the manuscript; Zheng GX and Qu AL performed the experiments and analyses; Yang YM, Zhang X and Zhang SC were responsible for collection of samples and acquiring of clinical data; all authors read and approved the final manuscript.
Supported by the National Natural Science Foundation of China, No. 81472025; Outstanding Young Scientist Research Award Fund of Shandong Province, No. BS2014YY023; Projects of Medical and Health Technology Development Program of Shandong Province, No. 2014WS0124; Science Foundation of Qilu Hospital of Shandong University, No. 2015QLQN37; Fundamental Research of Shandong University and the National Key Clinical Medical Specialties Foundation.
Institutional review board statement: The study was reviewed and approved by the Institution Review Board of Qilu Hospital of Shandong University.
Informed consent statement: All study participants provided informed written consent prior to study enrollment.
Conflict-of-interest statement: No potential conflicts of interest relevant to this article exist.
Data sharing statement: 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: Chuan-Xin Wang, MD, PhD, Department of Clinical Laboratory, Qilu Hospital of Shandong University, 107 Wenhua Xi Road, Jinan 250012, Shandong Province, China. cxwang@sdu.edu.cn
Telephone: +86-531-86927544 Fax: +86-531-86927544
Received: March 11, 2016
Peer-review started: March 11, 2016
First decision: March 31, 2016
Revised: April 25, 2016
Accepted: May 21, 2016
Article in press: May 23, 2016
Published online: June 28, 2016
Abstract

AIM: To determine the expression of miR-422a in colorectal cancer (CRC) tissues and to further explore the prognostic value and function of miR-422a in CRC carcinogenesis.

METHODS: miR-422a expression was analyzed in 102 CRC tissues and paired normal mucosa adjacent to carcinoma by quantitative real-time PCR. The relationship of miR-422a expression with clinicopathological parameters was also analyzed. Kaplan-Meier analysis and Cox multivariate analysis were performed to estimate the potential role of miR-422a. Cell proliferation, migration, and invasion were used for in vitro functional analysis of miR-422a.

RESULTS: The levels of miR-422a were dramatically reduced in CRC tissues compared with normal mucosa (P < 0.05), and significantly correlated with local invasion (P = 0.004) and lymph node metastasis (P < 0.001). Kaplan-Meier survival and Cox regression multivariate analyses revealed that miR-422a expression (HR = 0.568, P = 0.015) and clinical TNM stage (HR = 2.942, P = 0.003) were independent prognostic factors for overall survival in CRC patients. Furthermore, in vitro experiments showed that overexpression of miR-422a inhibited the proliferation, migration, and invasion of SW480 and HT-29 cells.

CONCLUSION: Down-regulation of miR-422a may serve as an independent prognosis factor in CRC. MiR-422a functions as a tumor suppressor and regulates progression of CRC.

Keywords: Colorectal cancer, MicroRNA, miR-422a, Prognosis, In vitro function

Core tip: In the present study, we found that miR-422a was dramatically reduced in colorectal cancer (CRC) tissues, and significantly correlated with local invasion and lymph node metastasis. miR-422a expression and clinical TNM stage were independent prognostic factors for overall survival in CRC patients. Furthermore, in vitro experiments showed that overexpression of miR-422a inhibited the proliferation, migration, and invasion of SW480 and HT-29 cells. These results indicated that down-regulation of miR-422a might serve as an independent prognosis factor in CRC, and miR-422a functions as a tumor suppressor and regulates progression of CRC.