Basic Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 14, 2015; 21(18): 5454-5464
Published online May 14, 2015. doi: 10.3748/wjg.v21.i18.5454
Downregulation of rho-associated protein kinase 1 by miR-124 in colorectal cancer
Zuo-Wu Xi, Shi-Yong Xin, Li-Qing Zhou, Hai-Xin Yuan, Qian Wang, Kai-Xuan Chen
Zuo-Wu Xi, Kai-Xuan Chen, Department of Anorectal Surgery, Henan province Hospital of Traditional Chinese Medicine (Second Affiliated Hospital of Henan University of traditional Chinese medicine), Zhengzhou 450002, Henan Province, China
Shi-Yong Xin, Hai-Xin Yuan, Qian Wang, Department of Urology, First Affiliated Hospital of Henan University of Science and Technology, Luoyang 471003, Henan Province, China
Li-Qing Zhou, Department of Rheumatism Immunity, First Affiliated Hospital of Henan University of Science and Technology, Luoyang 471003, Henan Province, China
Author contributions: Chen KX, Xin SY and Xi ZW designed the study and wrote the manuscript; Zhou LQ and Yuan HX performed the majority of the experiments; Wang Q provided vital reagents and analytical tools and revised he manuscript; Xin SY and Zhou LQ collected all the human material and provided financial support for this work.
Ethics approval: The study was approved by the Ethics Committee of Henan University of Traditional Chinese Medicine on Human Research (No. H20130816).
Conflict-of-interest: All authors have no conflict of interest related to the manuscript.
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-Xuan Chen, MD, Department of Anorectal Surgery, Henan province Hospital of Traditional Chinese Medicine (Second Affiliated Hospital of Henan University of traditional Chinese medicine), Dongfeng Road No. 6, Zhengzhou 450002, Henan Province, China. doctkxchen@163.com
Telephone: +86-371-60979725 Fax: +86-371-60979726
Received: November 21, 2014
Peer-review started: November 22, 2014
First decision: December 26, 2014
Revised: January 21, 2015
Accepted: February 11, 2015
Article in press: February 11, 2015
Published online: May 14, 2015
Abstract

AIM: To investigate the roles and interactions of rho-associated protein kinase (ROCK)1 and miR-124 in human colorectal cancer (CRC).

METHODS: Expression of ROCK1 protein was examined by Western blotting, and quantitative reverse transcriptase PCR was performed to measure expression of ROCK1 mRNA and miR-124. Two cancer cell lines were transfected with pre-miR-124 (mimic) and anti-miR-124 (inhibitor) and the effects on ROCK1 protein and mRNA expression were observed. In addition, cell proliferation was assessed via a 5-ethynyl-2′ deoxyuridine assay. Soft agar formation assay, and cell migration and invasion assays were used to determine the effect of survivin on the transformation and invasion activity of CRC cells.

RESULTS: miR-124 was significantly downregulated in CRC compared to normal specimens (0.603 ± 0.092 vs 1.147 ± 0.286, P = 0.016) and in metastatic compared to nonmetastatic CRC specimens (0.416 ± 0.047 vs 0.696 ± 0.089, P = 0.020). Expression of miR-124 was significantly associated with CRC metastasis, tumor T and N stages, and tumor grade (all P < 0.05). ROCK1 protein was significantly increased in CRC compared to normal tissues (1.896 ± 0.258 vs 0.866 ± 0.136, P = 0.026), whereas ROCK1 mRNA expression was unaltered (2.613 ± 0.251 vs 2.325 ± 0.246). miR-124 and ROCK1 were inversely expressed in CRC tissues and cell lines. ROCK1 mRNA was unaltered in cells transfected with miR-124 mimic and miR-124 inhibitor, compared to normal controls. There was a significant reduction in ROCK1 protein in cells transfected with miR-124 mimic and a significant increase in cells transfected with miR-124 inhibitor (Ps < 0.05). Transformation and invasion of cells transfected with miR-124 inhibitor were significantly increased compared to those in normal controls (P < 0.05). Cells transfected with miR-124 inhibitor showed increased cell proliferation.

CONCLUSION: miR-124 promotes hyperplasia and contributes to invasion of CRC cells, but downregulates ROCK1. ROCK1 and miR-124 may play important roles in CRC.

Keywords: Cell invasion, Colorectal cancer, miR-124, Rho-associated protein kinase

Core tip: miR-124 inhibits neoplastic transformation, cell proliferation, and metastasis, and downregulates rho-associated protein kinase (ROCK)1 in some cancers. In this study, we investigated the roles and interactions of ROCK1 and miR-124 in human colorectal cancer (CRC). miR-124 promoted cell hyperplasia and contributed to invasion, but downregulated ROCK1 in CRC. ROCK1 and miR-124 may play important roles in CRC.