Basic Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Oct 21, 2015; 21(39): 11127-11140
Published online Oct 21, 2015. doi: 10.3748/wjg.v21.i39.11127
Effect of fibulin-5 on adhesion, migration and invasion of hepatocellular carcinoma cells via an integrin-dependent mechanism
Jia-Cheng Tang, Jing-Hua Liu, Xiao-Long Liu, Xiao Liang, Xiu-Jun Cai
Jia-Cheng Tang, Jing-Hua Liu, Xiao-Long Liu, Xiao Liang, Xiu-Jun Cai, Key Lab of Surgery of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, Zhejiang Province, China
Author contributions: Tang JC carried out the experiments and drafted the manuscript; Liu JH and Liu XL participated in the experiments; Liang X analysed the data; Cai XJ designed the study and directed its implementation; all authors drafted the article and made critical revisions related to the intellectual content of the manuscript, and approved the final version of the article to be published.
Supported by Zhejiang Provincial Natural Science Foundation of China, No. LY13H180001; and Education Bureau of Zhejiang Province, No. N20130416.
Institutional review board statement: All samples from the patients were taken after informed consent and ethical permission were obtained for participation in the study.
Conflict-of-interest statement: To the best of our knowledge, all the listed authors have participated actively in the study, and have seen and approved the submitted manuscript. The authors do not have any possible conflicts of interest.
Data sharing statement: We confirm that no additional unpublished data are available.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: Xiu-Jun Cai, MD, PhD, Key Lab of Surgery of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University, 3 East Qingchun Road, Hangzhou 310016, Zhejiang Province, China. cxjzu@hotmail.com
Telephone: +86-571-86006605 Fax: +86-571-86006605
Received: May 18, 2015
Peer-review started: May 20, 2015
First decision: June 19, 2015
Revised: July 8, 2015
Accepted: August 30, 2015
Article in press: August 30, 2015
Published online: October 21, 2015
Processing time: 153 Days and 14.3 Hours
Abstract

AIM: To elucidate the role of fibulin-5 (FBLN-5) as a suppressor of hepatocellular carcinoma (HCC) cell metastasis via integrin.

METHODS: The expression of FBLN-5 was determined by immunohistochemistry in 140 HCC samples and matched normal tissues, and was further confirmed by RT-PCR and Western blot analyses in various cell lines. Recombinant FBLN-5 was expressed in Escherichia coli BL21(DE3), purified and used in cell attachment assays. Expression of a specific plasmid or a specific siRNA in HCC cells resulted in the overexpression or knockdown of FBLN-5, respectively. Further, the migration and invasion of HCC cells were investigated using the Boyden chamber and transwell assays. The concentration of secreted matrix metalloproteinase 7 (MMP-7) was determined using ELISA.

RESULTS: FBLN-5 expression was found to be downregulated in HCC. Its expression was significantly correlated with advanced tumor metastasis; this was indicative of poor 5-year overall survival. Recombinant full-length human FBLN-5 promoted the attachment of HCC cells via integrins: it inhibited HCC cell adhesion and migration to fibronectin in a concentration-dependent manner. It also inhibited HCC cell migration and invasion through an integrin-binding arginine-glycine-aspartic acid (RGD) motif by downregulating MMP-7.

CONCLUSION: These results suggest that lower FBLN-5 expression is an important indicator of poor survival and that FBLN-5 inhibits HCC motility via an integrin-dependent mechanism. RGD-dependent suppression of MMP-7 by FBLN-5 might contribute to the development of new therapeutic strategies for HCC.

Keywords: Fibulin-5; Hepatocellular carcinoma; Integrin; Adhesion; Migration; Invasion

Core tip: Fibulin-5 (FBLN-5) is a matricellular protein that contains an arginine-glycine-aspartic acid motif, the role of which is to bind certain integrins and thereby mediate cancer cell motility. Several studies have revealed that FBLN-5 may promote or suppress tumor progression through its interaction with integrins in various human tumors in a context-specific manner, which might be a crucial event in the invasiveness of malignant tumor cells.