Basic Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 14, 2018; 24(34): 3884-3897
Published online Sep 14, 2018. doi: 10.3748/wjg.v24.i34.3884
Formin-like 3 regulates RhoC/FAK pathway and actin assembly to promote cell invasion in colorectal carcinoma
Yuan-Feng Zeng, Yi-Sheng Xiao, Yong Liu, Xiao-Jiang Luo, Li-Dan Wen, Qian Liu, Min Chen
Yuan-Feng Zeng, Yong Liu, Qian Liu, Min Chen, Department of Pathology, Jiangxi Provincial People’s Hospital, Nanchang 330006, Jiangxi Province, China
Yi-Sheng Xiao, Teaching and Researching Section of Morphology, College of Basic Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, Jiangxi Province, China
Xiao-Jiang Luo, Department of General Surgery, Jiangxi Provincial People’s Hospital, Nanchang 330006, Jiangxi Province, China
Li-Dan Wen, Clinical Medical Sciences Institute, Jiangxi Provincial People’s Hospital, Nanchang 330006, Jiangxi Province, China
Author contributions: Zeng YF, Xiao YS, Liu Y, Luo XJ, Wen LD, Liu Q and Chen M carried out the experiment; Zeng YF conceived experiments and analyzed data; all authors were involved in writing this paper and had final approval of the submitted and published versions.
Supported by the National Natural Science Foundation of China, No. 81201972; the China Postdoctoral Science Foundation, No. 2013M531555; and the Postdoctoral Science Foundation of Jiangxi province, No. 2013KY44.
Institutional review board statement: The study was reviewed and approved by Ethical Committee of Jiangxi Provincial People’s Hospital.
Conflict-of-interest statement: The authors declare no conflicts of interest in the present study.
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: Yuan-Feng Zeng, PhD, Chief Doctor, Department of Pathology, Jiangxi Provincial People’s Hospital, 152 Patriotic Road, Donghu District, Nanchang 330006, Jiangxi Province, China. zyf760928@163.com
Telephone: +86-791-86895672 Fax: +86-791-86895672
Received: May 5, 2018
Peer-review started: May 7, 2018
First decision: May 23, 2018
Revised: June 16, 2018
Accepted: June 27, 2018
Article in press: June 27, 2018
Published online: September 14, 2018
Processing time: 131 Days and 19.5 Hours
Abstract
AIM

To clarify the underlying mechanism of formin-like 3 (FMNL3) in the promotion of colorectal carcinoma (CRC) cell invasion.

METHODS

The in vitro biological function analyses of FMNL3 were performed by gain- and loss-of function approaches. Changes in the F-actin cytoskeleton were detected by the technologies of phalloidin-TRITC labeling and confocal microscopy. The signaling pathway mediated by FMNL3 was explored by western blot, gelatin zymograph assay, co-immunoprecipitation (co-IP), immunofluorescence co-localization, and glutathione S-transferase (GST) pull-down assay.

RESULTS

The in vitro experimental results showed that FMNL3 significantly promoted the proliferation, invasion, and migration of CRC cells (P < 0.05 and P < 0.01). Moreover, FMNL3 regulated the remodeling of actin-based protrusions such as filopodia and lamellipodia in a RhoC-dependent manner. The western blot and gelatin zymograph assay results indicated that FMNL3 was involved in the RhoC/ focal adhesion kinase (FAK) pathway and acted as an effector of RhoC to activate the downstream signaling of p-FAK as well as p-MAPK and p-AKT. This resulted in the increased expression of matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9) and vascular endothelial growth factor (VEGF), and the subsequent promotion of CRC cell invasion. The results of TAE226, U0126 or Ly294002 treatment confirmed an essential role of FMNL3 in activation of the RhoC/FAK pathway and the subsequent promotion of CRC invasion. Co-IP, co-localization and GST pull-down assays showed the direct interaction of FMNL3 with RhoC in vivo and in vitro.

CONCLUSION

FMNL3 regulates the RhoC/FAK signaling pathway and RhoC-dependent remodeling of actin-based protrusions to promote CRC invasion.

Keywords: Formin-like 3; Colorectal carcinoma; Invasion; RhoC/FAK pathway; Actin assembly

Core tip: Formin-like 3 (FMNL3) belongs to the subfamily of diaphanous-related formins, which govern the actin-dependent processes, including cell motility and invasion. The increased expression of FMNL3 in colorectal carcinoma (CRC) was shown to contribute to metastasis and poor prognosis of patients in previous studies, however its regulatory mechanism remains unclear. This work reveals that FMNL3 plays a positive role in CRC cell proliferation, invasion and migration. Moreover, FMNL3 activates the RhoC/FAK signaling pathway, and also regulates RhoC-dependent remodeling of actin-based protrusion, such as filopodia and lamellipodia, to promote CRC cell invasion. FMNL3 can be applied as a promising specific biomarker for CRC progression and metastasis.