Basic Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 21, 2016; 22(15): 3969-3977
Published online Apr 21, 2016. doi: 10.3748/wjg.v22.i15.3969
Integrin-linked kinase overexpression promotes epithelial-mesenchymal transition via nuclear factor-κB signaling in colorectal cancer cells
Hong Shen, Jun-Li Ma, Yan Zhang, Gan-Lu Deng, Yan-Ling Qu, Xiao-Ling Wu, Jing-Xuan He, Sai Zhang, Shan Zeng
Hong Shen, Jun-Li Ma, Yan Zhang, Gan-Lu Deng, Yan-Ling Qu, Xiao-Ling Wu, Shan Zeng, Department of Oncology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
Hong Shen, Jing-Xuan He, Sai Zhang, Institute of Medical Sciences, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
Author contributions: Shen H and Zeng S designed research; Shen H, Ma JL, Zhang Y, Deng GL, Qu YL, Wu XL, He JX, Zhang S and Zeng S performed research; Ma JL, Zhang Y, Deng GL and Qu YL contributed new reagents/analytic tools; Shen H and Zeng S analyzed data and wrote the paper.
Supported by the National Natural Science Foundation of China (Beijing, China; grant No’s. 30770971, 81172470, 81070362 and 81372629).
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board of Xiangya Hospital.
Conflict-of-interest statement: We declare that there are no conflicts of interest to disclose in our study.
Data sharing statement: No additional data 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: Shan Zeng, MD, PhD, Department of Oncology, Xiangya Hospital, Central South University, 87 Xiangyan Road, Changsha 410008, Hunan Province, China. zengshan2000@yeah.net
Telephone: +86-731-89753034 Fax: +86-731-84327633
Received: October 24, 2015
Peer-review started: October 25, 2015
First decision: November 27, 2015
Revised: December 6, 2015
Accepted: December 30, 2015
Article in press: December 30, 2015
Published online: April 21, 2016
Abstract

AIM: To investigate the effect of integrin-linked kinase (ILK) on proliferation, metastasis, and invasion of the colorectal cancer cell line SW480.

METHODS: In this study, the colorectal cancer cell line SW480 was stably transfected with ILK plasmids, and small interfering RNA (siRNA) was used to knockdown expression of nuclear factor (NF)-κB/p65. Methylthiazole tetrazolium (MTT) assay was performed to measure proliferation, and the wound healing migration assay and matrigel invasion assay were used to test the metastasis and invasion ability of SW480 cells. To explore the epithelial-mesenchymal transition (EMT) process, embryonic development, and the invasion and metastasis of tumors, the protein level of E-cadherin, vimentin, snail, and slug was detected by western blot. Immunofluorescence was also used to detect E-cadherin expression. Western blot was used to determine the level of phosphorylated-inhibitor of kappa B (IκB)a, inhibitor of gamma B (IγB)a, and nuclear factor kappa B (NF-κB) expressions and to explore the ILK signaling pathway.

RESULTS: Western blot results revealed that ILK expression significantly increased when ILK was overexpressed in SW480 cells (P < 0.05). Proliferation, metastasis, and invasion ability were improved in the vector-ILK group compared to the vector group (P < 0.05). Immunofluorescence results revealed that E-cadherin fluorescence intensity decreased after ILK was overexpressed (P < 0.05). Western blot results revealed that the protein expression of E-cadherin was reduced, while vimentin, snail, and slug were upregulated when ILK was overexpressed in SW480 cells (P < 0.05). In order to determine the role of the NF-κB signaling pathway in ILK overexpression promoted EMT occurrence, we overexpressed ILK in SW480 cells and found that levels of NF-κB/p65 and cytoplasmic phosphorylated-IκBa were increased and that cytoplasmic IкBa levels were decreased compared to the control group (P < 0.05). Furthermore, NF-κB/p65 knockout revealed that E-cadherin was increased in the overexpressed ILK group.

CONCLUSION: ILK overexpression improved the proliferation, metastasis, and invasion ability of SW480 cells, and this effect may be mediated by the NF-κB signaling pathway.

Keywords: Colorectal cancer, Integrin-linked kinase, Epithelial-mesenchymal transition, Nuclear factor-κB, Overexpression

Core tip: In this study, the colorectal cancer cell line SW480 was stably transfected with integrin-linked kinase (ILK) plasmids, and the proliferation, metastasis, and invasion ability of the cells were tested. The results demonstrated that ILK overexpression improved the proliferation, metastasis, and invasion ability of cell line SW4802 and promoted the occurrence of the epithelial-mesenchymal transition in colorectal cancer cells. These effects may be mediated by the nuclear factor-κB signaling pathway.