Basic Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 7, 2017; 23(13): 2318-2329
Published online Apr 7, 2017. doi: 10.3748/wjg.v23.i13.2318
Cullin 4A is associated with epithelial to mesenchymal transition and poor prognosis in perihilar cholangiocarcinoma
Tong-Jun Zhang, Dong Xue, Cheng-De Zhang, Ze-Dong Zhang, Qing-Ran Liu, Jian-Qiang Wang
Tong-Jun Zhang, Cheng-De Zhang, Ze-Dong Zhang, Qing-Ran Liu, Department of Interventional Vascular Surgery, The People’s Hospital of Binzhou, Binzhou 256610, Shandong Province, China
Dong Xue, Jian-Qiang Wang, Department of General Surgery, The People’s Hospital of Binzhou, Binzhou 256610, Shandong Province, China
Author contributions: Zhang TJ, Xue D, Zhang CD, Zhang ZD, Liu QR, and Wang JQ substantially contributed to the conception and design of the study as well as the acquisition, analysis and interpretation of the data; 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.
Institutional review board statement: All perihilar cholangiocarcinoma specimens 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, no conflict of interest exists.
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:
Correspondence to: Dong Xue, MD, PhD, Department of General Surgery, The People’s Hospital of Binzhou, No. 515, Seventh Huanghe Road, Binzhou 256610, Shandong Province, China.
Telephone: +86-54-33283293 Fax: +86-54-33282503
Received: November 15, 2016
Peer-review started: November 17, 2016
First decision: December 19, 2016
Revised: January 5, 2017
Accepted: March 2, 2017
Article in press: March 2, 2017
Published online: April 7, 2017
Processing time: 141 Days and 21.6 Hours

To explore the functional role of cullin 4A (CUL4A), a core subunit of E3 ubiquitin ligase, in perihilar cholangiocarcinoma (PHCC).


The expression of CUL4A in PHCC cell lines was evaluated by Western blot and quantitative reverse transcription-polymerase chain reaction. Immunohistochemistry (IHC) was adopted to investigate the relationship between CUL4A expression and clinicopathological characteristics of PHCC. Univariate analysis and multivariate regression analysis were performed to analyze the risk factors related to overall survival (OS) and progression-free survival (PFS) of PHCC patients. Wound healing, Transwell and Matrigel assays were utilized to explore the function of CUL4A in PHCC metastasis. Furthermore, expression of epithelial to mesenchymal transition (EMT) markers was verified in cells with CUL4A knockdown or overexpression. The relationship between CUL4A expression and E-cadherin expression was also analyzed by IHC assay. Finally, the role of ZEB1 in regulating CUL4A mediated PHCC was detected by IHC, Western blot, Transwell and Matrigel assays.


CUL4A overexpression was detected in PHCC cell lines and clinical specimens. Clinicopathological analysis revealed a close correlation between CUL4A overexpression and tumour differentiation, T, N and TNM stages in PHCC. Kaplan-Meier analysis revealed that high CUL4A expression was correlated with poor OS and PFS of PHCC patients. Univariate analysis identified the following four parameters as risk factors related to OS rate of PHCC: T, N, TNM stages and high CUL4A expression; as well as three related to PFS: N stage, TNM stage and high CUL4A expression. Further multivariate logistic regression analysis identified high CUL4A expression as the only independent prognostic factor for PHCC. Moreover, CUL4A silencing in PHCC cell lines dramatically inhibited metastasis and the EMT. Conversely, CUL4A overexpression promoted these processes. Mechanistically, ZEB1 was discovered to regulate the function of CUL4A in promoting the EMT and metastasis.


CUL4A is an independent prognostic factor for PHCC, and it can promote the EMT by regulating ZEB1 expression. CUL4A may be a potential therapeutic target for PHCC.

Keywords: Perihilar cholangiocarcinoma, Epithelial to mesenchymal transition, ZEB1, Cullin 4A, Metastasis, Prognosis

Core tip: Cullin 4A (CUL4A), a core subunit of E3 ubiquitin ligase, was confirmed to promote the metastasis and the epithelial to mesenchymal transition (EMT) in perihilar cholangiocarcinoma (PHCC) in the present study. High CUL4A expression was revealed to be correlated with poor overall survival (OS) and progression-free survival (PFS) of PHCC patients. CUL4A expression was detected to be the only independent risk factor for OS and PFS in PHCC. Mechanistically, ZEB1 was verified to mediate the function of CUL4A in regulating PHCC metastasis and the EMT.