Basic Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Nov 7, 2018; 24(41): 4679-4690
Published online Nov 7, 2018. doi: 10.3748/wjg.v24.i41.4679
Overexpression of G protein-coupled receptor 31 as a poor prognosticator in human colorectal cancer
Yu-Ming Rong, Xiao-Ming Huang, De-Jun Fan, Xu-Tao Lin, Feng Zhang, Jian-Cong Hu, Ying-Xin Tan, Xi Chen, Yi-Feng Zou, Ping Lan
Yu-Ming Rong, VIP Region, Sun Yat-sen University Cancer Center, Guangzhou 510060, Guangdong Province, China
Xiao-Ming Huang, Department of Hepatobiliary Surgery, the Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510655, Guangdong Province, China
Xiao-Ming Huang, De-Jun Fan, Xu-Tao Lin, Jian-Cong Hu, Ying-Xin Tan, Xi Chen, Yi-Feng Zou, Ping Lan, Guangdong Institute of Gastroenterology; Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, the Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510655, Guangdong Province, China
De-Jun Fan, Xu-Tao Lin, Department of Gastrointestinal Endoscopy, the Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510655, Guangdong Province, China
Feng Zhang, Department of Rheumatology, the Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510655, Guangdong Province, China
Jian-Cong Hu, Ying-Xin Tan, Xi Chen, Yi-Feng Zou, Ping Lan, Department of Colorectal Surgery, the Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510655, Guangdong Province, China
Author contributions: Rong YM, Huang XM and Fan DJ contributed equally to this paper. Rong YM, Huang XM, Fan DJ and Lin XT performed the majority of experiments and analyzed the data; Zhang F, Hu JC, Tan YX and Chen X collected the clinicopathological data and tissue of patients; Huang XM, Zou YF and Lan P designed and coordinated the research; Rong YM, Fan DJ and Lin XT wrote the paper; Huang XM, Zhang F and Zou YF revised the paper.
Supported by National Key Clinical Discipline; and the Medical Scientific Research Foundation of Guangdong Province, No. A2016198; and the Science and Technology Planning Project of Guangdong Province, No. 20160916, No. 2015B020229001 and No. 2014SC111.
Institutional review board statement: Our research was based on resources from our database and specimen library and it did not involve human or animal subjects. Thus, the approval of institutional review board was waived.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
Data sharing statement: No additional data are available.
ARRIVE guidelines statement: The ARRIVE guidelines have been adopted in this study.
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: Yi-Feng Zou, MD, PhD, Department of Colorectal Surgery, the Sixth Affiliated Hospital, Sun Yat-sen University, 26 Yuancun Er Heng Road, Guangzhou 510655, Guangdong Province, China. zouyif@mail.sysu.edu.cn
Telephone: +86-13719225862 Fax: +86-20-38254009
Received: August 8, 2018
Peer-review started: August 9, 2018
First decision: August 24, 2018
Revised: September 13, 2018
Accepted: October 5, 2018
Article in press: October 5, 2018
Published online: November 7, 2018
Processing time: 91 Days and 15.2 Hours
Abstract
AIM

To investigate the expression of G protein-coupled receptor 31 (GPR31) and its clinical significance in human colorectal cancer (CRC).

METHODS

To determine the association between the GPR31 expression and the prognosis of patients, we obtained paraffin-embedded pathological specimens from 466 CRC patients who underwent initial resection. A total of 321 patients from the First Affiliated Hospital of Sun Yat-sen University from January 1996 to December 2008 were included as a training cohort, whereas 145 patients from the Sixth Affiliated Hospital of Sun Yat-sen University from January 2007 to November 2008 were included as a validation cohort. We examined GPR31 expression levels in CRC tissues from two independent cohorts via immunohistochemical staining. All patients were categorized into either a GPR31 low expression group or a GPR31 high expression group. The clinicopathological factors and the prognosis of patients in the GPR31 low expression group and GPR31 high expression group were compared.

RESULTS

We compared the clinicopathological factors and the prognosis of patients in the GPR31 low expression group and GPR31 high expression group. Significant differences were observed in the number of patients in pM classification between patients in the GPR31 low expression group and GPR31 high expression group (P = 0.007). The five-year survival and tumor-free survival rates of patients were 84.3% and 82.2% in the GPR31 low expression group, respectively, and both rates were 59.7% in the GPR31 high expression group (P < 0.05). Results of the Cox proportional hazard regression model revealed that GPR31 upregulation was associated with shorter overall survival and tumor-free survival of patients with CRC (P < 0.05). Multivariate analysis identified GPR31 expression in colorectal cancer as an independent predictive factor of CRC patient survival (P < 0.05).

CONCLUSION

High GPR31 expression levels were found to be correlated with pM classification of CRC and to serve as an independent predictive factor of poor survival of CRC patients.

Keywords: G protein-coupled receptor 31; Colorectal cancer; Predictive factor; Metastasis; Clinical significance

Core tip: G protein-coupled receptor 31 (GPR31) is a member of the G protein-coupled receptor superfamily whose biological function remains unclear in colorectal cancer (CRC). Expression of GPR31 and its prognostic significance in human CRC have not been studied. The present study aimed to investigate the expression of GPR31 and its clinical significance in human CRC. In our study, high GPR31 expression levels were found to be correlated with pM classification of CRC and to serve as an independent predictor of poor survival in patients with CRC.