Basic Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 28, 2021; 27(36): 6064-6078
Published online Sep 28, 2021. doi: 10.3748/wjg.v27.i36.6064
CircRNA_0084927 promotes colorectal cancer progression by regulating miRNA-20b-3p/glutathione S-transferase mu 5 axis
Feng Liu, Xiao-Li Xiao, Yu-Jing Liu, Ruo-Hui Xu, Wen-Jun Zhou, Han-Chen Xu, Ai-Guang Zhao, Yang-Xian Xu, Yan-Qi Dang, Guang Ji
Feng Liu, Xiao-Li Xiao, Yu-Jing Liu, Ruo-Hui Xu, Wen-Jun Zhou, Han-Chen Xu, Yan-Qi Dang, Guang Ji, Institute of Digestive Diseases, Longhua Hospital, China-Canada Center of Research for Digestive Diseases (ccCRDD), Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China
Feng Liu, Ai-Guang Zhao, Department of Oncology, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China
Yang-Xian Xu, Department of General Surgery, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China
Author contributions: Liu F and Xiao XL contributed equally to this work. Ji G and Dang YQ should be regarded as co-corresponding authors; Ji G and Dang YQ conceived, designed, and supervised the study; Dang YQ, Xu YX, and Xu HC collected the samples; Liu F, Xiao XL, Liu YJ, and Xu RH performed the experiments; Dang YQ, Liu F, and Zhou WJ analyzed the data; Dang YQ and Liu F wrote the paper; Zhou WJ, Zhao AG, and Ji G revised the manuscript; all authors reviewed and approved the final manuscript.
Supported by the National Natural Science Foundation of China, No. 81804018 and No. 81874206; and the Key Project of the Shanghai 3-Year Plan, No. ZY[2018-2020]CCCX-2002-01.
Institutional review board statement: The study was reviewed and approved by the Medical Ethics Committee of Longhua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine (No. 2019LCSY020).
Conflict-of-interest statement: The authors have no conflicts of interest to declare.
Data sharing statement: The original data of this study will be available upon request from corresponding author.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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/
Corresponding author: Guang Ji, MD, PhD, Professor, Institute of Digestive Diseases, Longhua Hospital, China-Canada Center of Research for Digestive Diseases (ccCRDD), Shanghai University of Traditional Chinese Medicine, No. 725 South Wanping Road, Shanghai 200032, China. jiliver@vip.sina.com
Received: March 3, 2021
Peer-review started: March 3, 2021
First decision: June 3, 2021
Revised: June 4, 2021
Accepted: August 9, 2021
Article in press: August 9, 2021
Published online: September 28, 2021
Abstract
BACKGROUND

Colorectal cancer (CRC) is the third most common cancer and the second most common cause of cancer-related death worldwide. The 5-year survival rate of patients with early-stage CRC could reach 90%, but it is very low in patients with advanced-stage CRC. Recent studies have shown that circular RNAs play important roles in regulating the migration and invasion of CRC cells.

AIM

To elucidate the role of circRNA_0084927 (circ_0084927) in the migration and invasion of CRC cells and its underlying mechanism.

METHODS

Clinical tissue samples and cells were collected, and the expression of circ_0084927 was detected by quantitative polymerase chain reaction (qPCR). The diagnostic performance of circ_0084927 was assessed by receiver operating characteristic curve analysis. The role of circ_0084927 in CRC cell proliferation, migration, and invasion was determined using cell counting kit-8 assay, wound healing assay, and transwell assay, respectively. The regulatory relationship among circ_0084927, miRNA-20b-3p (miR-20b-3p), and glutathione S-transferase mu 5 (GSTM5) was identified using databases, luciferase reporter assay, qPCR, and Western blot analysis. AKT-mTOR signaling was also verified after circ_0084927 knockdown or miR-20b-3p mimic treatment.

RESULTS

The expression of circ_0084927 was significantly increased in CRC tissues and cells, and it was higher in advanced-stage CRC compared with early-stage CRC. The area under the curve (AUC) of circ_0084927 was 0.806 [95% confidence interval (CI): 0.683-0.896]. In addition, the AUC was 0.874 (95%CI: 0.738-0.956) in patients with advanced-stage CRC and 0.713 (95%CI: 0.555-0.840) in those with early-stage CRC. Knockdown of circ_0084927 inhibited the migration and invasion of HCT116 cells. Moreover, circ_0084927 was found to act as a sponge of miR-20b-3p. MiR-20b-3p activation reduced the circ_0084927 level, whereas miR-20b-3p inhibition increased the circ_0084927 level. But the effect was not found after circ_0084927 mutation. In addition, miR-20b-3p expression in CRC patients was also reduced and negatively correlated with circ_0084927 expression. The function of circ_0084927 in HCT116 cells with circ_0084927 knockdown was rescued by miR-20b-3p. Moreover, GSTM5 expression was significantly decreased after overexpressing miR-20b-3p or inhibiting circ_0084927, but its expression was rescued when circ_0084927 and miR-20b-3p were both inhibited. Finally, AKT-mTOR signaling was markedly regulated by circ_0084927 and miR-20b-3p.

CONCLUSION

The expression of circ_0084927 is significantly increased in CRC and higher in advanced-stage CRC than in early-stage CRC. Moreover, circ_0084927 potentially regulates CRC cell migration and invasion via the miR-20b-3p/GSTM5/ AKT/mTOR pathway.

Keywords: Colorectal cancer, CircRNA_0084927, MiRNA-20b-3p, Glutathione S-transferase mu 5, Migration, Invasion

Core Tip: The 5-year survival rate of patients with early-stage colorectal cancer (CRC) could reach 90%, but it is very low in patients with advanced-stage CRC. Recent studies have shown that circular RNAs play important roles in regulating the migration and invasion of CRC cells. To elucidate the role of circRNA_0084927 (circ_0084927) in the migration and invasion of CRC cells and the underlying mechanism, this study was performed. The expression of circ_0084927 was significantly increased in CRC tissues and cells, and it was markedly higher in advanced-stage CRC compared with early-stage CRC. Knockdown of circ_0084927 inhibited the migration and invasion of HCT116 cells. Moreover, circ_0084927 potentially regulates CRC migration and invasion via the miRNA-20b-3p/glutathione S-transferase mu 5 pathway.