Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Dec 6, 2021; 9(34): 10400-10417
Published online Dec 6, 2021. doi: 10.12998/wjcc.v9.i34.10400
Role of circular RNAs in gastrointestinal tumors and drug resistance
Shi-Jun Xi, Wen-Qi Cai, Qin-Qi Wang, Xiao-Chun Peng
Shi-Jun Xi, Wen-Qi Cai, Qin-Qi Wang, Xiao-Chun Peng, Department of Pathophysiology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou 434023, Hubei Province, China
Author contributions: Peng XC designed and supervised the study; Xi SJ reviewed the references; Xi SJ and Peng XC wrote the manuscript; Xi SJ, Cai WQ and Wang QQ contributed to tables and figures.
Supported by Natural Science Foundation of Hubei Province, China, No. 2017CFB786; Hubei Province Health and Family Planning Scientific Research Project, China, No. WJ2016Y10; Jingzhou Science and Technology Bureau Project, China, No. 2017-93; the College Students Innovative Entrepreneurial Training Program in Yangtze University, China, No. 2019376; and Postgraduate Innovation Fund Project of Yangtze University, China, No. 200202.
Conflict-of-interest statement: The authors declared no conflict of interest.
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:
Corresponding author: Xiao-Chun Peng, PhD, Doctor, Department of Pathophysiology, School of Basic Medicine, Health Science Center, Yangtze University, No. 1 Nanhuan Road, Jingzhou 434023, Hubei Province, China.
Received: February 7, 2021
Peer-review started: February 7, 2021
First decision: March 14, 2021
Revised: March 26, 2021
Accepted: August 5, 2021
Article in press: August 5, 2021
Published online: December 6, 2021

The incidence of gastrointestinal cancers has increased significantly over the past decade and gastrointestinal malignancies now rank among the leading causes of mortality globally. Although newer therapeutic strategies such as targeted therapies have greatly improved patient outcomes, their clinical success is limited by drug resistance, treatment failure and recurrence of metastatic disease. Therefore, there is an urgent need for further research identifying accurate and reliable biomarkers for precise treatment strategies. Circular RNAs (circRNAs) exhibit a covalently closed structure, high stability and biological conservation, and their expression is associated with the occurrence and development of gastrointestinal tumors. Moreover, circRNAs may significantly influence drug resistance of gastrointestinal cancers. In this article, we review the role of circRNAs in the occurrence and development of gastrointestinal cancer, their association with drug resistance, and potential application for early diagnosis, treatment and prognosis in gastrointestinal malignancies. Furthermore, we summarize characteristics of circRNA, including mechanism of formation and biological effects via mRNA sponging, chromatin replication, gene regulation, translational modification, signal transduction, and damage repair. Finally, we discuss whether circRNA-related noninvasive testing may be clinically provided in the future. This review provides new insights for the future development of diagnostics and therapeutics based on circRNAs in gastrointestinal tumors.

Keywords: Gastrointestinal cancer, Circular RNA, Drug resistance, Genomics, Targeted therapy, Molecular mechanics

Core Tip: Circular RNAs (circRNAs) were first discovered in 1976, and then more related biological functions were discovered. For example, as a miRNA sponge, circRNA participates in tumor-related processes, translation modification, signal transduction, and DNA damage repair. Gastrointestinal tumors have a high incidence, and some patients also show drug resistance during treatment. On this basis, we reviewed the relationship between circRNA and gastrointestinal tumors and the relevance of drug resistance, hoping to conduct more in-depth research on circRNA. At the same time, it is hoped that circRNA will provide new directions and strategies for future cancer treatment.