Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Feb 15, 2017; 9(2): 62-69
Published online Feb 15, 2017. doi: 10.4251/wjgo.v9.i2.62
Circular RNAs in colorectal cancer: Possible roles in regulation of cancer cells
María Isabel Taborda, Sebastián Ramírez, Giuliano Bernal
María Isabel Taborda, Sebastián Ramírez, Giuliano Bernal, Laboratory of Molecular and Cell Biology of Cancer (CancerLab), Department of Biomedical Sciences, Faculty of Medicine, Universidad Católica del Norte, Coquimbo 1781421, Chile
Author contributions: Taborda MI performed the literature review, analysis and article’s writing; Ramírez S provided ideas regarding the conception of this paper and contributed with the graphic design; Bernal G contributed to this paper with a critical revision, editing and approval of the final version.
Conflict-of-interest statement: The authors declare no conflict of interest.
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: Giuliano Bernal, PhD, Laboratory of Molecular and Cell Biology of Cancer (CancerLab), Department of Biomedical Sciences, Faculty of Medicine, Universidad Católica del Norte, at Larrondo 1281, Coquimbo 1781421, Chile.
Telephone: +56-51-2205988
Received: April 29, 2016
Peer-review started: May 4, 2016
First decision: July 20, 2016
Revised: November 5, 2016
Accepted: December 13, 2016
Article in press: December 14, 2016
Published online: February 15, 2017

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the world and the fourth principal cause of cancer deaths worldwide. Currently, there is a lack of low cost and noninvasive screening tests for CRC, becoming a serious health problem. In this context, a potential biomarker for the early detection of CRC has recently gained attention. Circular RNAs (circRNA), a re-discovered, abundant RNA specie, is a type of noncoding covalent closed RNAs formed from both exonic and intronic sequences. These circular molecules are widely expressed in cells, exceeding the abundance of the traditional linear mRNA transcript. They can regulate gene expression, acting as real sponges for miRNAs and also regulate alternative splicing or act as transcriptional factors and inclusive encoding for proteins. However, little is known about circRNA and its relationship with CRC. In this review, we focus on the biogenesis, function and role of these circRNAs in relation to CRC, including their potential as a new biomarker.

Keywords: Circular RNA, Colorectal cancer, Gene regulation, CircRNA, Non-coding RNAs, Long non-coding RNA, Circularization

Core tip: Circular RNAs (circRNAs) are noncoding RNAs, characterized for its circularized shape. These circRNAs are abundant and might play important roles in cancer. In particular, they exhibit altered expression in colorectal cancer, and its activity as miRNA sponge might be involved in the control of cancer progression. Moreover, owing to their stability, could serve as diagnostic or predictive biomarkers for colorectal cancer.