Recent advances of circular RNAs in gastrointestinal cancer

Non-coding RNAs, which do not encode proteins, significantly influence signal regulation. Circular RNAs (circRNAs), produced through a post-splicing mechanism, constitute a recently identified subset of non-coding RNAs distinguished by their multifunctional covalently closed loop structures. With an in-depth exploration of circRNAs' biological characteristics, their potential roles in gastrointestinal cancer have garnered significant attention. CircRNAs can significantly influence tumor initiation and progression. This review consolidates recent research progress on circRNAs in digestive system cancers such as esophageal, gastric, hepatic, pancreatic, and colorectal cancer. We explore the potential of circRNAs as biomarkers and therapeutic targets, alongside their roles in immune modulation and chemoresistance. This review seeks to offer a thorough understanding of circRNAs' implications in digestive system tumors by outlining the current research landscape and identifying existing challenges, thereby encouraging further exploration in this emerging field.