The biological function and mechanism of action of circRNA as a potential target in colorectal cancer.

Colorectal cancer (CRC) is one of the most common malignancies worldwide. Its incidence continues to rise, and treatment options for advanced stages are still limited. In recent years, circular RNAs (circRNAs), a special class of non-coding RNAs, have demonstrated potential applications in cancer therapy. CircRNAs exhibit high stability and tissue specificity, and they play roles in tumorigenesis and progression through multiple mechanisms, such as acting as microRNA (miRNA) sponges, interacting with proteins, modulating transcription, and participating in signal transduction. In CRC specific circRNAs can regulate gene expression within the tumor microenvironment, thereby influencing tumor cell behavior, angiogenesis, immune evasion, and metabolic reprogramming. Moreover, circRNAs hold promise as potential diagnostic and prognostic biomarkers, as well as therapeutic targets for CRC. Although an increasing number of original studies have revealed the diverse functions of circRNAs in CRC, comprehensive reviews that synthesize these findings and relate them to clinical relevance remain scarce. This narrative review explores the latest advances in circRNA research in CRC and discusses their clinical potential as diagnostic and prognostic biomarkers, therapeutic agents, and drug targets.