Exosome-Derived Circular RNAs in Colorectal Cancer: Emerging Roles in Tumorigenesis, Diagnosis, and Therapy.

Circular RNAs (circRNAs) are a class of non-coding RNAs characterized by their covalently closed loop structures, which confer remarkable stability. Recent studies have highlighted the role of exosomal circRNAs, which are encapsulated within extracellular vesicles known as exosomes, in intercellular communication and tumor progression. In colorectal cancer (CRC), exosomal circRNAs have been implicated in various oncogenic processes, including cell proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), and drug resistance. These molecules exhibit dysregulated expression patterns in CRC tissues and bodily fluids, making them promising candidates for non-invasive biomarkers. Moreover, their functional roles in modulating signaling pathways and the tumor microenvironment suggest their potential therapeutic applications. This review summarizes our current understanding of exosomal circRNA biology, highlights their roles in the CRC development and progression, and discusses their clinical significance as diagnostic, prognostic and therapeutic tools.