Abstract
Circular RNAs (circRNAs) represent a fascinating class of covalently closed RNA molecules that have emerged as critical regulators of gene expression. Unlike their linear counterparts, circRNAs are resistant to exonuclease degradation, conferring remarkable stability and enabling diverse regulatory roles. This review synthesizes current understanding of circRNA biogenesis, their mechanisms of action, and their implications across various biological processes and diseases. CircRNAs can function as potent microRNA (miRNA) sponges, sequestering miRNAs and thereby modulating miRNA target gene expression [3, 16]. They can also interact with RNA-binding proteins (RBPs), influencing RBP availability and activity, or even act as scaffolds for protein complexes [1, 9, 18]. Emerging evidence points to their involvement in epigenetic regulation, development, and cellular differentiation [2, 21]. Dysregulation of circRNAs has been implicated in numerous pathologies, including various cancers, cardiovascular diseases, and metabolic disorders, highlighting their potential as diagnostic biomarkers and therapeutic targets [5, 7, 8, 10, 19]. This article reviews the foundational knowledge and recent advancements in the field, underscoring the expanding repertoire of circRNA functions and their profound impact on cellular homeostasis and disease pathogenesis. Future research directions, including advanced detection methods and functional validation strategies, are also discussed.