Circular RNAs as central regulators of RNA stability

Circular RNAs (circRNAs) are a class of covalently closed, single-stranded RNAs generated predominantly through back-splicing of pre-mRNAs. Unlike their linear counterparts, circRNAs lack free 5' and 3' termini, rendering them intrinsically resistant to exoribonucleolytic degradation and conferring exceptional stability. In addition, accumulating evidence has revealed that circRNAs actively participate in regulating the stability of other RNA species. This review explores the current understanding of intrinsic molecular features dictating circRNA stability. Furthermore, we emphasize recent progress on how circRNAs crosstalk with and regulate the stability of other RNA species, including mRNAs and microRNAs, through various mechanisms. Ultimately, we provide an integrated perspective for understanding circRNA-centered regulation of RNA stability.