Research progress on circRNAs in type 2 CRS.

Circular RNAs (circRNAs) constitute a recently identified class of non-coding RNAs that are widely distributed in eukaryotes. Characterized by the absence of 5' caps and 3' polyadenylated tails, circRNAs may regulate gene expression through multiple mechanisms. Recent studies have shown that certain circRNAs contain binding sites complementary to microRNAs (miRNAs), enabling them to function as molecular sponges that sequester miRNAs and inhibit their suppressive effects on mRNA expression. Emerging evidence indicates that specific circRNAs are involved in the regulation of immune cells and cytokines associated with type 2 chronic rhinosinusitis; however, direct clinical evidence supporting associations between circRNAs and the diagnosis or severity of type 2 chronic rhinosinusitis remains unavailable. In this study, the molecular mechanisms of circRNAs in type 2 inflammation are systematically summarized, established experimental evidence is distinguished from clinical applications that remain to be validated, and a theoretical basis is provided for future research on type 2 chronic rhinosinusitis.