Epigenetic Mechanisms in CRSwNP: The Role of MicroRNAs as Potential Biomarkers and Therapeutic Targets.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a prevalent inflammatory disease of the upper airway, contributing significantly to the global disease burden. CRSwNP is characterized by sustained and exaggerated inflammation, accompanied by marked changes in gene and protein expression regulated through intricate molecular mechanisms. MicroRNAs (miRNAs), small single-stranded RNA molecules that regulate gene expression at transcriptional and post-transcriptional levels, have emerged as pivotal players in CRSwNP pathophysiology. Dysregulated miRNA expression is implicated in numerous human diseases, including cancer, asthma, and inflammatory disorders, highlighting their broad clinical relevance. In CRSwNP, miRNAs influence important inflammatory pathways, including T2 immune responses and epithelial-mesenchymal transition (EMT), which leads to chronic inflammation and tissue remodeling. Profiling studies have identified specific miRNAs as potential biomarkers for disease severity, prognosis, and therapeutic response, offering a pathway to personalized medicine. Furthermore, advances in small extracellular vesicles (sEVs) and exosomes, which naturally transport miRNAs, provide innovative avenues for targeted miRNA delivery, minimizing systemic side effects. This review explores current knowledge on miRNA expression and function in CRSwNP, emphasizing their role in disease pathogenesis and their potential as biomarkers and therapeutic targets.