Emerging role of non-coding RNA in oral cancer.

Oral squamous cell carcinoma (OSCC) is characterized by genomic and epigenomic alterations. However, the mechanisms underlying oral squamous cell carcinoma tumorigenesis and progression remain to be elucidated. Long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and extracellular RNAs (exRNAs) are emerging groups of regulatory RNAs, which possess low or no protein-coding potential. Emerging lines of evidence indicates that deregulated expression of lncRNAs and circular RNAs are associated with the induction and progression of various cancers, including oral cancer, through epigenetic, transcriptional, and post-transcriptional alterations. In this review, we highlight the expression and functional roles of extracellular RNAs, lncRNAs, and circular RNAs in oral squamous cell carcinoma and discuss their potential clinical applications as diagnostic or prognostic biomarkers, and therapeutic targets.