Expression profile of circular RNAs in oral lichen planus

Background: This study sought to identify the circular RNAs (circRNAs) differentially expressed in oral lichen planus (OLP) to investigate the possible role of circRNAs in this disease's pathogenesis. Methods: Six OLP and six normal oral mucosal tissues were used for circRNA detection and sequencing. 10 selected circRNAs were verified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A gene ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to predict the functions of circRNAs in OLP. TargetScan and miRanda were applied to predict targeted micro (mi)RNAs and messenger (m) RNAs of circRNAs, and competing endogenous (ce)RNA networks were mapped. Results: One hundred and thirty-five circRNAs were identified differentially expressed in OLP tissues compared to normal control tissues, including 83 upregulated circRNAs, and 52 down-regulated circRNAs. RT-qPCR confirmed that 10 circRNAs were all abnormally expressed in OLP. The GO functional analysis and KEGG pathway analysis showed that differentially expressed circRNAs were involved in 535 GO functional items and 78 signal pathways. A ceRNA network analysis showed that circRNAs might interact with a variety of miRNAs. Conclusions: This study mapped the expression profile of abnormally expressed circRNAs in OLP tissues for the first time and showed that circRNAs appear to play an important role in the pathogenesis of OLP.