[Identification of circular RNA expression profiles in oral lichen planus]

To construct the expression profile of circular RNA (circRNA) in human oral lichen planus (OLP), and to identify and validate the differentially expressed circRNA in oral lichen planus tissues and provide theoretical basis for the diagnosis and treatment of this disease.

Six patients newly diagnosed with OLP from September to December 2018 in the Department of Oral Mucosal Diseases, Shanghai Ninth People's Hospital and 6 healthy volunteers were enrolled in this study. RNA sequencing and evaluation in OLP tissues and normal oral mucosa were performed by high-throughput RNA sequencing technology, and the differences between groups were analyzed. qRT-PCR was used to validate the results. Statistical analysis was conducted with SPSS 24.0 software package. Finally, bioinformatics techniques GO (Gene Ontology) enrichment analysis and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway were used to analyze the functions and related pathways of the dysregulated genes.

According to the sequencing results, 85 differentially expressed circRNAs with fold change > 2 were identified in OLP tissues compared to the normal oral mucosa, including 66 upregulated circRNAs and 19 downregulated circRNAs. Three circRNAs with the most significant up-regulation and down-regulation were selected for qRT-PCR verification in expanded samples, and the results were consistent with the sequencing results. Bioinformatics analysis suggested that the differentially expressed circRNAs may play an important role in the occurrence and progression of oral lichen planus.

Differentially expressed circRNAs between oral lichen planus tissues and normal oral mucosa were identified, which may be involved in the pathogenic mechanism of oral lichen planus and could be potential biomarkers for diagnosis and treatment of this disease.