Comprehensive circular RNA expression profiling with associated ceRNA network in orbital venous malformation

PURPOSE: Orbital venous malformation (OVM), the most common type of vascular malformation in adults, has a great impact on both visual and cosmetic factors. Circular RNAs (circRNAs) play important roles in various ophthalmological diseases; however, little is known about their function in the pathogenesis of OVM. METHODS: We obtained differentially expressed circRNAs, mRNAs, and miRNAs based on RNA sequencing of four OVM tissues and four normal orbital vascular tissues. The circRNA–mRNA coexpression network and circRNA–miRNA–mRNA and competing endogenous RNA (ceRNA) networks were constructed using miRanda software. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to identify the up- and downregulated mRNAs in the circRNA–miRNA–mRNA ceRNA network. RESULTS: Overall, we identified 45 upregulated and 144 downregulated circRNAs, as well as 2,175 upregulated and 1,274 downregulated mRNAs and 156 upregulated and 168 downregulated miRNAs in OVM samples compared with normal orbital vascular tissues. The expression changes of mRNAs and circRNAs detected by quantitative real-time PCR (qRT-PCR) were in line with the RNA-seq results. Then, a ceRNA regulatory network was constructed with these differentially expressed circRNAs, mRNAs, and miRNAs. GO functional analysis revealed that most related biological processes involved extracellular matrix organization, positive regulation of actin nucleation, and so on, which were thought to be involved in the evolution of OVM. KEGG pathway analysis of upregulated mRNAs showed that mucin-type O-glycan biosynthesis, glycosaminoglycan degradation, and the PI3K (Gene ID: 5290; OMIM: 613089)-AKT (Gene ID: 207; OMIM: 114500) signaling pathway were all enriched in OVM samples. CONCLUSIONS: Our study provides novel insight into the regulatory mechanism of circRNAs, miRNAs, and mRNAs in the pathogenesis of OVM.