High-throughput sequencing reveals the epitranscriptome-wide landscape of m6A-modified circRNA in oral squamous cell carcinoma

Abstract Emerging transcriptome high throughput screenings reveal the landscape and functions of RNAs, such as circular RNAs (circRNAs), in human cancer. In addition, the post-transcriptional internal modifications, especially N6-methyladenosine (m6A), greatly enrich the variety of RNAs metabolism. However, the m6A modification on circRNAs has yet to be addressed. Here, we report an epitranscriptome-wide mapping of m6A-modified circRNAs (m6A-circRNA) in oral squamous cell carcinoma (OSCC). Utilizing the data of MeRIP-seq and m6A-circRNAs epitranscriptomic microarray analysis, we found that m6A-circRNAs exhibited their particular modification style in OSCC, which was independent of m6A-mRNA. Besides, m6A modification on circRNAs frequently occurred on the long exons in the front part of the coding sequence (CDS), which was distinct from m6A-mRNA that in 3’-UTR or stop codon. In conclusion, our work preliminarily demonstrates the traits of m6A-circRNAs and probed into the association of m6A-circRNAs and m6A-mRNA, which may bring enlighten for the roles of m6A-circRNAs in OSCC.