To explore the characteristics and predict the function of the circular RNA hsa_circ_0004777 derived from SOX13.

The basic features of hsa_circ_0004777 were explored in terms of back-splicing sites verification, RNase R digestion, cytoplasmic and nuclear distribution of the intracellular RNA, and prediction of protein translational potential. In addition, bioinformatics approach was used to predict the microRNAs (miRNAs) that hsa_circ_0004777 binds to and the miRNA targets; a circRNA-miRNA-mRNA network was subsequently mapped. Gene ontology (GO) function enrichment and signaling pathway enrichment analyses were performed on the predicted target genes of miRNA.

Hsa_circ_0004777 was formed by back-splicing from exon 4 to exon 2 of SOX13 gene, resistant to RNase R digestion, and was mainly localized in the cytoplasm. Bioinformatics prediction demonstrated that hsa_circ_0004777 functions as a sponge to eight miRNAs (hsa-miR-1225-3p, hsa-miR-637, hsa-miR-139-5p, hsa-miR-145-5p, hsa-miR-384, hsa-miR-660-5p, hsa-miR-942-5p, and hsa-miR-331-3p) . The target genes of these eight miRNAs potentially bound by hsa_circ_0004777 were found to be significantly enriched in biological processes such as positive regulation of transcription from polymerase II promoter, DNA-templated, and skeletal muscle cell differentiation.

The SOX13-derived circular RNA hsa_circ_0004777 was successfully characterized, and its function was predicted based on the circRNA-miRNA-mRNA network map. These findings would back up further studies on hsa_circ_0004777 and offer insights into SOX13.

SOX13; circular RNA; hsa_circ_0004777; Protein translation prediction; Function prediction