CircRNAs: Biogenesis, identification and expression analysis

Circular ribonucleic acids (CircRNAs) represent a category of noncoding RNAs characterized by a circular structure bonded through covalent bonds. Unlike linear RNAs, CircRNAs are not affected by exonucleases and exhibit more stable expression. Research suggests that CircRNAs may have the ability to be translated through the internal ribosome entry sites (IRESs) mechanism and it could enable CircRNAs to produce proteins despite lacking a 5’ cap structure.  They have gained attention due to their diverse functions, including acting as miRNA sponges, participating in complex gene expression regulation, and disease markers. CircRNAs play crucial roles in various biological processes, including cancer development and progression.  These cyclic molecules have garnered significant interest for their diverse effects in humans. Furthermore, CircRNAs have been implicated in human genetic diseases, offering insights into potential diagnostic and therapeutic avenues. They are formed through back-splicing of pre-mRNA transcripts, resulting in covalently closed loops. Recent studies have highlighted the significance of CircRNAs in cancer biology, such as their involvement in modulating gene expression, acting as micro RNA (miRNA) sponges, and regulating cellular processes. There are some detection methods including computational models, experimental techniques, and advanced RNA-based and CLIP-Seq-based methods. This review could help to understand the key points regarding biogenesis, biological function, literature trend and biological function of CircRNAs.