Fig. 2
From: circRNAs and their relationship with breast cancer: a review
Functional mechanisms of circRNAs. A miRNA sponging. circRNAs are rich in miRNA binding sites (miRNA response elements, MRE) and act as miRNA sponges to prevent miRNA from interacting with mRNA, thus indirectly regulating the expression of downstream target genes of miRNA. B Protein/peptide template. Some circRNAs can be translated by ribosomes and encode peptides to perform regulatory functions. C–E Regulating parental genes. Some circRNAs can bind with host genes (C) or cis-acting elements (D), thus directly or indirectly modulating host gene transcription. In addition, circRNAs can change splicing patterns or mRNA stability by binding to RNA-binding proteins (RBPs) (E), thus regulating parental gene transcription