Figure 2.

A miRNA-circRNA-mRNA network. It has been proposed that circRNA can act as a miRNA sponge, therefore competing with a linear target for the binding of the RISC complex. In the absence of circRNA, miRNAs are free to bind to their linear target, determining their repression. When the circRNA is expressed, the miRNA will guide the RISC complex to bind the circRNA, ultimately causing the de-repression of the mRNA. mRNA is depicted as an Open Reading Frame (ORF) with a 5′ cap (m⁷G) and a 3′ poly(A) tail.