Research Paper Volume 11, Issue 22 pp 10220—10241

Circular RNA CircCCNB1 sponges micro RNA-449a to inhibit cellular senescence by targeting CCNE2

Figure 9. Schematic diagram of CircCCNB1 function in human diploid fibroblasts. Our model suggests that CircCCNB1 functions as a CeRNA to sponge miR-449a whereby CircCCNB1 facilitates the expression of the target CCNE2 required for cell cycle development by preventing miR-449a from acting on the target mRNAs. The reduced expression of CircCCNB1 in senescent cells leads to elevated levels of functional miR449a, which in turn represses miR-449a target gene expression contributing to growth suppression and cellular senescence.