YAP1, a vital effector of Hippo pathway, promotes cancer development via transcriptionally
regulating a batch of target genes involved in various signaling pathways, including
proliferation, apoptosis, and cell drug sensitivity. Recently, circular RNAs (circRNAs)
have been shown to control gene expression post-transcriptionally and become a new
layer of gene regulation. However, whether circRNAs play roles in YAP1-induced tumorigenesis
is still largely elusive. Here, we identify circRNA-000425 as a new inhibitory target
of YAP1, and also find that it binds to miR-17/miR-106b, and thus suppresses cancer
cell growth induced by these miRNAs. circRNA-000425 is revealed as a YAP1 target through
circRNA microarray analysis of RNAs extracted from cells treated with or without YAP1
siRNAs, and further confirmed by RT-q-PCR and ChIP assays. Interestingly, bioinformatics
analysis, luciferase assay, and RT-q-PCR results showed that circRNA-000425 binds
to miR-17 and miR-106b, but not let-7a, and rescues the inhibitory effect of miR-17/miR-106
on the expressions of both p21 and BIM. In addition, colony formation and MTT assay
showed that circRNA-000425 inhibits cancer cell growth induced by miR-17. These findings
reveal a mechanism by which YAP1 promotes oncogenic activities of miR-17 and miR-106b
through transcriptionally inhibiting circRNA-000425 expression.