CircRNA_100290 promotes colorectal cancer progression through miR-516b-induced downregulation of FZD4 expression and Wnt/β-catenin signaling.

Accumulating evidence indicates that circular RNAs (circRNA) exert crucial functions in the development and advance of cancers. CircRNA_100290 has been reported to promote proliferation in oral cancer. However, whether it participates in colorectal cancer (CRC) remains unclear. Here, our report showed that circRNA_100290 level was significantly increased in CRC tissues and cell lines. Besides, circRNA_100290 expression was positively correlated with tumor metastasis while inversely correlated with prognosis. Silencing circRNA_100290 markedly reduced cell proliferation rate, inhibited migration and invasion abilities, but promoted apoptosis in vitro. Mechanistically, our data revealed circRNA_100290 was a competing endogenous RNA (ceRNA) of FZD4 by sponging miR-516b, leading to activation of Wnt/β-catenin pathway. Rescue assay indicated that FZD4-induced activation of β-catenin pathway is indispensable for the function of circRNA_100290 in CRC. In summary, our study for the first time revealed a novel regulatory loop of circRNA_100290/miR-516b/FZD4/Wnt/β-catenin implicated in CRC progression.