CircRNA circ_0067934 promotes tumor growth and metastasis in hepatocellular carcinoma through regulation of miR-1324/FZD5/Wnt/β-catenin axis

Recently, increasing evidences demonstrate that circular RNAs (circRNAs) exert very important functions in the progression of human cancers. However, the functions and molecular mechanism of circ_0067934 in hepatocellular carcinoma (HCC) are largely unknown. In the present study, we found that the expression of circ_0067934 was significantly upregulated in HCC tissues and cell lines compared to adjacent normal tissues. Furthermore, we showed that circ_0067934 knockdown remarkably suppressed the proliferation, migration and invasion of Hep3B and HuH7 cells while inducing their apoptosis. In terms of mechanism, we found that circ_0067934 directly suppressed miR-1324, which targeted the 3'-UTR of FZD5 mRNA and subsequently downregulated the Wnt/β-catenin signaling pathway in HCC. Through rescue experiments, we demonstrated that circ_0067934 enhanced the proliferation, migration and invasion of HCC cells by the inhibition of miR-1324 and concomitant activation of FZD5/Wnt/β-catenin signaling pathway. In summary, the circ_0067934/miR-1324/FZD5/β-catenin signaling axis might serve as a promising therapeutic target for HCC intervention.