Dishevelled 3 (Dvl3) is upregulated and enhances cell migration and invasion in hepatocellular carcinoma

Abstract

Hepatocellular carcinoma (HCC) is one of the most common fatal malignancies in the world and is particularly prevalent in China and Southeast Asia. Although the risk factors are well known, the molecular mechanisms underlying hepatocarcinogenesis is unclear. Alteration of Wnt signaling pathway is one of the key events in HCC development and so we performed a low-density array (LDA) analysis on 38 pairs of HCC samples and their corresponding non-tumorous livers to examine the expression profiles of different Wnt signaling components. We found that, among the genes studied, Dishevelled 3 (Dvl3) was significantly overexpressed in HCCs as compared with the corresponding non-tumorous liver tissues. In addition, Dvl3 overexpression in HCC was significantly associated with presence of venous invasion (P = .021). The overexpression result was confirmed by expansion of the sample size using quantitative real-time PCR (q-PCR). Next, we investigated the effects of Dvl3 on the migratory and invasive abilities of HCC cells. We established stable shRNA Dvl3-knockdown clones in PLC/PRF/5 HCC cells and found that knockdown of Dvl3 suppressed the migratory and invasive abilities of HCC cells using transwell migration and invasion assays, respectively, suggesting an enhancing role of Dvl3 in HCC cell movement and cell invasion. Although cell proliferation assay in vitro showed no significant difference between the stable Dvl3 knockdown and non-target control PLC/PRF/5 cells, in vivo study in SCID mice showed that the stable Dvl3-knockdown cells resulted in a lower incidence of tumors formed and a smaller tumor size. Furthermore, since Dvl3 is an upstream regulator of the Wnt/β-catenin pathway, using the TOPFOP luciferase reporter assay, we found that transient transfection of Dvl3 in PLC/PRF/5 and BEL-7402 HCC cell lines enhanced the β-catenin-dependent transcriptional activity. In conclusion, upregulation of Dvl3 was frequent in human HCCs. Dvl3 enhanced cell migration and invasion in vitro and tumorigenicity in vivo in SCID mice, and activated canonical β-catenin pathway. It may play an oncogenic role in HCC development.