Discovering the Role of FZD4 Gene in Human Cutaneous Squamous Cell Carcinoma

BACKGROUND: Frizzled 4 (FZD4) is an important receptor for Wnt proteins that stimulate several downstream signaling pathways. It has been known that the FZD4–Wnt interaction is involved in many types of cancers. However, the role of FZD4 in cutaneous squamous cell carcinoma (CSCC) has not been well studied. AIMS: We sought to investigate the association between FZD4 expression level and tumor cell proliferation and apoptosis rates in CSCC. METHODS: Expression of FZD4 at mRNA level in CSCC tissues and controls was measured. Colo16 cell proliferation and viability were measured by CCK-8 assay and flow cytometry respectively after siRNA and plasmid transfection. RESULTS: We discovered a significant downregulation of FZD4 expression in CSCC tissues and cell lines compared to controls. Furthermore, our data suggested that over expression of FZD4 inhibited proliferation and promoted apoptosis of Colo16 cells. CONCLUSION: The results indicated that FZD4 may play as a tumor suppressor gene in the pathogenesis of CSCC.