The interaction of hepatoma-derived growth factor and β-catenin promotes tumorigenesis of synovial sarcoma.

To clarify the clinicopathological and biological role of hepatoma-derived growth factor (HDGF) and β-catenin in synovial sarcoma. Our results showed that histological type and HDGF/β-catenin expression were the two important independent prognostic factors for overall survival in synovial sarcoma patients. HDGF knockdown dramatically inhibited cellular proliferation, colony formation, and migration but induced G1 phase arrest and apoptosis in SW982 cells. Recombinant HDGF enhanced synovial sarcoma cell growth and partially retrieved the cell growth suppression in SW982 cells upon HDGF knockdown. HDGF knockdown dramatically suppressed β-catenin and its downstream gene expression in SW982 cells. Intriguingly, β-catenin knockdown dramatically suppressed HDGF expression in SW982 cells. A direct interaction of HDGF and β-catenin was found in SW982 cells. Three HDGF-binding elements in β-catenin promoter were found and specific for transcriptional activation of β-catenin in SW982 cells. In conclusion, our findings first indicate that the interaction of HDGF and β-catenin may play a crucial role in tumorigenesis of synovial sarcoma.