A novel multi-kinase inhibitor pazopanib suppresses growth of synovial sarcoma cells through inhibition of the PI3K-AKT pathway.

Synovial sarcoma is an aggressive soft tissue sarcoma with only a modest response to conventional cytotoxic agents. In the present study, we evaluated the potential antitumor effects of a novel anti-angiogenesis agent, pazopanib, against synovial sarcoma cells. We found that pazopanib directly inhibited the growth of synovial sarcoma cells by inducing G1 arrest. Multiplex analyses revealed that the PI3K-AKT pathway was highly suppressed in pazopanib-sensitive synovial sarcoma cells. Furthermore, administration of pazopanib highly suppressed the tumor growth in a xenograft model. Taken together, these results suggest pazopanib as a possible agent against synovial sarcoma and may warrant further clinical studies.