EXPRESSION OF C-MET RECEPTOR AND HEPATOCYTE GROWTH-FACTOR SCATTER FACTOR IN SYNOVIAL SARCOMA AND EPITHELIOID SARCOMA

Overexpression of c-Met receptor/hepatocyte growth factor (scatter fac tor) system (c-Met/HGF/SF) as a physiologically paracrine cellular sig naling system is thought to be involved in the progression of malignan t rumours. In 26 synovial sarcomas and epithelioid sarcomas, c-Met and HGF/SF expression was analysed immunohistochemically. There were 10 b iphasic synovial sarcomas, 7 of which showed moderate to strong c-Met expression in epithelial areas compared with the fibrous component, wi th corresponding expression of HGF/SF. Six of 9 monophasic fibrous syn ovial sarcomas showed only very faint c-Met and corresponding HGF/SF e xpression. In 7 epithelioid sarcomas strong expression of c-Met and HG F/SF was observed within epithelioid tumour cells. Non-radioactive in situ hybridization demonstrated the synthesis of c-Met receptor in tum or cells by detecting c-met-mRNA. This analysis shows that in synovial sarcomas and epithelioid sarcomas, tumour entities with epithelial an d mesenchymal structures, c-Met and HGF/SF overexpression can be detec ted, indicating a role of this signaling system in these subtypes of s arcoma, and especially in the more epithelioid tumour phenotype. An au tocrine interaction between overexpressed c-Met receptor and HGF/SF ma y be hypothesized.