Regulation of expression of the hepatocyte growth factor scatter factor receptor, c-met, by cytokines

The c-met proto-oncogene product is a 190 kDa heterodimeric receptor tyrosine kinase activated by the binding of its li,gand, hepatocyte growth factor/scatter factor (HGF/SF), a cytokine known to stimulate cell growth, motility and morphogenesis. Altered expression of c-met receptor levels in tumour cells may therefore play an important role in regulating the metastatic progression of cancers. We have determined the effects of a number of cytokines on c-met expression in the colon cancer cell line HT29. We report that c-met message and protein levels are up-regulated by the cytokines IL-5, IL-10, TGF-beta, PDGF and basic FCF while down-regulation occurred after treatment with IFN-gamma. We conclude that up-regulation of the HGF/SF receptor in vivo by the above cytokines may enhance tumour cell sensitivity to HGF/SF and therefore be an important step in the progression of metastatic spread.