Hepatocyte growth factor-stimulated invasiveness of monocytes.

Hepatocyte growth factor (HGF) is a pluripotent cytokine with mitogenic, motogenic, and morphogenic activity for mainly epithelial and endothelial target cells. We previously demonstrated that the specific HGF receptor, MET, is induced in stimulated peripheral blood monocytes. In this study, we analyzed the functional consequences of MET activation in primary cultures of peripheral blood monocytes from healthy donors. After stimulation of MET-expressing monocytes with recombinant HGF, the gene-expression profile of peripheral blood mononuclear cells and monocytes was significantly modulated, especially with regard to genes involved in cell movement. After stimulation of primary cultured monocytes with HGF, invasion assays showed a significantly increased matrigel invasion rate that was completely abolished by neutralizing antibodies to HGF. The HGF-activated invasiveness and the altered gene-expression profile suggest a proinflammatory role for HGF stimulation of monocytes and support the hypothesis that the HGF/MET signaling system plays an important part in the activation of the nonspecific cellular inflammatory response. (Blood. 2000;95:3964-3969)