The interaction of HGF-SF with other cytokines in tumor invasion and angiogenesis.

Scatter factor (SF) is a glycoprotein which is secreted by mesenchymal cells and which causes cohesive epithelial cell colonies to spread out, separate into individual cells, and assume a fibroblastic morphology (i.e., to "scatter"). SF is now known to be identical or nearly identical to hepatocyte growth factor, a serum-derived mitogen for various normal cell types. SF, tumor necrosis factor-alpha (TNFa), and interleukin-1 (IL1) share the ability to stimulate scattering, motility, and protease production in a variety of human tumor cell types. SF and TNFa stimulate vascular endothelial cell motility in vitro and induce angiogenesis, the formation of new blood vessels, in vivo. These factors may participate in a cytokine network which regulates tumor invasion and metastasis directly by enhancing the malignant epithelial phenotype and indirectly by inducing tumor neovascularization.