title: Mechanisms and significance of bifunctional NK4 in cancer treatment.
abstract: Based on the background that hepatocyte growth factor (HGF) and c-Met/HGF receptor tyrosine kinase play a definite role in tumor invasion and metastasis, NK4, four-kringles containing intramolecular fragment of HGF, was isolated as a competitive antagonist for the HGF-c-Met system. Independent of its HGF-antagonist action, NK4 inhibited angiogenesis induced by vascular endothelial cell growth factor and basic fibroblast growth factor, as well as HGF, indicating that NK4 is a bifunctional molecule that acts as an HGF-antagonist and angiogenesis inhibitor. Interestingly, kringle domains in distinct types of proteins, e.g., plasminogen, prothrombin, plasminogen activators, apolipoprotein(a), and HGF, share angioinhibitory actions. In experimental models of distinct types of cancers, NK4 protein administration or NK4 gene therapy inhibited tumor invasion, metastasis, and angiogenesis-dependent tumor growth. Cancer treatment with NK4 may prove to suppress malignant tumors to be 'static' in both tumor growth and spreading, as based on biological characteristics of malignant tumors.
authors.affiliation: Division of Molecular Regenerative Medicine, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
authors.forename: Kunio
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D020533:Angiogenesis Inhibitors / Q000008:administration & dosage*; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage; D017228:Hepatocyte Growth Factor / Q000008:administration & dosage* / Q000378:metabolism; D006801:Humans; D008934:Mitogens / Q000008:administration & dosage* / Q000378:metabolism; D009369:Neoplasms / Q000098:blood supply* / Q000188:drug therapy* / Q000378:metabolism; D009389:Neovascularization, Pathologic / Q000378:metabolism* / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D020533:Angiogenesis Inhibitors; D000970:Antineoplastic Agents; C066855:HGF protein, human; D008934:Mitogens; D017228:Hepatocyte Growth Factor