title: Both tissue inhibitors of metalloproteinases-1 (TIMP-1) and TIMP-2 activate Ras but through different pathways.
abstract: Tissue inhibitors of metalloproteinases-1 (TIMP-1) and TIMP-2 have growth-stimulating activity for a wide range of cell types. Ras, which comprises a family of three members, i.e, Ha-Ras, Ki-Ras, and H-Ras, is known to participate in growth control in all its facets, including cell proliferation, transformation, differentiation, and apoptosis. In this study, we tested the hypothesis that Ras might be involved in the cell growth-promoting activity of TIMPs. Using MG-63 human osteosarcoma cells, we demonstrated that both TIMP-1 and TIMP-2 caused an increase in the Ras-GTP level in a dose-dependent manner. Our previous results indicated that TIMP-1 activity is mediated through the tyrosine kinase (TYK)/mitogen-activated protein kinase (MAPK) pathway. Here, we demonstrated that Ras activation by TIMP-1 was inhibited by a specific TYK inhibitor, herbimycin A, suggesting that the TYK/MAPK signaling pathway was involved in Ras activation by TIMP-1. However, the activation of Ras by TIMP-2 was inhibited by an inhibitor specific for cyclic AMP-dependent protein kinase (PKA), H89, suggesting the involvement of the PKA-mediated pathway. Furthermore, TIMP-2 promoted the formation of a complex between Ras-GTP and phosphoinositide 3-kinase.
authors.affiliation: Department of Biochemistry, School of Dentistry, Aichi-Gakuin University, 464-8650, Nagoya, Japan
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.forename: Kyoko
authors.initials: K
authors.lastname: Yamashita
authors.forename: Kazushi
authors.initials: K
authors.lastname: Iwata
authors.forename: Taro
authors.initials: T
authors.lastname: Hayakawa
mesh_terms: D016227:Benzoquinones; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D047029:Lactams, Macrocyclic; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011809:Quinones / Q000494:pharmacology; D011994:Recombinant Proteins / Q000378:metabolism; D017828:Rifabutin / Q000031:analogs & derivatives; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism*; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D018631:ras Proteins / Q000378:metabolism*
chemical_list: D016227:Benzoquinones; D017868:Cyclic AMP-Dependent Protein Kinases; D004791:Enzyme Inhibitors; D047029:Lactams, Macrocyclic; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011809:Quinones; D011994:Recombinant Proteins; D017828:Rifabutin; D019715:Tissue Inhibitor of Metalloproteinase-1; D019716:Tissue Inhibitor of Metalloproteinase-2; D018631:ras Proteins; C020754:herbimycin