Elucidation of a signaling pathway induced by FGF-2 leading to uPA gene expression in NIH 3T3 fibroblasts.
Fibroblast growth factors (FGFs) play a role in biological processes such as cell growth and development, angiogenesis, and wound healing. Several genes have been shown to be induced by FGFs, but the underlying mechanisms have not been elucidated. We investigated the effect of FGF-2 (basic FGF) on the urokinase-type plasminogen activator (uPA) gene in NIH 3T3 fibroblasts. We found that the uPA gene is transcriptionally induced by FGF-2 as well as by 12-O-tetradecanoylphorbol-13 -acetate involving a PEA3/AP1 element located 2.4 kb upstream of the transcription initiation site; neither induction requires ongoing protein synthesis. Unlike 12-O-tetradecanoylphorbol-13-acetate induction, FGF-2 induction was not impaired by protein kinase C down-regulation. Analyses of various signaling molecules by Western blotting, extracellular signal-regulated kinase (ERK) activity assays, and transient transfection assays (cotransfection of a uPA-reporter gene construct with expression vectors for wild-type or dominant negative type of these molecules or for ERK-specific protein phosphatase MKP-1) showed that a Ras/Raf-1/MEK/ERK-2/JunD pathway is induced by FGF-2 and 12-O-tetradecanoylphorbol-13-acetate, leading to the activation of the uPA gene.
Friedrich Miescher Institute, Basel, Switzerland.
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Besser
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Presta
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Nagamine
D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000187:drug effects; D004789:Enzyme Activation; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D017346:Protein Serine-Threonine Kinases / Q000187:drug effects; D011518:Proto-Oncogene Proteins / Q000187:drug effects; D016755:Proto-Oncogene Proteins c-jun / Q000187:drug effects; D019908:Proto-Oncogene Proteins c-raf; D015398:Signal Transduction / Q000187:drug effects*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D018808:Transcription Factor AP-1 / Q000187:drug effects; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics*; D018631:ras Proteins / Q000187:drug effects
D011518:Proto-Oncogene Proteins; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1; D016222:Fibroblast Growth Factor 2; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D014568:Urokinase-Type Plasminogen Activator; D018631:ras Proteins; D013755:Tetradecanoylphorbol Acetate