title: Involvement of a mitogen-activated protein kinase signaling pathway in the regulation of urokinase promoter activity by c-Ha-ras.
abstract: The expression of the urokinase-type plasminogen activator, which plays a crucial role in tissue remodeling by controlling the synthesis of the broadly acting plasmin serine protease, is regulated by several tyrosine kinases. Since the actions of these tyrosine kinases is dependent on the activation of ras proteins, we undertook a study to identify signaling events downstream of ras responsible for the stimulation of urokinase promoter activity. Transient expression of an activated c-Ha-ras in OVCAR-3 cells, which do not harbor the mutated oncogene, led to a dose-dependent trans-activation of the urokinase promoter. A sequence residing between -2109 and -1964 was critical for the stimulation of the urokinase promoter by c-Ha-ras. Mutation of an AP-1 and a PEA3 site at -1967 and -1973, respectively, or the co-expression of a transactivation domain-lacking c-jun substantially impaired the ability of c-Ha-ras to stimulate urokinase promoter activity. The induction of the urokinase promoter by ras was completely blocked by expression of a dominant negative c-raf expression vector and substantially reduced in cells made to co-express a catalytically inactive mitogen-activated protein kinase kinase. Further, the expression of an ERK1/ERK2-inactivating phosphatase (CL100) abrogated the stimulation of the urokinase promoter by c-Ha-ras. These data argue for a role of a mitogen-activated protein kinase-dependent signaling pathway in the regulation of urokinase promoter activity by ras.
authors.affiliation: Department of Tumor Biology/Head and Neck Surgery, M.D. Anderson Cancer Center, Houston, Texas 77030, USA.
authors.forename: E
authors.initials: E
authors.lastname: Lengyel
authors.forename: E
authors.initials: E
authors.lastname: Stepp
authors.forename: R
authors.initials: R
authors.lastname: Gum
authors.forename: D
authors.initials: D
authors.lastname: Boyd
mesh_terms: D000230:Adenocarcinoma; D000595:Amino Acid Sequence; D001665:Binding Sites; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D003062:Codon; D000939:Epitopes / Q000032:analysis; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D016758:Genes, jun; D011905:Genes, ras; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D008969:Molecular Sequence Data; D010051:Ovarian Neoplasms; D011401:Promoter Regions, Genetic; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis; D019908:Proto-Oncogene Proteins c-raf; D011994:Recombinant Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D015398:Signal Transduction; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D015533:Transcriptional Activation; D014162:Transfection; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms; D014568:Urokinase-Type Plasminogen Activator / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: D003062:Codon; D000939:Epitopes; D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D015500:Chloramphenicol O-Acetyltransferase; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D014568:Urokinase-Type Plasminogen Activator