title: Id-1 is induced in MDCK epithelial cells by activated Erk/MAPK pathway in response to expression of the Snail and E47 transcription factors.
abstract: Id-1, a member of the helix-loop-helix transcription factor family has been shown to be involved in cell proliferation, angiogenesis and invasion of many types of human cancers. We have previously shown that stable expression of E47 and Snail repressors of the E-cadherin promoter in MDCK epithelial cell line triggers epithelial mesenchymal transition (EMT) concomitantly with changes in gene expression. We show here that both factors activate the Id-1 gene promoter and induce Id-1 mRNA and protein. The upregulation of the Id-1 gene occurs through the transactivation of the promoter by the Erk/MAPK signaling pathway. Moreover, oncogenic Ras is also able to activate Id-1 promoter in MDCK cells in the absence of both E47 and Snail transcription factors. Several transcriptionally active regulatory elements have been identified in the proximal promoter, including AP-1, Sp1 and four putative E-boxes. By EMSA, we only detected an increased binding to Sp1 and AP-1 elements in E47- and Snail-expressing cells. Binding is affected by the treatment of cells with PD 98059 MEK inhibitor, suggesting that MAPK/Erk contributes to the recruitment or assembly of proteins to Id-1 promoter. Small interfering RNA directed against Sp1 reduced Id-1 expression and the upregulation of the promoter, indicating that Sp1 is required for Id-1 induction in E47- and Snail-expressing cells. Our results provide new insights into how some target genes are activated during and/or as a consequence of the EMT triggered by both E47 and Snail transcription factors.
authors.affiliation: IDIBELL-Institut de Recerca Oncològica, Centre d'Oncologia Molecular, Barcelona, Spain.
authors.forename: Mireia
authors.initials: M
authors.lastname: Jordà
authors.forename: Antònia
authors.initials: A
authors.lastname: Vinyals
authors.forename: Anna
authors.initials: A
authors.lastname: Marazuela
authors.forename: Eva
authors.initials: E
authors.lastname: Cubillo
authors.forename: David
authors.initials: D
authors.lastname: Olmeda
authors.forename: Eva
authors.initials: E
authors.lastname: Valero
authors.forename: Amparo
authors.initials: A
authors.lastname: Cano
authors.forename: Angels
authors.initials: A
authors.lastname: Fabra
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004285:Dogs; D024202:Electrophoretic Mobility Shift Assay; D004847:Epithelial Cells / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology; D005786:Gene Expression Regulation; D051798:Inhibitor of Differentiation Protein 1 / Q000096:biosynthesis / Q000235:genetics*; D020935:MAP Kinase Signaling System; D051379:Mice; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D011401:Promoter Regions, Genetic; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D000071250:Snail Family Transcription Factors; D016329:Sp1 Transcription Factor / Q000378:metabolism; D051820:TCF Transcription Factors / Q000235:genetics / Q000378:metabolism*; D058125:Transcription Factor 7-Like 1 Protein; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D005419:Flavonoids; D051798:Inhibitor of Differentiation Protein 1; D047428:Protein Kinase Inhibitors; D000071250:Snail Family Transcription Factors; D016329:Sp1 Transcription Factor; D051820:TCF Transcription Factors; C544912:TCF7L1 protein, human; C544913:Tcf7l1 protein, mouse; D058125:Transcription Factor 7-Like 1 Protein; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D048049:Extracellular Signal-Regulated MAP Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one