title: Transforming growth factor beta-1 induces snail transcription factor in epithelial cell lines: mechanisms for epithelial mesenchymal transitions.
abstract: The Snail transcription factor has been described recently as a strong repressor of E-cadherin in epithelial cell lines, where its stable expression leads to the loss of E-cadherin expression and induces epithelial-mesenchymal transitions and an invasive phenotype. The mechanisms regulating Snail expression in development and tumor progression are not yet known. We show here that transforming growth factor beta-1 (TGFbeta1) induces Snail expression in Madin-Darby canine kidney cells and triggers epithelial-mesenchymal transitions by a mechanism dependent on the MAPK signaling pathway. Furthermore, TGFbeta1 induces the activity of Snail promoter, whereas fibroblast growth factor-2 has a milder effect but cooperates with TGFbeta1 in the induction of Snail promoter. Interestingly, TGFbeta1-mediated induction of Snail promoter is blocked by a dominant negative form of H-Ras (N17Ras), whereas oncogenic H-Ras (V12Ras) induces Snail promoter activity and synergistically cooperates with TGFbeta1. The effects of TGFbeta1 on Snail promoter are dependent of MEK1/2 activity but are apparently independent of Smad4 activity. In addition, H-Ras-mediated induction of Snail promoter, alone or in the presence of TGFbeta1, depends on both MAPK and phosphatidylinositol 3-kinase activities. These data support that MAPK and phosphatidylinositol 3-kinase signaling pathways are implicated in TGFbeta1-mediated induction of Snail promoter, probably through Ras activation and its downstream effectors.
authors.affiliation: Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM) and Departamento de Bioquímica (UAM), Arturo Duperier 4, 28029 Madrid, Spain.
authors.forename: Hector
authors.initials: H
authors.lastname: Peinado
authors.forename: Miguel
authors.initials: M
authors.lastname: Quintanilla
authors.forename: Amparo
authors.initials: A
authors.lastname: Cano
mesh_terms: D000818:Animals; D015820:Cadherins / Q000235:genetics; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000235:genetics*; D004285:Dogs; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D011905:Genes, ras / Q000502:physiology; D007668:Kidney / Q000166:cytology*; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D008648:Mesoderm / Q000166:cytology; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D010641:Phenotype; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000235:genetics*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1
chemical_list: D015820:Cadherins; D004268:DNA-Binding Proteins; D016222:Fibroblast Growth Factor 2; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; D020929:Mitogen-Activated Protein Kinase Kinases; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1