title: TGF-beta and the Smad signaling pathway support transcriptomic reprogramming during epithelial-mesenchymal cell transition.
abstract: Epithelial-mesenchymal transition (EMT) contributes to normal tissue patterning and carcinoma invasiveness. We show that transforming growth factor (TGF)-beta/activin members, but not bone morphogenetic protein (BMP) members, can induce EMT in normal human and mouse epithelial cells. EMT correlates with the ability of these ligands to induce growth arrest. Ectopic expression of all type I receptors of the TGF-beta superfamily establishes that TGF-beta but not BMP pathways can elicit EMT. Ectopic Smad2 or Smad3 together with Smad4 enhanced, whereas dominant-negative forms of Smad2, Smad3, or Smad4, and wild-type inhibitory Smad7, blocked TGF-beta-induced EMT. Transcriptomic analysis of EMT kinetics identified novel TGF-beta target genes with ligand-specific responses. Using a TGF-beta type I receptor that cannot activate Smads nor induce EMT, we found that Smad signaling is critical for regulation of all tested gene targets during EMT. One such gene, Id2, whose expression is repressed by TGF-beta1 but induced by BMP-7 is critical for regulation of at least one important myoepithelial marker, alpha-smooth muscle actin, during EMT. Thus, based on ligand-specific responsiveness and evolutionary conservation of the gene expression patterns, we begin deciphering a genetic network downstream of TGF-beta and predict functional links to the control of cell proliferation and EMT.
authors.affiliation: Ludwig Institute for Cancer Research, Uppsala, Sweden.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Valcourt
authors.forename: Marcin
authors.initials: M
authors.lastname: Kowanetz
authors.forename: Hideki
authors.initials: H
authors.lastname: Niimi
authors.forename: Carl-Henrik
authors.initials: CH
authors.lastname: Heldin
authors.forename: Aristidis
authors.initials: A
authors.lastname: Moustakas
mesh_terms: D000818:Animals; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D008648:Mesoderm / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D020411:Oligonucleotide Array Sequence Analysis; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects* / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
chemical_list: C525819:BMP7 protein, human; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; D004268:DNA-Binding Proteins; D018125:Receptors, Transforming Growth Factor beta; D015534:Trans-Activators; D016212:Transforming Growth Factor beta