title: The transcription factor snail mediates epithelial to mesenchymal transitions by repression of estrogen receptor-alpha.
abstract: The estrogen receptor (ER)-alpha (ESR1) is a key regulatory molecule in mammary epithelial cell development. Loss of ER-alpha in breast cancer is correlated with poor prognosis, increased recurrence after treatment, and an elevated incidence of metastasis. A proposed molecular pathway by which ER-alpha acts to constrain invasive growth in breast cancer cells involves direct, ER-alpha-dependent expression of metastasis-associated protein 3, a cell-type-specific component of the Mi-2/NuRD chromatin remodeling complex. MTA3 in turn represses expression of Snail, a transcription factor linked to epithelial to mesenchymal transition and cancer metastasis. To elucidate its role(s) in epithelial to mesenchymal transition (EMT), we expressed Snail in the noninvasive, ER-alpha-positive MCF-7 cell line. Snail expression led to decreased cell-cell adhesion and increased cell invasiveness. Furthermore, we observed loss of ER-alpha expression at both the RNA and protein level that was accompanied by direct interaction of Snail with regulatory DNA sequences at the ESR1 locus. A consequence of loss of ER-alpha function in this system was the increased abundance of key components of the TGF-beta signaling pathway. Thus, cross-talk among ER-alpha, Snail, and the TGF-beta pathway appears to control critical phenotypic properties of breast cancer cells.
authors.affiliation: Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, P.O. Box 12233, 111 TW Alexander Drive, Research Triangle Park, North Carolina 27709, USA.
authors.forename: Archana
authors.initials: A
authors.lastname: Dhasarathy
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kajita
authors.forename: Paul A
authors.initials: PA
authors.lastname: Wade
mesh_terms: D000107:Acetylation; D001943:Breast Neoplasms / Q000378:metabolism; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D015536:Down-Regulation; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism*; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D006801:Humans; D007438:Introns / Q000235:genetics; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D046228:Microarray Analysis; D010641:Phenotype; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D015398:Signal Transduction; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D006657:Histones; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D016212:Transforming Growth Factor beta