Letter | Published:

A SNAIL1–SMAD3/4 transcriptional repressor complex promotes TGF-β mediated epithelial–mesenchymal transition

Nature Cell Biology volume 11, pages 943950 (2009) | Download Citation



Epithelial–mesenchymal transition (EMT) is essential for organogenesis and is triggered during carcinoma progression to an invasive state1. Transforming growth factor-β (TGF-β) cooperates with signalling pathways, such as Ras and Wnt, to induce EMT2,3,4,5, but the molecular mechanisms are not clear. Here, we report that SMAD3 and SMAD4 interact and form a complex with SNAIL1, a transcriptional repressor and promoter of EMT6,7. The SNAIL1–SMAD3/4 complex was targeted to the gene promoters of CAR, a tight-junction protein, and E-cadherin during TGF-β-driven EMT in breast epithelial cells. SNAIL1 and SMAD3/4 acted as co-repressors of CAR, occludin, claudin-3 and E-cadherin promoters in transfected cells. Conversely, co-silencing of SNAIL1 and SMAD4 by siRNA inhibited repression of CAR and occludin during EMT. Moreover, loss of CAR and E-cadherin correlated with nuclear co-expression of SNAIL1 and SMAD3/4 in a mouse model of breast carcinoma and at the invasive fronts of human breast cancer. We propose that activation of a SNAIL1–SMAD3/4 transcriptional complex represents a mechanism of gene repression during EMT.

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We thank Carl-Henrik Heldin (Ludwig Institute for Cancer Research, Uppsala Branch) and Ola Hermansson (Department of Neuroscience, Karolinska Institute, Sweden) for fruitful discussions; Clara Francí (IMIM-Hospital del Mar, Barcelona) for the initial immunohistochemical analysis of human tumors; Anita Bergström, Silvia Menéndez and Marta Garrido for excellent technical assistance and Olov Andersson (Department of Cell and Molecular Biology, Karolinska Institute) for antibodies. Jonas Fuxe was supported by grants from the Swedish Research Council, the Swedish Wenner-Gren Foundation, the Swedish Childhood Cancer Foundation and an International Union Against Cancer (UICC), American Cancer Society International Fellowship for Beginning Investigators. Theresa Vincent was supported by the Swedish Research Council. Philip Leopold and Ronald Crystal were supported by the National Institutes of Health (NIH) by PO1 HL59312 and Antonio García de Herreros, Joan Albanell and Federico Rojo by RD06/0020/109, RD06/0020/040, FIS PI061513, SAF2006-00339 and Fundació Privada Cellex.

Author information


  1. Ludwig Institute for Cancer Research, Stockholm Branch, 17177 Stockholm, Sweden.

    • Theresa Vincent
    • , Etienne P. A. Neve
    •  & Ralf F. Pettersson
  2. Department of Cell and Molecular Biology, Karolinska Institute, 17177 Stockholm, Sweden.

    • Jill R. Johnson
    • , Alexander Kukalev
    • , Lennart Philipson
    •  & Jonas Fuxe
  3. Oncology Department, Programa de Recerca en Càncer, IMIM-Hospital del Mar, 08003 Barcelona, Spain.

    • Federico Rojo
    • , Joan Albanell
    •  & Antonio Garcia de Herreros
  4. Institute of Biomedicine/Anatomy, FI-00014, University of Helsinki, Finland.

    • Ismo Virtanen
  5. Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology, New Jersey 07030, USA.

    • Philip L. Leopold
  6. Department of Genetic Medicine, Weill Medical College of Cornell University, New York 10065, USA.

    • Ronald G. Crystal
  7. Ludwig Institute for Cancer Research, Uppsala Branch, SE-75124 Uppsala, Sweden.

    • Aristidis Moustakas
  8. Department of Cell and Developmental Biology, Weill Medical College of Cornell University, New York 10065, USA.

    • Theresa Vincent
  9. Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institute, 17177 Stockholm, Sweden.

    • Etienne P. A. Neve
  10. Servicio de Anatomia Patologica, Fundación Jiménez Díaz, Madrid, Spain.

    • Federico Rojo
  11. Servei d'Oncologia Patologica, Hospital del Mar, Barcelona, Spain.

    • Joan Albanell
  12. Department of Biochemistry and Biophysics, Matrix Division, Karolinska Institute, 17177 Stockholm, Sweden.

    • Jill R. Johnson
    • , Kristian Pietras
    •  & Jonas Fuxe


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T.V., E.P.A.N. and J.F. initiated the research, designed experiments and analysed data. T.V., E.P.A.N. and J.R.J. performed the in vitro experiments and discussed and analysed data. J.F. supervised the work and wrote the manuscript. T.V., E.P.A.N. and J.R.J. provided substantial input into preparation of the manuscript. F.R. and J.A. performed studies involving human tumours and analysed data. A.G.deH. designed and supervised studies on the human tumour samples. A.M. initiated experiments and discussed data involving SMADs. A.K. worked on protein interactions. K.P. performed experiments and analysed data from the mouse model. I.V. provided essential reagents. L.P., R.F.P., P.L.L. and R.G.C. discussed data, initiated experiments and provided significant intellectual contributions.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Jonas Fuxe.

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