The tumour stroma is believed to contribute to some of the most malignant characteristics of epithelial tumours. However, signalling between stromal and tumour cells is complex and remains poorly understood. Here we show that the genetic inactivation of Pten in stromal fibroblasts of mouse mammary glands accelerated the initiation, progression and malignant transformation of mammary epithelial tumours. This was associated with the massive remodelling of the extracellular matrix (ECM), innate immune cell infiltration and increased angiogenesis. Loss of Pten in stromal fibroblasts led to increased expression, phosphorylation (T72) and recruitment of Ets2 to target promoters known to be involved in these processes. Remarkably, Ets2 inactivation in Pten stroma-deleted tumours ameliorated disruption of the tumour microenvironment and was sufficient to decrease tumour growth and progression. Global gene expression profiling of mammary stromal cells identified a Pten-specific signature that was highly represented in the tumour stroma of patients with breast cancer. These findings identify the Pten–Ets2 axis as a critical stroma-specific signalling pathway that suppresses mammary epithelial tumours.

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  1. 1.

    & Stromal effects on mammary gland development and breast cancer. Science 296, 1046–1049 (2002)

  2. 2.

    & Of extracellular matrix, scaffolds, and signaling: tissue architecture regulates development, homeostasis, and cancer. Annu. Rev. Cell Dev. Biol. 22, 287–309 (2006)

  3. 3.

    & Friends or foes – bipolar effects of the tumour stroma in cancer. Nature Rev. Cancer 4, 839–849 (2004)

  4. 4.

    Pregnancy-associated breast cancer and metastasis. Nature Rev. Cancer 6, 281–291 (2006)

  5. 5.

    , & Coevolution of cancer and stromal cellular responses. Cancer Cell 7, 499–500 (2005)

  6. 6.

    , & Stromal fibroblasts in cancer initiation and progression. Nature 432, 332–337 (2004)

  7. 7.

    & Fibroblasts in cancer. Nature Rev. Cancer 6, 392–401 (2006)

  8. 8.

    , , & Beyond PTEN mutations: the PI3K pathway as an integrator of multiple inputs during tumorigenesis. Nature Rev. Cancer 6, 184–192 (2006)

  9. 9.

    et al. Extracellular matrix signature identifies breast cancer subgroups with different clinical outcome. J. Pathol. 214, 357–367 (2008)

  10. 10.

    et al. The lipid phosphatase activity of PTEN is critical for its tumor supressor function. Proc. Natl Acad. Sci. USA 95, 13513–13518 (1998)

  11. 11.

    et al. Negative regulation of PKB/Akt-dependent cell survival by the tumor suppressor PTEN. Cell 95, 29–39 (1998)

  12. 12.

    , & Tenets of PTEN tumor suppression. Cell 133, 403–414 (2008)

  13. 13.

    , , & The roles of PTEN in development, physiology and tumorigenesis in mouse models: a tissue-by-tissue survey. Oncogene 27, 5398–5415 (2008)

  14. 14.

    , , & Pten is essential for embryonic development and tumour suppression. Nature Genet. 19, 348–355 (1998)

  15. 15.

    et al. Direct evidence for epithelial–mesenchymal transitions in breast cancer. Cancer Res. 68, 937–945 (2008)

  16. 16.

    et al. Expression of the neu protooncogene in the mammary epithelium of transgenic mice induces metastatic disease. Proc. Natl Acad. Sci. USA 89, 10578–10582 (1992)

  17. 17.

    et al. Development of the mammary gland requires DGAT1 expression in stromal and epithelial tissues. Development 131, 3047–3055 (2004)

  18. 18.

    et al. Amplification of the neu/erbB-2 oncogene in a mouse model of mammary tumorigenesis. Proc. Natl Acad. Sci. USA 97, 3444–3449 (2000)

  19. 19.

    et al. Initiating oncogenic event determines gene-expression patterns of human breast cancer models. Proc. Natl Acad. Sci. USA 99, 6967–6972 (2002)

  20. 20.

    et al. PGC-1α-responsive genes involved in oxidative phosphorylation are coordinately downregulated in human diabetes. Nature Genet. 34, 267–273 (2003)

  21. 21.

    et al. DAVID: Database for Annotation, Visualization, and Integrated Discovery. Genome Biol. 4, 3 (2003)

  22. 22.

    , & Systematic and integrative analysis of large gene lists using DAVID bioinformatics resources. Nature Protocols 4, 44–57 (2009)

  23. 23.

    , , , & PTEN blocks insulin-mediated ETS-2 phosphorylation through MAP kinase, independently of the phosphoinositide 3-kinase pathway. Hum. Mol. Genet. 11, 1687–1696 (2002)

  24. 24.

    et al. Persistent activation of mitogen-activated protein kinases p42 and p44 and ets-2 phosphorylation in response to colony-stimulating factor 1/c-fms signaling. Mol. Cell. Biol. 18, 5148–5156 (1998)

  25. 25.

    et al. Rapid phosphorylation of Ets-2 accompanies mitogen-activated protein kinase activation and the induction of heparin-binding epidermal growth factor gene expression by oncogenic Raf-1. Mol. Cell. Biol. 17, 2401–2412 (1997)

  26. 26.

    et al. ets-2 is a target for an akt (Protein kinase B)/jun N-terminal kinase signaling pathway in macrophages of motheaten-viable mutant mice. Mol. Cell. Biol. 20, 8026–8034 (2000)

  27. 27.

    et al. The Ets-1 and Ets-2 transcription factors activate the promoters for invasion-associated urokinase and collagenase genes in response to epidermal growth factor. Int. J. Cancer 77, 128–137 (1998)

  28. 28.

    et al. Activated Ets2 is required for persistent inflammatory responses in the motheaten viable model. J. Immunol. 173, 1374–1379 (2004)

  29. 29.

    Local proteolytic activity in tumor cell invasion and metastasis. Bioessays 27, 1181–1191 (2005)

  30. 30.

    et al. Ets1 and Ets2 are required for endothelial cell survival during embryonic angiogenesis. Blood 114, 1123–1130 (2009)

  31. 31.

    et al. Progression to malignancy in the polyoma middle T oncoprotein mouse breast cancer model provides a reliable model for human diseases. Am. J. Pathol. 163, 2113–2126 (2003)

  32. 32.

    et al. Defective trophoblast function in mice with a targeted mutation of Ets2. Genes Dev. 12, 1315–1326 (1998)

  33. 33.

    , , , & Processing of VEGF-A by matrix metalloproteinases regulates bioavailability and vascular patterning in tumors. J. Cell Biol. 169, 681–691 (2005)

  34. 34.

    et al. High affinity VEGF binding and developmental expression suggest Flk-1 as a major regulator of vasculogenesis and angiogenesis. Cell 72, 835–846 (1993)

  35. 35.

    , , , & Essential role of Flk-1 (VEGF receptor 2) tyrosine residue 1173 in vasculogenesis in mice. Proc. Natl Acad. Sci. USA 102, 1076–1081 (2005)

  36. 36.

    et al. Conformational HER-2/neu B-cell epitope peptide vaccine designed to incorporate two native disulfide bonds enhances tumor cell binding and antitumor activities. J. Biol. Chem. 280, 54–63 (2005)

  37. 37.

    et al. Stromal gene expression predicts clinical outcome in breast cancer. Nature Med. 14, 518–527 (2008)

  38. 38.

    et al. A functional genetic approach identifies the PI3K pathway as a major determinant of trastuzumab resistance in breast cancer. Cancer Cell 12, 395–402 (2007)

  39. 39.

    et al. Recurrent gross mutations of the PTEN tumor suppressor gene in breast cancers with deficient DSB repair. Nature Genet. 40, 102–107 (2008)

  40. 40.

    et al. Poor prognosis in carcinoma is associated with a gene expression signature of aberrant PTEN tumor suppressor pathway activity. Proc. Natl Acad. Sci. USA 104, 7564–7569 (2007)

  41. 41.

    , , & Ets2-dependent microenvironmental support of mouse mammary tumors. Oncogene 24, 6870–6876 (2005)

  42. 42.

    et al. Ets2 transcription factor in normal and neoplastic human breast tissue. Eur. J. Cancer 42, 485–491 (2006)

  43. 43.

    et al. Heterologous tissue culture expression signature predicts human breast cancer prognosis. PLoS One 2, e145 (2007)

  44. 44.

    et al. ERK phosphorylation is linked to VEGFR2 expression and Ets-2 phosphorylation in breast cancer and is associated with tamoxifen treatment resistance and small tumours with good prognosis. Oncogene 24, 4370–4379 (2005)

  45. 45.

    et al. Activation of synovial fibroblasts in rheumatoid arthritis: lack of Expression of the tumour suppressor PTEN at sites of invasive growth and destruction. Arthritis Res. 2, 59–64 (2000)

  46. 46.

    et al. Negative regulation of myofibroblast differentiation by PTEN (phosphatase and tensin homolog deleted on chromosome 10). Am. J. Respir. Crit. Care Med. 173, 112–121 (2006)

  47. 47.

    & Oxidative processes in the brain and non-neuronal tissues as biomarkers of Alzheimer’s disease. Front. Biosci. 7, d1007–d1015 (2002)

  48. 48.

    , , & Prognostic and predictive factors in breast cancer by immunohistochemical analysis. Mod. Pathol. 11, 155–168 (1998)

  49. 49.

    & A simplified method for passage and long-term growth of human mammary epithelial cells. In Vitro Cell. Dev. Biol. 22, 6–12 (1986)

  50. 50.

    Generalized lacZ expression with the ROSA26 Cre reporter strain. Nature Genet. 21, 70–71 (1999)

  51. 51.

    , , , & In situ localization of gelatinolytic activity in the extracellular matrix of metastases of colon cancer in rat liver using quenched fluorogenic DQ-gelatin. J. Histochem. Cytochem. 51, 821–829 (2003)

  52. 52.

    et al. Gene-resolution analysis of DNA copy number variation using oligonucleotide expression microarrays. BMC Genomics 8, 111 (2007)

  53. 53.

    et al. Eos, MITF, and PU.1 recruit corepressors to osteoclast-specific genes in committed myeloid progenitors. Mol. Cell. Biol. 27, 4018–4027 (2007)

  54. 54.

    & Resampling-Based Multiple Testing: Examples and Methods for p-Value Adjustment (John Wiley, 1993)

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We thank M. Rawahneh and J. Moffitt for histotechnical assistance, K. Kornacker, S. Cory and I. Vasudeva Murthy for bioinformatics assistance, P. Gulati for statistics assistance, the Ohio State University Human Tissue Resource Network and the Ohio State University Comprehensive Cancer Center Microarray, Nucleic Acids, Trangenics and Flow Cytometry Shared Facilities for technical assistance. MMTV-ErbB2 mice were provided by W. Muller. This work was funded by the National Institutes of Health to G.L. (R01CA85619, R01HD47470, P01CA097189) and to M.C.O. (R01CA053271, P01CA097189), by the Komen Breast Cancer Foundation and Evelyn Simmers Charitable Trust to M.C.O., by the Terry Fox New Frontiers Group Grant to M.P., and by the Natural Science and Engineering Research Council of Canada Discovery Grants Program grant to M.H. F.L. and F.P. were funded by Department of Defense Pre-doctoral Fellowships and J.-L.C. was funded by a Department of Defense Postdoctoral Fellowship. G.L. is the recipient of the Pew Charitable Trusts Scholar Award and the Leukemia and Lymphoma Society Scholar Award. M.P. holds the Diane and Sal Guerrera Chair in Cancer Genetics at McGill University.

Author Contributions G.L. and M.C.O. designed and supervised this study, analysed data, and helped write and edit the manuscript. A.J.T., C.Z.C., F.L. and J.A.W. designed and performed experiments, collected and analysed data, and co-wrote the paper. N.C., J.C.T., H.W., J-L.C., S.M.S. and M.N.G. technically assisted with experiments, and collected and analysed data. G.W., A.J.T., M.L.R and M.W performed experiments in initial stages of the project, particularly in designing and characterizing the mouse models. S.N., P.S. and T.J.R. contributed to the histopathological analysis of the mouse mammary tumour models and writing the manuscript. S.H.B. and L.Y. contributed to the histopathological analysis of human samples and writing the manuscript. S.A.F. and J.A.S. contributed to the statistical analyses of data and writing the manuscript. A.M., F.P., J.A.W., E.C., M.H. and M.P. contributed to the analysis and comparison of mouse and human microarray data and writing the mansucript.

Author information

Author notes

    • Anthony J. Trimboli
    • , Carmen Z. Cantemir-Stone
    •  & Fu Li

    These authors contributed equally to this work.

    • Sanford H. Barsky
    •  & Michael L. Robinson

    Present addresses: Department of Pathology, University of Nevada School of Medicine, Reno, Nevada 89557, and Nevada Cancer Institute, Las Vegas, Nevada 89135, USA (S.H.B.); Department of Zoology, Miami University, Oxford, Ohio 45056, USA (M.L.R.).


  1. Department of Molecular Genetics, College of Biological Sciences,

    • Anthony J. Trimboli
    • , Fu Li
    • , Nicholas Creasap
    • , John C. Thompson
    • , Enrico Caserta
    • , Hui Wang
    • , Jean-Leon Chong
    • , Shan Naidu
    • , Guo Wei
    • , Michael B. Weinstein
    •  & Gustavo Leone
  2. Department of Molecular Virology, Immunology and Medical Genetics,

    • Anthony J. Trimboli
    • , Nicholas Creasap
    • , John C. Thompson
    • , Enrico Caserta
    • , Hui Wang
    • , Jean-Leon Chong
    • , Shan Naidu
    • , Michael B. Weinstein
    •  & Gustavo Leone
  3. Department of Molecular and Cellular Biochemistry, College of Medicine,

    • Carmen Z. Cantemir-Stone
    • , Fu Li
    • , Julie A. Wallace
    • , Anand Merchant
    • , Guo Wei
    • , Sudarshana M. Sharma
    •  & Michael C. Ostrowski
  4. Department of Veterinary Biosciences, College of Veterinary Medicine,

    • Shan Naidu
    • , Thomas J. Rosol
    •  & Paul C. Stromberg
  5. Center for Biostatistics, Office of Health Sciences,

    • Julie A. Stephens
    •  & Soledad A. Fernandez
  6. Department of Biomedical Informatics,

    • Metin N. Gurcan
  7. Department of Pathology and,

    • Sanford H. Barsky
  8. Department of Surgery, School of Medicine, The Ohio State University, Columbus, Ohio 43210, USA

    • Lisa Yee
  9. Center for Molecular and Human Genetics, Columbus Children’s Research Institute, Columbus, Ohio 43205, USA

    • Michael L. Robinson
  10. Department of Biochemistry, Rosalind and Morris Goodman Cancer Center,

    • Francois Pepin
    • , Michael Hallett
    •  & Morag Park
  11. McGill Center for Bioinformatics,

    • Francois Pepin
    •  & Michael Hallett
  12. Department of Oncology, McGill University, Québec H3A 1A1, Canada

    • Morag Park
  13. Tumor Microenvironment Program, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA

    • Michael C. Ostrowski
    •  & Gustavo Leone


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Correspondence to Michael C. Ostrowski or Gustavo Leone.

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