Periostin gene expression in neu-positive breast cancer cells is regulated by a FGFR signaling cross talk with TGFβ/PI3K/AKT pathways

Breast Cancer Res. 2021 Nov 22;23(1):107. doi: 10.1186/s13058-021-01487-8.


Background: Breast cancer is a highly heterogeneous disease with multiple drivers and complex regulatory networks. Periostin (Postn) is a matricellular protein involved in a plethora of cancer types and other diseases. Postn has been shown to be involved in various processes of tumor development, such as angiogenesis, invasion, cell survival and metastasis. The expression of Postn in breast cancer cells has been correlated with a more aggressive phenotype. Despite extensive research, it remains unclear how epithelial cancer cells regulate Postn expression.

Methods: Using murine tumor models and human TMAs, we have assessed the proportion of tumor samples that have acquired Postn expression in tumor cells. Using biochemical approaches and tumor cell lines derived from Neu+ murine primary tumors, we have identified major regulators of Postn gene expression in breast cancer cell lines.

Results: Here, we show that, while the stromal compartment typically always expresses Postn, about 50% of breast tumors acquire Postn expression in the epithelial tumor cells. Furthermore, using an in vitro model, we show a cross-regulation between FGFR, TGFβ and PI3K/AKT pathways to regulate Postn expression. In HER2-positive murine breast cancer cells, we found that basic FGF can repress Postn expression through a PKC-dependent pathway, while TGFβ can induce Postn expression in a SMAD-independent manner. Postn induction following the removal of the FGF-suppressive signal is dependent on PI3K/AKT signaling.

Conclusion: Overall, these results reveal a novel regulatory mechanism and shed light on how breast tumor cells acquire Postn expression. This complex regulation is likely to be cell type and cancer specific as well as have important therapeutic implications.

Keywords: AKT; Breast cancer; FGF; Gene regulation; Periostin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / metabolism
  • Cell Adhesion Molecules / genetics*
  • Cell Adhesion Molecules / metabolism
  • Cell Line, Tumor
  • Epithelial Cells / metabolism
  • Female
  • Fibroblast Growth Factors / pharmacology
  • Gene Expression Regulation, Neoplastic* / drug effects
  • Humans
  • Mice
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Receptor, ErbB-2 / metabolism
  • Receptors, Fibroblast Growth Factor / metabolism*
  • Signal Transduction / drug effects
  • Transforming Growth Factor beta / metabolism*
  • Transforming Growth Factor beta / pharmacology


  • Cell Adhesion Molecules
  • POSTN protein, human
  • Receptors, Fibroblast Growth Factor
  • Transforming Growth Factor beta
  • Fibroblast Growth Factors
  • ERBB2 protein, human
  • Receptor, ErbB-2
  • Proto-Oncogene Proteins c-akt

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