Inhibitor of differentiation 1 (Id1) and Id3 proteins play different roles in TGFβ effects on cell proliferation and migration in prostate cancer cells

Prostate. 2013 May;73(6):624-33. doi: 10.1002/pros.22603. Epub 2012 Oct 11.

Abstract

Background: In prostate cancer cells, transforming growth factor β (TGFβ) inhibits proliferation in earlier stages of the disease; however, the cancer cells become refractory to growth inhibitory effects in advanced stages where TGFβ promotes cancer progression and metastasis. Inhibitor of differentiation (Id) family of closely related proteins (Id1-Id4) are dominant negative regulators and basic helix loop helix (bHLH) transcription factors and in general promote proliferation, and inhibit differentiation. In the present study, we have investigated the role of Id1 and Id3 proteins in the growth inhibitory effects of TGFβ on prostate cancer cells.

Methods: The effect of TGF β on proliferation and Id1 and Id3 expression were investigated in PZ-HPV7, DU145, and PC3 cells. Id1 silencing through siRNA was also used in DU145 and PC3 cells to examine its role in anti-proliferative and migratory effects of TGFβ.

Results: TGFβ increased expression of Id1 and Id3 in all cell lines followed by a later down regulation of Id1 in PZ-HPV7 expression and DU145 cells but not in PC3 cells. Id3 expression remained elevated in all three cell lines. This loss of Id1 protein correlated with an increase of CDKNI p21. Id1 knockdown in both DU145 and PC3 cells resulted in decreased proliferation. However, while TGFβ caused a further decrease in proliferation of DU145, but had no further effects in PC3 cells. Knockdown of Id1 or Id3 inhibited TGFβ1induced migration in PC3 cells.

Conclusions: These findings suggest an essential role of Id1 and Id3 in TGFβ1 effects on proliferation and migration in prostate cancer cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cell Differentiation / drug effects
  • Cell Differentiation / physiology
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Cell Movement / physiology*
  • Cell Proliferation / drug effects
  • Epithelial Cells / drug effects
  • Epithelial Cells / pathology
  • Epithelial Cells / physiology
  • Gene Expression Regulation, Neoplastic / physiology
  • Growth Inhibitors / metabolism
  • Growth Inhibitors / pharmacology
  • Humans
  • Inhibitor of Differentiation Protein 1 / genetics*
  • Inhibitor of Differentiation Protein 1 / metabolism
  • Inhibitor of Differentiation Proteins / genetics*
  • Inhibitor of Differentiation Proteins / metabolism
  • Male
  • Neoplasm Proteins / genetics*
  • Neoplasm Proteins / metabolism
  • Prostatic Neoplasms* / genetics
  • Prostatic Neoplasms* / metabolism
  • Prostatic Neoplasms* / pathology
  • RNA, Small Interfering / genetics
  • Transforming Growth Factor beta1 / metabolism*
  • Transforming Growth Factor beta1 / pharmacology

Substances

  • Growth Inhibitors
  • ID1 protein, human
  • Inhibitor of Differentiation Protein 1
  • Inhibitor of Differentiation Proteins
  • Neoplasm Proteins
  • RNA, Small Interfering
  • TGFB1 protein, human
  • Transforming Growth Factor beta1
  • ID3 protein, human