Reduced PTEN expression in the pancreas overexpressing transforming growth factor-beta 1

Br J Cancer. 2002 Jan 21;86(2):257-62. doi: 10.1038/sj.bjc.6600031.


PTEN is a candidate tumour suppressor gene and frequently mutated in multiple cancers, however, not in pancreatic cancer. Recently, it has been demonstrated that PTEN expression is regulated by TGF-beta1. Using TGF-beta1 transgenic mice (n=7) and wildtype littermates (n=6), as well as pancreatic tissues obtained from organ donors (n=10) and patients with pancreatic cancer (n=10), we assessed the expression of PTEN by means of immunohistochemistry and semiquantitative PCR analysis. In addition, PANC-1 cells were treated with TGF-beta1 in vitro and the levels of PTEN mRNA were determined in these cells. In human pancreatic cancers PTEN mRNA levels were significantly decreased (P<0.05). In addition, in the pancreas of TGF-beta1 transgenic mice the expression of PTEN was significantly reduced (P<0.01), as compared to wildtype littermates and incubation of PANC-1 cells with TGF-beta1 decreased PTEN mRNA levels after 24 h. Inasmuch as TGF-beta1 decreases PTEN expression in human pancreatic cancer cells and human pancreatic cancers overexpress TGF-beta1, the reduced expression of PTEN in pancreatic cancer may be mediated by TGF-beta1 overexpression. Thus, although PTEN is not mutated in pancreatic cancers, the reduction of its expression may give pancreatic cancer cells an additional growth advantage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Immunohistochemistry
  • Mice
  • Mice, Transgenic
  • PTEN Phosphohydrolase
  • Pancreatic Neoplasms / genetics*
  • Pancreatic Neoplasms / pathology
  • Phosphoric Monoester Hydrolases / biosynthesis*
  • Phosphoric Monoester Hydrolases / pharmacology
  • Polymerase Chain Reaction
  • RNA, Messenger / analysis
  • Transforming Growth Factor beta / biosynthesis*
  • Transforming Growth Factor beta1
  • Tumor Suppressor Proteins / biosynthesis*
  • Tumor Suppressor Proteins / pharmacology


  • RNA, Messenger
  • TGFB1 protein, human
  • Tgfb1 protein, mouse
  • Transforming Growth Factor beta
  • Transforming Growth Factor beta1
  • Tumor Suppressor Proteins
  • Phosphoric Monoester Hydrolases
  • PTEN Phosphohydrolase
  • PTEN protein, human