Regulation and functional role of the Runt-related transcription factor-2 in pancreatic cancer

Br J Cancer. 2007 Oct 22;97(8):1106-15. doi: 10.1038/sj.bjc.6603984. Epub 2007 Sep 18.

Abstract

Recent evidence suggests that Runt-related transcription factors play a role in different human tumours. In the present study, the localisation of the Runt-related transcription factor-2 (Runx2), its transcriptional activity, as well as its regulation of expression was analysed in human pancreatic ductal adenocarcinoma (PDAC). Quantitative real-time PCR and immunohistochemistry were used for Runx2 expression and localisation analysis. Runt-related transcription factor-2 expression was silenced using specific siRNA oligonucleotides in pancreatic cancer cells (Panc-1) and immortalised pancreatic stellate cells (IPSCs). Overexpression of Runx2 was achieved using a full-length expression vector. TGF-beta1, BMP2, and other cytokines were assessed for their potential to regulate Runx2 expression. There was a 6.1-fold increase in median Runx2 mRNA levels in PDAC tissues compared to normal pancreatic tissues (P<0.0001). Runt-related transcription factor-2 was localised in pancreatic cancer cells, tubular complexes, and PanIN lesions of PDAC tissues as well as in tumour-associated fibroblasts/stellate cells. Coculture of IPSCs and Panc-1 cells, as well as treatment with TGF-beta1 and BMP2, led to increased Runx2 expression in Panc-1 cells. Runt-related transcription factor-2 overexpression was associated with decreased MMP1 release as well as decreased growth and invasion of Panc-1 cells. These effects were reversed by Runx2 silencing. In conclusion, Runx2 is overexpressed in PDAC, where it is regulated by certain cytokines such as TGF-beta1 and BMP2 in an auto- and paracrine manner. In addition, Runx2 has the potential to regulate the transcription of extracellular matrix modulators such as SPARC and MMP1, thereby influencing the tumour microenvironment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Carcinoma, Pancreatic Ductal / genetics
  • Carcinoma, Pancreatic Ductal / metabolism*
  • Cell Line, Tumor
  • Core Binding Factor Alpha 1 Subunit / genetics
  • Core Binding Factor Alpha 1 Subunit / metabolism*
  • Enzyme-Linked Immunosorbent Assay
  • Gene Expression
  • Humans
  • Immunohistochemistry
  • Matrix Metalloproteinase 1 / biosynthesis
  • Pancreatic Neoplasms / genetics
  • Pancreatic Neoplasms / metabolism*
  • RNA, Messenger / analysis
  • RNA, Small Interfering
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transfection

Substances

  • Core Binding Factor Alpha 1 Subunit
  • RNA, Messenger
  • RNA, Small Interfering
  • RUNX2 protein, human
  • Matrix Metalloproteinase 1