Overexpression of c-myc in pancreatic cancer caused by ectopic activation of NFATc1 and the Ca2+/calcineurin signaling pathway

EMBO J. 2006 Aug 9;25(15):3714-24. doi: 10.1038/sj.emboj.7601246. Epub 2006 Jul 27.

Abstract

The nuclear factor of activated T cell (NFAT) proteins are a family of Ca2+/calcineurin-responsive transcription factors primarily recognized for their central roles in T lymphocyte activation and cardiac valve development. We demonstrate that NFATc1 is commonly overexpressed in pancreatic carcinomas and enhances the malignant potential of tumor cells through transcriptional activation of the c-myc oncogene. Activated NFATc1 directly binds to a specific element within the proximal c-myc promoter and upregulates c-myc transcription, ultimately resulting in increased cell proliferation and enhanced anchorage-independent growth. Conversely, c-myc transcription and anchorage-dependent and -independent cell growth is significantly attenuated by inhibition of Ca2+/calcineurin signaling or siRNA-mediated knock down of NFATc1 expression. Together, these results demonstrate that ectopic activation of NFATc1 and the Ca2+/calcineurin signaling pathway is an important mechanism of oncogenic c-myc activation in pancreatic cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites
  • Calcineurin / metabolism*
  • Calcium Signaling*
  • Cell Line, Tumor
  • Cell Proliferation
  • Humans
  • Molecular Sequence Data
  • NFATC Transcription Factors / genetics
  • NFATC Transcription Factors / metabolism*
  • Pancreatic Neoplasms / genetics
  • Pancreatic Neoplasms / metabolism*
  • Promoter Regions, Genetic
  • Proto-Oncogene Proteins c-myc / genetics
  • Proto-Oncogene Proteins c-myc / metabolism*
  • Transcriptional Activation
  • Up-Regulation

Substances

  • MYC protein, human
  • NFATC Transcription Factors
  • NFATC1 protein, human
  • Proto-Oncogene Proteins c-myc
  • Calcineurin