Analysis of the epidermal growth factor receptor promoter: the effect of nuclear factor-kappaB

Int J Mol Med. 2003 Jan;11(1):49-55.

Abstract

The epidermal growth factor receptor gene is highly regulated and responsive to extracellular stimuli that control cell growth. We have identified five putative nuclear factor-kappaB (NF-kappaB) binding sites within the epidermal growth factor receptor (EGFR) promoter region by sequence analysis. We have analyzed the potential role of NF-kappaB family members in the regulation of the EGFR transcription. Electrophoretic mobility shift analysis demonstrated that the p50 and p49, subunit proteins of the NF-kappaB, bound to the EGFR promoter at four out of five of these sites. However, it was found that NF-kappaB could not transactivate the EGFR by cotransfection experiments with each NF-kappaB subunit, using p50, p65 and c-Rel and an EGFR promoter luciferase reporter. Treatment of cells with tumor necrosis factor (TNF)-alpha, which could degrade the I-kappaB and then result in translocation of NF-kappaB to nucleus, did not enhance EGFR promoter reporter gene transcription. Also, TNF-alpha did not induce EGFR expression at the protein level. These results indicate that even though purified NF-kappaB can bind to the putative sites, there is no evidence that NF-kappaB transactivates the EGFR promoter region.

MeSH terms

  • 3T3 Cells
  • Animals
  • Base Sequence
  • Binding Sites
  • Breast Neoplasms
  • Consensus Sequence
  • ErbB Receptors / genetics*
  • Female
  • Gene Expression Regulation*
  • Genes, Reporter
  • Humans
  • Luciferases / genetics
  • Mice
  • Molecular Sequence Data
  • NF-kappa B / metabolism*
  • Promoter Regions, Genetic*
  • Protein Subunits / metabolism
  • Transcription, Genetic
  • Transcriptional Activation
  • Transfection
  • Tumor Cells, Cultured

Substances

  • NF-kappa B
  • Protein Subunits
  • Luciferases
  • ErbB Receptors