Induction of the angiogenic modulator fibroblast growth factor-binding protein by epidermal growth factor is mediated through both MEK/ERK and p38 signal transduction pathways

J Biol Chem. 2000 Apr 14;275(15):10802-11. doi: 10.1074/jbc.275.15.10802.

Abstract

Fibroblast growth factor-binding protein (FGF-BP) is a secreted protein that binds and activates fibroblast growth factors (FGF-1 and FGF-2) and induces angiogenesis in some human cancers. FGF-BP is expressed at high levels in squamous cell carcinoma (SCC) cell lines and tumor samples and has been shown to be rate-limiting for the growth of SCC tumors in vivo. In this study, we examine the regulation of FGF-BP by epidermal growth factor (EGF) and the signal transduction mechanisms that mediate this effect. We found that EGF treatment of the ME-180 SCC cell line caused a rapid induction of FGF-BP gene expression. This induction was mediated transcriptionally through the AP-1 (c-Fos/JunD) and CCAAT/enhancer-binding protein elements as well as through an E-box repressor site in the proximal regulatory region of the FGF-BP promoter. Pharmacological inhibition of protein kinase C and mitogen-activated protein kinase/extracellular signal-regulated kinase kinase 1/2 (MEK1/2) completely blocked EGF induction of FGF-BP mRNA, whereas inhibition of phosphatidylinositol 3-kinase had no effect. Additionally, both EGF- and anisomycin-induced FGF-BP mRNA was abrogated by inhibition of p38 mitogen-activated protein kinase, demonstrating a role for p38 in the regulation of FGF-BP. Co-transfection of the FGF-BP promoter with dominant negative forms of MEK2, extracellular signal-regulated kinase 2, and p38 significantly decreased the level of EGF induction, whereas expression of a dominant negative c-Jun N-terminal kinase mutant or expression of c-Jun N-terminal kinase inhibitory protein had no effect. Similarly, activation of the p38 pathway by overexpression of wild-type p38 or MKK6 enhanced FGF-BP transcription. These results demonstrate that EGF induction of FGF-BP occurs selectively through dual activation of the stress-activated p38 and the MEK/extracellular signal-regulated kinase mitogen-activated protein kinase pathways, which ultimately leads to activation of the promoter through AP-1 and CCAAT/enhancer-binding protein sites.

Publication types

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

MeSH terms

  • CCAAT-Enhancer-Binding Proteins
  • Calcium-Calmodulin-Dependent Protein Kinases / physiology*
  • Carrier Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • Epidermal Growth Factor / pharmacology*
  • Female
  • Humans
  • Intercellular Signaling Peptides and Proteins
  • JNK Mitogen-Activated Protein Kinases*
  • MAP Kinase Kinase 4
  • Mitogen-Activated Protein Kinase 1 / physiology*
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinase Kinases / physiology
  • Mitogen-Activated Protein Kinases / physiology*
  • Nuclear Proteins / metabolism
  • Promoter Regions, Genetic
  • Protein Kinase C / physiology
  • Response Elements
  • Signal Transduction*
  • Sp1 Transcription Factor / metabolism
  • Transcription Factor AP-1 / metabolism
  • Tumor Cells, Cultured
  • p38 Mitogen-Activated Protein Kinases

Substances

  • CCAAT-Enhancer-Binding Proteins
  • Carrier Proteins
  • DNA-Binding Proteins
  • Intercellular Signaling Peptides and Proteins
  • Nuclear Proteins
  • Sp1 Transcription Factor
  • Transcription Factor AP-1
  • FGFBP1 protein, human
  • Epidermal Growth Factor
  • Protein Kinase C
  • Calcium-Calmodulin-Dependent Protein Kinases
  • JNK Mitogen-Activated Protein Kinases
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases
  • MAP Kinase Kinase 4
  • Mitogen-Activated Protein Kinase Kinases