Pituitary adenylate-cyclase-activating polypeptide stimulates proto-oncogene expression and activates the AP-1 (c-Fos/c-Jun) transcription factor in AR4-2J pancreatic carcinoma cells

Eur J Biochem. 1996 Dec 15;242(3):467-76. doi: 10.1111/j.1432-1033.1996.467rr.x.


Pituitary adenylate-cyclase-activating polypeptide (PACAP) has been shown to possess mitogenic activity in various tumor cells. The present study was designed to investigate signal transduction mechanisms and expression of the proto-oncogenes c-fos and c-jun linked to the mitogenic effect of PACAP in the pancreatic carcinoma cell line AR4-2J. PACAP-(1-27)-peptide and PACAP-(1-38)-peptide, but not the structurally related vasoactive intestinal polypeptide (VIP), potently stimulated [3H]thymidine incorporation and cell number at doses of 0.1-10 nM. Both molecular forms of PACAP strongly increased formation of cAMP and inositol trisphosphate, elevated cytosolic Ca2+ levels and induced mitogen-activated protein (MAP) kinase activity. Quantitative reverse-transcription PCR revealed that PACAP-(1-27)-peptide and PACAP-(1-38)-peptide elevated c-fos mRNA levels 50-100-fold, whereas c-jun mRNA levels increased only moderately (2-3-fold). The effect of PACAP on c-fos and c-jun expression in AR4-2J cells was rapid (20 min), transient (1-2 h), dose-dependent IC50, 0.5 nM) and was abolished by the specific PACAP receptor antagonist PACAP-(6-38)-peptide or inhibitors of protein kinase C or tyrosine kinases. Compared with PACAP, epidermal growth factor and gastrin equipotently stimulated c-fos transcription whereas VIP, secretin, forskolin or phorbolester showed only marginal effects. Both PACAP (1-27)-peptide and PACAP-(1-38)-peptide strongly increased the DNA binding activity of the c-fos/ c-jun heterodimer transcription factor AP-1 at 10 nM and also stimulated AP-1 transcriptional activity up to 20-fold in AR4-2J cells. These findings indicate that the mitogenic effect of PACAP mediated via activation of the GTP-binding protein coupled PACAP/VIP-1 (PV1) receptor is linked to the MAP kinase cascade, increased expression of the proto-oncogenes c-fos and c-jun and activation of the heterodimeric transcription factor AP-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism
  • Cell Cycle
  • Cyclic AMP / metabolism
  • Cytosol / metabolism
  • Enzyme Inhibitors / pharmacology
  • Gene Expression Regulation*
  • Genes, fos*
  • Genes, jun*
  • Inositol 1,4,5-Trisphosphate / metabolism
  • Mitogens*
  • Neuropeptides / physiology*
  • Pituitary Adenylate Cyclase-Activating Polypeptide
  • Protein Kinase C / antagonists & inhibitors
  • Protein-Tyrosine Kinases / antagonists & inhibitors
  • RNA, Messenger / metabolism
  • Rats
  • Signal Transduction / drug effects
  • Sulfonamides / pharmacology
  • Transcription Factor AP-1 / metabolism*


  • Adcyap1 protein, rat
  • Enzyme Inhibitors
  • Mitogens
  • Neuropeptides
  • Pituitary Adenylate Cyclase-Activating Polypeptide
  • RNA, Messenger
  • Sulfonamides
  • Transcription Factor AP-1
  • W 7
  • Inositol 1,4,5-Trisphosphate
  • Cyclic AMP
  • Protein-Tyrosine Kinases
  • Protein Kinase C
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Calcium