Bile acids induce cyclooxygenase-2 expression via the epidermal growth factor receptor in a human cholangiocarcinoma cell line

Gastroenterology. 2002 Apr;122(4):985-93. doi: 10.1053/gast.2002.32410.

Abstract

Background & aims: Although bile acids have been implicated in colon cancer development, their role in biliary tract carcinogenesis remains unexplored. Because receptor tyrosine kinases and cyclooxygenase (COX)-2 have been implicated in carcinogenesis, we examined the hypothesis that bile acids modulate these enzymes in KMBC cells, a human cholangiocarcinoma cell line.

Methods: The effect of bile acids on epidermal growth factor receptor (EGFR) stimulation, mitogen-activated protein kinase (MAPK) activation, and COX-2 expression was evaluated.

Results: Bile acids both induced EGFR phosphorylation and enhanced COX-2 protein expression. Bile acid-induced EGFR phosphorylation was associated with subsequent activation of MAPK p42/44, p38, and c-Jun-N-terminal kinase (JNK). The MAPK inhibitors, PD098059 for MAP or extracellular signal-regulated kinase 1, SB203580 for p38, and BAY 37-9751 for Raf-1, blocked COX-2 induction by bile acids. However, inhibition of JNK activity did not block bile acid-mediated COX-2 induction.

Conclusions: The results show that EGFR is activated by bile acids and functions to induce COX-2 expression by an MAPK cascade. This induction of COX-2 may participate in the genesis and progression of cholangiocarcinomas.

Publication types

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

MeSH terms

  • Bile Acids and Salts / pharmacology*
  • Bile Duct Neoplasms*
  • Bile Ducts, Intrahepatic
  • Cholangiocarcinoma*
  • Cyclooxygenase 2
  • ErbB Receptors / metabolism*
  • Gene Expression Regulation, Enzymologic / drug effects
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Isoenzymes / genetics*
  • JNK Mitogen-Activated Protein Kinases*
  • MAP Kinase Kinase 4
  • MAP Kinase Signaling System / drug effects
  • Membrane Proteins
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinase Kinases / metabolism
  • Mitogen-Activated Protein Kinases / metabolism
  • Prostaglandin-Endoperoxide Synthases / genetics*
  • Tumor Cells, Cultured
  • p38 Mitogen-Activated Protein Kinases
  • src-Family Kinases / metabolism

Substances

  • Bile Acids and Salts
  • Isoenzymes
  • Membrane Proteins
  • Cyclooxygenase 2
  • PTGS2 protein, human
  • Prostaglandin-Endoperoxide Synthases
  • ErbB Receptors
  • src-Family 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