Essential role of c-Jun induction and coactivator p300 in epidermal growth factor-induced gene expression of cyclooxygenase-2 in human epidermoid carcinoma A431 cells

Lei Chin Chen, Ben Kuen Chen, Jia Ming Chang, Wen Chang Chang

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41 Citations (Scopus)


Cyclooxygenase-2 (COX-2) is an inducible enzyme responsible for high-level prostaglandin production during inflammation and carcinogenesis. In this study, the transcriptional regulation of COX-2 expression induced by epidermal growth factor (EGF) in human epidermoid carcinoma A431 cells was studied. EGF treatment induced the expression of COX-2 mRNA, protein, promoter and enzyme activity in a time-dependent manner. EGF-induced COX-2 promoter activity was inhibited by overexpression of the dominant-negative forms of Ras and ERK2. Induction of COX-2 and c-Jun by EGF was completely suppressed by MEK inhibitor combined with JNK inhibitor. Analysis of the COX-2 promoter binding proteins by gel mobility shift assay and DNA affinity precipitation assay revealed that c-Jun and p300 binding to CRE/E-box site were responsible for the EGF-induced COX-2 gene transcription. Overexpression of p300 significantly enhanced COX-2 promoter activity in cells overexpressed of c-Jun or treated with EGF. EGF- and c-Jun-induced transcription of COX-2 promoter was repressed by cotransfection of E1A in a dose-dependent manner. All together, these results indicated that the EGF-induced expression of COX-2 in A431 cells was mediated through the Ras-ERK/JNK signaling pathway, and subsequent induction of c-Jun following MAPK activation, in cooperation with coactivator p300, was required for the EGF response.

Original languageEnglish
Pages (from-to)38-48
Number of pages11
JournalBiochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
Issue number1-3
Publication statusPublished - Jul 5 2004
Externally publishedYes



  • c-Jun
  • Cyclooxygenase-2
  • Mitogen-activated protein kinase
  • p300

ASJC Scopus subject areas

  • Cell Biology
  • Molecular Biology
  • Biophysics

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