Carcinogenesis, Teratogenesis & Mutagenesis ›› 2009, Vol. 21 ›› Issue (5): 358-361.doi: 10.3969/j.issn.1004-616x.2009.05.007

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TPA Responsiveness of ezrin Gene Promoter in Esophageal Carcinoma Cells

GAO Shu-ying1;3; LI En-min1;DU Ze-peng1; LU Xiao-feng2; XU Li-yan2;   

  1. 1. Department of Biochemistry and Molecular Biology, Medical College of Shantou University，Shantou 515041; 2. Institute of Oncologic Pathology, Medical College of Shantou University, Shantou 515041;3. Shenzhen PKU-HKUST Medical Center, Shenzhen 518036,Guangdong, China
  • Received:2009-02-11 Revised:2009-04-10 Online:2009-09-30 Published:2009-09-30
  • Contact: LI En-min

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Abstract: BACKGROUND AND AIM: To identify the TPA responsiveness of ezrin gene promoter and the mitogen-activated protein kinase(MAPK) signal pathway of TPA-induced ezrin transcription in esophageal carcinoma cells. MATERIALS AND METHODS: The potential transcription factors and TPA-responsive elements(TRE) were analyzed and predicted using transcription factor database. Using dual-luciferase reporter assay system, we determined the promoter activity and TPA responsiveness of ezrin gene －87/＋134 sequence, the transactivation of TRE binding proteins Sp1 and AP-1 on ezrin, and the inhibition of MAPK inhibitors on TPA-induced ezrin transactivation. RESULTS: Ezrin gene －87/＋134 sequence had potential TPA-responsive elements and exhibited promoter activity. 5 ng/ml TPA increased ezrin promoter activity significantly(P<0.01). Sp1 and AP-1 transactivated ezrin gene. MEK1/2 specific inhibitors U0126 and PD98059 decreased the TPA-induced ezrin transactivation. CONCLUSION: Ezrin gene promoter demonstrated TPA responsiveness in esophageal carcinoma cells. TPA may regulate ezrin transcription via MEK/ERK1/2 phosphoryla- ting Sp1 and AP-1 pathways.

Key words: TPA responsiveness, ezrin gene, esophageal carcinoma cell, promoter activity, dual-luciferase reporter assay system

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