title: Adrenomedullin Up-regulates the Expression of Vascular Endothelial Growth Factor in Epithelial Ovarian Carcinoma Cells via JNK/AP-1 Pathway.
abstract: OBJECTIVE
  Adrenomedullin (AM), a potent vasodilator peptide, presents in various kinds of tumors and promotes angiogenesis. We have previously reported that AM is expressed in epithelial ovarian carcinoma tissue. Here, we investigated the hypothesis that AM might regulate production of vascular endothelial growth factor (VEGF) in epithelial ovarian carcinoma and further promote angiogenic processes.
  
  
  METHODS
  The messenger RNA expression of VEGF in human epithelial ovarian carcinoma cells (HO-8910) was examined by real-time polymerase chain reaction. Transcriptional control was analyzed by transient transfection assay of VEGF promoter-luciferase hybrid genes and chromatin immunoprecipitation assay. Activation of c-Jun N-terminal kinase (JNK) was detected by Western blotting. The formation of capillarylike structures by EA.hy926 cells cocultured with HO-8910 cells on Matrigel was also studied.
  
  
  RESULTS
  We found that in HO-8910 cells, AM (10⁻¹⁰ to 10⁻⁷ mol/L) enhanced VEGF messenger RNA expression in a time- and concentration-dependent manner, as well as promoter activity. Furthermore, JNK was activated by AM stimulation. The AM-induced increase in VEGF expression was significantly attenuated by SP600125, a specific JNK inhibitor. Chromatin immunoprecipitation assay and promoter activity analysis showed that VEGF expression induced by AM required the activator protein 1 motif on the VEGF promoter. In an in vitro angiogenesis system for endothelial cells (EA.hy926) cocultured with HO-8910 cells, we observed that the addition of AM stimulated endothelial cell tube formation, which could be abolished by VEGF neutralizing antibody.
  
  
  CONCLUSIONS
  Our findings suggest that the JNK/Activator protein 1 pathway is involved in AM-induced VEGF expression in HO-8910 cells.
authors.affiliation: *Department of Gynecology, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China; and †Department of Gynecology and Obstetrics, Jin hua Municipal Central Hosptial, Jin hua, Zhejiang, China.
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Chen
authors.forename: Pan
authors.initials: P
authors.lastname: Chen
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Pang
authors.forename: Yanling
authors.initials: Y
authors.lastname: Hu
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D053607:Adrenomedullin / Q000494:pharmacology*; D000959:Antihypertensive Agents / Q000494:pharmacology; D015153:Blotting, Western; D000077216:Carcinoma, Ovarian Epithelial; D047369:Chromatin Immunoprecipitation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D009375:Neoplasms, Glandular and Epithelial / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000188:drug therapy / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D050436:Regulatory Elements, Transcriptional / Q000187:drug effects / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
chemical_list: D000959:Antihypertensive Agents; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D053607:Adrenomedullin; D048031:JNK Mitogen-Activated Protein Kinases