title: ErbB2/Her-2 regulates the expression of Akt2 in prostate cancer cells.
abstract: BACKGROUND
  We have previously reported that ErbB family members regulate the signaling pathway leading to Akt and NF-kappaB activation in prostate cancer cells. In this study, the regulation of Akt2 expression in LNCaP, DU145, and PC-3 prostate cancer cell lines was investigated.
  
  
  METHODS
  Akt-2 expression was analyzed by western-blotting and Q-PCR in cell lines. We also analyzed the Akt-2 protein expression in a tissue microarray from 64 prostate cancer patients. Akt-2 promoter activity was assessed and analyzed by luciferase assay.
  
  
  RESULTS
  A concomitant over-expression of Her-2 and Akt2 expression was observed by western-blotting and quantitative-PCR in prostate cancer cell lines. A significant correlation between Her-2 and Akt2 protein expression was also observed by immunohistochemistry assay on prostate cancer tissues. In LNCaP cells, over-expression of Akt2 protein and mRNA was decreased by Her-2 pharmacologic inhibitors as well as small interfering RNA (siRNA) specific to Her-2. Cloning of the AKT2 promoter in a luciferase reporter plasmid further showed that Akt2 over-expression in cell lines is associated with increased AKT2 promoter activity suggesting that Her-2 modulates a signaling pathway involving AKT2 gene regulation.
  
  
  CONCLUSIONS
  This study reveals a novel mechanism of Akt2 regulation in prostate cancer cells.
authors.affiliation: Centre de recherche du Centre hospitalier de l'Université de Montréal and Institut du cancer de Montréal, Montreal, Quebec, Canada.
authors.forename: Cécile
authors.initials: C
authors.lastname: Le Page
authors.forename: Ismaël Hervé
authors.initials: IH
authors.lastname: Koumakpayi
authors.forename: Benjamin
authors.initials: B
authors.lastname: Péant
authors.forename: Nathalie
authors.initials: N
authors.lastname: Delvoye
authors.forename: Fred
authors.initials: F
authors.lastname: Saad
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Mes-Masson
mesh_terms: D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D011401:Promoter Regions, Genetic; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D051057:Proto-Oncogene Proteins c-akt / Q000096:biosynthesis* / Q000235:genetics; D034741:RNA, Small Interfering / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D051057:Proto-Oncogene Proteins c-akt; D034741:RNA, Small Interfering; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human; C494921:AKT2 protein, human