title: Increased activation and differentiated localization of native and phosphorylated STAT3 in nasal polyps.
abstract: BACKGROUND
  Chronic rhinosinusitis with nasal polyps (CRSwNP) is a multifactorial disease; the underlying mechanisms of cell signalling are not fully understood. STAT3 (signal transducer and activator of transcription 3) is a phosphokinase and a key signalling molecule implicated in cell cycle regulation. We studied the distribution and expression of STAT3 to examine the role of STAT3 in the pathogenesis of CRSwNP.
  
  
  METHODS
  We investigated tissue samples of the nasal polyps and inferior turbinate of patients with CRSwNP as well as samples of the inferior turbinate of subjects without chronic sinusitis. The expression levels of STAT3 and its activated form pSTAT3 were analysed using Western blotting, protein array, DNA microarray and immunohistochemistry.
  
  
  RESULTS
  No significant differences were found in STAT3-mRNA levels between the samples of nasal polyps and inferior turbinates of the same patient. However, the amount of pSTAT3 was increased in the polyp tissue compared to the inferior turbinates from both CRSwNP patients and control subjects (p < 0.01), indicating an activation of STAT3 in polyps. We identified a varying distribution pattern of pSTAT3; pSTAT3 was primarily found in superficial epithelial cells but not in the basal layer of the epithelium of the turbinate, whereas pSTAT3 was located in all layers of the epithelium of the polyp and mostly noted in the basal layer.
  
  
  CONCLUSIONS
  Our results of the activation and varying localisation of STAT3 and its phosphorylated form in nasal polyps suggest that pSTAT3 plays a crucial role in the proliferative development of nasal polyps.
authors.affiliation: Department of Otorhinolaryngology and Facial Plastic Surgery, University of Lübeck, Lübeck, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Linke
authors.forename: Ralph
authors.initials: R
authors.lastname: Pries
authors.forename: Michael
authors.initials: M
authors.lastname: Könnecke
authors.forename: Karl Ludwig
authors.initials: KL
authors.lastname: Bruchhage
authors.forename: Robert
authors.initials: R
authors.lastname: Böscke
authors.forename: Maximilian
authors.initials: M
authors.lastname: Gebhard
authors.forename: Barbara
authors.initials: B
authors.lastname: Wollenberg
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009297:Nasal Mucosa / Q000378:metabolism / Q000473:pathology; D009298:Nasal Polyps / Q000209:etiology* / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation; D012220:Rhinitis / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D012852:Sinusitis / Q000150:complications / Q000378:metabolism* / Q000473:pathology
chemical_list: D050796:STAT3 Transcription Factor