title: Increased expression of matrix metalloproteinase-2 in nasal polyps.
abstract: OBJECTIVE
  The formation and growth of nasal polyps requires remodeling of the extracellular matrix. Matrix metalloproteinases (MMPs) are a family of endopeptidases that can collectively degrade almost all extracellular matrix components. The aim of this study was to investigate the role of MMPs in nasal polyps.
  
  
  METHODS
  The expression of MMP-2 and -9 was investigated in the nasal polyps of 20 patients undergoing endonasal sinus surgery and compared with that in control nasal mucosal samples obtained from 20 non-allergic hypertrophic rhinitis patients. Tissue samples were either homogenized for reverse transcriptase polymerase chain reaction analysis or frozen for immunohistochemistry.
  
  
  RESULTS
  MMP-2 mRNA expression was observed only in the nasal polyp samples and not in the control tissues. MMP-9 mRNA was not expressed in either type of tissue. Similarly, MMP-2 expression was observed in the nasal polyps of chronic sinusitis patients but not in the inferior turbinate mucosa of the control subjects. MMP-2 positivity was present in basal cells in the surface epithelium and in infiltrating cells in subepithelial tissues. MMP-9-positive cells were not observed in either nasal polyps or inferior turbinates. These results suggest that MMP-2 expression is characteristic of nasal polyps.
  
  
  CONCLUSIONS
  MMP-2 may play a role in the remodeling of nasal polyps.
authors.affiliation: Department of Otorhinolaryngology, Mie University School of Medicine, Mie, Japan.
authors.forename: Alok
authors.initials: A
authors.lastname: Bhandari
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Takeuchi
authors.forename: Shinya
authors.initials: S
authors.lastname: Suzuki
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Harada
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Hayashi
authors.forename: Kyoko
authors.initials: K
authors.lastname: Imanaka-Yoshida
authors.forename: Toshimichi
authors.initials: T
authors.lastname: Yoshida
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Majima
mesh_terms: D000199:Actins / Q000378:metabolism; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008875:Middle Aged; D009297:Nasal Mucosa / Q000201:enzymology; D009298:Nasal Polyps / Q000150:complications / Q000201:enzymology* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012852:Sinusitis / Q000150:complications / Q000201:enzymology; D014420:Turbinates
chemical_list: D000199:Actins; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9