title: Metalloproteinases and their inhibitors in squamous cell carcinoma of the hypopharynx: indicators of individual tumor aggressiveness.
abstract: BACKGROUND
  Matrix metalloproteinases (MMP) are proteolytic enzymes capable of degrading connective tissue components. MMP activity is modulated by tissue inhibitors of metalloproteinases (TIMP). Imbalanced secretion of certain MMP or disturbances in the differential control of MMP by TIMP have been implicated in the invasive potential of malignant tumors.
  
  
  METHODS
  Thirty-nine surgically obtained specimens of the hypopharynx were immunohistochemically stained with antibodies against MMP-1, MMP-2, MMP-3, MMP-9 and their inhibitors, TIMP-1 and TIMP-2. Thirty-one samples derived from primary tumors (PT-group) and 8 samples from recurrent tumors (RT-group).
  
  
  RESULTS
  In the PT-group, MMP-1 was expressed in almost all tumors. Expression of TIMP-1 was rarer than of TIMP-2. Relapse occurred in 8/31 cases expressing MMP-1 or MMP-9 (4 cases each). Staining for TIMP-1 was negative in these patients, while TIMP-2 was expressed in most cases. In the RT-group, MMP-1 and MMP-9 stained positive in an almost equal number of cases. Only TIMP-1 was not expressed in any tumor. Patients who died of tumor were uniformly negative for TIMP-1.
  
  
  CONCLUSIONS
  The findings suggest that the presence of MMP-9 and concomitant lack of TIMP-1 serve as prognostic indicators of tumor aggressiveness and increased risk of relapse.
authors.affiliation: Department of Otorhinolaryngology, University of Kiel, Germany.
authors.forename: M C
authors.initials: MC
authors.lastname: Heissenberg
authors.forename: T
authors.initials: T
authors.lastname: Görögh
authors.forename: B M
authors.initials: BM
authors.lastname: Lippert
authors.forename: J A
authors.initials: JA
authors.lastname: Werner
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor; D002294:Carcinoma, Squamous Cell / Q000737:chemistry*; D005260:Female; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000737:chemistry*; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D019714:Tissue Inhibitor of Metalloproteinases / Q000032:analysis*; D014407:Tumor Cells, Cultured
chemical_list: D014408:Biomarkers, Tumor; D019714:Tissue Inhibitor of Metalloproteinases