title: Comparative analysis of the immunohistochemical expression of collagen IV, MMP-9, and TIMP-2 in odontogenic cysts and tumors.
abstract: OBJECTIVE
  The aim of this study was to evaluate the immunohistochemical expression of collagen IV, matrix metalloproteinase (MMP) 9 and tissue inhibitor of MMP (TIMP) 2 in dentigerous cysts (DCs), radicular cysts (RCs), keratocystic odontogenic tumors (KOTs), and ameloblastomas.
  
  
  METHODS
  Twenty cases of DCs, 20 RCs, 20 KOTs, and 20 ameloblastomas were selected and analyzed by immunohistochemistry.
  
  
  RESULTS
  Most DCs and RCs showed continuous and >50% staining for collagen IV in the basement membrane of the epithelium, whereas predominantly discontinuous thin and ≤ 50% staining was observed in KOTs and ameloblastomas, with a significant difference in staining percentage (P < .001). MMP-9 was diffusely distributed and localized in both epithelial and mesenchymal cells of all of the lesions analyzed. The staining percentage was higher in the epithelium (P = .058) and mesenchyme (P = .005) of KOTs and ameloblastomas. Moreover, the distribution pattern, location, and percentage of expression of TIMP-2 were similar in the lesions studied, except for ameloblastoma, with a significant difference in staining percentage (P < .001).
  
  
  CONCLUSIONS
  These results demonstrate that the interaction between collagen IV, MMP-9, and TIMP-2 is an important factor for the establishment of differences in the biologic behavior of the odontogenic cysts and tumors studied.
authors.affiliation: Department of Dentistry, Federal University of Rio Grande do Norte, Natal, Brazil.
authors.forename: Águida Cristina Gomes
authors.initials: ÁC
authors.lastname: Henriques
authors.forename: Marcelo Gadelha
authors.initials: MG
authors.lastname: Vasconcelos
authors.forename: Hébel Cavalcanti
authors.initials: HC
authors.lastname: Galvão
authors.forename: Lélia Batista
authors.initials: LB
authors.lastname: de Souza
authors.forename: Roseana
authors.initials: R
authors.lastname: de Almeida Freitas
mesh_terms: D000564:Ameloblastoma / Q000201:enzymology / Q000473:pathology*; D001485:Basement Membrane / Q000201:enzymology / Q000473:pathology; D024141:Collagen Type IV / Q000032:analysis*; D004396:Coloring Agents; D003238:Connective Tissue / Q000201:enzymology / Q000473:pathology; D003803:Dentigerous Cyst / Q000201:enzymology / Q000473:pathology; D042783:Endothelial Cells / Q000201:enzymology / Q000473:pathology; D004847:Epithelial Cells / Q000201:enzymology / Q000473:pathology; D004848:Epithelium / Q000201:enzymology / Q000473:pathology; D005347:Fibroblasts / Q000201:enzymology / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D020780:Matrix Metalloproteinase 9 / Q000032:analysis*; D008648:Mesoderm / Q000201:enzymology / Q000473:pathology; D009807:Odontogenic Cysts / Q000201:enzymology / Q000473:pathology*; D011480:Protease Inhibitors / Q000032:analysis*; D011842:Radicular Cyst / Q000201:enzymology / Q000473:pathology; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000032:analysis*
chemical_list: D024141:Collagen Type IV; D004396:Coloring Agents; D011480:Protease Inhibitors; C560823:TIMP2 protein, human; D019716:Tissue Inhibitor of Metalloproteinase-2; D020780:Matrix Metalloproteinase 9