title: Immunohistochemical analysis of matrix metalloproteinases   (1, 2, and 9), Ki-67, and myofibroblasts in keratocystic   odontogenic tumors and pericoronal follicles.
abstract: BACKGROUND
  Keratocystic odontogenic tumor (KCOT) is a benign tumor that arises sporadically or associated with nevoid basal cell carcinoma syndrome (NBCCS). Its locally aggressive behavior contrasts with its cystic histological appearance. To better understand the interaction between tumor cells and the stroma, the present study aimed to evaluate and compare the immunohistochemical expression of matrix metalloproteinases (MMP-1, -2, and -9), the cellular proliferation index (Ki-67), and the presence of myofibroblasts (MFs) in KCOTs.
  
  
  METHODS
  Eleven cases of isolated KCOT (G1) and 12 cases of KCOT associated with NBCCS (G2) were selected for an immunohistochemical investigation of the proteins MMP-1, MMP-2, MMP-9, Ki-67, and α-smooth muscle actin (α-SMA) in MFs. A group of 6 pericoronal follicles (G3) was included as a normal odontogenic tissue control.
  
  
  RESULTS
  Significant differences between the G3 and G1/G2 groups regarding the expression of MMP-1, MMP-9 (in connective tissue), and Ki-67 were observed. In KCOT, there was a positive correlation between the Ki-67 antigen and MMP-1 and between MFs and MMP-1 in the parenchyma. No statistical differences were found between G1 and G2 groups.
  
  
  CONCLUSIONS
  MMP-1, MMP-9, and proliferative activity appear to play important roles in KCOT pathogenesis. The increased proliferative activity with KCOT was associated with elevated MMP-1 production in the parenchyma, which influenced the growth of the lesion in association with an increased number of MFs.
authors.forename: Grasieli
authors.initials: G
authors.lastname: de Oliveira Ramos
authors.forename: Aline
authors.initials: A
authors.lastname: Costa
authors.forename: Maria I
authors.initials: MI
authors.lastname: Meurer
authors.forename: Daniella S C
authors.initials: DS
authors.lastname: Vieira
authors.forename: Elena R C
authors.initials: ER
authors.lastname: Rivero
mesh_terms: D000199:Actins / Q000032:analysis; D001478:Basal Cell Nevus Syndrome / Q000378:metabolism / Q000473:pathology; D049109:Cell Proliferation; D003238:Connective Tissue / Q000737:chemistry / Q000473:pathology; D003795:Dental Sac / Q000737:chemistry* / Q000473:pathology; D004848:Epithelium / Q000737:chemistry / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D019394:Ki-67 Antigen / Q000032:analysis*; D020781:Matrix Metalloproteinase 1 / Q000032:analysis*; D020778:Matrix Metalloproteinase 2 / Q000032:analysis*; D020780:Matrix Metalloproteinase 9 / Q000032:analysis*; D058628:Myofibroblasts / Q000473:pathology*; D009808:Odontogenic Tumors / Q000737:chemistry* / Q000473:pathology; D017154:Stromal Cells / Q000737:chemistry / Q000473:pathology
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D019394:Ki-67 Antigen; D007633:Keratins; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9; C522360:MMP1 protein, human; D020781:Matrix Metalloproteinase 1