title: Presence of myofibroblasts and matrix metalloproteinase 2 in radicular cysts, dentigerous cysts, and keratocystic odontogenic tumors: a comparative immunohistochemical study.
abstract: BACKGROUND
  The aim of this study was to analyze the presence of myofibroblasts and matrix metalloproteinase 2 (MMP-2) in radicular cysts (RCs), dentigerous cysts (DCs), and keratocystic odontogenic tumors (KOTs).
  
  
  METHODS
  For the study, 29 RCs, 19 DCs, and 15 KOTs were selected. Immunohistochemical reactions were performed by using anti-MMP-2 and anti-α-smooth muscle actin (SMA) antibodies. For the analysis, 10 high-power fields were observed in each case to determine the percentage of positive cells, which was classified as negative, weak, or strong.
  
  
  RESULTS
  The presence of myofibroblasts (α-SMA-positive cells) was most common in KOTs (46.67%), followed by DCs (36.84%) and RCs (31.04%); however, it was not statistically significant (P = .8). The stromal MMP-2 expression was positive in all lesions but 1 case of KOT. Most cases of RC and DC presented strong MMP-2 expression in the stroma, whereas half of the KOTs showed similar classification. The MMP-2 expression was commonly found in the epithelial lining of the lesions; it was strong in almost all KOTs. No correlation between epithelial and stromal MMP-2 and α-SMA expressions was observed.
  
  
  CONCLUSIONS
  Myofibroblasts and MMP-2 are frequent in RCs, DCs, and KOTs and eventually can contribute to bone resorption, favoring the progression and growth of these lesions.
authors.affiliation: School of Dentistry, University of Ribeirao Preto, Ribeirao Preto, Sao Paulo, Brazil.
authors.forename: Michele Regina
authors.initials: MR
authors.lastname: Nadalin
authors.forename: Eduardo Rodrigues
authors.initials: ER
authors.lastname: Fregnani
authors.forename: Yara Teresinha Correa
authors.initials: YT
authors.lastname: Silva-Sousa
authors.forename: Danyel Elias
authors.initials: DE
authors.lastname: da Cruz Perez
mesh_terms: D000199:Actins / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D016130:Immunophenotyping; D020778:Matrix Metalloproteinase 2 / Q000032:analysis / Q000378:metabolism*; D058628:Myofibroblasts / Q000378:metabolism* / Q000473:pathology; D009807:Odontogenic Cysts / Q000201:enzymology* / Q000473:pathology*; D009808:Odontogenic Tumors / Q000201:enzymology* / Q000473:pathology*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric
chemical_list: D000199:Actins; D020778:Matrix Metalloproteinase 2