IMMUNOHISTOCHEMICAL EVALUATION OF UPA, UPAR, AND PAI-1 IN AMELOBLASTOMAS AND ODONTOGENIC KERATOCYSTS

Abstract

<h3>Objectives</h3> To comparatively analyze the immunoexpression of plasminogen activator system (PAS) proteins (uPA, uPAR, and PAI-1) in ameloblastomas (AMBs) and odontogenic keratocysts (OKCs) and to investigate possible correlations between these proteins. <h3>Study Design</h3> Twenty solid AMBs and 20 OKCs were selected for immunohistochemical analysis. In each case, the immunoexpression of uPA, uPAR, and PAI-1 was evaluated semiquantitatively based on the percentage of positivity in odontogenic epithelial cells. <h3>Results</h3> The immunoexpression of uPA was significantly lower in AMBs when compared to OKCs (<i>P</i> = .001), and the immunostaining of uPAR in AMBs was significantly higher compared to OKCs (<i>P</i> < .001). There were no significant differences in PAI-1 immunoexpression between the groups studied (<i>P</i> = 1.000). The correlations between expressions of the proteins studied were not statistically significant. <h3>Conclusions</h3> PAS proteins might be involved in the pathogenesis of AMBs and OKCs. uPA is implicated in the development of OKCs, and uPAR may participate in tumorigenesis in AMBs. However, PAI-1 does not seem to directly contribute to the development of these lesions. Furthermore, the proteins studied do not appear to act synergistically.