Expressão imuno-histoquímica das proteínas ING1 e ING2 em lesões odontogênicas epiteliais benignas

Abstract

Epithelial odontogenic lesions are a heterogeneous group of lesions whose biological behavior is still the target of investigation. Such lesions originate from epithelial and / or ectomesenchymal tissues of the dental organ. Defects in cell cycle regulation may be involved in the development and progression of these lesions. INGs (inhibitors of growth) proteins play an important role in controlling mechanisms related to the cell cycle. The aim of this study was therefore to investigate the expression of ING1 and ING2, to better understand the possible role of these proteins in ameloblastoma (AMB) (n = 20), adenomatoid odontogenic tumor (TOA) (n = 20), odontogenic keratocyst ( CO) (n = 20) and dental follicle (FD) (n = 10) as a control. The immunohistochemical expression of ING1 and ING2 was assessed quantitatively by a single examiner. In five histological fields of each lesion, positive and negative cells in the nucleus and / or cytoplasm were quantified, establishing the percentage of positive cells in relation to the total number of cells. The data were subjected to statistical analysis using the KruskalWallis (KW) tests, post-test using the Dunn Method and Spearman (r) correlation calculation, with the significance level set at 5% (p <0.05). There was significant difference between ING1 nuclear labeling in the analyzed groups. AMBs and COs exhibited significantly lower ING1 expression than DFs (p = 0.0002 and p = 0.042). There was a difference in the concomitant nucleus / cytoplasmic labeling of ING1, with a significantly high expression in cases of AMB when compared to the other groups with TOA exclusion (p <0.05). For the ING2 protein, there was a difference in nuclear labeling between the groups analyzed (p = 0.0001), with a significantly lower expression being observed in the cases of AMBs, TOAs and COs when compared to the FDs (p <0.05). When comparing groups two by two in the expression nucleus / cytoplasmic, it was observed that the group of AMBs and COs showed a higher expression than TOA (p = 0.002 and p = 0.0001). For all groups studied, there was a negative correlation between ING1 and ING2 labeling in the nucleus / cytoplasm with the cytoplasm restricted labeling. The results of this study suggest the participation of ING1 and ING2 proteins in the pathogenesis of the studied lesions and the immunostaining of ING1 and ING2 and their cell location in AMBs and COs indicates that these proteins contribute to more aggressive biological behavior.