Avaliação da imunoexpressão de PI3K e PTEN em ceratocistos odontogênicos e ameloblastomas

Abstract

Odontogenic cysts are relatively common lesions that cause bone destruction in the jaws. They are classified according to their origin in: developmental cysts, including odontogenic keratocyst (OKC), or in inflammatory cysts. Odontogenic tumors correspond to a complex group of lesions of different histopathological types and clinical behaviors, being classified according to their origin. Among tumors of odontogenic epithelial origin, ameloblastoma (AM) is often significant, tumor due to its slow growth and clinical feature of local invasiveness. The pathogenesis of odontogenic cysts and tumors is still little elucidated and studies aim to identify mechanisms and pathways involved in the formation and progression of these lesions. In this context, the PI3K / AKT / PTEN pathway has been analyzed in some odontogenic cysts and tumors in order to understand mechanisms involved in these lesions. Thus, the present study aimed to analyze and compare the immunohistochemical expression of PI3K and PTEN in odontogenic keratocysts and ameloblastomas. The sample consisted of 10 OKC and 10 AM. Immunohistochemical screening was performed using the anti-PI3K (1:400) and anti-PTEN (1:400). Mean ± SEM of the calculated cell counts and histories were expressed and analyzed by the Mann-Whitney test, followed by Dunn's post-test and correlated using Spearman's correlation. The categorical data were expressed as absolute frequency and compared using Fisher's Exact or Pearson's Chi-square test. Immunohistochemical analysis showed positive immunoblot in all cases of the sample. The total nuclear-stained cells for OKC PTEN were 39.21 ± 12.38 immunopositive cells and AM were 93.60 ± 2.45 (p <0.001). The cytoplasmic immunoexpression of PTEN to OKC was 87.35 ± 5.72 cells immunolabelled and 99.30 ± 0.48 for AM (p = 0.023). The comparison between the histoscore nucleus of PTEN in the OKC (4.90 ± 1.36) and in the AM (11.20 ± 0.53) (p=0.003), also evidencing statistical significance in the comparison of histoscore cytoplasm (p=0.011). The correlation between the percentages of PI3K and PTEN immunoblotting in OKC showed a statistically significant relationship between the percentage of cytoplasmic immunoexpression (p=0.019). Considering the results obtained in this research, it can be concluded that PI3K and PTEN are present in the epithelial constituents of OKC and AM. It is suggested that the PI3K / PTEN pathway may be active in OKC because the negative correlation of PI3K and PTEN is found in this odontogenic cyst.