Avaliação da imunoexpressão do fator induzido por hipóxia 1α (hif-1α) em cistos radiculares e dentígeros

Abstract

Odontogenic cysts are classified according to their origin in: developmental cysts, which include the dentigerous cyst (CD), or in inflammatory cysts, which have the root cyst (CR) as the main representative. In lesional microenvironments with low oxygen concentrations, the Hypoxia Induced Factor 1α (HIF-1) influences mechanisms responsible for cell survival. Thus, the aim of this research was to analyze the immunoexpression of HIF-1α in root and dentigerous cysts. The sample consisted of 40 cases of odontogenic cysts, 20 of CD and 20 of CR. Verification of HIF-1α expression was performed by the immunohistochemistry technique using anti-HIF-1α primary antibody (Clone EP1215Y, Abcam®, 1: 500, overnight, citrate pH 6, Pascal). Quantitative analysis was performed by counting the number of epithelial cells with immunostaining in the cytoplasm or nucleus in five fields photographed at a magnification of 400x. A qualitative analysis was also performed, observing the intensity of cytoplasmic immunostaining. The collected clinical data, such as sex, age and location site, were expressed in absolute and percentage frequency form and compared by Pearson's Chi-square test or Fisher's Exact and by Binomial Logistic Regression. The number of positive epithelial cells was expressed as mean and standard deviation and analyzed using the Student's T-test using the Statistical Package for the Social Sciences program. For all the tests performed, a significance level of 5% (p <0.05) was established. Immunohistochemical analysis evidenced positive marking throughout the sample. For the total number of cells with cytoplasmic immunostaining, between CR (67.7 ± 12.6) and CD (64.5 ± 16.1), there was no significant difference between the lesions (p = 0,480) and the Same result was found for nuclear immunostaining (p = 0.354). When the intensity of strong cytoplasmic immunostaining was observed and the clinical characteristics, the CD group presented a lower number of cells immunized by HIF-1α (11.7 ± 13.6) for the age group up to 30 years when compared to the age group of Individuals older than 30 years (34.5 ± 20.0), showing statistical difference (p = 0.010). When the strong cytoplasmic immunostaining was observed between the CR and CD groups in the anterior region of the jaws, it was verified that the CR group presented a greater quantity of immunolabelled cells (28.5 ± 8.5) than the CD group (14 , 0 ± 11.4), with statistical difference (p = 0.014). Considering the results obtained in this research, it can be concluded that HIF-1α is present in the epithelial constituents of CR and CD. However, further studies are needed to better elucidate the role of HIF-1α in odontogenic cysts.