Imunoexpressão da Yes-Associated Protein (YAP) em hiperceratoses e displasias epiteliais orais

Abstract

The search for a biomarker that helps to predict the risk of malignant transformation of oral potentially malignant disorders (OPMDs) represents a great challenge, as it can help in the early and adequate management of patients. This study evaluated the immunoexpression of Yes-Associated Protein (YAP) in intraoral leukoplastic, erythroplastic or leukoerythroplastic lesions, with histopathological diagnosis of hyperkeratosis or oral epithelial dysplasia (OED), correlating this immunoexpression with the degree of morphological severity of these lesions. The sample consisted of 20 cases of hyperkeratosis and 53 cases of OED, in addition to 10 cases of normal oral mucosa (control group). To assess the degree of dysplasia, the WHO grading (EL-NAGGAR et al., 2017) and the Binary System (KUJAN et al., 2006) were used, and the immunohistochemical profile of the YAP protein was evaluated through scores, which ranged from 0 to 3, based on their intracellular location (cytoplasmic or nuclear) and their distribution in the epithelial tissue. For the analysis of the studied parameters, Pearson's Chi-square and Fisher's Exact statistical tests were performed, in addition to non-parametric tests (significance level of 95%). Mild dysplasias were classified (100%) in the low risk of malignant transformation, while the moderate ones were divided between low (47%) and high risk (53%), with severe dysplasias, for the most part (71%), classified as high risk (p < 0.001). The control group exhibited score 0 of immunostaining (80%), hyperkeratosis and mild dysplasias (80% of booth) exhibit score 1, whereas in moderate (63%) and severe dysplasia (79%), the predominant scores was 2 and 3; with a pattern of nuclear immunostaining associated with the high risk of malignant transformation suggested by the Binary System (p = 0.002). The immunoexpression of YAP was similar between hyperkeratosis and mild dysplasias, which should attract greater attention from professionals in cases of hyperkeratosis. Furthermore, the expression of YAP appears to dichotomize OPMDs between lesions with low risk of malignant transformation and lesions with high risk, which may suggest, in the future, its use as a potential predictive marker of the progression for these lesions.