Imunoexpressão de twist e e-caderina em queilites actínicas

Abstract

Background: Actinic cheilitis (AC) is a potentially malignant oral lesion (PMOL) that results from chronic exposure to the sun's rays. Currently, it is not possible to predict which cases of AC will progress to squamous cell carcinoma of the lower lip, therefore, some biomolecular markers have been subject of investigation. In this context, Twist protein, a highly conserved transcription factor that belongs to the family of helix-loop-helix acts on the negative regulation of E-cadherin acting as a great regulator of the mesenchymal phenotype. Little is known about the role of Twist in PMOLs, however, recent studies have shown that this transcription factor may be involved in the process of oral carcinogenesis process since its early stages. Aim: This study aims to evaluate the immunoexpression of Twist and E-cadherin in ACs as well as to verify if this expression is associated with the morphological progression of these lesions. Methods: The epithelial immunoexpression of E-cadherin and Twist was analyzed semi-quantitatively in 86 cases of ACs with different degrees of epithelial dysplasia, according to the scores: (1) <25% positive cells; (2) 25 to 50% positive cells; (3) 50 to 75% positive cells and (4) >75% positive cells. Median comparisons of the E-cadherin and Twist expression scores with the actinic cheilitis’ histological grade were performed using the non-parametric Mann-Whitney test. Results: Analysis of Twist and E-cadherin expression in the actinic cheilitis’ epithelium revealed membrane and cytoplasmic immunoreactivity for E-cadherin in all epithelial layers except in the keratin layer. For Twist, nuclear and cytoplasmic immunoreactivity were observed in all epithelial layers, except for the keratin layer. Statistically significant differences were not found in the medians of total E-cadherin and Twist scores and in the different cell compartments analyzed (membrane and cytoplasmic for E-cadherin and nuclear and cytoplasmic for Twist) in relation to the actinic cheilitis’ histological grade (p > 0,05). Conclusion: The results of this study suggest a high immunoexpression of Twist and E-cadherin in cases of ACs, however, these proteins appear not to be associated with morphological progression in the analyzed cases.