Freitas, Roseana de AlmeidaMorais, Everton Freitas de2022-04-262022-04-262022-02-24MORAIS, Everton Freitas de. Biomarcadores da transição epitélio-mesenquimal em desordens potencialmente malignas e carcinoma de células escamosas de língua oral. 2022. 122f. Tese (Doutorado em Ciências Odontológicas) - Centro de Ciências da Saúde, Universidade Federal do Rio Grande do Norte, Natal, 2022.https://repositorio.ufrn.br/handle/123456789/47053During oral carcinogenesis, malignant cells acquire an aggressive phenotype that results in increased individual motility and the ability to invade surrounding tissues. Therefore, malignant epithelial cells develop a regulatory and programmed process called epithelial-mesenchymal transition (EMT), which is crucial for the acquisition of this aggressive malignant phenotype. The aim of the present study was to investigate the role of immunohistochemical expression of EMT signaling proteins in oral epithelial dysplasias and oral squamous cell carcinomas of the tongue (OTSCC), evaluating their respective associations with clinicopathological and prognostic parameters. Initially, aiming to obtain a deeper understanding of the proposed topic, two systematic literature reviews were developed evaluating the role of EMT as a possible prognostic marker in cases diagnosed as oral epithelial dysplasia and the role of nuclear transcription factors associated with the MET process in regulation of cellular plasticity and biological behavior in head and neck squamous cell carcinoma cell lines. For the immunohistochemical study, 47 cases of oral epithelial dysplasias and 41 cases diagnosed with OTSCC were selected, in which the immunoexpression of Twist1, Snail1, E-cadherin and Ncadherin proteins were analyzed. Possible associations between the expression pattern of these proteins and the histopathological grading of epithelial dysplasias and with the clinicopathological aspects, recurrence and survival in OTSCC were investigated. Different staining patterns were observed between the analyzed groups, with a significant loss of membrane E-cadherin expression in cases of OTSCC compared to cases of oral epithelial dysplasias (p = <0.0001). Worse overall survival was observed in cases with low membrane E-cadherin expression (HR = 0.27; p = 0.033) and high cytoplasmic Twist1 expression (HR = 3.19; p = 0.010). When analyzing the expression intensity parameter alone, an association was observed between high cytoplasmic N-cadherin intensity and overall survival (HR = 4.93; p = 0.006). Our findings suggest that loss of E-cadherin expression and increased expression of N-cadherin and nuclear transcription factors Twist1 and Snail1 are associated with the development and progression of oral carcinogenesis. Alone, loss of membrane expression of E-cadherin and increased cytoplasmic expression of Twist1 and N-cadherin were associated with worse survival.Acesso AbertoCarcinoma de células escamosasTransição epitélio-mesenquimalFatores de transcriçãoPrognósticodoctoralThesis