Associação da imunoexpressão das proteínas Ecaderina, SHH e GLI-1 com parâmetros clinicopatológicos em Carcinoma Epidermóide de Língua Oral / Association of immunoexpression of Ecadherin, SHH and GLI-1 proteins with clinicopathological parameters in Oral Tongue Squamous Cell Carcinoma

RESUMO

O potencial de invasão do carcinoma epidermoide requer modifcações fenotípicas nas células parenquimatosas de forma que essas adquiram capacidade de sobreviver e invadir o microambiente tumoral. Esse processo de modificação fenotípica é denominado de transição epitélio-mesenquimal (TEM), cujo as células epiteliais perdem parte de suas características e adquirem outras inerentes às células mesenquimais, de forma controlada por diversos fatores de transcrição indutores destas alterações, conferindo além das habilidades citadas, características de célula tronco, de resistência ao tratamento antineoplásico e angiogênese. O objetivo do presente estudo foi investigar associações da expressão imunoistoquímica das proteínas E-caderina, Shh e Gli-1, sinalizadoras da TEM, com caraterísticas clinicopatológicas de carcinomas epidermoides de língua oral (CELO). A imunoexpressão dessas proteínas foi analisada em 42 casos de CELO, de forma semiquantitativa, nas células neoplásicas do front de invasão tumoral e nos brotamentos tumorais. Os CELOs foram classificados como de baixa e alta expressão proteíca. As gradações de Almangush et al. (2015) e de Boxberg et al. (2017) mostraram categorização semelhante para os casos de CELOs, todavia, a gradação de Almangush et al. (2015) apresentou melhor associação com os parâmetros clínicos, destacando o tamanho do tumor (p=0,013) e o desfecho de óbito (p<0,01). A análise imunoistoquímica revelou predomínio de baixa expressão membranar da E-caderina, apresentando associação significativa com o comprometimento linfonodal (p=0,042). A expressão do Shh foi bem variável e não mostrou associações significativas. A expressão do Gli-1 foi predominantemente alta, mostrando relações significativas com parâmetros clinicopatológicos, como comprometimento linfonodal (p=0,024), estágio clínico do tumor (p=0,016), profundidade de invasão (p=0,015), atividade de brotamentos tumorais (p=0,033), menor tamanho do ninho tumoral (p=0,020) e o grau de diferenciação (p=0,033), sendo estes quatro últimos associados com os brotamentos tumorais. A análise estatística evidenciou ausência de associações significativas entre as variáveis imunoistoquímicas e indicadores de prognóstico do CELO. Os resultados deste estudo indicam que os sistemas de gradação morfológica analisados mostraram-se eficazes na identificação de casos de CELOs mais agressivos, com maior destaque para o proposto por Almangush et al (2015) e, em relação aos achados imunoistoquímicos, os resultados sugerem que a menor expressão membranar da E-caderina e a alta expressão nuclear/citoplasmática de Gli-1 associaram-se ao parâmetro clínico de pior prognóstico, referente ao comprometimento nodal. Diante do modelo do estudo, não se observou associação da imunoexpressão das proteínas estudadas com a sobrevida dos pacientes (AU).

ABSTRACT

The potential for squamous cell carcinoma invasion requires phenotypic modifications in the parenchymal cells so that they acquire the ability to survive and invade the tumor microenvironment. This process of phenotypic modification is called epithelialmesenchymal transition (EMT), which is crucial for the acquisition of this aggressive malignant phenotype. In this process, the epithelial cells lose part of their characteristics and acquire others inherent to the mesenchymal cells, in a controlled manner, inducing by various transcription factors, conferring, in addition to the aforementioned abilities, stem cell characteristics, resistance to anti-neoplastic treatment and angiogenesis. The aim of the present study was to investigate associations between the immunohistochemical expression of E-cadherin, Shh e, Gli-1 proteins, signaling TEM, with clinicopathological characteristics of oral tongue squamous cell carcinoma (OTSCC). The immunoexpression of these proteins was analyzed in 42 cases of OTSCC, in a semiquantitative way, in the neoplastic cells of the tumor invasion front and in the cells that make up the tumor budding. OTSCCs were classified as low and high protein expression. Aiming at the association of immunohistochemical findings with clinicopathological variables and survival rates, cases were classified into low expression and high expression categories. Initially, statistical differences between the histopathological gradations of malignancy by Almangush et al. (2015) and that of Boxberg et al. (2017) regarding clinical parameters. Both, the gradations showed similar categorization for OTSCC cases, were able to categorize the tumors, however, the gradation by Almangush et al. (2015) showed a better association with clinical parameters, highlighting tumor size (p=0.013) and the outcome of death (p<0.01). The immunohistochemical analysis revealed a predominance of low membrane expression of E-cadherin, with a statistically significant association with lymph node involvement (p=0.042). The expression of Shh was quite variable and had no statistically significant associations. Gli-1 had a prevalence of high expression, showing significant relationships with clinicopathological parameters, such as the occurrence of lymph node involvement (p=0.024), clinical stage of the tumor (p=0.016), depth of invasion (p=0.015), activity of tumor budding (p=0.033), smaller size of the tumor nest (p=0.020) and degree of differentiation (p=0.033), the last four being associated with tumor budding. Some correlations between markers were found, such as the positive correlation between the cytoplasmic expression of E-cadherin with Shh (p=0.030) and the immunoexpression of Gli-1 in the cytoplasm/nucleus with Shh (p=0.041). Statistical analysis evidenced the absence of significant associations between immunohistochemical variables and OTSCC prognostic indicators. The findings of this study suggest the expression pattern of E-cadherin, Shh and Gli-1 in OTSCC, in addition to indicating a better clinicopathological association with the malignancy gradation of Almangush et al. (2015). However, the expression of these biomarkers may not be related to patient survival. In addition, no significant differences were observed between the expression of the proteins studied in tumor budding when other cells in the invasion front were evaluated, suggesting a similar cell phenotype for both. The results of this study indicate that the analyzed morphological grading systems proved to be effective in identifying cases of more aggressive OTSCC, with greater emphasis on the one proposed by Almangush et al (2015) and, in relation to the immunohistochemical findings, the results suggest that the lower membrane expression of E-cadherin and the high nuclear/cytoplasmic expression of Gli-1 were associated with the clinical parameter of worse prognosis (AU).