RESUMEN
OBJECTIVE: To analyze the immunohistochemical expression of YAP and its correlation with markers involved in cell proliferation and apoptosis in benign epithelial odontogenic lesions. STUDY DESIGN: The sample consisted of 95 cases of odontogenic lesions (25 dentigerous cysts, 30 non-syndromic odontogenic keratocysts, 30 conventional ameloblastomas, and 10 unicystic ameloblastomas) and 10 dental follicles used as normal odontogenic tissue. The histological sections were submitted to immunohistochemistry with YAP, cyclin D1, Ki-67, and Bcl-2 antibodies. Immunoexpression was analyzed qualitatively and quantitatively using an adapted method. The collected data were analyzed descriptively and statistically (p ≤ 0.05). RESULTS: The highest YAP expression was observed in odontogenic keratocysts, followed by unicystic ameloblastomas and conventional ameloblastomas, which exhibited moderate immunoreactivity predominantly in peripheral cells. Furthermore, significant differences in YAP immunoexpression were observed between the groups analyzed, with significant positive correlations between YAP and cyclin D1 in dentigerous cysts and unicystic ameloblastomas and between YAP and Ki-67 in unicystic ameloblastomas (p < 0.05). However, there were no statistically significant correlations between YAP and Bcl-2 immunoexpression in the groups studied. CONCLUSION: YAP may influence epithelial cell proliferation in odontogenic cysts and tumors, suggesting its possible participation in the progression of the odontogenic lesions studied.
RESUMEN
O carcinoma epidermoide oral (CEO) é uma neoplasia maligna de patogenia complexa, já a displasia epitelial oral (DEO) é uma entidade que, na dependência de sua evolução, exibe riscos de transformação maligna para o CEO. A expressão alterada de genes supressores tumorais e proteínas reguladoras do ciclo celular apresentam relação com a etiopatogênese de diferentes cânceres. Entre os genes supressores tumorais destaca-se a família de inibidores de crescimento (inhibitor of growth - ING), que impedem o crescimento celular descontrolado. Dentre as proteínas reguladoras do ciclo celular podemos citar a Ciclina D1, que atua na progressão da fase S para a fase G1, permitindo a proliferação celular. O objetivo do presente estudo foi analisar a imunoexpressão das proteínas ING3 e Ciclina D1 em 28 espécimes de DEO e 25 de CEO localizados em língua, bem como avaliar morfologicamente e reclassificar as lesões segundo os critérios estabelecidos pela Organização Mundial da Saúde (OMS), além de modelo binário (Kujan et al. 2006), para DEO, e modelo buds-depth of invansion (BD) (Almagunsh et al. 2015) para CEO. A imunoexpressão das proteínas foi analisada de forma quantitativa, considerando a localização celular (citoplasmática e/ou nuclear para ING3 e nuclear para Ciclina D1) presentes no componente epitelial. A expressão das proteínas foi comparada entre os dois grupos de lesões, bem como com os parâmetros clínico-patológicos das lesões estudadas, através dos testes estatísticos Mann-Whitney (U) e teste de correlação de Spearman adotando um nível de significância de 5% para todos os testes considerando o valor de p ≤ 0,05. Dos 28 casos de DEO analisados 53,6% apresentaram-se como lesões de alto risco segundo o modelo binário, assim como dos 25 casos de CEO analisados foram considerados escores de alto risco (48%) de acordo com o modelo BD. Não foram encontradas associações estatisticamente significativas entre as variáveis morfológicas das lesões estudadas e as características clínicas (p>0,05). Com relação a expressão de Ciclina D1, esta foi significativamente maior em DEO quando comparada aos casos de CEO (p<0,05). A expressão de ING3 núcleo-citoplasmática foi significativamente menor nos casos de CEO, quando comparada aos casos de DEO (p<0,05), já a expressão de ING3, restrita ao citoplasma, foi maior nos casos de DEO, quando comparadas aos casos de CEO (p<0,05). Os resultados do presente estudo sugerem que a expressão das proteínas não tem relação com as gradações das lesões, porém, há notável diminuição da expressão nuclear de ING3 conforme a progressão maligna, indicando função supressora tumoral alterada desta proteína em DEO e CEOs. Destacamos, ainda, o aumento da expressão de Ciclina D1 em DEOs, mostrando que as lesões detêm uma taxa de proliferação celular significativa (AU).
Oral squamous cell carcinoma (OSCC) is a malignant neoplasm of complex pathogenesis. In turn, oral epithelial dysplasia (OED) is an entity that, depending on its evolution, exhibits varied risks of malignant transformation to OSCC. The altered expression of tumor suppressor genes and cell cycle regulatory proteins are related to the etiopathogenesis of different malignant tumors. Among the tumor suppressor genes, the family of inhibitors of growth (ING) stands out, which prevents uncontrolled cell formation. Amid the cell cycle regulatory proteins, Cyclin D1 acts in the progression from S to G1 phase, allowing cell proliferation. The aim of the present study was to analyze the immunoexpression of ING3 and Cyclin D1 proteins in 28 OED and 25 OSCC specimens, located on the tongue, as well as to morphologically evaluate and to reclassify the lesions following the criteria established by World Health Organization (WHO) and the model proposed by Kujan et al. (2006), for OED; for OSCC, the system proposed by Almagunsh et al. (2015) was used. Protein immunoexpression was quantitatively evaluated, considering the cellular location (cytoplasmic and/or nuclear for ING3 and nuclear for Cyclin D1), present in the epithelial component. Protein expression was compared between the two groups of samples, as well as with the clinical-pathological parameters of the lesions studied, through the Mann-Whitney (U) statistical tests and the Spearman correlation test, adopting a significance level of 5% for all tests considering the value of p≤ 0.05. Of the 28 cases of OED analyzed, 53.6% were high-risk lesions according to the binary model and of the 25 cases of OSCC analyzed, 48% were considered high-risk scores according to the BD model. No statistically significant associations were found between the morphological variables of the lesions studied and the clinical characteristics (p>0.05). A statistically significant difference was observed between the absence of ING3 expression and the grading of OEDs, according to the WHO (p<0.05). Regarding the expression of Cyclin D1, it was significantly higher in OED, when compared to OSCC cases (p<0.05). Nucleocytoplasmic ING3 expression was significantly lower in OSCC cases when compared to OED cases (p<0.05). Cytoplasm-restricted ING3 expression was higher in OED cases when compared to OSCC cases (p<0.05). The results of the present study suggest that, although there is no evidence of a significant relationship between the expression of proteins and the histopathological gradations of the lesions, there is a notable decrease in the nuclear expression of ING3, with an increase in the severity of the lesions, indicating an altered tumor suppressor function of this protein in OED and OSCCs. We also highlight the increased expression of Cyclin D1 in OEDs, showing that these lesions have a significant rate of cell proliferation (AU).
