Souza, Lelia Batista deSantos, André Azevedo dos2021-06-162021-06-162021-03-30SANTOS, André Azevedo dos. Perfil imuno-histoquímico de marcadores de células-tronco tumorais em neoplasias de glândula salivar. 2021. 111f. Dissertação (Mestrado em Ciências Odontológicas) - Centro de Ciências da Saúde, Universidade Federal do Rio Grande do Norte, Natal, 2021.https://repositorio.ufrn.br/handle/123456789/32732Salivary gland tumors (SGTs) are characterized by complex clinicopathological features and morphological diversity, as well as different clinical behaviors and prognoses. There is strong evidence that tumor stem cells (TSCs) play important roles in tumorigenesis of different neoplasms. However, the role of TSCs in the behavior and prognosis of SGTs has not been fully elucidated. This study aimed to describe the immunoexpression profile of TSCs biomarkers (CD44, ALDH1, OCT4, and SOX2) in parenchyma and stroma of minor and major SGTs (20 pleomorphic adenomas [PAs], 20 adenoid cystic carcinomas [ACCs], and 20 mucoepidermoid carcinomas [MECs]). Data were analyzed adopting a level of significance of 5% (p<0.05). Differences were observed between the parenchymal immunoexpression profiles of the biomarkers in the tumors studied. In PAs and ACCs, marked immunoexpression of ALDH1 and OCT4, respectively, was found, with preferential staining of luminal cells for ALDH1 and of non-luminal cells for OCT4. No difference between the immunoexpression of the biomarkers was observed in MECs. CD44, OCT4, and SOX2 staining were detected in epidermoid and intermediate cells, and ALDH1 expression was also detected in some mucosal cells of MECs. Regarding the immunostained cellular compartment, CD44 was predominantly expressed on the membrane, ALDH1 in the cytoplasm, and OCT4 and SOX2 in the nucleus. Cytoplasmic staining for CD44 and OCT4 was also observed. Comparison of parenchymal immunoexpression between the groups of tumors showed higher expression of ALDH1, OCT4, and SOX2 in PAs, ACCs, and MECs, respectively. However, parenchymal immunoexpression of ALDH1 was absent in most ACCs and the MEC cases exhibited high parenchymal immunoexpression of SOX2, differing from the other tumors. Furthermore, immunoexpression of all biomarkers, except for SOX2, was found in the stroma of most PAs, ACCs, and MECs. Statistical analysis revealed higher parenchymal immunoexpression of ALDH1 in major SGTs (p=0.021) and OCT4 in minor SGTs (p=0.011); higher parenchymal immunoexpression of SOX2 in tumors without myoepithelial differentiation (p<0.001) and of OCT4 in tumors with myoepithelial differentiation (p=0.009); higher parenchymal immunoexpression of ALDH1 in benign tumors (p<0.001) and of SOX2 in malignant tumors (p=0.002). CD44 was the only biomarker whose parenchymal immunoexpression was significantly associated with clinical parameters of malignant tumors. Higher expression of CD44 was related to less aggressive tumors and cases showing a better prognosis. Stromal immunoexpression of CD44, ALDH1, and OCT4 was significantly associated with malignant tumors. Significant correlations between the immunoexpression of the biomarkers were observed in the general sample, as well as in each tumor group analyzed individually. The expression of TSCs biomarkers evidenced in the parenchyma and stroma of SGTs suggests the participation of tumor stem cells in the pathogenesis of the studied lesions. The results also suggest the existence of distinct subpopulations of TSCs in SGTs.Acesso AbertoGlândulas salivaresNeoplasiasCélulas tronco tumoraisImunohistoquímicamasterThesis