Banca de DEFESA: GUSTAVO ALCANTARA DA TRINDADE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : GUSTAVO ALCANTARA DA TRINDADE
DATE: 20/02/2020
TIME: 09:00
LOCAL: SALA IV DEPARTAMENTO DE ODONTOLOGIA
TITLE:

Immunohistochemical analysis of protein aldehyde dehydrogenase 1 in benign epitelial dental injuries

KEY WORDS:

Stem cells; Protein Aldehyde Dehydrogenase 1; Benign Epithelial Odontogenic Lesions; Immunohistochemistry.

PAGES: 63
BIG AREA: Ciências da Saúde
AREA: Odontologia
SUMMARY:

Odontogenic cysts and tumors are heterogeneous lesions that originate from some remnant of odontogenesis. Among these, the dentigerous cyst (DC), the odontogenic keratocyst (OK), the ameloblastoma (AM) and the adenomatoid odontogenic tumor (AOT) are odontogenic lesions of epithelial origin that present several biological profiles and are the target of constant investigations. Among stem cell markers, the aldehyde dehydrogenase (ALDH) family has been used in studies in several neoplasms and its high expression was associated with some clinical characteristics of these neoplasms. The aim of this study was to analyze the presence, quantity and distribution of tumor stem cells, through the immunohistochemical expression pattern of the ALDH-1 protein in odontogenic cysts and tumors of epithelial origin. The sample consisted of 80 cases (20 DCs, 20 OKs, 20 AMs and 20 AOTs). The evaluation was carried out by a single evaluator at two different times, using the immunoreactivity scoring system, considering the percentage of positive cells, as well as the intensity of the immunostaining, using scores from 0 to 3. The final score was determined by the formula ''Immunoexpression score = intensity × percentage of cells '', being defined as low expression the scores from 0 to 4 and high expression the scores from 6 to 9. Also, the expression of that protein in the stroma was analyzed in tumor and cystic capsule, with 0 = negative and 1 = positive. In all variables, the Kruskal-Wallis (KW) and Mann-Whitney (U) non-parametric tests were performed with a significance level of 5% (p<0.05). The immunoexpression of ALDH-1 showed nucleus-cytoplasmic marking, mainly in the cells of the tumor parenchyma and cystic epithelium. When comparing the lesions, in relation to the medians of the obtained scores and the expression pattern and intensity of immunoexpression of ALDH-1 in the epithelial component of the lesions, a significantly higher expression of ALDH-1 in OKs was demonstrated in comparison to AMs (p<0.0001) and TOAs (p <0.0001). Higher expression of ALDH-1 was observed in DCs compared to AMs (p <0.0001) and TOAs (p <0.0001). When evaluating stroma and cystic capsule, immunoreactivity was observed in all cases of odontogenic cysts studied and in 85% and 90% of AMs and TOAs, respectively. The expression of ALDH-1 in the odontogenic lesions studied suggests the presence of stem cells in them, highlighting the odontogenic cysts that presented higher epithelial expressions compared to tumors.

BANKING MEMBERS:
Externa à Instituição - JAMILE MARINHO BEZERRA DE OLIVEIRA MOURA - UERN
Interno - 344668 - LEAO PEREIRA PINTO
Presidente - 346077 - LELIA BATISTA DE SOUZA