Banca de DEFESA: CÍNTIA BARRETO DE OLIVEIRA VARELA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : CÍNTIA BARRETO DE OLIVEIRA VARELA
DATE: 08/09/2020
TIME: 14:00
LOCAL: PLATAFORMA REMOTA - GOOGLE MEET
TITLE:

ASSOCIATION BETWEEN IMMUNOHISTOCHEMICAL EXPRESSION OF 8-OHDG AND THE DEGREE OF SEVERITY IN ACTINIC CHEILITIS

KEY WORDS:

Cheilitis, Carcinoma, Squamous Cell. 8OHdG. Oxidative Stress

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

Actinic cheilitis (QA) is a potentially malignant disorder that can progress to lower lip squamous cell carcinoma (LLSCC). It is not yet well established which factors may be associated with the probability of malignant transformation of this condition, even though it is known that exposure to ultraviolet radiation is its main risk factor, as well as for LLSCC. Ultraviolet radiation causes oxidative damage to DNA, which leads to the formation of 8-hydroxy-2′deoxyguanosine (8-OHdG), a protein that is associated with the process of carcinogenesis in some human neoplasms. This research aimed to evaluate the expression of 8-OHdG in a series of QA cases and to associate its expression with clinical-pathological parameters. The sample consisted of 57 cases of AK, classified according to the histopathological gradation of epithelial dysplasia (WHO) into mild epithelial dysplasia (22), moderate epithelial dysplasia (17) and severe epithelial dysplasia (11). Seven cases of AQ that did not present epithelial dysplasia were also included. The analysis of the expression of 8-OHdG was performed in a semi-quantitative way by two examiners, calibrated and trained (Kappa = 0.79). The data were submitted to statistical analysis using the non-parametric Mann-Withney and Kruskall-Wallis tests, with a significance level of 5% (p <0.05). The results revealed a strong immunohistochemical expression of 8-OHdG in QA, suggesting the participation of oxidative stress in the pathogenesis of this disorder. According to the immunoreactivity score, weak immunoreactivity was observed in 21.1% of the sample, moderate immunoreactivity in 14% and strong immunoreactivity in 64.9%. The statistical tests did not show statistically significant differences between the expression of 8-OHdG and the clinical aspects of QA; there was also no statistical significance between the expression of 8-OHdG and the degree of epithelial dysplasia in the sample (p = 0.350). Based on these results, we conclude that 8-OHdG may be involved in the development of AK, however it is not indicated as a biomarker to assess its degree of severity.

BANKING MEMBERS:
Externo à Instituição - EDJA MARIA MELO DE BRITO COSTA - UEPB
Interna - 1258693 - LELIA MARIA GUEDES QUEIROZ
Presidente - 2644142 - PATRICIA TEIXEIRA DE OLIVEIRA