ASSOCIATION BETWEEN CONNEXIN 43 AND Bcl-2 IN ORAL CARCINOMAS

SECCHI DG; BRUNOTTO M; GONZALEZ SEGURA, I; CENTENO V

Roma

Congreso; 7th World Congress of the International Academy of Oral Oncology (IAOO2019); 2019

IAOO

OBJECTIVE: to analyze the expression of differentiation biomarker, connexin 43 (Cx43) and anti-apoptotic protein, Bcl-2, in biopsies of oral cancer (OC). METHODS: retrospective study of 13 adult patients biopsies, both genders, served in Section ?A? of Stomatology, Facultad de Odontología, UNC (approved by IRB Protocol No. 1379). The histopathological diagnosis was carried out according to classification ICD10 code C00-C14. The studies were contrasted with biopsies of patients with other diseases not associated with cancer and pre-cancers and clinically normal. The expression levels of Cx43 and Bcl-2 were assessed using immunohistochemical staining with monoclonal antiCx43 antibody (1:200; SIGMA-ALDRICH, USA) and monoclonal antiBcl-2 (1:500; Cell Marque-SIGMA, USA), respectively. Cx43 and Bcl-2 immunostaining were evaluated on digital microphotographs on 3 fields of 10-3 mm2 (Motic-BA 400 Asia Hong Kong) using Image Pro Plus software and graded as low, moderate and high expression. Nucleus/cytoplasm ratio (N/C) was analyzed. Correlations between both biomarkers were subjeted to statistical analysis using χ2 test. RESULTS: Bcl-2 expression levels in biopsies from OC were higher compared to healthy tissue (70.2% high, 27.7% moderate and 2% low levels in OC). Cx43 inmunostaining was located in cytoplasm and membrane; a differential pattern of expression was related to phenotype of the sample analyzed. Cx43 expression in anatomopathological low-grade carcinomas was lower than in normal mucosa samples. Significant correlation between Cx43 and Bcl-2 expression was observed. Low and moderate score of Cx43 expression was associated with high score of Bcl-2 expression. On the contrary, high score of Cx43 expression was associated with low-moderate score Bcl-2 expression. Histomorphometric analysis of Cx43 positive cells showed that N/C ratio, it was higher in cells of the biopsies of OC (p=0,039). CONCLUSION: Data showed a negative association between Cx43 and Bcl-2 expression in OC biopsies, indicating that abnormal expressions of this proteins are associated a tumoral phenotype. This results suggests that the lost of capacity to induce apoptosis is associated with a lower degree of differentiation observed in samples of OC.