Asociación de la infección por el virus de Epstein Barr (EBV) con la expresión de p53 y bcl-2 en Carcinoma Nasofaríngeo Pediátrico

DE MATTEO, E; PAOLA ANDREA CHABAY; ZUBIZARRETA, P.; GALLO, G.; PRECIADO, M. V.

Buenos Aires

Congreso; Conferencia Latinoamericana de Patología Pediátrica; 2000

Introduction: The Nasopharyngeal Carcinoma (NPC) it is not a very frequent malignant neoplasm in our population and in children, but is common in the Asian southeast. The etiologic factors involved in NPC includes the Epstein Barr virus (EBV) infection, p53 and bcl-2 oncogenes overexpression, dietary factors, etc. Objective: we intended to study the association of this pathology with the EBV infection and overexpression of the mentioned oncogenes in our pediatric population. Materials and Methods: 15 pediatric patients with undifferentiated NPC, treated at the Hospital de Pediatría SAMIC “J. P. Garrahan”,and at the Hospital de Niños Ricardo Gutiérrez among 1988-1998 were studied. The patients´ age range was 8-20 years (median: 12); the distribution for sexes was 1 woman and 14 males.  EBV presence was assesed on formalin fixed paraffin embedded tissue sections using EBERs in situ hibridization and latent membrane protein 1 (LMP-1) by immunohistochemical labeling; p53 and bcl-2 oncogenes were also detected by this last methodology.  Results: EBERs staining in the nucleus of tumor cells and LMP -1 labeling in the cytoplasm of them were observed in 100% of the studied cases. Regarding p53 and bcl-2 overexpression, 80% of the cases were positive for p53, showing most of them (58%) among 25-50% of positive cells, and 15,4% were bcl-2 positive in epithelial cells.  Conclusions: these results indicate a strong association among EBV infection and p53 overexpression, which is not observed with bcl-2.  This suggests that the EBV might interact with p53 or contribute to its aberrant expression.