Epstein Barr virus associated pediatric nasopharyngeal carcinoma: its correlation with p53 and bcl-2 expression.
BACKGROUND
Pediatric nasopharyngeal carcinoma (NPC) is relatively rare. The Epstein Barr virus (EBV) association with the oncogenesis of NPC is well established. Apoptosis-related proteins, p53 and bcl-2, have also been described in adult NPC pathogenesis.


METHODS
From 1988 to 1998, 16 patients with NPC were treated at R. Gutierrez Children's Hospital and the National J.P. Garrahan Pediatric Hospital. Their median age was 12 years (range 8-20), 2 females and 14 males. The presence of p53, bcl-2 and latent membrane protein-1 (LMP-1) of EBV expression was studied by immunohistochemistry and Epstein Barr encoded RNAs (EBERs) by in situ hybridization in tissue sections from formalin-fixed, paraffin-embedded NPC biopsies


RESULTS
EBV presence and LMP-1 expression in epithelial tumor cells were detected in all the biopsies studied. p53 was expressed in 13/16 NPCs, but the frequency of positive malignant cells differed from case to case, ranging from less than 25 to 100% with heterogeneous staining intensity. Bcl-2 positive staining in tumor epithelial cells was detected in 2/16; whereas 10/16 cases showed bcl-2 positivity in infiltrating lymphocytes.


CONCLUSIONS
Although our series is small, we conclude that the pathogenesis of pediatric NPC as a multistep process may well involve EBV infection. This leads to LMP-1 expression and p53 overexpression in epithelial tumor cells, whereas bc-2 seems unrelated to the development of this disorder.
Preciado
María Victoria
MV
Virology Laboratory, Ricardo Gutierrez Children's Hospital, Buenos Aires, Argentina. preciado@conicet.gov.ar
Chabay
Paola A
PA
De Matteo
Elena N
EN
Gismondi
María Inés
MI
Rey
Guadalupe
G
Zubizarreta
Pedro
P
D000293:Adolescent; D000328:Adult; D002277:Carcinoma / Q000235:genetics* / Q000821:virology*; D002648:Child; D004273:DNA, Neoplasm / Q000235:genetics*; D020031:Epstein-Barr Virus Infections / Q000150:complications*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D009303:Nasopharyngeal Neoplasms / Q000235:genetics* / Q000821:virology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D012313:RNA; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis*; D014763:Viral Matrix Proteins / Q000096:biosynthesis*
D004273:DNA, Neoplasm; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D014763:Viral Matrix Proteins; D012313:RNA