Immunohistochemical expression of Bcl-2 oncoprotein in EBV-associated nasopharyngeal carcinoma correlated to histological type and survival

• Vera Sempere, F. J. ^[1] ; Burgos, J. S. ^[1] ; Botella, M. S. ^[1] ; Morera, C. ^[2]
  1. [1] Service of Pathology II, Laboratory of Molecular Pathology, Hospital La Fe. Medical School of Valencia University, Valencia, Spain
  2. [2] Service of Otolaryngology, Hospital La Fe. Medical School of Valencia University, Valencia, Spain
• Localización: Histology and histopathology: cellular and molecular biology, ISSN-e 1699-5848, ISSN 0213-3911, Vol. 12, Nº. 1, 1997, págs. 9-18
• Idioma: inglés
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• Resumen

  • Expression of BcI-2 is associated with inhibition of apoptosis and extension of cell survival. In vitro Bcl-2 protein expression is up-regulated by the EBV-latency associated antigen latent membrane protein (LMP-l). We have investigated the relationship between the presence of EBV-DNA screened by means of sensitive nested-PCR, nasopharyngeal carcinoma (NPC) histological types according to two different schemata (WHO and Micheau classifications) and BcI-2-124 immunohistochemical expression in 55 biopsy samples of NPC. EBV genome was detected in 100% of samples with sufficient DNA quality to support the previous view that all types of NPC are variants of EBV-infected neoplasia. BcI-2 was observed in the basal layer of normal nasopharyngeal mucosa and also at cytoplasmic level in 42 of 55 (76.4%) NPC cases. Mitotic neoplastic cells usually showed strong cytoplasmic and chromosomal staining, a finding not well referred to previously. BcI-2 expression was significantly associated (p<0.05) to undifferentiated NPC (UNPC) when a histological classification with only two major microscopical types was applied. No close correlations were found between the presence of EBV-DNA, NPC location, clinical stage and age or sex of the patients in relation to Bcl-2 positive expression. However, when comparing Bcl-2 expression and known survival mean of the patients, significant differences were observed (p