Expression of BARF1 gene encoded by Epstein-Barr virus in nasopharyngeal carcinoma biopsies.
Résumé
We reported previously that the EBV BARF1 open reading frame encodes a Mr 31,000-33,000 protein (p31) with potential transforming and oncogenic properties. This gene was found capable of transforming both: (a) the rodent fibroblast lines Balbc/3T3 and NIH3T3 into cells producing aggressive tumors in newborn rats; and (b) the human EBV-negative B-cell line Louckes into cells leading to small tumors, which disappeared 3 weeks after injection. Our recent study showed that BARF1 ORF expression may confer the property of immortalization to primary kidney epithelial cells (M. X. Wei et al., Oncogene, 14: 3073-3081, 1997). Because this suggested that BARF1 could be involved in epithelial malignancy, we investigated its transcriptional and translational expressions in Algerian nasopharyngeal carcinoma (NPC) biopsies by reverse transcription-PCR and immunoblotting using rabbit polyclonal antisera prepared against two synthetic peptides corresponding to distinct, predicted epitopes of the BARF1 protein (NGGVMKEKD, amino acids 172-180, and GKNDKEE, amino acids 203-209). The BARF1 ORF was found to be transcribed and translated in >85% of our NPC biopsies, with high p31 protein level detected in several NPC patient biopsies as well as in NPC-derived xenografts. Our observation of BARF1 expression in a large proportion of NPC epithelial cells suggests that this EBV gene might play an important role in the malignant transformation of human epithelial cells in vivo.
Mots clés
Animals
Biopsy
Cell Line
Comparative Study
Epstein-Barr Virus Infections/complications/genetics/*metabolism
Gene Expression
Herpesvirus 4
Human/*genetics
Humans
Immunohistochemistry
Lymphocytes/metabolism
Mice
Nude
Nasopharyngeal Neoplasms/genetics/*metabolism/*virology
Neoplasm Transplantation
Open Reading Frames
Protein Biosynthesis
Research Support
Non-U.S. Gov't
Reverse Transcriptase Polymerase Chain Reaction
Transcription
Genetic
Transplantation
Heterologous
Viral Proteins/*biosynthesis/genetics