Abstract
Epstein-Barr virus (EBV) is a ubiquitous human herpes virus that infects over 90% of the adult human population of the world. Although association of EBV with Burkitt's lymphoma and nasopharyngeal carcinoma is well established, reports on the association of EBV with oral squamous cell carcinoma (OSCC) are inconclusive. To find out expression pattern of EBV genes in OSCC, we isolated wild type EBV infected OSCC cell lines by co-culture and limiting dilution techniques, and investigated the latent gene expression pattern of EBV in these cell lines. EBV nuclear antigen (EBNA)-1 protein was detected by indirect immunofluorescence in all of the infected cell lines. EBV encoded small RNA (EBER)-1, Cp/Wp-initiated EBNA-1, EBNA-2, latent membrane protein (LMP)-1 and BamHI-A rightward open reading frame (BARF0) gene expression were detected in isolated OSCC cells by RT-PCR and Southern blot hybridization. However, LMP-2A and -2B expression were not detected. The latent gene expression pattern was similar to those in undifferentiated nasopharyngeal carcinoma and Hodgkin's disease (i.e., type II latency of EBV). This is the first report concerning successful infection of wild type EBV to OSCC cells. These results could bring about a better understanding of the influence of EBV on OSCC cells.
