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Abstract

Title: CpG methylation of the major Epstein-Barr virus latency promoter in Burkitt's lymphoma and Hodgkin's disease.
Author: Robertson KD, Manns A, Swinnen LJ, Zong JC, Gulley ML, Ambinder RF
Journal: Blood 88(8):3129-3136
Year: 1996
Month: October

Abstract: The Epstein-Barr virus (EBV) latency C promoter drives expression of a family of viral proteins commonly targeted by CD8 cytotoxic T cells. These proteins are not generally expressed in African Burkitt's lymphoma and in EBV-associated Hodgkin's disease. The failure to express these proteins is almost certainly an important factor in the evasion of immunosurveillance by EBV-associated tumors. In a previous study, we have shown that transcriptional activation of the C promoter is inhibited by methylation of a particular CpG site upstream of the promoter that prevents binding of a cellular protein (CBF2), and we have shown that this and adjacent CpG sites are methylated in a Burkitt's lymphoma cell line. In the present study, we show that CpG sites in the CBF2 binding region are predominantly methylated in African Burkitt's lymphoma and in EBV-associated Hodgkin's disease. In addition, we present the first direct evidence that the C promoter is transcriptionally silent in Burkitt's lymphoma. In contrast, we show a complete absence of methylation in the CBF2 binding region in a case of reversible EBV-associated B-cell lymphoma arising in an immunocompromised patient whose tumor shows C promoter transcriptional activity. By inhibiting expression of highly antigenic viral proteins, methylation of transcriptional control sequences may veil the presence of virus in tumor tissue from CD8(+) cytotoxic T-cell immune surveillance and thus facilitate viral tumorigenesis.