IUBMB Life, 48: 231–236, 1999 Copyright c ° 1999 IUBMB 1521-6543/99 $12.00 + .00 Original Research Article Correlation between EBV DNA and Rearrangement and Expression of Bcl-2 Gene in Aggressive Non-Hodgkin’s Lymphoma Sanaa Eissa, Samar K. Kassim, Maha Imam, and Ali Khalifa Oncology Diagnostic Unit, Biochemistry Department, Ain Shams Faculty of Medicine, Abbassia, Cairo, Egypt 11566 Summary Previous in vitro studies have shown that bcl-2 expression can be induced by transfection of Epstein-Barr virus (EBV)-negative non-Hodgkin’s lymphoma (NHL) cell lines with EBV. This induced expression of bcl-2 isimportantforthelong survival ofEBV-positive cells and might be a rst step in tumorigenesis. The purpose of the present study was to investigate the possibility of similar correlation between bcl-2 expression and EBV infection in vivo in a cohort of patients with aggressive NHL, who were uniformly evaluated and treated with effective chemotherapy. The 42 patients included were 25–65 years old. None had prior treatment, discordant lymphoma, or human immunodeciency virus seropositivity. Fresh biopsied samples were obtained and stored frozen for analysis of bcl-2 gene rearrangement major break point and of EBV DNA by PCR. Bcl-2 protein expression was estimated by Western blot, and enzyme im- munoassay. With a median follow-up of 30 months, overall survival (OS) and disease-free survival (DFS) were measured to determine the prognostic signicance of these variables. Analyzable DNA was present in all samples, 24% demonstrating bcl-2 rearrangement and 33% showing EBV DNA. Patients with bcl-2 gene rearrange- ment tended to have shorter DFS, and OS than patients without translocation. Bcl-2 protein expression was not correlated to gene rearrangement and had no signicant inuence on survival. The presence of EBV DNA in NHL had no prognostic signicance but was correlated to bcl-2 expression. EBV-positive tumors showed higher bcl-2 expression than EBV-negative tumors did. Our results suggest a role of EBV infection in inducing bcl-2 expression as a survival factor for EBV-positive cells. IUBMB Life, 48: 231–236, 1999 Keywords Apoptosis;Epstein–Barrvirus;non-Hodgkin’slymphoma. INTRODUCTION The chromosomal abnormality t(14;18)(q32; q21) occurs in the majority of follicular and a minority of diffuse non-Hodgkin’s Received 31 March 1999; 13 April 1999. Address correspondence to Sanaa Eissa. E-mail: samar kassim@ usa.net lymphomas (NHL) 1 (1). It involves the translocation of bcl-2 oncogene from its position on chromosome 18 to lie juxtaposed to the joining region (JH) of the immunoglobulin heavy-chain (IgH) gene on chromosome 14. The breakpoints cluster within well-dened regions on chromosome 18, known as the major breakpoint region (mbr), which spans only 150 bases and in which 60% of translocations occur (2, 3), and the minor cluster region, in which » 25% of breakpoints occur and a breakpoint of a region of 500 bases is involved (4, 5). The clustering of the breakpoints on chromosome 18 with or near the bcl-2 oncogene facilitates the application of polymerase chain reaction (PCR) to amplify this bcl-2/JH breakpoint fragment (6, 7). Epstein–Barr virus (EBV) is a ubiquitous human herpesvirus that infects B-lymphocytes and certain epithelial cells and is implicated in several human malignancies, including Burkitt’s lymphoma and nasopharyngeal carcinoma (8). Although EBV infection is also detected in Hodgkin’s lymphoma and NHL, the oncogenic function of EBV in these lymphoproliferative dis- eases is not well delineated (9–11). Gregory et al. have shown that the activation of EBV latent genes protects human B cells from death by apoptosis (12). Finke et al. have recently reported that the expression of bcl-2 protein can be transactivated by transfection of EBV-negative Burkitt’s or NHL cell lines with EBV latent membrane protein (LMP) gene carrying expression vectors (13). We therefore have asked whether a similar corre- lation also exists between the presence of EBV DNA and bcl-2 gene rearrangement and expression in vivo. PATIENTS AND METHODS Forty-two patients were included in this study. All had advanced-stage NHL and were ages 20 to 65 years. No patients 1 Abbreviations: DFS, disease-free survival; EBV, Epstein–Barr virus; EIA, enzyme immunoassay; JH, joining region; LMP, latent membrane protein; mAb, monoclonal antibody; mbr, major breakpoint region; NC, nitrocellulose; NHL, non-Hodgkin’s lymphoma; OS, overall survival; PCR, polymerase chain reaction. 231