Correlation between EBV DNA and rearrangement and expression of bcl-2 genein aggressive non-Hodgkin's lymphoma

Previous in vitro studies have shown that bcl-2 expression can be induced b y transfection of Epstein-Barr virus (EBV)-negative non-Hodgkin's lymphoma (NHL) cell lines with EBV, This induced expression of bcl-2 is important fo r the long survival of EBV-positive cells and might be a first step in tumo rigenesis, The purpose of the present study was to investigate the possibil ity of similar correlation between bcl-2 expression and EBV infection in vi vo in a cohort of patients with aggressive NHL, who were uniformly evaluate d and treated with effective chemotherapy, The 42 patients included were 25 -65 years old, None had prior treatment, discordant lymphoma, or human immu nodeficiency virus seropositivity, Fresh biopsied samples were obtained and stored frozen for analysis of bcl-2 gene rearrangement major break point a nd of EBV DNA by PCR, Bcl-2 protein expression was estimated by Western blo t, and enzyme immunoassay, With a median follow-up of 30 months, overall su rvival (OS) and disease-free survival (DFS) were measured to determine the prognostic significance of these variables. Analyzable DNA was present in a ll samples, 24% demonstrating bcl-2 rearrangement and 33% showing EBV DNA, Patients with bcl-2 gene rearrangement tended to have shorter DFS, and OS t han patients without translocation, Bcl-2 protein expression was not correl ated to gene rearrangement and had no significant influence on survival. Th e presence of EBV DNA in NHL had no prognostic significance but was correla ted 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.