Abstract

Bcl-2 oncoprotein is being localized to mitochondria and interfering with programmed cell death (apoptosis) independent of promoting cell division in the lymphoid and nonlymphoid cells. The bcl-2 oncoprotein expression has been reported in follicular lymphomas as well as in diffuse non-Hodgkin's lymphoma, leukemia and a variable propotion of Hodgkin's lymphoma cases. Recent evidence suggests that some lymphomas protected from apoptosis is conferred through expression of Epstein-Barr virus(EBV) latent membrane protein which turn to cause upregulation of bcl-2. To define the role of the bcl-2 oncoprotein and EBV in lymphoid malignancy, we tried immunohistochemical studies with anti-bcl-2 antibody and In situ hybridization (ISH) with EBV-encoded small nuclear RNAs(EBER) in the paraffin embedded sections of 46 non-Hodgkin's lymphoma (NHL) cases and 20 Hodgkin's lymphoma (HL) cases. Bcl-2 oncoprotein expression was found in 37 of 46 cases (80%) of NHL with relatively strong cytoplasmic staining, and in 14 of 20 cases (70%) of HL with weak cytoplasmic staining in limited small numbers of RS, Hodgkin and lacunar cells. The widespread presence of bcl-2 oncogene in many different types of both NHL and HL supports that the extended cell survival through overexpression of bcl-2 gene protein may be a growth advantage of neoplastic lymphoid cells. In the ISH analysis for EBV, the presence of EBV was detected in 17 of 20 cases (85%) of HL, compared to 6 of 44 cases(13.6%) of NHL. It appears to be no direct correlation between overexpression of bcl-2 oncoprotein by neoplastic lymphoid cells and the presence of EBV in NHL but it seems to be a definite association between EBV and HL.

• Keywords: Bcl-2 oncoprotein;Epstein-Barr virus;non-Hodgkin's and Hodgkin's lymphoma;