Involvement of the Bcl-2 Gene in Hodgkin's Disease

A major obstacle to investigations of Hodgkin's disease is the paucity of malignant cells, i.e., Reed-Sternberg cells and their variants, in tissues of patients with this disease. Consequently, the pathogenesis, cell of origin, and clonality of this relatively frequent lymphoma have remained unresolved. Results of recent studies suggest that in some instances Reed-Sternberg cells carry rearranged immunoglobulin heavy-chain joining region (JH) loci as well as chromosomal translocations involving band 14q32. Prompted by these findings, we sought to determine if the t(14;18) (q32;q21) translocation of follicular, non-Hodgkin's B-cell lymphoma was associated with Hodgkin's disease. To detect the possible t(14;18) (q32;q21) translocation within the rare malignant cells of Hodgkin's disease, we amplified sequences created by the t(14;18) translocation using the polymerase chain reaction (PCR). With this approach, DNA sequences carrying the direct fusion of the major breakpoint region of the candidate oncogene, bcl-2, derived from chromosome 18q21, with JH on chromosome 14q32 can be detected in as few as one in 10(5)-10(6) cells. In the present study, joined bcl-2/JH sequences were detected in tissues involved by Hodgkin's disease in 17 of 53 (32%) patients. The frequent association of bcl-2 translocation with Hodgkin's disease suggests that this oncogene has a role in the pathogenesis of Hodgkin's disease. That bcl-2 is involved in a major class of lymphoma in addition to follicular lymphoma implies a role for additional factors responsible for generating the two distinctive clinical and pathologic disease states.