EPSTEIN-BARR-VIRUS (EBV) GENOMES AND C-MYC ONCOGENE IN ORAL BURKITTS LYMPHOMAS

In addition to Burkitt's lymphomas, tentative evidence suggests the involvement of Epstein-Barr virus (EBV) in malignant lymphomas of T-cell origin. The c-myc proto-oncogene is strongly associated with the development of lymphoid neoplasias. In the present study, a series of 38 biopsies of oral lymphomas (29 Burkitt's lymphomas, 9 malignant lymphomas of other type) obtained from patients in Tanzania were studied using in situ hybridization (ISH) and polymerase chain reaction (PCR) for detection of EBV DNA and c-myc oncogene. In ISH applied on formalin-fixed, paraffin wax-embedded biopsies, the Bam HI W fragment of EBV DNA was used as the probe. Amplification of c-myc oncogene was studied by PCR with a primer set from Exon II area. As an internal standard beta-globin gene was simultaneously amplified. EBV DNA was disclosed by ISH in five Burkitt's lymphomas only. Using the PCR, 20 of the 29 cases (70%) of Burkitt's lymphomas showed amplification for EBV DNA. Of the other EBV-positive lymphomas, two were of the lymphocytic type (large non-cleaved cell), one histiocytic and one Burkitt's-like lymphoma. All EBV-positive cases found on the agarose gel were positive also with the dot blot, when hybridized with the P-32-labeled EBV Bam HI W-fragment probe. All lymphomas showed similar bands on the gel for c-myc and beta-globin indicating that no amplification of c-myc was present.