High frequency of EBV association with non-random abnormalities of the chromosome region 1q21-25 in AIDS-related Burkitt's lymphoma-derived cell lines.

Chromosome 1q abnormalities represent the second most frequent cytogenetic lesion of Burkitt lymphoma (BL) and acute lymphoblastic leukemia (ALL)-L3. The most frequent change is partial duplication of the long arm of chromosome 1, involving variable bands but consistently including 1q23. Among AIDS-related BL similar chromosome 1q abnormalities have also been found. We have now characterized in detail the chromosome 1q abnormalities of 4 AIDS-BL cell lines and compared them to other molecular features of the tumor clone, namely infection by Epstein Barr virus (EBV). Immunophenotypic characteristics were also assessed by conventional in situ immunocytochemical and flow cytometric procedures. The B-cell origin of all cell lines was demonstrated by the expression of B-cell-restricted markers (e.g., CD19). Analysis of Ig light chains confirmed their monoclonal nature. The t(8;14) was present in 3 of the 4 lines, whereas variant translocation t(8;22) was detected in the remaining cell line. Additional chromosomal changes were found in all cases, with chromosome 1 being involved in all. Structural changes encompassed in each case the 1q21-25 bands, in either duplication or partial trisomy. EBER ISH studies identified EBV association in 3 of the 4 AIDS-BL cell lines in contrast to previous studies of BL of immunocompetent individuals. Our findings of a high frequency of chromosome 1q abnormalities in EBV-infected AIDS-related BL cell lines demonstrate that such chromosomal abnormality and EBV positivity are not mutually exclusive and are possibly independent factors, whereas their close association in AIDS may be related to the immunodeficiency.