Variant translocation of the BCL6 gene to immunoglobulin kappa light chain gene in B-cell lymphoma.
A lymphoma cell line with a variant type of translocation, t(2;3)(p11;q27), was established from a patient who had received liver transplantation. To elucidate the molecular mechanism of the t(2;3)(p11;q27) chromosomal translocation, we compared the structures of both derivative (der) chromosomal breakpoints with those of their germline predecessors. We noted that the BCL6 gene on chromosome 3 was juxtaposed with the immunoglobulin kappa light chain (Ig kappa) gene on chromosome 2 in a head-to-head configuration. The breakpoint of the BCL6 gene was within a previously reported breakpoint cluster region. The breakpoint on chromosome 2 was within the intron between the leader (L) and variable (V) sequences of one of the V kappa genes, which was fused to the J kappa 3 (J = joining) segment. At chromosomal junctures, a direct repeat duplication of chromosome 3 sequences and a deletion of chromosome 2 sequences were discovered. These results are consistent with a translocation model with illegitimate pairing of staggered double-stranded DNA breaks at 3q27 and 2p11, repair, and ligation to generate der(3) and der(2) chromosomes.
First Department of Internal Medicine, Tokyo Medical and Dental University.
K
K
Suzuki
T
T
Miki
N
N
Kawamata
S
S
Hirosawa
K
K
Yoshizawa
K
K
Kiyosawa
N
N
Aoki
D001483:Base Sequence; D002869:Chromosome Aberrations / Q000235:genetics*; D025063:Chromosome Disorders; D002889:Chromosomes, Human, Pair 2; D002893:Chromosomes, Human, Pair 3; D003001:Cloning, Molecular; D004273:DNA, Neoplasm / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D015328:Gene Rearrangement, B-Lymphocyte, Light Chain; D005803:Genes, Immunoglobulin; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D016393:Lymphoma, B-Cell / Q000235:genetics*; D008969:Molecular Sequence Data; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D051560:Proto-Oncogene Proteins c-bcl-6; D015183:Restriction Mapping; D014157:Transcription Factors / Q000235:genetics*; D014178:Translocation, Genetic; D014407:Tumor Cells, Cultured; D016335:Zinc Fingers
D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D007145:Immunoglobulin kappa-Chains; D011518:Proto-Oncogene Proteins; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors