Molecular analysis of the t(2;8)/MYC–IGK translocation in high‐grade lymphoma/leukemia by long‐distance inverse PCR

Abstract

Burkitt lymphoma and a subset of diffuse large B-cell lymphomas are characterized by chromosomal alterations affecting the MYC oncogene on 8q24. In most cases MYC is found juxtaposed to the immunoglobulin heavy chain (IGH) gene locus. Translocations to the immunoglobulin kappa (IGK) gene locus on 2p11 are observed in around 5-10% of cases. Little data exist on the molecular mechanisms leading to this aberration. The chromosomal breakpoints on chromosome 8 have been found dispersed over a large area 3' of MYC. In order to obtain a better understanding of this chromosomal translocation we developed a long-distance inverse (LDI) PCR method for the identification of chromosomal translocations affecting the IGK locus. We investigated a number of cytogenetically mostly uncharacterized high-grade lymphoma samples and identified a MYC-IGK juxtaposition in seven patients and three t(2;8)-positive cell lines. The chromosomal breakpoints were molecularly characterized and analyzed. The linear distance of the breakpoints on chromosome 8 to MYC ranged from some 100 bp to more than 0.5 MB. The reciprocal translocated allele could be characterized in the majority of cases. This study represents the largest series of t(2;8)-positive cases analyzed so far. The LDI PCR method developed here should also be useful for the analysis of chromosomal translocations affecting the IGK locus in general.

Chromosomal Loop Domains Direct the Recombination of Antigen Receptor Genes

“…These findings explain how paired bona fide RSSs within a Tcrα excision circle fragment integrated into the HPRT locus in leukemia cells causes further genomic aberrations (Messier et al, 2006) and also support the hypothesis that translocations downstream of c-Myc in human B cell lymphomas involve cryptic RSSs (Kroenlein et al, 2011). Given that cryptic RSS targeting downstream of c-Myc occurs in both WT and ATM-deficient pro-B cells, one role of ATM in suppressing such translocations would be through stabilizing ends in RAG post-cleavage complexes to facilitate their joining via V(D)J recombination (Bredemeyer et al, 2006).…”

Fine mapping of V(D)J recombinase mediated rearrangements in human lymphoid malignancies

“…MYC -IGK breakpoints near ours have been reported. In a recent report of breakpoints for 10 high-grade lymphoma samples with t(2;8), one patient sample and one cell line had der(8) breakpoints between IGKJ4 and IGKJ5, similar to our IGK der(8) breakpoint [12]. One patient sample in their cohort showed a 435 bp deletion from der(2), similar in size to our der(2) deletion.…”

DNA nanomapping using CRISPR-Cas9 as a programmable nanoparticle

“…It may be possible to combine HS-AFM nanomapping with hybrid capture or “inverse” long PCR, for instance, to isolate translocations breakpoint regions using only limited knowledge of the loci involved in the translocation 35 , 36 . Breakpoint position and identity of the translocation partners would be resolved by “molecular barcoding” with CRISPR-Cas9.…”