Alternative translocation breakpoint cluster region 5' to BCL-6 in B-cell non-Hodgkin's lymphoma

Cancer Res. 2002 Jul 15;62(14):4089-94.

Abstract

Chromosomal translocations involving band 3q27 with various different partner chromosomes represent a recurrent cytogenetic abnormality in B-cell non-Hodgkin's lymphoma. In a fraction of these translocations, the chromosomal breakpoint is located within the 5' noncoding region of the BCL-6 proto-oncogene where the BCL-6 major breakpoint region (MBR) maps. As a result of the translocation, BCL-6 expression is deregulated by promoter substitution. However, between 30 and 50% of lymphomas with cytogenetically detectable translocations affecting band 3q27 retain a germ-line configuration at the BCL-6 locus. To identify possible additional breakpoint clusters within 3q27, we cloned a t(3;14)(q27;q32) lymphoma without MBR rearrangement and found a novel breakpoint site located between 245 and 285 kb 5' to BCL-6. Breakpoints within this newly described region, which we called the alternative breakpoint region (ABR), were found to be recurrent in lymphomas carrying t(3q27) chromosomal translocations but devoid of BCL-6 MBR rearrangements. Comparative analysis of multiple lymphomas carrying rearrangements within the ABR showed that the breakpoints cluster within a 20-kb distance. Translocations involving the ABR may juxtapose BCL-6 to distantly acting, heterologous transcriptional regulatory elements which cause deregulation of the proto-oncogene. The identification of BCL-6 ABR provides new tools for the diagnosis of lymphomas carrying aberrations at 3q27 and deregulated BCL-6 genes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Base Sequence
  • Chromosome Breakage
  • Chromosomes, Human, Pair 14
  • Chromosomes, Human, Pair 3*
  • Cloning, Molecular
  • DNA-Binding Proteins / genetics*
  • Gene Expression Regulation, Neoplastic / genetics
  • Humans
  • Lymphoma, B-Cell / genetics*
  • Molecular Sequence Data
  • Proto-Oncogene Mas
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins c-bcl-6
  • Transcription Factors / genetics*
  • Translocation, Genetic

Substances

  • DNA-Binding Proteins
  • MAS1 protein, human
  • Proto-Oncogene Mas
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-bcl-6
  • Transcription Factors