Activation induced deaminase mutational signature overlaps with CpG methylation sites in follicular lymphoma and other cancers

Sci Rep. 2016 Dec 7;6:38133. doi: 10.1038/srep38133.

Abstract

Follicular lymphoma (FL) is an uncurable cancer characterized by progressive severity of relapses. We analyzed sequence context specificity of mutations in the B cells from a large cohort of FL patients. We revealed substantial excess of mutations within a novel hybrid nucleotide motif: the signature of somatic hypermutation (SHM) enzyme, Activation Induced Deaminase (AID), which overlaps the CpG methylation site. This finding implies that in FL the SHM machinery acts at genomic sites containing methylated cytosine. We identified the prevalence of this hybrid mutational signature in many other types of human cancer, suggesting that AID-mediated, CpG-methylation dependent mutagenesis is a common feature of tumorigenesis.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • B-Lymphocytes / metabolism
  • Carcinogenesis / genetics
  • CpG Islands / genetics*
  • Cytosine / metabolism
  • DNA Methylation / genetics*
  • Humans
  • Lymphoma, Follicular / genetics*
  • Mutagenesis / genetics
  • Mutation / genetics*
  • Nucleoside Deaminases / genetics*
  • Nucleotides / genetics

Substances

  • Nucleotides
  • Cytosine
  • Nucleoside Deaminases