Acquired cross-linker resistance associated with a novel spliced BRCA2 protein variant for molecular phenotyping of BRCA2 disruption

Cell Death Dis. 2017 Jun 15;8(6):e2875. doi: 10.1038/cddis.2017.264.

Abstract

BRCA2 encodes a protein with a fundamental role in homologous recombination that is essential for normal development. Carrier status of mutations in BRCA2 is associated with familial breast and ovarian cancer, while bi-allelic BRCA2 mutations can cause Fanconi anemia (FA), a cancer predisposition syndrome with cellular cross-linker hypersensitivity. Cancers associated with BRCA2 mutations can acquire chemo-resistance on relapse. We modeled acquired cross-linker resistance with an FA-derived BRCA2-mutated acute myeloid leukemia (AML) platform. Associated with acquired cross-linker resistance was the expression of a functional BRCA2 protein variant lacking exon 5 and exon 7 (BRCA2ΔE5+7), implying a role for BRCA2 splicing for acquired chemo-resistance. Integrated network analysis of transcriptomic and proteomic differences for phenotyping of BRCA2 disruption infers impact on transcription and chromatin remodeling in addition to the DNA damage response. The striking overlap with transcriptional profiles of FA patient hematopoiesis and BRCA mutation associated ovarian cancer helps define and explicate the 'BRCAness' profile.

Publication types

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

MeSH terms

  • Alternative Splicing*
  • Animals
  • BRCA2 Protein / genetics*
  • BRCA2 Protein / metabolism*
  • Breast Neoplasms / drug therapy
  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism
  • Cell Line, Tumor
  • DNA Damage
  • Drug Resistance, Neoplasm*
  • Exons
  • Fanconi Anemia / drug therapy
  • Fanconi Anemia / genetics
  • Fanconi Anemia / metabolism
  • Female
  • Genes, BRCA2*
  • Genetic Predisposition to Disease
  • Humans
  • Introns
  • K562 Cells
  • Leukemia, Myeloid, Acute / drug therapy
  • Leukemia, Myeloid, Acute / genetics
  • Leukemia, Myeloid, Acute / metabolism
  • Mice
  • Mutation*
  • Neoplasm Recurrence, Local
  • Ovarian Neoplasms / drug therapy
  • Ovarian Neoplasms / genetics
  • Ovarian Neoplasms / metabolism
  • Phenotype
  • RNA Splicing
  • Transcription, Genetic

Substances

  • BRCA2 Protein
  • BRCA2 protein, human