Heterozygous mutations in PALB2 cause DNA replication and damage response defects

Jenni Nikkilä, Ann Christin Parplys, Katri Pylkäs, Muthiah Bose, Yanying Huo, Kerstin Borgmann, Katrin Rapakko, Pentti Nieminen, Bing Xia, Helmut Pospiech, Robert Winqvist

Research output: Contribution to journalArticlepeer-review

58 Scopus citations

Abstract

Besides mutations in BRCA1/BRCA2, heterozygous defects in PALB2 are important in breast cancer predisposition. PALB2 heterozygosity increases the risk of malignancy about sixfold. PALB2 interacts with BRCA1 and BRCA2 to regulate homologous recombination and mediate DNA damage response. Here we show, by analysing lymphoblastoid cell lines from heterozygous female PALB2 mutation carriers, that PALB2 haploinsufficiency causes aberrant DNA replication/damage response. Mutation carrier cells show increased origin firing and shorter distance between consecutive replication forks. Carrier cell lines also show elevated ATR protein, but not phosphorylation levels, and a majority of them display aberrant Chk1-/Chk2-mediated DNA damage response. Elevated chromosome instability is observed in primary blood lymphocytes of PALB2 mutation carriers, indicating that the described mechanisms of genome destabilization operate also at the organism level. These findings provide a new mechanism for early stages of breast cancer development that may also apply to other heterozygous homologous recombination signalling pathway gene mutations in hereditary cancer predisposition.

Original languageEnglish (US)
Article number2578
JournalNature communications
Volume4
DOIs
StatePublished - Oct 24 2013

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • General Biochemistry, Genetics and Molecular Biology
  • General
  • General Physics and Astronomy

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