Assessment of SLX4 Mutations in Hereditary Breast Cancers

PLoS One. 2013 Jun 26;8(6):e66961. doi: 10.1371/journal.pone.0066961. Print 2013.

Abstract

Background: SLX4 encodes a DNA repair protein that regulates three structure-specific endonucleases and is necessary for resistance to DNA crosslinking agents, topoisomerase I and poly (ADP-ribose) polymerase (PARP) inhibitors. Recent studies have reported mutations in SLX4 in a new subtype of Fanconi anemia (FA), FA-P. Monoallelic defects in several FA genes are known to confer susceptibility to breast and ovarian cancers.

Methods and results: To determine if SLX4 is involved in breast cancer susceptibility, we sequenced the entire SLX4 coding region in 738 (270 Jewish and 468 non-Jewish) breast cancer patients with 2 or more family members affected by breast cancer and no known BRCA1 or BRCA2 mutations. We found a novel nonsense (c.2469G>A, p.W823*) mutation in one patient. In addition, we also found 51 missense variants [13 novel, 23 rare (MAF<0.1%), and 15 common (MAF>1%)], of which 22 (5 novel and 17 rare) were predicted to be damaging by Polyphen2 (score = 0.65-1). We performed functional complementation studies using p.W823* and 5 SLX4 variants (4 novel and 1 rare) cDNAs in a human SLX4-null fibroblast cell line, RA3331. While wild type SLX4 and all the other variants fully rescued the sensitivity to mitomycin C (MMC), campthothecin (CPT), and PARP inhibitor (Olaparib) the p.W823* SLX4 mutant failed to do so.

Conclusion: Loss-of-function mutations in SLX4 may contribute to the development of breast cancer in very rare cases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Base Sequence
  • Breast Neoplasms / genetics*
  • Cell Line
  • DNA Mutational Analysis
  • Genetic Predisposition to Disease / genetics
  • Humans
  • Middle Aged
  • Mutation*
  • Recombinases / genetics*
  • Young Adult

Substances

  • Recombinases
  • SLX4 protein, human

Supplementary concepts

  • Breast Cancer, Familial