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Secondary mutations of BRCA1/2 and drug resistance

Kiranjit K Dhillon1, Elizabeth M Swisher, Toshiyasu Taniguchi

  • 1Howard Hughes Medical Institute, Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.

Cancer Science
|January 6, 2011
PubMed

Insights

Inherited BRCA1/2 mutations increase cancer risk. Acquired resistance to cancer drugs like cisplatin can occur when secondary mutations restore BRCA1/2 gene function, aiding tumor survival.

Area of Science:

  • Oncology
  • Cancer Genetics
  • Molecular Biology

Background:

  • Germline mutations in BRCA1 and BRCA2 tumor suppressor genes significantly elevate the risk of breast and ovarian cancers.
  • BRCA1/2-deficient tumors exhibit impaired DNA repair via homologous recombination, rendering them susceptible to DNA crosslinking agents and PARP inhibitors.
  • These targeted therapies, including cisplatin, carboplatin, and poly(ADP-ribose) polymerase inhibitors, are effective against BRCA1/2-deficient cancers.

Purpose of the Study:

  • To review the mechanisms of acquired drug resistance in BRCA1/2-mutated cancers.
  • To explore how secondary mutations can restore tumor suppressor gene function and lead to treatment failure.

Main Methods:

  • This review synthesizes existing research on BRCA1/2 mutations and drug resistance.
  • Analysis of genetic reversion events in cancer cells treated with DNA-damaging agents.

Main Results:

  • BRCA1/2-mutated tumors often develop resistance to standard therapies.
  • Restoration of BRCA1/2 function through secondary mutations is a key mechanism of acquired resistance.
  • This genetic reversion allows cancer cells to survive and proliferate despite treatment.

Conclusions:

  • Acquired resistance to DNA repair-targeting drugs in BRCA1/2-mutated cancers can be driven by genetic reversion.
  • Understanding these resistance mechanisms is crucial for developing more effective and durable cancer treatments.
  • Targeted therapies may face challenges due to the evolutionary capacity of cancer cells to regain gene function.

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