Scientists have gained new insight into how changes in BRCA2 can affect a cancer's resistance to therapy. BRCA2 mutations are associated with an increase in breast and ovarian cancer risk, as the gene's normal function is to repair damaged DNA. But these cancer-causing faults are bad news for the tumour itself, as they also render it sensitive to DNA-damaging chemotherapy drugs like cisplatin. Unfortunately, many BRCA2 tumours develop resistance to cisplatin.
Two papers published online in Nature reveal how this resistance occurs. The teams, led by Alan Ashworth and Toshiyasu Taniguchi, show that some cancer cells can acquire secondary 'reactivating' mutations in their BRCA2 gene, switching it back on and allowing the cancer to repair the DNA damaged by the drug's assault. Such mutations were found in several cisplatin-resistant ovarian cancer patients. The discovery raises the possibility that blocking BRCA2 function in such patients might allow doctors to overcome drug resistance and continue with cisplatin treatment.
Alan Ashworth (The Institute of Cancer Research, London, UK) Author paper 
Toshiyasu Taniguchi (Fred Hutchinson Cancer Research Center, Seattle, WA, USA) Author paper 
Abstracts available online:
Abstract of Paper 1.
Abstract of Paper 2.
(C) Nature press release.
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