NEW YORK (Reuters Health) - Blocking a DNA repair enzyme called poly (ADP-ribose) polymerase (PARP) may help slow the growth of BRCA1- or BRCA2-mutant breast cancers, UK researchers report in the April 14th issue of Nature.
Dr. Alan Ashworth of the Institute of Cancer Research, London and colleagues note that BRCA1 and BRCA2 play a key role in DNA double-strand break repair, whereas PARP is primarily involved in single-strand repair. However, the two repair pathways are interrelated and cover for the other when one is not functional.
In breast cancers with BRCA1/BRCA2 mutations, PARP allows the malignant cells to thrive. In the study, the researchers blocked PARP in a murine model of BRCA1/BRCA2-related breast cancer.
As theorized, blocking PARP in cells that already lack BRCA1/BRCA2 activity led to DNA damage, chromosomal instability, cell cycle arrest, and ultimately apoptosis.
The authors note that this approach should be more specific than cytotoxic chemotherapy as only cells deficient in BRCA1/BRCA2 would be affected. This, they add, could result in less toxic therapies.
Source: Nature 2005;434:917-921. [ Google search on this article ]
MeSH Headings:Breast Neoplasms: Neoplasms: Neoplasms by Site: Genes, BRCA1: DiseasesCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.