CANCER RESEARCH:
New Model for Hereditary Breast Cancer
Michael Hagmann
Researchers now have an important new clue about how breast cancer develops, at least in women who have mutations in BRCA1, one of two genes linked to the 5% or so of the cases that are hereditary. In a paper in the May issue of Nature Genetics, researchers report that they have inactivated, or knocked out, the BRCA1 gene in mice exclusively in the cells where breast cancer normally originates--the epithelial cells lining the milk ducts. In contrast to previous BRCA1 knockouts, some of these animals developed breast tumors. The researchers also found that breast cells lacking an active BRCA1 gene are prone to accumulating additional genetic defects that might be crucial contributors to cancer development. Such an animal model will be invaluable for understanding the role of BRCA1 in familial breast cancer, researchers say.
