BRCA2 and p53 work together in breast cancer

There is now unequivocal evidence linking BRCA2 and p53 in breast cancer, say scientists from the Netherlands Cancer Institute, Amsterdam. To make this discovery, Anton Berns and colleagues used a new technique, called Cre-loxP technology, to develop experimental models in which combinations of the two genes were knocked out in specific cells, rather than the entire animal.
Previous attempts to develop a mouse model for breast cancer have failed because mice with mutations that block BRCA2 function die when they are still embryos.

The findings are reported in Nature Genetics (2001; 29: 418–25), and describe transgenic mice with restricted inactivation of BRCA2 in epithelial cells, including mammary-gland epithelium; the mice were healthy and tumour free. Using the same strategy, a second set of mice was developed, with inactivation of the p53 tumour-suppressor gene that is frequently mutated in BRCA2-associated malignant diseases. Mice with inactivation of the p53 gene in all cells develop nonepithelial tumours and die before the age of 9 months.