Mutations in the BRCA1 breast cancer gene appear to be linked
with the loss of a protein important for braking cell growth,
scientists reported on Sunday.
The breakthrough could lead to more effective therapies for
women with an aggressive and especially deadly cancer that does not
respond to current advanced drugs.
Scientists have known for more than a decade that women with
certain alterations in the BRCA1 gene were at high risk for breast
cancer. What they have not understood is exactly how a mutation in
this gene leads to cancer.
Researchers at Columbia University, working with at team at
Sweden's Lund University, now believe mutations in the BRCA1 gene
can leave cells incapable of repairing routine DNA damage. When
such damage occurs in a protein called PTEN, which regulates the
growth of cells, cell growth is unchecked and tumors form.
Women with faulty copies of BRCA1 or BRCA2 have a 50 to 85
percent chance of getting breast cancer. Mutations in these genes
account for 5 to 10 percent of breast cancer cases.
(Agencies via Xinhua News Agency December 11, 2007)