How loss of Angelina Jolie gene results in breast cancer

Washington D.C.: A team of researchers has provided deeper insight into how the Angelina Jolie gene, BRCA1, functions in normal breast tissue and how its loss results in breast cancer.

BRCA1 is known to suppress cancer by repairing breaks in DNA, the molecule that contains the genetic blueprint of each cell. This DNA damage occurs with aging and environmental insults.

In the new study, The Cancer Therapy & Research Center ( CTRC) researchers found that BRCA1 also serves as a limiter or governor on a gene called COBRA1 that regulates breast cell growth.

Lead author Rong Li said that they now have solid and compelling evidence that BRCA1 in breast tissue is doing something independent of DNA repair. The researchers still think DNA repair is important for BRCA1 to suppress tumor development, but they just don't think it's the whole story.

Scientists including Dr. Li have been puzzled over why loss of BRCA1 function predisposes women to only breast and ovarian cancers. Also, diminished BRCA1 activity doesn't affect men significantly, as it does women.

"From very early on, we and others in the field speculated that maybe there is a DNA repair-independent function associated with BRCA1 that can better explain this tissue and gender specificity," Dr. Li said.

The new finding provides at least part of that answer, he said, and could one day translate into better diagnostic and treatment tools for this form of breast cancer. The ultimate goal would be to slow down or even prevent breast cancer development in BRCA1 mutation carriers, he added.

The study is published in Nature Communications.