Only part of the story

It’s been dubbed the Angelina Jolie gene, the BRCA1 gene mutation that put the actress at higher risk for invasive breast cancer and led to her undergoing a double mastectomy to prevent it.

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

In a new study, published in Nature Communications, Cancer Therapy & Research Center researchers found that BRCA1 also serves as a limiter or governor on a gene called COBRA1 that regulates breast cell growth.

“We now have solid and compelling evidence that BRCA1 in breast tissue is doing something independent of DNA repair,” said study lead author Rong Li, Ph.D., professor of molecular medicine. “We still think DNA repair is important for BRCA1 to suppress tumor development, but we just don’t think it’s the whole story.”

Since DNA repair is needed in every cell of the body, scientists have 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 said.