Gene linked to breast, ovarian cancer also linked to Alzheimer's

by Lynne Terry for the Oregonian:

A gene linked to both breast and ovarian cancer also appears to play a role in Alzheimer's, a new study shows.

Researchers in California found that people who died from Alzheimer's or even suffered cognitive decline had low levels of the BRCA1 gene. They also found a similar depletion of the gene in mice genetically engineered to develop Alzheimer's. BRCA1 plays a key role in repairing broken strands of DNA, a molecule that carries our genetic code.

Mutant forms of BRCA1 are linked to both breast and ovarian cancer.

"It is extremely interesting that one molecule can be critically involved in two apparently opposing conditions: cancer, in which too many cells are born and neurodegenerative disease, in which too many brain cells die off," Dr. Lennart Mucke, director of the Gladstone Institute of Neurological Disease, San Francisco, told the National Institute of Health.

The study, published in Nature Communications, found that BRCA1 plays a critical role in repairing DNA in central neurons and that reductions of the protein were associated with cellular dysfunction and cognitive decline. Autopsies showed that people who had Alzheimer's or even mild cognitive impairment had lower levels of BRCA1 in their brain than people who did not have those conditions. Those lower levels were associated with a build-up of amyloid beta, a key component in the plaque that clogs the brains of Alzheimer's patients.

The researchers said their study raises questions about whether mutations in BRCA1 associated with breast and ovarian cancer also affects the protein in the brain. They also said that BRCA1 may have other functions besides DNA repair.

"Additional studies are needed to address these possibilities and explore the therapeutic potential of enhancing DNA repair in Alzheimer's disease and related conditions," the study said.

Source: http://bit.ly/1TqRlkJ