People inherit two copies of each gene -; one from each parent -; an evolutionary fail-safe to ensure survival even when one of them doesn't function. For cancer-suppressor genes like BRCA1 , researchers have long hypothesized that a single healthy copy could still guard against tumor development. Yet women with one harmful BRCA1 mutation are far more likely to develop breast cancer -; a risk traditionally explained by a second mutation that arises later in life, damages the healthy copy of the gene, and triggers disease.
But does this two-hit model tell the whole story? Likely not, according to the findings of a new study led by scientists at Harvard Medical School. The research, published Nov.11 Nature Genetics , shows that even in the absence of a second mutational hit, a single faulty copy of BRCA1 renders breast cells more vulnerable to cancer and is sufficient to ignite tumor growth.
Our work provides an answer to what's been a lingering question in the field. It shows why and how even a single defective copy of BRCA1 can alter cells in a way that accelerates cancer. Our findings show that the two-hit hypothesis of cancer development offers only a partial explanation.
" Joan Brugge, study senior author, the Louise Foote Pfeiffer Professor of Cell Biology at HMS The research suggests that cells with a single BRCA1 mutation can somehow prime breast cells to develop cancer in ways researchers did not fully understand before. If replicated in further research in humans, the .
