A protein that senses a cell's metabolic state may serve as a 'switch' to allow breast cancer to develop. This could be a molecular reason for why a high intake of calories and weight gain are strong risk factors for breast cancer.
Kevin Gardner of the National Cancer Institute in Bethesda, Maryland, and his colleagues looked at the protein CtBP, which acts as a metabolic sensor. The protein is activated when it binds to NADH, an important indicator of a cell's metabolic activity. The researchers found that silencing CtBP expression increased expression of BRCA1, a tumour-suppressor gene associated with breast cancer. This suggests that greater activation of CtBP lowers the protective effects of BRCA1.