Breast cancers may be linked with cholesterol byproduct

(News Observer, November 28, 2013)

Studies have long shown a link between obesity and breast cancer, and now scientists at Duke Cancer Institute may have found one important explanation: a byproduct of cholesterol that fuels tumors in some of the most common forms of the disease. The researchers wondered how large a role was played by the high cholesterol levels often associated with obesity. Using human tumor cells and mice bred to be especially vulnerable to breast cancer, they found that a molecule called 27-hydroxycholesterol or 27HC, which is converted from cholesterol in the body, fuels the growth and spread of tumors. They also determined that raising cholesterol levels raised risk, and that reducing cholesterol had an effect similar to suppressing its dangerous byproduct, resulting in tumors that grew at significantly slower rates. Also, the study data suggest that tumors aren’t reliant on the presence of 27HC in the blood. They are capable of producing large amounts of an enzyme that converts cholesterol to 27HC. That means that the tumors can essentially feed their own growth.