High Cholesterol Feeds Breast Cancer

Previously, a number of studies have suggested a connection between elevated cholesterol and breast cancer risk, but the mechanism for this action has remained unclear.  Donald McDonnell, from Duke University School of Medicine (North Carolina, USA), and colleagues studied whether an estrogen-like cholesterol compound, that 27-hydroxycholesterol – or 27HC, exerts a role in estrogen receptor (ER)-positive breast cancers. Using mouse models, the team demonstrated that the direct involvement of 27HC in breast tumor growth, as well as the aggressiveness of the cancer to spread to other organs. They also noted that the activity of this cholesterol metabolite was inhibited when the lab animals were treated with anti-estrogens or when exposure to 27HC was halted. The studies were substantiated using human breast cancer tissue. Additionally, the researchers found that the human tissue showed a direct correlation between the aggressiveness of the tumor and an abundance of the enzyme that makes the 27HC molecule. The study authors submit that: " lowering circulating cholesterol levels or interfering with its conversion to 27HC may be a useful strategy to prevent and/or treat breast cancer.”