Beaker bytes:
High cholesterol may accelerate prostate cancer
Population studies have linked prostate cancer with high cholesterol levels and Western-style, high-cholesterol diets. Now, a Children's Hospital Boston team, led by Michael Freeman, PhD, director of the Urological Diseases Research Center, has found that high cholesterol levels accelerate prostate tumor growth by altering chemical signaling patterns within tumor cells. Reporting in the April 1 Journal of Clinical Investigation, the team also presents evidence that cholesterol-lowering "statin" drugs may inhibit cancer growth.
The researchers injected human prostate cancer cells into mice and found that those whose cholesterol had been raised through diet had a more than doubled tumor incidence, and their tumors were markedly larger. The cholesterol accumulated in tumor-cell membranes in structures called lipid rafts, then activated a "cell-survival" pathway, enabling tumor cells to resist chemical instructions to commit suicide and allowing the cancer to proliferate. When tumor cells were treated with the cholesterol-lowering drug Zocor, the cell-survival pathway was inhibited and tumor cells died off.
Intriguingly, recent studies have found that people taking statins have a significantly lower incidence of prostate and other cancers. Freeman believes the group's findings support the idea of testing such drugs as preventive or adjunctive therapy for prostate cancer.
