Vitamin E Suppresses Prostate Cancer

MCancer researcher, Shuyuan Yeh, and her team, recently discovered that a special protein in the body, called alpha tocopherol protein, or TAP, allows Vitamin E tocopherol (vitamin E succinate) to fight prostate cancer. The protein is produced within the liver, in addition to other cells.

Prostate cancer is the most common cancer in U.S. men with one out of every six men developing it, which makes this discovery so important. “Vitamin E can influence the mortality of the cancer rate,” says Yeh. Many prior studies have shown that Vitamin E has a modifying effect on prostate cancer. With continued research into TAP, levels of the protein could be used by doctors to predict both a cancer’s aggressiveness, as well as a patient’s potential responsiveness to treatment.

What inspired this Yeh to investigate prostate cancer was that currently, scientists do not know why that, despite the fact that prostate cancer “invariably” goes away after treatment, it always returns. Advanced- stage prostate cancer treatments presently focus on reducing testosterone levels, because the male hormones—known as androgens— are known to contribute to prostate cancer. Many studies focus on trying to block the development of any chemicals, which might stimulate androgen production and thus feed the growth rate of the cancer. What Yeh’s research team discovered is that TAP disrupts a signaling pathway in prostate cancer cells, which suppresses the growth of cancer. The TAP also allows beneficial Vitamin E to be held in the cancer cells longer, further halting growth of the cancer.

High levels of TAP were found in normal, healthy prostate tissue epithelial cells. The recent study proved for the first time that TAP supports the retention of Vitamin E. In addition, the team found the way in which Vitamin E enters cells—with the assistance of TAP. The TAP increases Vitamin E’s ability to slow the growth of cancer cells.

In prostate cancer, levels of TAP are much lower than in a normal prostate. Because of this, TAP may become a valuable warning signal for those at risk for prostate cancer. High levels of TAP protein in prostate cells might have a protective function due, in part, to its relationship to Vitamin E. Possible future uses of TAP include treatment for the disease itself.1

References:
1. Cancer Research 2005; Nov 1;Vol 65, issue 21, pp 9807-16.