Issues

Prostate cancer is the most common cancer among men in the United States. It has a long latent period for precancerous lesions to develop into carcinomas, thus providing opportunities for prevention. Although the most commonly used form of vitamin E, α-tocopherol, was not shown to prevent prostate cancer, other vitamin E forms (γ- and δ-forms of tocopherols and tocotrienols) have shown anti-cancer activities in lab studies. In the article starting on page 233, Wang and colleagues compared the inhibitory activities of the α-, γ- and δ-forms of tocopherols and tocotrienols against six prostate cancer cell lines and found that d-tocotrienol (δ-T3) had the highest activities. δ-T3 (0.05% in the diet) also impeded the formation of prostate adenocarcinoma in prostate specific Pten knockout mice. Proposed mechanisms include the inhibition of cell proliferation and angiogenesis and promotion of apoptosis. δ-T3 is found in rice oil, palm oil, other dietary sources and annatto, a topical plant. The cover image shows the inhibition of angiogenesis in the lesioned gland of the dorsal-lateral-central lobes as determined by C31/Pecam 1 immunochemical staining in mice in the control group (upper left) versus those treated with δ-T3 (upper right). The bottom panels show the blood vessel-rich stroma from mice in the control group (lower left) and the δ-T3-treated group (lower right).