Gamma Tocotrienol and Prostate Cancer: The Regulation of Two Independent Pathways to Potentiate Cell Growth Inhibition and Apoptosis
Document Type
Article
Publication Date
10-1-2008
Description
Dietary vitamin E, highly expressed in palm oil, exists as either tocopherols or tocotrienols. Evidence indicates that vitamin Es maybe potent cancer preventive agents. In this study, the y- and O- isoforms of vitamin E were found to he the most effective at cancer cell growth inhibition, with the tocotrienols being more effective than the tocopherols in androgen-independent PC-3 prostate cancer cells. To assure that these compounds were selective toward cancer cells, the growth arrest of PrEC normal prostate cells was compared to PC-3 cells. At concentrations of -30 iM dietary, y-vitamin Es showed no signficant growth arrest on PrEC cell growth, hut selectively inhibited growth in the PC-3 cancer cells. Moreover y-Tocotrienol demonstrated a greater potential to inhibit growth in cancer cells at these lower concentrations than did y-Tocopherol. Two independent pathways important in carcinogenesis were tested: PPAR y and NFicB. The PPAR y was up regulated by both dietary y-vitamin Es by the modulation of the endogenous ligand 15-S-HETE, while NFicB was only regulated by y-Tocotrienol. The modulation of NFicB was confirmed by the down regulation of the pro-Apoptotic proteins clAP, xIAP, and BcL-2 which potentiate apoptosis and are down stream effectors of NFicB.
Citation Information
Campbell, S.; Whaley, S. G.; Phillips, R.; Aggarwal, B. B.; Stimmel, J. B.; Leesnitzer, L.; Blanchard, S. G.; Stone, W. L.; Christian, Muenyi; and Krishnan, K.. 2008. Gamma Tocotrienol and Prostate Cancer: The Regulation of Two Independent Pathways to Potentiate Cell Growth Inhibition and Apoptosis. Journal of Oil Palm Research. (SPEC. ISS. OCTOBE). 33-43. ISSN: 1511-2780