TY - JOUR TI - Phytochemicals for prostate cancer prevention DO - https://doi.org/doi:10.7282/T3SQ922M PY - 2015 AB - Prostate cancer is the most prevalent type of non-skin cancer among men in the United States. The development of prostate cancer generally consists of three stages—initiation, promotion and progression. Many phytochemical display preventive effects against prostate cancer by blocking the tumor initiation and/or suppressing the promotion and progression. Nrf2 is a master regulator of the antioxidant response and xenobiotic metabolism through the regulation of a wide range of antioxidant and phase II detoxification genes. Nrf2 protects cells from stressors, including endogenous substances, reactive oxygen species, radiation, environmental toxins, and xenobiotics from food. The protective role of Nrf2 points its potential importance in prostate carcinogenesis. Coincidentally, our group has reported that as prostate progresses in the transgenic adenocarcinoma of mouse prostate (TRAMP) model, there is a progressive loss of expression of Nrf2 and its downstream target genes, which is associated CpG hypermethylation in the promoter region. Curcumin (CUR), tocopherols (T) and tocotrienols (T3) were found to be powerful cancer chemopreventive agents using animal models of different cancers including prostate cancer. Using TRAMP C1 cells, we demonstrated that CUR is a potent demethylation agent and it restores the epigenetically silenced Nrf2 gene through DNA demethylation. In addition, we showed that a γ-tocopherol-rich mixture of tocopherols (γTmT) treatment reduced the incidence of palpable tumor incidence in TRAMP mice. γTmT also inhibited the CpG hypermethylation in the Nrf2 promoter during prostate cancer progression and maintained Nrf2 and its downstream target NQO1 in the prostate. A global gene expression analysis comparing the TRAMP and non-transgenic mice revealed dramatic difference in the prostate, including genes encoding phase II detoxification enzymes and cell cycle controlling proteins. Short-term treatment of γTmT could partly prevent the alteration of genes identified in the prostate of TRAMP mice. Furthermore, we found that a mixture of tocotrienols, a less-recognized subclass of vitamin E, suppressed xenografted VCaP prostate tumor in nude mice in part by modulating cell cycle progression. KW - Pharmaceutical Science KW - Phytochemicals--Therapeutic use KW - Prostate--Cancer--Treatment KW - Cancer--Prevention LA - eng ER -