The present study shows that oral gavage of 6 mumol d,l-sulforaphane (SFN), a synthetic analogue of cruciferous vegetable-derived L isomer, thrice per week beginning at 6 weeks of age, significantly inhibits prostate carcinogenesis and pulmonary metastasis in TRAMP mice without causing any side effects. The incidence of the prostatic intraepithelial neoplasia and well-differentiated (WD) carcinoma were approximately 23% to 28% lower (P < 0.05 compared with control by Mann-Whitney test) in the dorsolateral prostate (DLP) of SFN-treated mice compared with controls, which was not due to the suppression of T-antigen expression.
View Article and Find Full Text PDFIdentification of agents that are nontoxic but can delay onset and/or progression of prostate cancer, which is the second leading cause of cancer-related deaths among men in the United States, is highly desirable. We now show that p.o.
View Article and Find Full Text PDFPurpose: This study was undertaken to determine the efficacy of honokiol, a constituent of oriental medicinal herb Magnolia officinalis, against human prostate cancer cells in culture and in vivo.
Experimental Design: Honokiol-mediated apoptosis was assessed by analysis of cytoplasmic histone-associated DNA fragmentation. Knockdown of Bax and Bak proteins was achieved by transient transfection using siRNA.
We have shown recently that diallyl trisulfide (DATS), a cancer-chemopreventive constituent of garlic, inactivates Akt to trigger mitochondrial translocation of proapoptotic protein BAD in human prostate cancer cells. Because Akt activation is implicated in the promotion of endothelial cell survival and angiogenesis, we hypothesized that DATS may inhibit angiogenesis. In the present study, we tested this hypothesis using human umbilical vein endothelial cells (HUVECs) as a model.
View Article and Find Full Text PDFThe present study was undertaken to gain insights into the molecular mechanism of apoptosis induction by phenethyl isothiocyanate (PEITC), which is a cancer chemopreventive constituent of cruciferous vegetables, using PC-3 human prostate cancer cells as a model. The PEITC-induced cell death in PC-3 cells was associated with disruption of the mitochondrial membrane potential, release of apoptogenic molecules (cytochrome c and Smac/DIABLO) from mitochondria to the cytosol and generation of reactive oxygen species (ROS), which were blocked in the presence of a combined mimetic of superoxide dismutase and catalase (Euk134). Ectopic expression of Bcl-xL, whose protein level is reduced markedly on treatment of PC-3 cells with PEITC, conferred partial protection against PEITC-induced apoptosis only at higher drug concentrations (>10 microM).
View Article and Find Full Text PDFWe have shown previously that generation of reactive oxygen species (ROS) is a critical event in G(2)-M phase cell cycle arrest caused by diallyl trisulfide (DATS), which is a highly promising anticancer constituent of processed garlic. Using DU145 and PC-3 human prostate cancer cells as a model, we now report a novel mechanism involving c-Jun NH(2)-terminal kinase (JNK) signaling axis, which is known for its role in regulation of cell survival and apoptosis, in DATS-induced ROS production. The DATS-induced ROS generation, G(2)-M phase cell cycle arrest and degradation, and hyperphosphorylation of Cdc25C were significantly attenuated in the presence of EUK134, a combined mimetic of superoxide dismutase and catalase.
View Article and Find Full Text PDFThe ultimate diol epoxide carcinogens derived from polycyclic aromatic hydrocarbons, such as benzo[a]pyrene (BP), are metabolized primarily by glutathione (GSH) conjugation reaction catalyzed by GSH transferases (GSTs). In human liver and probably lung, the alpha class GSTs are likely to be responsible for the majority of this reaction because of their high abundance. The catalytic efficiency for GSH conjugation of the carcinogenic (+)-anti-benzo[a]pyrene-7,8-diol-9,10-epoxide [(+)-anti-BPDE] is more than 5-fold higher for hGSTA1-1 than for hGSTA2-2.
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