Phytoestrogen and Antioxidant Regulation of Prostate Cancer

描述(申请人提供)：膳食补充剂被消费者用于预防和治疗前列腺癌。最近，一个动物前列腺癌模型已经允许对这些补充剂的安全性和有效性进行测试。我们已经建立了转基因小鼠前列腺癌(TRAMP)小鼠、雌激素受体缺陷(ERalphaKO和ERbetaKO)小鼠以及表达TRAMP转基因的ER缺陷小鼠的克隆。因此，一种系统的方法现在可以用来识别植物药物影响肿瘤发生和发展的分子机制。我们模型中令人兴奋的数据清楚地表明，ERalphaKO小鼠对前列腺癌(低分化癌)具有高度保护作用，而ERbetaKO小鼠对PDC高度敏感。除了雌激素信号外，还有两个信号通路被认为在前列腺癌的发生和发展中起重要作用：DNA甲基化和抗氧化信号。我们的总体假设是，植物雌激素对ERa和ERP的不同调控，基本上作为天然的SERM，将在人类前列腺癌的预防和治疗中发挥有效的作用。我们的目标是表征关键的前列腺癌生物标志物对植物类药物的反应，并为这些反应提供新的分子机制。目的：我们将利用TRAMP小鼠模型，以两种不同剂量的植物成分(菠菜和绿茶及其生物活性标志物/成分)对ER WT或ER-阴性/TRAMP小鼠进行体内肿瘤预防实验，以探讨ERα和ERβ蛋白在前列腺癌发生中的作用及其对前列腺癌发生发展的影响。目的Ib：我们将证实我们之前的研究结果，即在TraMP小鼠中，ERpha促进前列腺PDC的发育，而ERbeta通过ERpha和ERbeta特异性配体阻止前列腺癌的发展。目的：我们将描述相同的两种优先植物药及其生物活性标志物加金雀异黄素对培养的人和小鼠前列腺癌细胞内选定的DNA甲基化、雌激素和抗氧化途径的影响的分子机制。最后，在目标3：我们将在体内从目标1的小鼠组织中确认选定的植物药物及其生物活性标记物在调控对癌症发生至关重要的细胞途径中的作用，包括选定的细胞内DNA甲基化、雌激素和抗氧化途径。我们还将使用已经收集的金雀异黄素治疗的组织样本，因为报道了金雀异黄素对PDC的影响，以及我们发现其对WDC(高分化癌)的影响。这些研究将提供对前列腺癌生物学的基本见解，并评估这些植物药在改变人类前列腺癌的发生和发展中的作用。

DESCRIPTION (provided by applicant): Dietary supplements are used by consumers to prevent and to treat prostate cancer. Recently, an animal prostate cancer model has allowed the safety and efficacy of these supplements to be tested. We have established colonies of TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) mice, estrogen receptor-deficient (ERalphaKO and ERbetaKO) mice, and ER-deficient mice expressing the TRAMP transgene. Thus, a systematic approach is now possible for the identification of molecular mechanisms through which botanicals affect tumor incidence and progression. Exciting data from our model clearly show that ERalphaKO mice are highly protected against PDC (poorly differentiated carcinoma) of the prostate and ERbetaKO mice are highly susceptible to PDC. In addition to estrogen-signaling, two more signaling pathways are also believed important in mediating the initiation and progression of prostate cancer: DNA methylation and antioxidant- signaling. Our overall hypothesis is that differential regulation of ERalpha and ERP by plant phytoestrogens, acting essentially as natural SERMs, will be effective in human prostate cancer prevention and treatment. Our goals are to characterize responses of key prostate tumor biomarkers to botanicals and to provide novel molecular mechanisms for these responses. Aim la: We will use the TRAMP mouse model to perform in vivo cancer prevention trials with 2 high priority botanicals (spinach and green tea; and their bioactive markers/components) using two doses in ER WT or ER-minus / TRAMP mice to investigate the in vivo roles of ERalpha and ERbeta proteins in prostate tumorigenesis and their impact on the development of PDC. Aim Ib: We will confirm our previous findings that in TRAMP mice the development of PDC of the prostate is promoted by ERalpha and prevented by ERbeta using ERalpha and ERbeta specific ligands. Aim 2: We will profile the molecular mechanisms by which the same 2 priority botanicals and their bioactive markers plus genistein induce the effect on selected intracellular DNA methylation, estrogenic and antioxidant pathways in both human and mice cultured prostate tumor cells. Finally, in Aim 3: We will confirm in vivo in mouse tissues from Aim #1, the role of selected botanicals and their bioactive markers in regulation of cellular pathways of importance to carcinogenesis, including selected intracellular DNA methylation, estrogenic and antioxidant pathways. We will also use already collected genistein-treated tissue samples because of genistein's reported effect on PDC and our finding of its effect on WDC (well differentiated carcinoma). These studies will provide fundamental insights into prostate tumor biology, and assess the role of these botanicals in modifying the incidence and progression of prostate tumors in humans.