Prostate Cancer Prevention by Procyanidins in Grape Seed

描述(申请人提供)：在最近的研究中，我们发现葡萄籽提取物(GSE)显著抑制DU145裸鼠移植瘤的生长。机制研究表明，GSE抑制ErbB1-Erki/2-AP1和NF-kB的激活，b)改变细胞周期调节因子，c)激活caspase，这些事件与人前列腺癌(Pca)DU145细胞生长抑制、G1期停滞和细胞凋亡性死亡有关。为了对GSE中的活性成分进行详细的机制研究，我们分离到了对DU145细胞生长抑制作用更强的原花青素B3，并在DU145细胞中分离到具有比GSE更强的S和/或G2-M阻滞和诱导凋亡的作用。在这项资助中，我们建议在细胞培养和肿瘤移植中使用原花青素B3进行深入的机制和肿瘤疗效研究。核心假设是原花青素B3抑制a)有丝分裂和细胞存活信号，b)通过改变细胞周期调节因子诱导S和/或G2-M期停滞，c)通过抑制生存信号、线粒体损伤和Caspase激活而导致细胞凋亡。总而言之，这些作用导致了它对前列腺癌的预防和治疗效果。以下是提出的具体目标，将利用正常的人前列腺上皮和前列腺癌LNCaP和DU145细胞。1)评估和确定原花青素B3对细胞有丝分裂和细胞存活信号的影响。2)评估和确定原花青素B3对S和G2-M细胞周期调节因子的影响。3)评估和确定原花青素B3对细胞凋亡调节因子的作用。4)评价和建立原花青素B3对裸鼠移植瘤的疗效。5)继续鉴定GSE中的生物活性部位(S)，并对其中存在的单个化合物进行表征。作为一种实用和翻译的方法，建议的研究结果将成为进一步研究临床前PCA模型的基础，随后将在PCA患者中进行临床试验，以进一步确定和确定从GSE中分离的原花青素B3的预防和治疗效果。

DESCRIPTION (provided by applicant): In recent studies, we found that grape seed extract (GSE) significantly inhibits DU145 xenograft growth in nude mice. Mechanistic studies showed that GSE inhibits erbB1-ERKI/2-AP1 and NF-kB activation, b) alters cell cycle regulators and c) activates caspases, and that these events are associated with human prostate cancer (PCA) DU145 cell growth inhibition, G1 arrest and apoptotic death. In an attempt to conduct detailed mechanistic studies with active compound in GSE, we were able to isolate procyanidin B3 that showed even stronger DU145 cell growth inhibitory, and S and/or G2-M arrest and apoptotic death inducing efficacy than GSE in DU145 cells. In this grant, we propose in depth mechanistic followed by tumor efficacy studies with procyanidin B3 in cell culture and tumor xenografts. The central hypothesis is that procyanidin B3 inhibits a) mitogenic and cell survival signaling, b) induces S and/or G2-M arrest depending on its concentration via alteration in cell cycle regulators, and c) causes apoptosis via inhibition of survival signal, mitochondrial damage and Caspases activation. Collectively, these effects lead to its preventive and therapeutic efficacy against PCA. Following specific aims are proposed that will utilize normal human prostate epithelial and PCA LNCaP and DU145 cells. 1) To assess and define the effect of procyanidin B3 on mitogenic and cell survival signaling. 2) To assess and define the effect of procyanidin B3 on S and G2-M cell cycle regulators. 3) To assess and define the effect of procyanidin B3 on apoptosis regulators. 4) To assess and establish the efficacy of procyanidin B3 in nude mice tumor xenografts. 5) To continue identification of biologically active fraction(s) in GSE, and characterize individual compounds present therein. As a practical and translational approach, outcome of the proposed studies will form a basis for additional studies in pre-clinical PCA models followed by clinical trials in PCA patients to further define and establish the preventive and therapeutic efficacy of procyanidin B3 isolated from GSE.