Nexrutine Phellodendron amurense bark extract: Potential use in Pancreatic Cancer

描述（由申请人提供）：尽管在了解胰腺癌（PanCA）的性质和发展方面取得了重大进展，但它仍然是一种几乎一致致命的疾病。防止PanCA发展和进步的创新策略是其管理的迫切需要。本探索性申请是为了响应PA-08-185而提交的，目的是测试从黄柏树皮中提取的草药Nexrutine是否能在体内抑制胰腺癌的发展，并确定Nexrutine介导的Akt信号的抑制是否足以抑制胰腺癌的生长。这一目标是基于我们实验室的支持数据显示：(1)抑制增殖；（ii）诱导细胞凋亡和（iii）用耐肽定治疗K-Ras状态不同的多种胰腺癌细胞系后pAkt水平的降低。对文献的回顾表明，没有已知的研究被用于评估耐克鲁汀在体外或体内对胰腺癌的影响。我们提出了两个具体目标。目的1：在临床前LSL K-ras G12D/ pdx - 1re转基因模型中建立耐克鲁肽的预防功效和生物利用度。4-5周龄LSL K-ras G12D/ pdx - 1re转基因小鼠分别饲喂0、150、300、600和900 mg/kg耐克鲁肽6个月。肿瘤发展的预防将通过(i)非侵入性氟-18氟脱氧葡萄糖正电子发射断层扫描（FDG-PET）在8周、16周和研究结束时依次监测，以及（ii）在实验结束时对mPanIN病变进行组织学评估。利用高效液相色谱和免疫组织化学分别分析胰腺中Nexrutine的水平和Akt信号分子的表达。目的2：证明Akt及其上下游信号通路在耐昔汀诱导的增殖抑制中的作用。多种生物化学（细胞增殖、细胞凋亡）、分子和遗传方法（敲入和敲除）将被用于探索PI3K/Akt信号在介导Nexrutine在胰腺癌细胞中的抗增殖活性中的作用。成功完成这个具有高转化潜力的探索性项目将(i)确定用于预防PanCA的无毒化合物；（ii）确定Akt和下游信号成分作为Nexrutine作用的标志物。此外，这些研究将提供足够的初步数据，以确定耐旭如汀的疗效是否针对任何特定阶段的PanCA，在临床前模型中逆转化疗诱导的耐药，并描述耐旭如汀的确切作用机制。LSL K-ras G12D/Pdx-1Cre转基因模型是一种非常合适的小鼠模型，可以再现人类胰腺癌的发展和进展。此外，由于Nexrutine已经在人体中使用，从这项研究中获得的结果可以扩展到探索其作为人类胰腺癌预防剂的用途。

DESCRIPTION (provided by applicant): Despite significant progress in understanding the nature and development of pancreatic cancer (PanCA), it still remains a disease of near uniform lethality. Innovative strategies to prevent the development and progression of PanCA are urgently needed for its management. The goal of this exploratory application submitted in response to PA-08-185 is to test whether Nexrutine, an herbal extract from the bark of Phellodendron amurense can inhibit pancreatic cancer development in vivo and determine whether Nexrutine-mediated inhibition of Akt signaling is sufficient to inhibit pancreatic cancer growth. This goal is based on supporting data from our laboratory showing (i) inhibition of proliferation; (ii) induction of apoptosis and (iii) reduction in the levels of pAkt following treatment of multiple pancreatic cancer cell lines that differ in the status of K-Ras with Nexrutine. A review of the literature reveals that no known studies have been undertaken to assess the effect of Nexrutine in pancreatic cancer in vitro or in vivo. We have proposed two specific aims. Aim 1: Establish the preventive efficacy and bioavailability of Nexrutine in the pre clinical LSL K-ras G12D/Pdx-1Cre transgenic model. 4-5 week old LSL K-ras G12D/Pdx-1Cre transgenic mice will be administered 0, 150, 300, 600 and 900 mg/kg Nexrutine through diet for 6 months. Prevention of tumor development will be monitored by (i) non-invasive fluorine-18 fluorodeoxyglucose positron-emission tomography (FDG-PET) sequentially during progression at 8-weeks, 16-weeks and at the time of termination of the study and (ii) histological evaluation of the mPanIN lesions at the termination of the experiment. Levels of Nexrutine and expression of Akt signaling molecules will be analyzed in the pancreas using HPLC and immunohistochemistry respectively. Aim 2: Demonstrate the role of Akt and its upstream and downstream signaling pathways in Nexrutine-induced inhibition of proliferation. A variety of biochemical (cell proliferation, apoptosis), molecular and genetic approaches (knock-in and knock-out) will be used to explore the role of PI3K/Akt signaling in mediating the antiproliferative activity of Nexrutine in pancreatic cancer cells. Successful completion of this exploratory project with high translational potential will (i) identify a non-toxic compound for use in PanCA prevention; and (ii) identify Akt and down-stream signaling components as markers of Nexrutine action. Furthermore these studies will provide enough preliminary data to determine whether the efficacy of Nexrutine is specific to any particular stage of PanCA, to reverse chemotherapy induced drug resistance in preclinical models and to delineate the precise mechanism of action of Nexrutine. The LSL K-ras G12D/Pdx-1Cre transgenic model is highly appropriate murine model in which the development and progression of pancreatic cancer (PanCA) recapitulates human PanCA development and progression. Moreover since Nexrutine is already in human use the results obtained from this study may be extended to explore its use as a prevention agent for human pancreatic cancer. PUBLIC HEALTH RELEVANCE: Pancreatic cancer (PanCA) is a major health problem with incidence and mortality rates being equal. The goal of this application is to test a cost-effective and non toxic dietary supplement as an anti-PanCA agent using a preclinical model that recapitulates human pancreatic cancer. This is therefore very timely and highly significant.