Nexrutine Phellodendron amurense bark extract: Potential use in Pancreatic Cancer

描述(由申请人提供)：尽管在了解胰腺癌的本质和发展方面取得了重大进展，但它仍然是一种几乎一致的致命性疾病。迫切需要采取创新战略来防止泛卡病毒的发展和进展，以便对其进行管理。根据PA-08-185提交的这项探索性申请的目的是测试黄柏树皮中的草药提取物Nexrutin是否可以在体内抑制胰腺癌的发展，并确定Nexrutin介导的Akt信号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性数据，该数据显示：(I)抑制增殖；(Ii)诱导细胞凋亡；(Iii)用奈斯鲁廷治疗K-RAS状态不同的多个胰腺癌细胞株后，PAKT水平降低。对文献的回顾表明，目前还没有已知的研究来评估奈斯鲁汀在体外或体内对胰腺癌的疗效。我们提出了两个具体目标。目的1：建立临床前LSL K-ras G12D/PDX-1Cre转基因动物模型，观察Nexrutin对LSL K-ras G12D/PDX-1Cre转基因动物的预防作用和生物利用度。4~5周龄LSL K-ras G12D/PDX-1Cre转基因小鼠分别饲喂0、150、300、600和900 mg/kg奈斯鲁汀，连续6个月。肿瘤的预防将通过(I)在8周、16周和研究结束时的进展过程中顺序进行的非侵入性氟-18氟脱氧葡萄糖正电子发射断层扫描(FDG-PET)进行监测，以及(Ii)在实验结束时对mPanIN损伤进行组织学评估。Nexrutin的水平和Akt信号分子在胰腺中的表达将分别使用高效液相色谱法和免疫组织化学进行分析。目的2：阐明Akt及其上下游信号通路在奈斯鲁汀抑制细胞增殖中的作用。将利用多种生化手段(细胞增殖、细胞凋亡)、分子和遗传学方法(敲入和敲除)来探讨PI3K/Akt信号通路在介导Nexrutin抗胰腺癌细胞增殖活性中的作用。这一具有很高翻译潜力的探索性项目的成功完成将(I)确定一种用于预防panca的无毒化合物；以及(Ii)确定Akt和下游信号成分作为Nexrutle作用的标志。此外，这些研究将提供足够的初步数据，以确定奈斯鲁廷是否对PANCA的任何特定阶段具有特异性，在临床前模型中逆转化疗诱导的耐药性，并描绘奈斯鲁廷的确切作用机制。LSL K-ras G12D/PDX-1Cre转基因小鼠模型是一种高度合适的小鼠模型，其胰腺癌的发生发展概括了人胰腺癌的发生发展。此外，由于奈斯鲁汀已经用于人类，这项研究的结果可能会扩展到探索其作为人类胰腺癌预防药物的用途。 公共卫生相关性：胰腺癌(Panca)是一个主要的健康问题，发病率和死亡率相等。这项应用的目标是使用重现人类胰腺癌的临床前模型来测试一种成本效益高且无毒的膳食补充剂作为抗胰腺癌药物。因此，这是非常及时和非常重要的。

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.