Molecular mechanism of chemoprevention by benzylistothiocyanate in pancreatic can

描述（由申请人提供）：本临床前研究项目的总体目标是通过体外细胞培养和体内动物模型评估异硫氰酸苄酯（BITC）的功效，BITC是许多可食用十字花科蔬菜的成分，用于预防胰腺癌。这些研究的基本原理源于最近的流行病学数据以及我们实验室获得的初步结果。一些流行病学研究表明，经常摄入十字花科蔬菜与降低包括胰腺癌在内的各种人类癌症的风险有关。我们的初步体外研究使我们提出了一个新的假设，即BITC诱导的死亡受体和抗凋亡蛋白Bcl-xL的磷酸化可能是破坏胰腺癌细胞并阻止其进展的主要因素。BITC可能表现为一种能够同时干预致癌过程中多个靶点的制剂。这种类型的化合物被认为比其他单目标化合物具有选择性优势。特异性Aim 1将系统地确定内在（Bcl-xL的磷酸化和线粒体的参与）和外在（死亡受体介导的caspase-8的激活）途径在BITC介导的胰腺癌细胞凋亡诱导中的作用。在特定的Aim 2中，将研究口服BITC对条件KrasG12D小鼠模型胰腺上皮内瘤变（Pan In）进展的影响。我们认为胰腺导管腺癌是由前体病变Pan IN逐渐发展而来。因此，条件KrasG12D小鼠模型是研究Pan In生物学的重要工具。如果在BITC治疗的动物中出现任何延迟或预防Pan in进展的情况，生化分析也将用于评估体外研究（如死亡受体上调或Bcl-xL磷酸化）是否可以在体内翻译。综上所述，本研究计划中提出的研究从未探索过：1)确定BITC抑制人类胰腺癌细胞生长的机制，这可能有助于确定基于机制的生物标志物，用于未来的临床试验；2)使用已建立的动物模型评估BITC对胰腺癌的体内疗效，这是后续使用该化合物进行胰腺癌临床试验的先决条件。目前，胰腺癌是美国癌症死亡的第四大原因。该临床前研究项目的长期目标是通过体外和动物模型评估异硫氰酸苄酯（BITC）的功效，BITC是许多可食用十字花科蔬菜中的一种成分，用于预防胰腺癌。

DESCRIPTION (provided by applicant): The overall objective of this preclinical research project is to assess the efficacy of benzyl isothiocyanate (BITC), a constituent of many edible cruciferous vegetables for prevention of pancreatic cancer using in vitro cell culture and in vivo animal models. The rationale for these studies stems from recent epidemiological data as well as preliminary results obtained in our laboratory. Several epidemiological studies have supported that frequent intake of cruciferous vegetables is linked to a decreased risk in various type of human cancer including pancreatic carcinoma. Our preliminary studies in vitro led us to a novel hypothesis that BITC induced death receptor as well as phosphorylation of antiapoptotic protein Bcl-xL might be predominant factors to destroy pancreatic cancer cells and prevent its progression. BITC might behave as an agent that is capable of intervening simultaneously at several targets in the carcinogenic process. This type of compound is thought to have selective advantage over other single-target compounds. Specific Aim 1 will systemically determine the role of intrinsic (phosphorylation of Bcl-xL and involvement of mitochondria) and extrinsic (death receptor mediated activation of caspase-8) pathways in BITC mediated apoptosis induction in pancreatic cancer cells. In specific Aim 2, the effect of oral administration of BITC on the progression of Pancreatic Intraepithelial Neoplasia (Pan IN) in a conditional KrasG12D mouse model will be investigated. It is believed that pancreatic ductal adenocarcinoma gradually arises from precursor lesion Pan IN. In that respect conditional KrasG12D mouse model is a valuable tool to investigate Pan IN biology. Biochemical assays will also be deployed to assess whether in vitro studies such as death receptor up regulation or Bcl-xL phosphorylation can be translated in vivo if any delay or prevention of the progression of Pan IN occurs in BITC treated animals. In summary, the studies proposed in this research program never explored before will I) define the mechanism by which BITC inhibits growth of human pancreatic cancer cells that may be helpful to identify mechanism- based biomarkers for future clinical trials and II) assess in vivo efficacy of BITC against pancreatic cancer using established animal model, which is a prerequisite for ensuing any clinical trial with this compound against pancreatic cancer. PUBLIC HEALTH RELEVANCE: Project Narrative At present, pancreatic cancer ranks as the fourth leading cause of cancer mortality in the United States (U.S.). The long-term goal of this preclinical research project is to assess the efficacy of benzyl isothiocyanate (BITC), a constituent of many edible cruciferous vegetables for prevention of pancreatic cancer using in vitro as well as animal models.