Fatty acid synthase inhibitors and prostate cancer

脂肪酸合酶抑制剂与前列腺癌

基本信息

批准号：
7895851
负责人：
STEVEN J. KRIDEL
金额：
$ 24.73万
依托单位：
WAKE FOREST UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-09-01 至 2011-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7895851
关键词：
Active Sites Address Affect Antineoplastic Agents Apoptosis Binding Biochemical Biological Assay Biological Availability Cell Death Cell Survival Cells Cerulenin Complex Data Development Drug Kinetics Embryo Endoplasmic Reticulum Enzymes Epithelial FDA approved Fatty Acids Fatty-acid synthase Fibroblasts Fluorescence Foundations Genetic Goals Growth Hypoxia Image In Vitro Individual Laboratories Lead Ligands Link Luciferases Malignant Neoplasms Malignant neoplasm of prostate Mediating Modeling Monitor Mus Mutation Normal Cell Palmitates Palmitoyl Coenzyme A Pathway interactions Pharmaceutical Preparations Prostatic Neoplasms Publishing Reaction Research Personnel Resistance Roentgen Rays Role Series Signal Pathway Signal Transduction Site Specificity Stress Tests Structure System Testing Thapsigargin Time Toxic effect Translating Tumor Cell Line Up-Regulation Work X-Ray Crystallography analog arm base biological adaptation to stress cancer therapy clinically relevant cytotoxic cytotoxicity design ebelactone B endoplasmic reticulum stress fatty acid biosynthesis improved in vivo inhibitor/antagonist insight killings membrane biogenesis membrane synthesis mimetics mutant neoplastic cell novel orlistat overexpression programs research study response small molecule stressor therapeutic target tumor tumor xenograft

项目摘要

DESCRIPTION (provided by applicant): Fatty acid synthase (FAS), the enzyme that synthesizes the fatty acid palmitate, is overexpressed in prostate cancer and many other cancers of epithelial origin. We have discovered that orlistat, an FDA approved drug, is a novel inhibitor of the thioesterase (TE) domain of FAS. Inhibition of FAS by orlistat results in the selective killing of tumor cells in vitro and in vivo. The goal of this project is to determine the basic cellular and biochemical mechanisms of the anti-tumor effects of orlistat and other FAS inhibitors. To this end we have demonstrated that the endoplasmic reticulum (ER) stress response is activated in tumor cells upon FAS inhibitor treatment. Activation of the ER stress response appears to be upstream of apoptosis, perhaps engaging the cell death program. Moreover, the combination of FAS inhibitors with thapsigargin, another agent known to activate ER stress, yields a synergistic decrease in tumor cell survival. We have also determined the crystal structure of the TE domain (FAS-TE) in complex with orlistat. Orlistat binds to the active site in a manner contrary to a previously proposed model of substrate binding. Three specific aims are proposed to further explore these observations and to provide a critical foundation for the design and optimization of FAS inhibitors for cancer therapy. In Specific Aim 1 we will use tumor cell lines and transformed mouse embryonic fibroblasts (MEFs) with pathway specific mutations to determine the contribution of the PERK, IRE1 and ATF6 signaling pathways to the ER stress response when FAS is inhibited. In Specific Aim 2 the ability of thapsigargin and hypoxia to enhance the cytotoxic effects of FAS inhibitors will be determined. An in vivo imaging system will also be used to monitor ER stress-driven luciferase activity in tumor xenografts of mice treated with FAS inhibitors. In Specific Aim 3 we will use X-ray crystallography to determine the structural basis for the interactions between FAS-TE and orlistat and the orlistat analog Ebelactone B. We will also test whether substrate binds in a similar manner to orlistat by determining the crystal structures of substrate and product and analyzing the activity of site-directed mutants of conserved residues within the binding groove using a new, continuous assay. These studies will provide invaluable insights into how orlistat and other FAS inhibitors initiate apoptosis and how these compounds may be useful to increase the efficacy of current cancer drugs, particularly those where resistance has occurred. The proposed crystal structures will be instrumental to the rational design of analogs of orlistat with improved target specificity, bioavailability, and pharmacokinetics for the treatment of a variety of cancers.

描述（由申请人提供）：脂肪酸合酶（FAS），即合成脂肪酸棕榈酸酯的酶，在前列腺癌和许多其他上皮来源的癌症中过度表达。我们发现奥利司他是 FDA 批准的药物，是 FAS 硫酯酶 (TE) 结构域的新型抑制剂。奥利司他对 FAS 的抑制导致体外和体内选择性杀死肿瘤细胞。该项目的目标是确定奥利司他和其他 FAS 抑制剂抗肿瘤作用的基本细胞和生化机制。为此，我们证明了 FAS 抑制剂治疗后肿瘤细胞中的内质网 (ER) 应激反应被激活。内质网应激反应的激活似乎是细胞凋亡的上游，可能参与细胞死亡程序。此外，FAS 抑制剂与毒胡萝卜素（另一种已知可激活 ER 应激的药物）的组合可协同降低肿瘤细胞的存活率。我们还确定了与奥利司他复合的 TE 结构域 (FAS-TE) 的晶体结构。奥利司他以与先前提出的底物结合模型相反的方式结合到活性位点。提出了三个具体目标来进一步探索这些观察结果，并为癌症治疗 FAS 抑制剂的设计和优化提供关键基础。在具体目标 1 中，我们将使用具有通路特异性突变的肿瘤细胞系和转化的小鼠胚胎成纤维细胞 (MEF) 来确定 FAS 被抑制时 PERK、IRE1 和 ATF6 信号通路对 ER 应激反应的贡献。在具体目标 2 中，将确定毒胡萝卜素和缺氧增强 FAS 抑制剂细胞毒性作用的能力。体内成像系统还将用于监测经 FAS 抑制剂治疗的小鼠肿瘤异种移植物中内质网应激驱动的荧光素酶活性。在特定目标 3 中，我们将使用 X 射线晶体学来确定 FAS-TE 与奥利司他以及奥利司他类似物 Ebelactone B 之间相互作用的结构基础。我们还将通过确定晶体结构来测试底物是否以类似的方式与奥利司他结合底物和产物的分析，并使用新的连续测定分析结合槽内保守残基的定点突变体的活性。这些研究将为了解奥利司他和其他 FAS 抑制剂如何引发细胞凋亡以及这些化合物如何有助于提高当前抗癌药物（特别是那些已发生耐药性的抗癌药物）的疗效提供宝贵的见解。所提出的晶体结构将有助于合理设计奥利司他类似物，提高靶点特异性、生物利用度和药代动力学，用于治疗多种癌症。