Chemical Modulation of Orphan Nuclear Receptor Function

孤儿核受体功能的化学调节

基本信息

批准号：
8666893
负责人：
Sridhar Mani
金额：
$ 6.51万
依托单位：
ALBERT EINSTEIN COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-08-13 至 2015-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8666893
关键词：
Adopted Affinity Agonist Antineoplastic Agents Azoles Binding Binding Sites Biochemical Genetics Biological Assay Cell Proliferation Cells Chemicals Clinical Collaborations Complement Complex Computer Simulation Coumestrol Cytochromes Data Development Drug Interactions Drug resistance Generations Genetic Transcription Goals Grant Hepatic Human Imidazole Immune Ketoconazole Knowledge Laboratories Lead Libraries Ligand Binding Ligands Mammalian Cell Mediating Microsomes Modeling Modification Molecular Mus Mutation Nuclear Nuclear Orphan Receptor Nuclear Receptors Organ Orphan Paclitaxel Pharmaceutical Preparations Phenotype Play Protein Binding Proteins Receptor Activation Receptor Inhibition Research Personnel Resistance Role Site Structure Surface System Tamoxifen Testing Tissues Toxic effect Yeasts abstracting analog base cancer cell cytotoxicity glycidol improved inhibitor/antagonist monolayer mutant novel pharmacophore pregnane X receptor receptor receptor binding receptor function small molecule tool yeast two hybrid system

项目摘要

Project Summary/Abstract The central goal of this R01 is to focus on explicitly defining novel antagonist binding pharmacophore on Pregnane X Receptor (PXR). In doing so, additional goals include development of non-toxic azole antagonists that would serve to chemically probe PXR activity and phenotype(s) in different tissues. In silico modeling parameters will continuously be improved as we obtain potent and specific PXR inhibitors. These models could then guide the development of novel small molecule antagonists originating from different chemical entities. The long-term goal is to eventually develop non-toxic antagonists of PXR that can be used as clinical modulators of cancer cell proliferation and drug resistance (e.g., PXR activation induces cancer cell proliferation and drug resistance). It is also hoped that these antagonists will enhance the activity, and minimize the toxicity, of select antineoplastic agents (e.g., tamoxifen, paclitaxel are PXR agonist at concentrations observed at steady-state in humans). Towards this end, we have identified and characterized two novel PXR antagonists, ketoconazole and coumestrol, that specifically disrupt the function of activated (ligand-bound) PXR. In subsequent studies, we have shown that ketoconazole: (i) binds to receptor and disrupts coregulator-receptor interactions in activated PXR; (2) does not displace activating drugs from the ligand-binding pocket of PXR; (iii) retained antagonism of mutant forms of PXR containing ligand-binding pocket filling mutants; and (iv) is unable to antagonize mutant forms of PXR containing alterations in the surface coregulator AF-2 binding site. Thus, we have formulated a model for PXR antagonism in which disruption of function is mediated either by allosteric modification of the receptor or by competition with coregulator binding. We now propose to evaluate this model using structural, molecular, biochemical, and genetic systems to characterize the mechanism by which PXR-directed antagonist ketoconazole and related compounds inhibit receptor activation.

项目摘要/摘要该R01的核心目标是专注于明确定义新型拮抗剂结合妊娠X受体（PXR）的药效团。这样，其他目标包括开发非毒性偶氮拮抗剂，这些拮抗剂将用于化学探针PXR 不同组织中的活性和表型。在计算机建模中将参数随着我们获得有效和特定的PXR抑制剂，不断改进。这些然后，模型可以指导新型小分子拮抗剂的发展起源于不同的化学实体。长期目标是最终发展 PXR的无毒拮抗剂，可以用作癌细胞的临床调节剂增殖和耐药性（例如，PXR激活诱导癌细胞增殖和耐药性）。也希望这些拮抗剂能够增强活动，并最大程度地减少选择抗塑料剂的毒性（例如，他莫昔芬，紫杉醇是 PXR激动剂在人类稳态下观察到的浓度。在这一目标中，我们已经确定并表征了两个新型的PXR拮抗剂，酮康唑和 Coumestrol，特别破坏了激活（配体结合）PXR的功能。在随后的研究，我们表明酮康唑：（i）与受体结合并破坏激活的PXR中的coregulator受体相互作用；（2）不能取代激活药物从PXR的配体结合口袋中；（iii）保留PXR突变形式的拮抗作用包含配体结合口袋填充突变体；（iv）无法拮抗突变体 PXR的形式含有表面核心测量器AF-2结合位点中的改变。因此，我们已经制定了PXR拮抗模型，其中功能的破坏为通过变构修饰受体或与核心测量器结合。现在，我们建议使用结构，分子，生化和遗传系统以表征PXR导向的机制拮抗剂酮康唑和相关化合物抑制受体激活。