Aptamers for Imaging and Therapy

用于成像和治疗的适体

• 批准号: 7673662
• 负责人: RICHARD T HAMILTON
• 金额: $ 44.05万
• 依托单位: APTALOGIC, INC
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-10 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7673662
• 关键词: Affinity; Animals; Antibodies; Antigen Targeting; Area; Binding; Cell surface; Cells; Characteristics; Chronic Myeloid Leukemia; Clinic; Computer Simulation; Cultured Cells; Development; Diffusion; Disease; Drug Delivery Systems; Drug Design; Effectiveness; Enzymes; Family; Genes; Genetic; Goals; Image; Imaging technology; Immune response; Immune system; In Vitro; Individual; Kinetics; Life; Ligand Binding; Ligands; Link; Malignant Neoplasms; Molecular; Neurons; Neurosciences; Normal Cell; Nucleic Acids; Palpable; Penetrance; Pharmaceutical Preparations; Pharmacotherapy; Phase; Principal Investigator; Procedures; Property; Protein Tyrosine Kinase; Protocols documentation; Pyrimidine; Pyrimidines; RNA; Radioactive; Radiolabeled; Reagent; Research; Solid; Specificity; Therapeutic; Tissues; Tyrosine Kinase Inhibitor; analog; anticancer research; aptamer; base; cancer cell; cellular imaging; design; in vivo; innovation; mathematical model; novel; nucleic acid structure; programs; promoter; radiotracer

DESCRIPTION (provided by applicant): Phase I The current proposal describes the selection of an aptamer that recognizes the drug PD173955, which is one of large family of substituted pyrido[2,3-d]pyrimidine inhibitors of tyrosine protein kinases. An aptamer is a single stranded nucleic acid that acts like an antibody but that can be expressed and function inside cells. The PD173955 RNA aptamer will be selected to lay the groundwork for developing a novel imaging technology that could also be used for enhancing drug therapy. The Concept is that the aptamer, present inside the cell or targeted to the cell surface, could concentrate drug in or around the cell. A radioactive analogue of the drug could be used for imaging. The proposed basis of imaging involves accumulation of radiolabeled drug by aptamers. The increased intracellular or pericellular drug concentration in the cell should increase the effectiveness of the drug. However, the kinetic parameters of the aptamer are expected to be very important for optimal imaging and therapeutic enhancement. Therefore, we are developing a computational model that is based on a mathematical rendering of the kinetic and diffusion constants of the aptamer, drug and the enzyme targeted by the drug. Development of the mathematical model will proceed in parallel with the aptarner selection and guide the choice of selection protocols. The following specific aims are proposed for development of an aptamer to PD173955 for imaging and therapeutic applications: 1) prepare PD173955 linked to a solid support for aptamer selection, 2) select an RNA aptamer that recognizes PD173955, and 3) develop a mathematical model for the use of aptamers in imaging and enhancing drug therapy. Phase II The current proposal describes a novel nucleic acid structure based on aptamers that will be expressed in cells to mark them so they can be detected in viva by available imaging technology. We call the markers intracellular Multi-Aptamer Genetic Tags" (IMAGEtags). The basic innovation in the proposed IMAGEtag design is the expression, in living cells, of aptamers that can be used to track the cells in vivo by a noninvasive procedure. Cells that express IMAGEtags will be detected by virtue of the concentrated radiolabeled ligands that are bound and trapped in the cells by the aptarner components of IMAGEtags. The promoter from which the IMAGEtags are expressed will determine which cells can be imaged. For example, many genes that are responsible for increased proliferation are expressed in cancer cells and not in most normal cells. If these promoters, or a "synthetic" promoter that was highly expressed only in cancer cells, were used to drive IMAGEtag expression then cancer cells would be imaged. We also propose that the IMAGEtags could also be applied to enhancing drug therapy. Because the mechanism of imaging involves accumulation of ligand, IMAGEtas that recognize a particular drug could draw more drug into the cell and increase the effectiveness of the drug. The design and selection of IMAGEtags and their target ligands will be guided by computational modeling to optimize the kinetic characteristics of the aptamers and their ligands for imaging and enhanced therapeutic applications. Development of MAGEtags for imaging and therapeutic applications will be achieved by the following specific aims: 1) refine the PD173955 aptamer to function inside cells and prepare cells that stably express the aptamer, 2) refine the mathematical model for in vivo imaging, 3) validate the ability to image with aptamers in vivo using cultured cells, and 4) Use the PD173955 aptamer to image in animals.

描述（由申请人提供）： 第一阶段 目前的提案描述了识别药物 PD173955 的适体的选择，PD173955 是酪氨酸蛋白激酶的取代吡啶并[2,3-d]嘧啶抑制剂大家族之一。适体是一种单链核酸，其作用类似于抗体，但可以在细胞内表达和发挥作用。 PD173955 RNA适体将被选中为开发一种新型成像技术奠定基础，该技术也可用于增强药物治疗。这个概念是，存在于细胞内部或靶向细胞表面的适体可以将药物集中在细胞内或细胞周围。该药物的放射性类似物可用于成像。 所提出的成像基础涉及适体放射性标记药物的积累。细胞内或细胞周药物浓度的增加应增加药物的有效性。然而，适配体的动力学参数预计对于最佳成像和治疗增强非常重要。因此，我们正在开发一种计算模型，该模型基于适体、药物和药物靶向的酶的动力学和扩散常数的数学渲染。数学模型的开发将与适体选择并行进行，并指导选择协议的选择。 开发用于成像和治疗应用的 PD173955 适体的具体目标如下：1) 准备与适体选择的固体支持物连接的 PD173955，2) 选择识别 PD173955 的 RNA 适体，以及 3) 开发在成像和增强药物治疗中使用适体的数学模型。 第二阶段 目前的提案描述了一种基于适体的新型核酸结构，该结构将在细胞中表达以标记它们，以便可以通过可用的成像技术在体内检测到它们。我们将这些标记称为细胞内多适体遗传标签（IMAGEtags）。所提出的 IMAGEtag 设计的基本创新是在活细胞中表达适体，可用于通过非侵入性程序在体内追踪细胞。表达 IMAGEtags 的细胞将通过适体结合并捕获在细胞中的浓缩放射性标记配体进行检测。 IMAGEtags 的组成部分。表达 IMAGEtag 的启动子将决定哪些细胞可以成像。例如，许多负责增殖增加的基因在癌细胞中表达，而不是在大多数正常细胞中表达。如果使用这些启动子或仅在癌细胞中高度表达的“合成”启动子来驱动 IMAGEtag 表达，则将对癌细胞进行成像。 我们还建议 IMAGEtags 也可以应用于增强药物治疗。由于成像机制涉及配体的积累，因此识别特定药物的 IMAGEta 可以将更多药物吸引到细胞中并提高药物的有效性。 IMAGEtags 及其靶配体的设计和选择将由计算模型指导，以优化适体及其配体的动力学特征，用于成像和增强的治疗应用。 用于成像和治疗应用的 MAGEtag 开发将通过以下具体目标来实现：1) 精炼 PD173955 适体以在细胞内发挥作用并制备稳定表达适体的细胞，2) 精炼体内成像的数学模型，3) 验证使用培养细胞在体内使用适体成像的能力，以及 4) 使用 PD173955 适体 动物中的形象。