MR Signal Amplification for Receptor Imaging

用于受体成像的 MR 信号放大

• 批准号: 7645768
• 负责人: Alexei A Bogdanov
• 金额: $ 34.85万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7645768
• 关键词: Abnormal Cell; Achievement; Address; Adenocarcinoma; Animal Model; Animals; Antibodies; Antibody Therapy; Binding; Biological Markers; Brain; Cancer Model; Cell Adhesion Molecules; Cell physiology; Cells; Clinical; Clinical Trials; Detection; Development; Diabetes Mellitus; Disease; Disease Marker; Disease Progression; Early Diagnosis; Enzymes; Epidermal Growth Factor Receptor; Fc Receptor; Funding; Future; Genomics; Goals; Heart Diseases; Human; Image; Imagery; Imaging Device; Imaging Techniques; Immunoglobulin Fragments; Immunohistochemistry; In Vitro; Inflammatory Response; Label; Laboratory Animals; Laccase; Lanthanoid Series Elements; Lead; Life; Link; Magnetic Resonance Imaging; Malignant neoplasm of prostate; Mediating; Medical; Medicine; Modeling; Molecular; Molecular Probes; Molecular Target; Molecular Weight; Monitor; Nature; Neoplasm Metastasis; Non-Small-Cell Lung Carcinoma; Organ; Organism; Oxidoreductase; Patients; Pattern; Peroxidases; Pharmaceutical Preparations; Phenols; Physicians; Proteomics; Protocols documentation; Radioisotopes; Research; Resolution; Safety; Scientist; Signal Transduction; Site; Specificity; Substrate Specificity; System; TACSTD2 gene; Testing; Time; Tissues; Transgenic Model; Translating; Xenograft procedure; base; cancer cell; design; improved; in vivo; innovation; macromolecule; molecular imaging; molecular marker; monocyte; neoplastic cell; neutrophil; novel; novel marker; overexpression; polymerization; public health relevance; receptor; receptor expression; research study; response; scale up; tool; tumor

DESCRIPTION (provided by applicant): The pressing needs in translating recent achievements of genomic and proteomic screens ex vivo into the visualization of markers in living systems necessitate the development of novel molecular biomarker imaging techniques. The ability to apply molecular imaging to novel markers in vivo would have significant implications for early detection of disease, assessing patient-specific therapies and monitoring dynamic changes in expression patterns during disease progression. This application builds on our recent innovations in designing, testing and applying enzyme-mediated MR signal amplification strategy (MRamp) for imaging molecular targets. The proposed research is based on our observation that paramagnetic phenols in the presence of oxidoreductases give markedly enhanced relaxivity and MR signal. We previously proposed to harness MRamp effect and apply it for the needs of MR molecular imaging. As a result, we accomplished a transition of our research from in vitro level to in vivo experiments. Reaching the following milestones were instrumental in achieving the aims of the research: 1) designing and scaling up synthesis of MRamp substrates; 2) determining that the nature of aromatic reducing group linked to paramagnetic moiety defines substrate specificity and enzyme selectivity; 3) providing evidence that MRamp mechanism includes both polymerization and binding of paramagnetic oligomers to macromolecules; 4) optimizing a complete protocol for small conjugates of anti-receptor antibody and amplification enzymes ( binary amplification system ); 5) performing the testing of the developed system by using MRI in EGFR-expressing tumors; 6) testing alternative amplification enzymes and identifying a candidate for future research. By building on the above key findings we propose to achieve the following specific aims: Specific Aim. 1. Optimize and test in vivo single-enzyme targeted amplification imaging system. We hypothesize that MR signal amplification strategy could be improved by optimizing in vivo delivery. This can be achieved by using a) single, phenol- oxidizing enzyme covalently linked to F(ab')2 fragment of EGFR antibody. This hypothesis will be tested in EGFR-overexpressing tumor models. Specific Aim 2. Develop and test two-enzyme, bi-specific approach for imaging tumor cells co-expressing two different molecular markers. We hypothesize that by using two antibody fragments directed against different targets on the same cells we will image co-expression of adhesion molecule (EpCAM) and EGF receptor on non-small cell lung cancer (NSCLC) cells that are likely to respond to combined antibody therapy. This hypothesis will be tested in a model of NSCLC metastasis to the brain. Specific Aim 3. To use MRamp strategy for imaging inflammatory response and receptor repertoire of tumors in vivo. We hypothesize that monocyte/neutrophil component of inflammatory response can be imaged in tumors separately from receptors by using two MRamp substrates: the first having narrow myeloperoxidase specificity, and the second having laccase specificity. This hypothesis will be tested in transgenic model of prostate cancer. Public health relevance statement: The development of new drugs that can efficiently eliminate tumor cells or slow heart disease and diabetes requires ample testing in laboratory animals to prove safety and efficacy. The use of medical scanners that detect these cellular processes with high accuracy in live animals has the potential to significantly decrease the time between discovery of and subsequent clinical use of new medicines. This decreased time benefits both patients and taxpayers. We are proposing research approaches that will lead to the development of new tools (imaging drugs and compositions) for use with medical scanners. These tools will have applications for tracking the molecules that are linked to the abnormal cells. This research will help scientists and physicians to detect these cells and follow their response to medicines.

描述（由申请人提供）：迫切需要将基因组学和蛋白质组学的最新成果转化为生命系统中标记物的可视化，这就需要开发新的分子生物标记物成像技术。将分子成像应用于体内新标志物的能力将对疾病的早期检测、评估患者特异性治疗和监测疾病进展过程中表达模式的动态变化具有重要意义。该应用程序建立在我们最近的创新设计，测试和应用酶介导的磁共振信号放大策略（MRamp）成像分子目标。所提出的研究是基于我们的观察，顺磁酚在氧化还原酶的存在下显着增强了弛豫性和磁共振信号。我们之前提出利用MRamp效应并将其应用于磁共振分子成像的需要。因此，我们的研究完成了从体外水平到体内实验的过渡。达到以下里程碑有助于实现研究目标：1)设计和扩大MRamp底物的合成；2)确定顺磁基团连接的芳香还原基的性质决定了底物特异性和酶选择性；3)提供证据证明MRamp机制包括顺磁性低聚物与大分子的聚合和结合；4)优化抗受体抗体和扩增酶小分子偶联物的完整方案（二元扩增系统）；5)利用MRI对该系统在表达egfr的肿瘤中进行检测；6)测试可选的扩增酶并确定未来研究的候选酶。在上述主要发现的基础上，我们建议实现以下具体目标：优化和测试体内单酶靶向扩增成像系统。我们假设MR信号放大策略可以通过优化体内递送来改进。这可以通过使用与EGFR抗体的F(ab')2片段共价连接的单一酚氧化酶来实现。这一假设将在egfr过表达的肿瘤模型中得到验证。具体目标2。开发和测试双酶，双特异性方法成像肿瘤细胞共表达两种不同的分子标记。我们假设，通过使用针对同一细胞上不同靶点的两种抗体片段，我们将成像粘附分子（EpCAM）和EGF受体在非小细胞肺癌（NSCLC）细胞上的共同表达，这些细胞可能对联合抗体治疗有反应。这一假设将在非小细胞肺癌脑转移模型中得到验证。具体目标3。利用MRamp策略对体内肿瘤的炎症反应和受体库进行成像。我们假设炎症反应的单核细胞/中性粒细胞成分可以通过使用两种MRamp底物在肿瘤中与受体分开成像：第一种具有狭窄的髓过氧化物酶特异性，第二种具有漆酶特异性。这一假设将在前列腺癌转基因模型中得到验证。公共卫生相关声明：开发能够有效消除肿瘤细胞或减缓心脏病和糖尿病的新药需要在实验室动物中进行充分的试验，以证明其安全性和有效性。使用医学扫描仪在活体动物中高精度地检测这些细胞过程，有可能大大缩短新药发现和随后临床使用之间的时间。减少的时间对患者和纳税人都有好处。我们正在提出研究方法，这些方法将导致开发用于医疗扫描仪的新工具（成像药物和组合物）。这些工具将用于追踪与异常细胞相关的分子。这项研究将帮助科学家和医生检测这些细胞并跟踪它们对药物的反应。