Somatostatin Receptor Based PET Imaging of Gene Transfer

基于生长抑素受体的基因转移 PET 成像

• 批准号: 7433269
• 负责人: Buck E. Rogers
• 金额: $ 28.88万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7433269
• 关键词: Affinity; Animal Model; Antibodies; Antigens; Binding; Biopsy; Blood; Brain; Cell physiology; Cells; Characteristics; Clinical Trials; Detection; Development; Disease; Engineering; Epitopes; Extracellular Domain; GTP-Binding Proteins; Gamma Rays; Gene Proteins; Gene Transfer; Genes; Goals; Homeostasis; Human; Image; Immune response; Immunoglobulin Fragments; In Vitro; Infection; Kidney; Knock-out; Label; Ligand Binding; Ligands; Location; Magnetic Resonance Imaging; Mammalian Cell; Mediating; Methods; Modeling; Modification; Pancreas; Patients; Positron; Positron-Emission Tomography; Production; Protein Overexpression; Radioisotopes; Radiolabeled; Radiopharmaceuticals; Reporter; Reporter Genes; Reporting; Research Personnel; Route; Signal Pathway; Signal Transduction; Somatostatin Receptor; Spleen; System; Time; Tissues; United States; base; cancer therapy; extracellular; gene therapy; human tissue; improved; in vivo; mutant; novel; optical imaging; programs; radiotracer; receptor; receptor coupling; research clinical testing; single photon emission computed tomography; somatostatin analog; therapeutic gene; uptake

DESCRIPTION (provided by applicant): Gene therapy trials would benefit from the ability to determine the location, magnitude, and change in magnitude over time of the expression of delivered genes. Thus far, gene transfer efficiency has been evaluated by obtaining tissue biopsies at predetermined times post treatment. This method of determining gene transfer efficiency is undesirable due to its invasiveness and its inability to generate a global picture of gene transfer, since it is limited to the small piece of tissue(s) examined. Numerous groups have been developing methods for non-invasively imaging gene transfer. We have utilized the human somatostatin receptor subtype 2 (hSSTR2) as a reporter gene along with various radiolabeled somatostatin analogs for gamma ray imaging of gene transfer. However, this system is limited by 1) overexpression of hSSTR2 may have an impact on cell physiology and homeostasis; 2) hSSTR2 is endogenously expressed on certain human tissues; and 3) somatostatin analogs are eliminated through the kidneys which can interfere with signal detection. Therefore, we hypothesize that the hSSTR2 reporter system can be improved through modification of the receptor itself by uncoupling the receptor from G proteins and through the development of novel targeting ligands that recognize a novel epitope inserted into hSSTR2. The first Aim will investigate the ability of somatostatin analogs radiolabeled with positron emitters to quantify different levels of hSSTR2 expression, in vitro and in vivo. The second Aim will construct diabodies and minibodies targeted toward an alternative epitope inserted into hSSTR2 and evaluate these constructs in a manner similar to the somatostatin analogs in Aim 1. These first two Aims are intended to determine the most optimal radiopharmaceutical as a reporter probe for PET imaging. The third Aim will focus on making and evaluating mutants of hSSTR2 that uncouple the receptor from G proteins. The final Aim will use the best mutant hSSTR2 (developed in Aim 3) and the most optimal radiopharmaceutical to determine the activity and efficacy of a therapeutic gene. This is intended to demonstrate that the system can be used to non-invasively detect therapeutic gene transfer through PET imaging. This proposal should result in improvement of the existing hSSTR2 reporter system for imaging gene transfer.

描述(由申请人提供)： 基因治疗试验将受益于确定交付基因表达的位置、大小和随时间变化的大小的能力。到目前为止，基因转移效率是通过在治疗后预定时间获取组织活检来评估的。这种确定基因转移效率的方法是不可取的，因为它具有侵入性，而且它无法生成基因转移的全局图像，因为它仅限于被检查的一小片组织(S)。许多组织一直在开发非侵入性成像基因转移的方法。我们已经利用人类生长抑素受体亚型2(HSSTR2)作为报告基因，以及各种放射性标记的生长抑素类似物，用于基因转移的伽马成像。然而，这个系统受到以下因素的限制：1)hSSTR2的过表达可能会影响细胞的生理和动态平衡；2)hSSTR2在某些人体组织中内源性表达；3)生长抑素类似物通过肾脏被清除，这可能会干扰信号的检测。因此，我们假设hSSTR2报告系统可以通过将受体与G蛋白解偶联来修饰受体本身以及通过开发识别插入hSSTR2的新表位的新型靶向配体来改进。第一个目标是研究用正电子发射体放射性标记的生长抑素类似物在体外和体内量化不同水平hSSTR2表达的能力。第二个目标是构建针对插入到hSSTR2中的替代表位的双体和微体，并以类似于目标1中生长抑素类似物的方式评估这些构建体。前两个目标旨在确定作为PET成像报告探针的最佳放射性药物。第三个目标将集中在制造和评估hSSTR2的突变体，使受体与G蛋白解偶联。最终目标将使用最好的突变体hSSTR2(在目标3中开发)和最理想的放射性药物来确定治疗基因的活性和疗效。这是为了证明该系统可以通过PET成像非侵入性地检测治疗性基因转移。这项建议应该会改进现有的hSSTR2报告系统，用于成像基因转移。

项目成果

Adenoviral-mediated imaging of gene transfer using a somatostatin receptor-cytosine deaminase fusion protein.

使用生长抑素受体-胞嘧啶脱氨酶融合蛋白进行腺病毒介导的基因转移成像。

• DOI: 10.1038/cgt.2015.14
• 发表时间: 2015
• 期刊: Cancer gene therapy
• 影响因子: 6.4
• 作者: Lears,KA;Parry,JJ;Andrews,R;Nguyen,K;Wadas,TJ;Rogers,BE
• 通讯作者: Rogers,BE