Labeling nanobodies with 18F residualizing labels for HER2 specific PET imaging

使用 18F 残留标签标记纳米抗体，用于 HER2 特异性 PET 成像

• 批准号: 9057484
• 负责人: GANESAN VAIDYANATHAN
• 金额: $ 36.37万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9057484
• 关键词: Accounting; Adhesions; Adverse effects; Affinity; Animal Model; Antibodies; Autopsy; Binding; Biodistribution; Biological Assay; Breast Cancer Cell; Breast Cancer Patient; Breast Cancer cell line; Breast Carcinoma; Catabolism; Cell Line; Cells; Characteristics; Chemistry; Detection; Development; Diagnostic Neoplasm Staging; Drug Targeting; ERBB2 gene; Early Diagnosis; Economics; Effectiveness; Epidermal Growth Factor Receptor; Exclusion; Fab Immunoglobulins; Family member; Fluorescent in Situ Hybridization; Fluorine; Glycoproteins; Goals; Guanidines; Half-Life; Health; High Pressure Liquid Chromatography; Image; Imaging Device; Immunoglobulin G; Immunohistochemistry; In Vitro; Kinetics; Label; MCF7 cell; Malignant Neoplasms; Medical Oncology; Methods; Micrometastasis; Modeling; Molecular Weight; Monitor; Mus; Myocardial dysfunction; Normal tissue morphology; Oncogenes; Patients; Peptides; Positron-Emission Tomography; Process; Property; Prosthesis; Proteins; Radioactive Iodine; Radiochemistry; Radioisotopes; Radiolabeled; Reagent; Recurrence; Regimen; Research; Risk; Role; SKBR3; Signal Pathway; Therapeutic; Time; Trastuzumab; Woman; Xenograft procedure; accurate diagnosis; analog; base; cancer cell; cancer stem cell; cell growth; cost; design; gel electrophoresis; imaging agent; imaging modality; immunoreactivity; in vivo; malignant breast neoplasm; microPET; migration; molecular imaging; molecular targeted therapies; nanobodies; neoplastic cell; novel; overexpression; personalized medicine; phase I trial; protein degradation; radiochemical; radiotracer; receptor; research study; response; subcutaneous; targeted treatment; tumor; uptake; vector

 DESCRIPTION (provided by applicant): HER2 is overexpressed in 25-30% of breast cancers and is a major contributor to tumor aggressiveness and recurrence. This has led to the development of HER2-targeted therapies such as trastuzumab, which can be effective in patients overexpressing HER2. Accurate assessment of tumor HER2 levels in real time could help personalize HER2-targeted therapy and monitor therapy response. Unlike current methods for assessing HER2 levels such as immunohistochemistry and fluorescence in situ hybridization (FISH), quantitative positron emission tomography (PET) imaging is noninvasive, can be performed repeatedly, and could provide accurate levels of HER2 in real time. Moreover, the high sensitivity of PET imaging could permit the detection of occult micrometastases and possibly HER2-expressing breast cancer stem cells. Nanobodies (Nbs) are single domain antibodies with a tenth of the molecular weight of an IgG, making them an ideal targeting vector for use in combination with the most widely utilized PET radionuclide, 18F. Conventional methods for protein labeling may result in the loss of 18F from tumor cells after a protein undergoes internalization and intracellular catabolism. We plan to extend the residualizing label (RL) approach, used successfully with radioiodine, to synthesize novel reagents designed to generate 18F-labeled catabolites that will be trapped in tumor cells after Nb internalization. Fluorine-18- labeled analogues of N-succinimidyl 4-guanidinomethyl-3-iodobenzoate (SGMIB), the best residualizing agent that we developed for radioiodination of internalizing biomolecules, will be generated. We seek to combine a new HER2 targeted 2Rs15d Nb developed by our colleague in Brussels, with a novel 18F- labeling chemistry with the goal of generating a PET imaging tool for assessing HER2 levels in breast cancer and thereby for the personalization of HER2 targeted therapy. If successful, the 18F-labeling reagents and methods that we shall develop could be applied to other proteins and peptides targeting HER2 and other internalizing receptors that are over expressed on breast cancers. We propose the following specific aims: 1. Develop prosthetic groups for 18F-labeling of Nbs based on the best Nb radioiodination residualizing agent, N-succinimidyl 4-guanidinomethyl-3-[*I] iodobenzoate ([*I]SGMIB). 2. Label Nbs with these agents and determine the characteristics of the labeled Nb conjugates. 3. Evaluate labeled Nbs in vitro using HER2-expressing breast cancer cells. 4. Evaluate labeled Nbs in vivo in mice bearing breast carcinoma xenografts.

 描述(申请人提供)：HER2在25%-30%的乳腺癌中过度表达，是肿瘤侵袭性和复发的主要因素。这导致了HER2靶向治疗的发展，如曲妥珠单抗，它可以有效地治疗HER2过度表达的患者。对肿瘤HER2水平的实时准确评估可以帮助个性化HER2靶向治疗并监测治疗反应。不同于目前评估HER2水平的方法，如免疫组织化学和荧光原位杂交(FISH)，定量正电子发射断层扫描(PET)成像是无创的，可以重复进行，并且可以实时提供准确的HER2水平。此外，PET成像的高灵敏度可以检测到隐匿性的微转移，并可能检测到表达HER2的乳腺癌干细胞。纳米抗体(NBS)是一种单域抗体，其相对分子质量为免疫球蛋白的十分之一，使其成为与应用最广泛的PET放射性核素18F结合使用的理想靶向载体。传统的蛋白质标记方法可能会导致蛋白质内化和细胞内分解代谢后18F从肿瘤细胞中丢失。我们计划扩展残留标记(RL)方法，成功地与放射性碘一起使用，以合成新的试剂，旨在产生18F标记的分解代谢物，这些分解代谢物在NB内化后将被捕获在肿瘤细胞中。氟-18标记的N-琥珀酰亚胺4-胍甲基-3-碘苯甲酸酯(SGMIB)的类似物，是我们开发的用于内化生物分子放射性碘化的最好的残留剂。我们寻求将我们在布鲁塞尔的同事开发的新的HER2靶向2Rs15d NB与新的18F标记化学相结合，目标是生成一种PET成像工具，用于评估乳腺癌中的HER2水平，从而实现HER2靶向治疗的个性化。如果成功，我们将开发的18F标记试剂和方法可以应用于针对HER2和其他在乳腺癌上过度表达的内化受体的其他蛋白质和多肽。我们提出的具体目标如下：1.基于最好的Nb放射性标记残留剂N-琥珀酰亚胺基-4-胍甲基-3-[*i]碘苯甲酸酯([*I]SGMIB)，开发用于18F标记NBS的假基。2.用这些试剂标记NBS，并测定标记的Nb偶联物的性质。3.利用表达HER2的乳腺癌细胞对标记的NBS进行体外评价。4.评价标记NBS在荷瘤小鼠体内的作用。