Direct identification of ready-to-use peptoid-DOTA theranostic systems

描述（由申请人提供）：直接鉴定即用型类肽-DOTA治疗诊断系统将开发一种用于"治疗诊断剂"的快速和成本有效的技术，用于抗癌治疗和真实的时间治疗随访。目前开发治疗诊断剂的两种基本方法包括造影剂与治疗分子的化学连接，或将这两种组分包装在大分子系统如脂质体内。虽然化学修饰通常削弱药物的原始活性，但大分子通常表现出稳定性、生物分布和清除问题。努力 联合收割机来组合显著不同的组分，例如治疗剂和造影剂，作为最后一步产生了大多数这些问题。我们的新方法涉及合成一个单一的分子，该分子结合了治疗和成像成分，从而从整个开发过程的第一步就验证了目标。这个想法是开发已经与DOTA造影剂偶联的类肽组合文库，并使用我们独特的珠上双色细胞测定法直接鉴定细胞表面受体的"（类肽）3-DOTA"分子。当在筛选过程中靶受体选择某种（类肽）3-DOTA作为最佳结合配体时，该类肽上的DOTA支架已经看到了靶标，并表明它不会干扰所选类肽部分的结合。已报道类肽是具有自身拮抗活性的大的蛋白质结合配体。此外，DOTA支架可以与90Y络合并用于放射性核素治疗。在诊断上，这种DOTA支架可以与68 Ga或64 Cu络合用于PET成像，与Gd 3+络合用于MR成像应用。为了构建文库，DOTA支架将通过其一个臂加载到树脂珠上，其余3个臂将使用类肽残基多样化。该文库将针对表皮生长因子受体（EGFR）和肝配蛋白受体A2（EphA2）进行筛选，作为在许多癌症类型中过表达的模型靶系统，其理想地在细胞表面上形成多聚体簇。将验证鉴定的"命中"化合物[（类肽）3-DOTA]的结合，并使用标准蛋白质印迹分析通过对EGFR和EphA2受体磷酸化的影响来评估拮抗剂潜力。最后，Gd 3+复合物将用于细胞水平的MR成像检测，以探测其成像潜力，将体内PET应用作为近期目标。该提案的主要概念性进展是开发和验证治疗不确定剂作为“第一步的单一包装”。由于类肽化学的多功能性，整个开发过程可以快速完成，并具有成本效益。此外，当考虑到类肽的高度生物相容性特征，例如血清稳定性、非免疫原性和中等清除率时，可以预期这些类肽-DOTA试剂的增强的药物激动剂等性质，因此确保将来将实验室水平的先导分子快速且经济地转化为临床上适用的抗癌治疗诊断剂。 公共卫生相关性：具有治疗和诊断能力的试剂（“治疗诊断”试剂）将在一次治疗后验证药物是否达到其目标，如果治疗不起作用，则将立即知道该信息，以便可以毫不延迟地转换治疗，从而可能挽救癌症患者的生命。虽然传统的方法花费大量的时间和金钱试图“连接”现有的治疗和成像组件作为最后一步，我们建议开发一种快速，经济和简便的方法来“直接”识别现成的治疗剂。本申请中提出的技术可以应用于任何类型的癌症（甚至其他疾病），以创建一套全球工具来检测，治疗和监测肿瘤，从而使我们在未来更接近个性化医疗。

DESCRIPTION (provided by applicant): Direct identification of ready-to-use peptoid-DOTA theragnostic systems A rapid and cost effective technology for 'theragnostic agents' will be developed for use in anti-cancer therapy and real time treatment follow up. The two current basic approaches to develop theragnostic agents include the chemical linkage of a contrast agent to a therapeutic molecule, or to pack these two components inside a macromolecular system such as liposomes. While chemical modifications typically weaken the original activity of the drug, macromolecules generally exhibit stability, biodistribution and clearance issues. Efforts to combine significantly different components, such as therapeutics and contrast agents, as the last step create most of these problems. Our novel approach involves the synthesis of a single molecule that combines therapeutic and imaging components and thus validates the target of interest from the first step of the overall development process. The idea is to develop peptoid combinatorial libraries that are already coupled with a DOTA-contrast agent and directly identify '(peptoid)3-DOTA' molecules for cell surface receptors using our unique on-bead two-color cell assay. When a certain (peptoid)3-DOTA is picked up by the target receptor as the optimal binding ligand during the screen, the DOTA scaffold on that peptoid has already seen the target and signs that it would not interfere with the binding of the selected peptoid portion. Peptoids have been reported as great protein binding ligands with their own antagonist activities. In addition, the DOTA scaffold can be complexed with 90Y and used in radionuclide therapy. Diagnostically, this DOTA scaffold can be complexed with 68Ga or 64Cu for PET imaging and with Gd3+ for MR imaging applications. To build the library, DOTA scaffolds will be loaded on to the resin beads through one of its arms and the remaining 3 arms will be diversified using peptoid residues. This library will be screened against Epidermal Growth Factor Receptor (EGFR) and ephrin receptor A2 (EphA2) as model target systems that overexpress in many cancer types which ideally form multimeric clusters on the cell surface. Identified 'hit' compounds [(peptoid)3-DOTA] will be validated for binding and the antagonist potential will be evaluated by effects on EGFR and EphA2 receptor phosphorylation using standard western blot analysis. Finally, the Gd3+ complexes will be used in cellular level MR imaging assays to probe their imaging potential, leaving in vivo PET applications as the immediate future goals. The primary conceptual advancement of this proposal is the development and validation of a theragnostic agent as a 'single package from the first step'. Due to the versatility of peptoid chemistry, the overall development process can be completed rapidly and cost effectively. In addition, when considering the highly biological amenable features of peptoids, such as serum stability, non-immunogenicity and moderate clearance, one could expect enhanced pharamacokinetc properties of these peptoid-DOTA agents and therefore assure a rapid and economical conversion of bench level lead molecules into clinically applicable anti-cancer theragnostic agents in the future. PUBLIC HEALTH RELEVANCE: Agents that have both therapeutic and diagnostic capability ("theragnostic" agents) will verify that a drug has reached its target after one treatment and if te therapy is not working, that information will be known immediately so that therapy can be switched without delay, potentially saving a cancer patient's life. While conventional methods spend large sums of time and money trying to 'connect' existing therapeutic and imaging components as the final step, we propose developing a rapid, economical and facile method to 'directly' identify ready-to-use theragnostic agents. The technology proposed in this application can be applied on any type of cancer (or even other diseases), to create a global set of tools to detect, treat and monitor tumors thereby moving us one step closer to personalized medicine in the future.