Tumor Targeted Corroles for Detection and Intervention

描述(由申请人提供)：该提案将检验这样一种假设，即在单个自组装复合体中，非共价Corole组件同时介导肿瘤靶向检测和干预。磺化腐蚀剂是一种可溶于水的大环化合物，可能是金属化的，可以发出强烈的荧光。我们发现，腐蚀剂自发地与载体蛋白组装，而载体蛋白是促进细胞进入的必要条件，一旦进入细胞，腐蚀剂必须释放到细胞质中，引发细胞毒性，同时保持在细胞核之外，从而暗示胞液因子是Corole介导的毒性的靶标。我们的靶向细胞穿透蛋白HerPBK10能够在体外和体内使CoRole摄取HER2+癌细胞。HerPBK10由一个细胞靶向和内化配体和一个膜穿透区组成，该配体来源于Heregin蛋白，膜穿透区来源于腺病毒(Ad)衣壳五酮碱基。Corole荧光使体外和体内肿瘤细胞靶向可视化，与直接瘤内注射化疗药物阿霉素相比，体内肿瘤靶向导致肿瘤生长干预剂量减少近300倍。HER2+癌症已经成为我们实验室测试新的靶向治疗的模型系统。由于HER2(或ErbB2)亚单位的过表达增强了受体的亲和力，HER2+细胞类型是测试配体导向治疗的理想模型。更重要的是，由于HER2在乳腺癌中的过度表达与侵袭性的化疗耐药肿瘤相关，并预示着预后不良，因此替代标准方案的治疗方案可能会被证明对这类乳腺癌更有效，虽然不是大多数病例，但却是最致命的乳腺癌之一。然而，我们已经确定了HERG导向治疗的其他潜在靶点，包括卵巢、胶质瘤和前列腺癌细胞，它们高水平表达不同的HER亚单位。因此，除了HER2+乳腺癌外，本文提出的HER靶向系统可能对几种不同的肿瘤类型具有更广泛的应用。这项提议结合了多个合作者的专业知识，进一步将Corole组装成可成像的肿瘤靶向试剂。我们将评估靶细胞和免疫与载体蛋白的相互作用，以指导引入可能提高治疗效果和安全性的修饰。我们将探索的一个令人兴奋的方向是应用定向进化来选择载体蛋白结构域，以改善靶细胞相互作用和免疫逃避。我们将在体外和体内测试这些修饰的科罗尔递送，并利用腐蚀剂独特的光电子发射特性来检测体内肿瘤靶向。 公共卫生相关性：这项研究项目与公共健康相关，因为它将导致开发一种新型的自组装疗法，该疗法可以显著降低HER2+肿瘤(包括HER2+乳腺癌)的靶向，因此与非靶向标准化疗相比，剂量更安全。此外，这种治疗方法可以在治疗过程中成像，因此可以检测到肿瘤靶向。因此，这项技术在单个自组装的靶向复合体中结合了检测和干预。

DESCRIPTION (provided by applicant): This proposal will test the hypothesis that noncovalent corrole assemblies simultaneously mediate both tumor targeted detection and intervention in a single self-assembled complex. Sulfonated corroles are water soluble, macrocyclic compounds that may be metallated and can emit an intense fluorescence. We have found that corroles spontaneously assemble with carrier proteins, which are required to facilitate cel entry, and once entering cels, must be released into the cytoplasm to elicit cytotoxicity while remaining excluded from the nucleus, thus implicating cytosolic factors as the targets of corrole-mediated toxicity. Our targeted cell penetration protein, HerPBK10, enables corrole uptake into HER2+ cancer cells in vitro and in vivo. HerPBK10 is comprised of a cell-targeting and internalizing ligand derived from the heregulin protein, and membrane penetration domain derived from the adenovirus (Ad) capsid penton base. Corrole fluorescence enables visualization of tumor cell targeting in vitro and in vivo, and tumor targeting in vivo results in tumor growth intervention at nearly 300x less dosage in comparison to direct intratumoral delivery of the chemotherapy agent, doxorubicin. HER2+ cancer has served as a model system for testing new targeted therapeutics in our lab. As the overexpression of the HER2 (or ErbB2) subunit enhances receptor affinity, the HER2+ cell type is an ideal model for testing ligand-directed therapies. More importantly, as HER2 overexpression in breast cancer correlates with aggressive chemoresistant tumors and predicts a poor prognosis, alternative treatments to standard regimens may prove more effective on this subset of breast cancers that, while not comprising a majority of cases, are among the most deadly of breast cancers. Nevertheless, we have identified additional potential targets of our heregulin-directed therapeutics, including ovarian, glioma, and prostate cancer cells that express high levels of different HER subunits. Thus, the HER-targeted system presented here may have a broader application to several different tumor types in addition to HER2+ breast cancer. This proposal combines the expertise of multiple collaborators to further develop corrole assemblies into image-able tumor targeting agents. We will assess target cell and immune interactions with the carrier protein to direct efforts in introducing modifications that may enhance therapeutic efficacy and safety. One exciting direction we will explore is to apply directed evolution to select carrier protein domains to improve target cell interactions and immune evasion. We will test these modifications for corrole delivery in vitro and in vivo, and utilize the unique photoemission properties of corroles to detect in vivo tumor targeting. PUBLIC HEALTH RELEVANCE: This research project is relevant to public health because it will result in the development of a novel self-assembled therapeutic that can specifically target HER2+ tumors (which includes HER2+ breast cancer) at substantially lower, and thus safer doses compared to untargeted standard chemotherapy. Moreover, this therapeutic can be imaged during treatment so that tumor targeting can be detectable. Thus, this technology combines both detection and intervention in a single self-assembled targeted complex.