Tumor Targeted Corroles for Detection and Intervention

描述（由申请人提供）：本提案将检验非共价咔咯组装体在单个自组装复合物中同时介导肿瘤靶向检测和干预的假设。 磺化可咯是水溶性的大环化合物，其可以被金属化并且可以发射强烈的荧光。我们已经发现，corrole自发地与载体蛋白组装，载体蛋白是促进细胞进入所需的，并且一旦进入细胞，必须释放到细胞质中以引起细胞毒性，同时保持从细胞核中排除，从而暗示胞质因子作为corrole介导的毒性的靶点。我们的靶向细胞渗透蛋白HerPBK10能够在体外和体内将corrole摄取到HER2+癌细胞中。HerPBK10由源自调蛋白的细胞靶向和内化配体和源自腺病毒（Ad）衣壳五邻体基底的膜穿透结构域组成。Corrole荧光使得能够在体外和体内可视化肿瘤细胞靶向，并且与化疗剂阿霉素的直接瘤内递送相比，体内肿瘤靶向导致以近300倍的剂量进行肿瘤生长干预。 HER2+癌症已成为我们实验室测试新靶向疗法的模型系统。由于HER2（或ErbB2）亚基的过表达增强了受体亲和力，因此HER2+细胞类型是测试配体导向疗法的理想模型。更重要的是，由于乳腺癌中的HER2过表达与侵袭性化疗耐药肿瘤相关，并预测预后不良，因此标准方案的替代治疗可能对这一乳腺癌亚组更有效，虽然不包括大多数病例，但属于最致命的乳腺癌。然而，我们已经确定了我们的调蛋白导向治疗的其他潜在靶点，包括表达高水平不同HER亚基的卵巢癌、神经胶质瘤和前列腺癌细胞。因此，除了HER2+乳腺癌之外，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。 该提案结合了多个合作者的专业知识，进一步将corrole组装体开发成可成像的肿瘤靶向药物。我们将评估靶细胞和免疫与载体蛋白的相互作用，以指导引入可能增强治疗效果和安全性的修饰的努力。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用于corrole递送，并利用corroles的独特光电发射特性来检测体内肿瘤靶向。 公共卫生相关性：该研究项目与公共卫生相关，因为它将导致开发一种新型自组装治疗剂，该治疗剂可以特异性靶向HER2+肿瘤（包括HER2+乳腺癌），与非靶向标准化疗相比，剂量低得多，因此更安全。此外，这种治疗剂可以在治疗期间成像，从而可以检测肿瘤靶向。因此，该技术将检测和干预结合在单个自组装靶向复合物中。

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.