Detection, Radiosensitization and Theranostic Targeting of Metastatic Breast Cancer by PTPmu

无论是在中枢神经系统内还是在外周神经系统外，癌细胞都沿着生长， 神经作为侵袭和转移的途径称为神经侵袭。这种生长在几种癌中很常见 包括乳腺癌并且与不良预后相关。细胞粘附分子（CAM）的蛋白水解 发生在发育过程中，越来越多的证据表明这种翻译后修饰可能促进肿瘤的发生。 迁移和侵袭神经，最终导致各种肿瘤类型转移到大脑，包括 乳腺癌受体蛋白酪氨酸磷酸酶PTPµ是一种CAM，在癌细胞中被蛋白水解， 产生作为肿瘤微环境的独特成像生物标志物的细胞外片段。PTPµ- 我们开发的靶向药物与这种生物标志物结合， 原发性乳腺癌和已经转移到大脑的乳腺癌。PTPµ-的全身给药 在异种移植模型中，靶向剂在几分钟内与肿瘤细胞结合。使用3D冷冻成像 系统，我们分析了大脑内细胞迁移和扩散的程度。我们发现PTPµ-靶向 在小鼠模型中，试剂标记了远离神经上主要肿瘤块的所有分散肿瘤细胞的99%。 该提案代表了我们在神经科学、细胞粘附、成像和癌症方面的专业知识的融合 以测试PTPµ生物标志物是否可用于检测肿瘤沿导致脑转移的神经沿着生长。 金纳米颗粒（AuNPs）在生物医学应用中表现出出色的多功能性，包括 成像诊断、药物输送和放射治疗。在本提案中，我们描述了 用于检测和治疗乳腺癌转移的治疗诊断AuNP。我们将实现更敏感的 通过使用三组分治疗诊断剂检测和治疗侵袭性和转移性病变 纳米颗粒含有：1）肿瘤中PTPµ生物标志物的高度特异性靶向剂 微环境; 2）用于荧光成像的蛋白酶敏感性淬灭近红外荧光团;和3）用于荧光成像的蛋白酶敏感性淬灭近红外荧光团;和 金纳米粒子（AuNP）用于对放射疗法的敏化。我们将测试PTPµ靶向药物是否检测到 使用3D单细胞分辨率冷冻成像精确跟踪个体迁移的神经相关生长 神经上的癌细胞我们将利用我们建立的人类患者来源的转移性肿瘤的异种移植模型， 乳腺癌和从乳房转移到大脑的模型。转移性肿瘤对几乎 所有的化疗药物，如“物理”杀伤策略，如放射，必须得到改进，并用于更好地 治疗结果。通过将PTPµ靶向的结合AuNP直接递送至原发性和转移性乳腺癌， 我们将利用AuNP的放射增敏作用来减少治疗癌症所需的辐射剂量。 放射治疗，从而减少对正常周围组织的附带损伤。我们希望这些研究 将产生靶向纳米颗粒，检测和治疗神经相关肿瘤生长，同时涉及CAM 蛋白水解作为检测和治疗肿瘤侵袭神经的一种普遍机制。

Both inside the central nervous system and outside in the peripheral nervous system, cancer cells grow along nerves as routes of invasion and metastasis called neural invasion. This growth is common in several carcinomas including breast cancer and is associated with poor prognosis. Proteolysis of cell adhesion molecules (CAMs) occurs in development, and growing evidence suggests this post-translational modification may promote tumor migration and invasion on nerves that ultimately leads to metastasis to the brain in various tumor types including breast cancer. The receptor protein tyrosine phosphatase PTPµ is a CAM that is proteolyzed in cancer cells to generate an extracellular fragment that is a unique imaging biomarker of the tumor microenvironment. The PTPµ- targeted agents we developed bind to this biomarker and recognize human brain tumors as well as invasive primary breast cancer and breast cancer that has metastasized to the brain. Systemic delivery of the PTPµ- targeted agent results in binding to tumor cells within minutes in xenograft models. Using a 3D cryo-imaging system we analyzed the extent of cell migration and dispersal within the brain. We found that the PTPµ-targeted agent labels 99% of all dispersing tumor cells far away from the main tumor mass on nerves in mouse models. This proposal represents the convergence of our expertise in neuroscience, cell adhesion, imaging and cancer to test if the PTPµ biomarker can be used to detect tumor growth along nerves leading to brain metastases. Gold nanoparticles (AuNPs) have shown outstanding versatility in biomedical applications including imaging diagnostics, drug delivery, and radiation therapy. In this proposal, we describe the development of theranostic AuNPs for the detection and treatment of breast cancer metastases. We will achieve more sensitive detection and treatment of invasive and metastatic lesions through the use of a three component theranostic nanoparticle containing: 1) a highly specific targeting agent of the PTPµ biomarker in the tumor microenvironment; 2) a protease-sensitive quenched near infrared fluorophore for fluorescent imaging; and 3) a gold nanoparticle (AuNP) for sensitization to radiotherapy. We will test whether the PTPµ-targeted agents detects nerve associated growth using 3D single cell resolution cryo-imaging that precisely tracks migration of individual cancer cells on nerves. We will utilize our established human patient-derived xenograft models of metastatic breast cancer and models that metastasize from the breast to the brain. Metastatic tumors are resistant to almost all chemotherapeutics so “physical” killing strategies like radiation must be improved and employed for better therapeutic outcomes. By delivering PTPµ-targeted conjugated AuNPs directly to primary and metastatic breast cancer we will exploit the radiosensitization of AuNP to reduce the required dose of radiation needed for radiotherapy thereby reducing collateral damage to normal surrounding tissues. We expect that these studies will yield targeted nanoparticles that detect and treat nerve associated tumor growth while implicating CAM proteolysis as a generalizable mechanism for detecting and treating tumor invasion on nerves.