Developing targeted activatable peptides to amplify radiosensitizer delivery

开发靶向可激活肽以增强放射增敏剂的输送

• 批准号: 9379141
• 负责人: Sunil J Advani
• 金额: $ 7.75万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-15 至 2019-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9379141
• 关键词: Address; Advanced Malignant Neoplasm; Adverse effects; Architecture; Area; Biodistribution; Biosensing Techniques; Cancer Patient; Cells; Charge; Cleaved cell; Clinical; Cytotoxic Chemotherapy; DNA Repair; Data; Dependency; Development; Diagnosis; Diagnostic; Disease; Dose; Drug Delivery Systems; Drug Kinetics; Drug Monitoring; Drug Sensitization; Drug Targeting; Environment; Extracellular Matrix; Fluorescence Resonance Energy Transfer; Functional Imaging; Gelatinase A; Generations; Goals; Head and Neck Cancer; Head and neck structure; In Situ; Ionizing radiation; Irradiated tumor; Kinetics; Label; Link; MMP14 gene; Malignant Neoplasms; Matrix Metalloproteinase Inhibitor; Matrix Metalloproteinases; Measures; Modeling; Molecular; Monitor; Morbidity - disease rate; Mus; Neoplasm Metastasis; Normal tissue morphology; Organ Preservation; Patient-Focused Outcomes; Patients; Peptide Hydrolases; Peptides; Pharmaceutical Preparations; Pharmacology; Play; Prodrugs; Property; Quality of life; Radiation exposure; Radiation therapy; Radiation-Sensitizing Agents; Radioresistance; Radiosensitization; Resistance; Role; Technology; Testing; Therapeutic; Tissues; Toxic effect; Unresectable; Work; base; chemotherapy; cyanine dye 5; design; effective therapy; extracellular; flexibility; fluorophore; improved; improved outcome; inhibitor/antagonist; innovation; interest; killings; neoplastic cell; non-invasive imaging; overexpression; peptide drug; polypeptide; pre-clinical; ratiometric; response; theories; tool; tumor; tumor growth; tumor microenvironment; tumor progression; uptake

Project Summary/Abstract Tumor resistance to radiotherapy continues to be a significant problem in improving outcomes of patients diagnosed with locally advanced, unresectable cancers including head and neck (HNC). Cellular sensitivity to ionizing radiation (IR) is governed by intracellular and extracellular factors. To help overcome tumor radioresistance, drugs that sensitize tumor to ionizing radiation (IR) are used. In theory, more potent radiosensitizers should increase tumor kill and improve patient outcomes. In practice, the clinical utility of of such drugs is curtailed by side effects that limit doses. To address these issues, we are developing activatable cell penetrating peptide (ACPP) probes to monitor and selectively deliver conjugated radiosensitizers to tumors based on extracellular tumor protease activity. ACPP consist of a drug conjugated polycationic cell penetrating peptide and an autoinhibitory polyanionic peptide separated from each other by a flexible peptide linker. Our initial peptide linker is cleaved by matrix metalloproteinases (MMP) 2/9, abundantly expressed in tumors. Intact, drug conjugated ACPP is “pro-drug” where the the drug linked cell penetrating peptide is neutralized by the polyanionic peptide, blocking intracellular drug uptake. Upon encountering MMP 2/9 within tumors, ACPP is cleaved (i.e. “activated”) and releases the drug conjugated cell-penetrating peptide, which is then taken up by tumor cells. An advantage of our ACPP probes is that they can be designed to non-invasively image extracellular tumor protease activities by synthesizing ratiometric ACPP. Ratiometric ACPP are labeled with Cy5 and Cy7 on the polycationic and polyanionic peptide respectively, acting as a FRET donor/acceptor pair. By using different protease sensitive peptide linker sequences between the two charged polypeptides, ratiometric ACPP Cy5:Cy7 emission ratio non-invasively measures distinct tumor protease activities in situ. A unique property of ACPP is the dependency on protease cleavage begets enzymatic amplification in the area of interest. The goals of our proposal are to develop ACPP probes to selectively radiosensitize tumors. In Aim 1, we will test the pharmacokinetics, biodistribution and efficacy of ACPP conjugated radiosensitizers in murine HNC models. To achieve this, drugs and fluorophores will be conjugated to ACPP and combined with IR. In Aim 2, we will interrogate in situ how IR alters extracellular protease activities in a dose dependent and temporal manner using a panel of ratiometric ACPP with distinct linkers cleaved preferentially by specific proteases. Identifying IR inducible ACPP cleavage will promote IR guided drug delivery development. In summary, ACPP radiosensitizer delivery has several innovative features that warrant pre-clinical inquiry. Diagnostically, ratiometric ACPP allows for non-invasive imaging of intrinsic tumor microenvironment proteases and IR's extrinsic influence. Therapeutically, ACPP's modular architecture allows for permutations of different classes radiosensitizing drugs to be conjugated to ACPPs with distinct protease linkers. Together, our studies will test how ACPPs can be exploited to improve the therapeutic ratio of radiotherapy.

项目总结/摘要 肿瘤对放射治疗的抵抗仍然是改善患者预后的一个重要问题 被诊断为局部晚期、不可切除的癌症，包括头颈部（HNC）。细胞对 电离辐射（IR）受细胞内和细胞外因素控制。帮助克服肿瘤 为了提高肿瘤的放射抗性，使用使肿瘤对电离辐射（IR）敏感的药物。理论上， 放射增敏剂应该增加肿瘤杀伤并改善患者结果。在实践中， 这些药物的副作用限制了剂量。为了解决这些问题，我们正在开发可激活的 细胞穿透肽（ACPP）探针，用于监测并选择性地将缀合的放射增敏剂递送至肿瘤 基于细胞外肿瘤蛋白酶活性。ACPP由药物结合的聚阳离子细胞穿透剂组成， 肽和自身抑制性聚阴离子肽，其通过柔性肽接头彼此分开。我们 初始肽接头被基质金属蛋白酶（MMP）2/9切割，在肿瘤中大量表达。 完整的药物缀合的ACPP是“前药”，其中药物连接的细胞穿透肽被 聚阴离子肽，阻断细胞内药物摄取。当在肿瘤内遇到MMP 2/9时， 被切割（即“活化”）并释放药物缀合的细胞穿透肽， 肿瘤细胞。我们的ACPP探针的一个优点是，它们可以被设计为非侵入性成像， 细胞外肿瘤蛋白酶活性的合成比率ACPP。比率ACPP标记有 Cy 5和Cy 7分别在聚阳离子和聚阴离子肽上，充当FRET供体/受体对。 通过在两个带电多肽之间使用不同的蛋白酶敏感肽接头序列， 比率ACPP Cy 5：Cy 7发射比率非侵入性地原位测量不同的肿瘤蛋白酶活性。一 ACPP的独特性质是对蛋白酶切割的依赖性在该区域引起酶扩增 感兴趣我们的目标是开发ACPP探针选择性地放射增敏肿瘤。在Aim中 1、研究ACPP结合放射增敏剂在小鼠体内的药代动力学、生物分布和疗效 HNC模型。为了实现这一点，药物和荧光团将与ACPP缀合并与IR组合。 目的2，我们将在原位询问IR如何以剂量依赖性和剂量依赖性改变细胞外蛋白酶活性， 使用一组比率ACPP的时间方式，其中不同的接头优先被特异性切割， 蛋白酶鉴定IR诱导的ACPP切割将促进IR引导的药物递送的开发。在 总之，ACPP放射增敏剂递送具有几个值得临床前研究的创新特征。 在诊断上，比率ACPP允许内源性肿瘤微环境蛋白酶的非侵入性成像 以及IR的外在影响。在治疗上，ACPP的模块化架构允许不同治疗方案的排列， 类放射增敏药物与具有不同蛋白酶接头的ACPP缀合。我们的研究 将测试如何利用ACPP来提高放射治疗的治疗率。