PTD-Mediated Protein or Drug Delivery for Cancer Therapy

PTD 介导的蛋白质或药物递送用于癌症治疗

• 批准号: 7060844
• 负责人: VICTOR C YANG
• 金额: $ 25.38万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-04 至 2010-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7060844
• 关键词: antineoplastics; antitumor antibody; chemical conjugate; clinical research; disulfide bond; drug delivery systems; heparin; immunoconjugates; laboratory mouse; membrane permeability; membrane transport proteins; method development; pharmacokinetics; prodrugs; protamines; virus protein

DESCRIPTION (provided by applicant): Most existing anti-cancer drug therapies are relatively ineffective due to the presence of two bottleneck limitations: [1] the lack of selectivity of drug action towards cancer cells as opposed to normal tissues; and [2] the impermeability of the cell membrane that restricts drug uptake to simply small and hydrophobic agents. Proposed herein is a novel drug delivery approach that not only carries the potential to subdue these two limitations simultaneously but also be applied universally to delivery of drugs of all types (e.g. large or small) for treatment of cancers of all types (e.g. breast tumor, malignant melanoma). The approach utilizes the proven and unmatched trans-membrane ability of the so-called protein transduction domain (PTD) peptides (e.g. TAT from HIV protein) to ferry attached species across the membrane barrier in achieving highly effective cellular drug uptake, as well as the targeting and prodrug features to, yield selective drug actions and abort drug-induced toxic side effects. Briefly, the approach consists of a large complex made of two components: [1] a targeting component consists of a specific targeting moiety (e.g. antibody) linked with a heparin molecule and [2] a drug component is made by coupling, via cleavable S-S bonds, the delivered drug to a PTD peptide. These two components can associate automatically by a charge-charge interaction between the highly anionic heparin and cationic PTD. It has been confirmed in the literature that binding PTD with heparin would mask its trans-membrane activity; presumably due to inhibition of PTD adsorption to the cell surface. This prodrug feature would avoid drug uptake by normal cells, alleviating drug-induced toxic effects. Following tumor targeting by the antibody on the drug complex, protamine sulfate, a clinical heparin antidote that is known to bind heparin stronger than any existing PTD peptide, will be administered to unmask heparin-inhibition and restore the trans-membrane activity of PTD on the PTD-Drug conjugate. A study of the targeting pharmacokinetics will be carried out prior to protamine injection to determine the optimal dosing time of protamine (defined as the time when a maximum degree of the drug complexes has accumulated at the tumor target but a minimum amount is remained in the circulation), so that systemic toxicity caused by non-specific uptake of the PTD-Drug conjugates by normal tissues can be avoided. Once inside the tumor, the drug will be released by degradation of the S-S linkage by elevated cytosolic levels of glutathione and reductase activity, inducing apoptosis to primary tumor cells. If a large protein drug is used for delivery, the released drug will be unaffected by the multidrug resistant (MDR) effect because proteins are impermeable to cell membrane. Preliminary studies yielded extremely promising results, as a nearly complete tumor regression was observed in mice by using this approach in delivering a cell-impermeable protein toxin. In this application, we plan to conduct a full-scale study aimed at demonstrating the real-time feasibility and utility of this delivery system. A small conventional anti-tumor agent (doxorubicin) and a large hydrophilic protein drug (gelonin) are selected to represent the full spectrum of possible anti-tumor agents, whereas a highly effective vascular targeting strategy based on the use of VEGF121 is chosen to test the system in treating mice harboring a model CT-26 solid tumor. Aside from the universal applicability of this system to cancer treatment, the system could lead to discovery and development of a new arena of drugs that show great therapeutic promise but considered unusable due to poor cell uptake or acute toxic effects. To this regard, the true value and impact of this project is significant, far-reaching, and prevalent.

描述（由申请人提供）： 由于存在两个瓶颈的局限性，大多数现有的抗癌药物疗法相对无效：[1]与正常组织相比，药物对癌细胞的选择性缺乏选择性； [2]细胞膜的不渗透性将药物摄取限制为仅小型和疏水剂。本文提出的是一种新型的药物输送方法，不仅具有同时征服这两个局限性的潜力，而且还普遍应用于所有类型的药物（例如大或小）的药物，以治疗所有类型的癌症（例如乳腺癌，恶性，恶性黑色素瘤）。 The approach utilizes the proven and unmatched trans-membrane ability of the so-called protein transduction domain (PTD) peptides (e.g. TAT from HIV protein) to ferry attached species across the membrane barrier in achieving highly effective cellular drug uptake, as well as the targeting and prodrug features to, yield selective drug actions and abort drug-induced toxic side effects.简而言之，该方法由由两个组件组成的大型复合物组成：[1]一个靶向成分由与​​肝素分子相关的特定靶向部分（例如抗体）和[2] [2]通过耦合通过可切除的S-S-S-S-S-S-S-S-S-S-S-S-S-S-S-S-S-S-S-S键产生的药物成分，将药物交付给PTD肽。这两个组件可以通过高度阴离子肝素和阳离子PTD之间的电荷 - 电荷相互作用自动关联。在文献中已经证实，用肝素结合PTD会掩盖其跨膜活性。大概是由于PTD吸附到细胞表面的抑制作用。这种前药特征将避免正常细胞的药物摄取，从而减轻药物诱导的毒性作用。在抗体对药物复合物靶向肿瘤之后，硫酸蛋白酶硫酸质（一种临床肝素解毒剂，已知比任何现有的PTD肽都更强的肝素抗原剂，将施用以抑制肝素抑制并恢复PTD-Drug conjugate上PTD的跨膜活性。 A study of the targeting pharmacokinetics will be carried out prior to protamine injection to determine the optimal dosing time of protamine (defined as the time when a maximum degree of the drug complexes has accumulated at the tumor target but a minimum amount is remained in the circulation), so that systemic toxicity caused by non-specific uptake of the PTD-Drug conjugates by normal tissues can be avoided.一旦进入肿瘤，该药物将通过谷胱甘肽和还原酶活性升高S-S链接释放，从而诱导凋亡对原发性肿瘤细胞。如果使用大型蛋白质药物进行递送，则释放的药物将不受多药耐药性（MDR）效应的影响，因为蛋白质对细胞膜不可渗透。初步研究产生了极其有希望的结果，因为在小鼠中使用这种方法在递送可渗透细胞的蛋白质毒素时观察到了几乎完全的肿瘤消退。在此应用程序中，我们计划进行一项全面研究，旨在证明该交付系统的实时可行性和效用。选择了一种小型的常规抗肿瘤剂（阿霉素）和大型亲水蛋白药物（胶质素）来代表可能的抗肿瘤剂，而基于VEGF121使用的高效血管靶向策略，选择了使用VEGF121的高效血管靶向策略，以测试该系统，以治疗具有CT-26模型CT-26模型Tamor的系统。除了该系统对癌症治疗的普遍适用性外，该系统还可能导致发现和开发新的药物领域，这些药物表现出巨大的治疗前景，但由于细胞摄取不良或急性毒性作用而被认为是无法使用的。在这方面，该项目的真实价值和影响是重要的，深远的且普遍的。