Thermally Targeted Delivery of DOX

DOX 的热靶向输送

• 批准号: 7326310
• 负责人: RAYMOND J BUDDE
• 金额: $ 18万
• 依托单位: HOUSTON PHARMACEUTICALS, INC.
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-17 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7326310
• 关键词: Address; Adverse effects; Amino Acid Sequence; Animal Model; Antineoplastic Agents; Biopolymers; C-terminal; Cancerous; Cardiotoxicity; Cell Proliferation; Cell membrane; Cells; Cleaved cell; Clinical; Clinical Trials; Coupled; Cysteine; Dose; Doxorubicin; Drug Carriers; Drug Delivery Systems; Drug usage; Elastin; Engineering; Excision; Fever; Goals; HIV-1; Heating; Hematologic Neoplasms; In Vitro; Injection of therapeutic agent; Intravenous; Kinetics; Local Hyperthermia; Localized; Location; Lysosomes; Measures; Membrane; Modeling; Multi-Drug Resistance; Myelosuppression; Normal tissue morphology; Nude Rats; Operative Surgical Procedures; Outcome; Peptides; Pharmaceutical Preparations; Physiological; Plasma; Proteins; Quantitative Autoradiography; Radiation; Radiation therapy; Radiolabeled; Rattus; Research; Resistance; Rest; Site; Solid Neoplasm; Solutions; Specificity; Technology; Temperature; Therapeutic; Thigh structure; Tissues; Toxic effect; Toxicity due to chemotherapy; Treatment Efficacy; Tumor Tissue; Uterine Corpus Sarcoma; Xenograft procedure; antitumor agent; aqueous; base; cancer cell; chemotherapy; cytotoxicity; design; desire; hyperthermia treatment; in vivo; intraperitoneal; neoplastic; polypeptide; radiotracer; size; targeted delivery; tat Protein; therapeutic target; tumor; tumor growth; tumor xenograft

DESCRIPTION (provided by applicant): Current treatment of solid tumors is limited by inherent tumor resistance to radiation or chemotherapy and by toxicity from systemic administration of antineoplastic agents. Our long-term goal is to overcome these limitations by developing for localized tumors a targeted therapeutic approach that increases the specificity and efficacy of the therapy and reduces the cytotoxicity in normal tissues. We have developed a thermally responsive polypeptide carrier for the chemotherapeutic doxorubicin which inhibits proliferation of cancer cells in culture. Our hypothesis is that after systemic administration these genetically engineered polypeptides can be targeted to the tumor site by applying local hyperthermia. This will result in accumulation of the agent in the tumor with subsequent inhibition of tumor growth. The amino acid sequence of the designed polypeptides is based on elastin-like polypeptide (ELP) biopolymers which are soluble in aqueous solution at physiological temperature (37 ¿C), but aggregate when the temperature is raised above 40 ¿C. The Tat membrane translocating sequence, derived from the HIV-1 Tat protein, known to facilitate delivery of large cargo proteins across cell membranes, is conjugated to the ELP to facilitate cell entry. A tetrapeptide GFLG linker was included at the C-terminus of ELP. This lysosomally degradable peptide linker separates the ELP polypeptide from a cysteine residue that can be coupled to doxorubicin. Our preliminary in vitro results demonstrate a very significant effect of the Tat-ELP-Dox construct in MES-SA and MES-SA/Dx5 multidrug resistant uterine sarcoma cell cells when compared to a non-thermally responsive control peptide. In order to address the hypothesis that Tat-ELP-Dox can be thermally targeted to tumor tissue, the following specific aims will be addressed: (1) Measure the plasma kinetics and in vivo distribution of Tat- ELP-Dox in normal and neoplastic tissue in an athymic rat model by determining the plasma concentration curve and determination of the tissue concentrations with quantitative autoradiography, and (2) Evaluate the therapeutic efficacy of Tat-ELP-Dox in the treatment of neoplastic xenografts in the thigh of athymic rats with and without localized hyperthermia through repeated administration of the agent coupled with local hyperthermia. Specific targeting of the proposed chemotherapeutic polypeptide carrier to solid tumors by local hyperthermia would increase specificity and efficacy of treatment and reduce the cytotoxicity in normal tissues. The successful completion of the proposed research will provide technology which has competitive advantage over existing/alternate technologies and it would provide an alternative mean to effectively substitute or augment present therapy for treatment of localized tumors. Current treatment of solid tumors is limited as only a small fraction of the administered dose of drug reaches the tumor site, while the rest of the drug is distributed throughout the body causing undesirable side effects to normal tissue when drugs are used in the doses required to eradicate cancer cells. Our long term goal is to overcome this limitation by developing an approach that allows the drug to be delivered specifically to the tumor site. This will increase the specificity of the therapy and reduce the toxicity in normal tissues.

描述（由申请人提供）：目前实体瘤的治疗受到肿瘤对放射或化疗的固有抗性以及全身施用抗肿瘤药物的毒性的限制。我们的长期目标是通过针对局部肿瘤开发一种靶向治疗方法来克服这些限制，该方法可以提高治疗的特异性和功效并降低正常组织中的细胞毒性。我们开发了一种用于化疗药物阿霉素的热响应多肽载体，可抑制培养物中癌细胞的增殖。我们的假设是，全身给药后，这些基因工程多肽可以通过局部热疗靶向肿瘤部位。这将导致药物在肿瘤中积聚，随后抑制肿瘤生长。设计的多肽的氨基酸序列基于弹性蛋白样多肽（ELP）生物聚合物，其在生理温度（37℃）下可溶于水溶液，但当温度升高到40℃以上时会聚集。 Tat 膜易位序列源自 HIV-1 Tat 蛋白，已知可促进大货物蛋白跨细胞膜的传递，与 ELP 缀合以促进细胞进入。 ELP 的 C 末端包含四肽 GFLG 连接子。这种可溶酶体降解的肽接头将 ELP 多肽与可与阿霉素偶联的半胱氨酸残基分开。我们的初步体外结果表明，与非热响应对照肽相比，Tat-ELP-Dox 构建体对 MES-SA 和 MES-SA/Dx5 多重耐药子宫肉瘤细胞具有非常显着的作用。为了解决 Tat-ELP-Dox 可以热靶向肿瘤组织的假设，将解决以下具体目标：（1）通过确定血浆浓度曲线和定量放射自显影测定组织浓度，测量无胸腺大鼠模型中正常和肿瘤组织中 Tat-ELP-Dox 的血浆动力学和体内分布，以及（2）评估 通过重复给药联合局部热疗，Tat-ELP-Dox 在治疗有或没有局部热疗的无胸腺大鼠大腿肿瘤异种移植物中的治疗效果。通过局部热疗将所提出的化疗多肽载体特异性靶向实体瘤将增加治疗的特异性和功效并减少正常组织中的细胞毒性。拟议研究的成功完成将提供比现有/替代技术具有竞争优势的技术，并将提供有效替代或增强局部肿瘤治疗现有疗法的替代手段。目前实体瘤的治疗受到限制，因为所施用的药物剂量中只有一小部分到达肿瘤部位，而其余的药物分布在整个身体中，当以根除癌细胞所需的剂量使用药物时，会对正常组织产生不良副作用。我们的长期目标是通过开发一种允许药物特异性递送至肿瘤部位的方法来克服这一限制。这将增加治疗的特异性并减少正常组织的毒性。