Targeted Nanoparticle DNA Therapy for Ovarian Cancer

描述(由申请者提供)：对于晚期卵巢癌，有一种更有效的治疗方法显然是迫切需要的。为了满足这一需求，我们的长期目标是开发一种治疗晚期转移性卵巢癌的纳米疗法，有效地管理癌症，导致更长、更健康的生命。本实验的目的是对一种新型的阳离子、可生物降解的聚(2-氨基酯)聚合物进行修饰，以获得高效、靶向的DNA纳米颗粒输送到卵巢肿瘤细胞。拟议中的实验验证了这样一种假设，即在卵巢癌细胞体内注射旨在靶向运送编码所谓自杀基因的DNA的聚合物纳米颗粒将有效地杀死这些细胞，导致卵巢肿瘤的消退。我们将通过三种方法对聚合物进行修饰，旨在增强它们靶向向卵巢癌细胞运送DNA的能力，并提高它们对血清灭活的抵抗力。一种方法是聚乙二醇化聚合物，并将它们连接到两个单链可变抗体片段(ScFv)中的一个，该抗体片段与卵巢肿瘤细胞表面发现的蛋白质或叶酸具有反应性。第二种方法是将DNA聚(2-氨基酯)纳米颗粒与单链抗体或叶酸偶联的聚丙烯酸复合。第三种方法是对多(2-氨基酯)S的结构进行组合末端修饰。我们将使用高通量细胞转染实验来鉴定具有最高血清抵抗力和DNA递送能力的修饰聚合物。然后，我们将在三个活体小鼠模型中测试选定的聚合物配方的有效性：卵巢癌转基因模型、同基因小鼠/肿瘤细胞模型和人类肿瘤细胞异种移植模型。除了靶向向卵巢癌细胞运送DNA外，我们的目标是使用卵巢特异的启动子序列来靶向基因表达。我们将使用非侵入性成像技术(生物发光和显微CT)来纵向评估肿瘤对纳米颗粒递送的DT-A治疗的反应。此外，我们将确定这种疗法对寿命的影响，并确定该疗法是否会导致非特异性毒性。目前还没有针对晚期卵巢癌患者的有效治疗方法。我们的期望是，创新地使用纳米颗粒来靶向向卵巢癌细胞运送自杀基因，结合针对这些细胞的基因表达的策略，将导致这种致命疾病的有效治疗。虽然我们在这里专注于卵巢癌新疗法的开发，但这项研究将有助于确立纳米颗粒在基因治疗中的实用性，并为其在治疗其他类型的癌症和其他疾病中的更广泛应用铺平道路。 项目简介：聚(2-氨基酯)S是一种阳离子、可生物降解的聚合物，作为非病毒载体向癌细胞输送治疗性DNA显示出巨大的前景。对于初治无效或复发的晚期卵巢癌患者，目前还没有有效的治疗方法。本研究的目的是对多(2-氨基酯)S进行修饰，使其能够高效、靶向地将编码自杀基因的基因纳米粒输送到卵巢肿瘤细胞中。靶向纳米疗法，单独使用或作为辅助治疗，应该会为转移性卵巢癌患者带来更有效的治疗。

DESCRIPTION (provided by applicant): There is a clear and immediate need for a more effective therapy for advanced ovarian cancer. To address this need, our long-term goal is to develop a nanotherapy for advanced-stage metastatic ovarian cancer that effectively manages the cancer, resulting in a longer, healthy life. The objective of the proposed experiments is to introduce modifications to a promising new class of cationic, biodegradable poly(2-amino ester) polymers that result in efficient, targeted nanoparticle-delivery of DNA to ovarian tumor cells. The proposed experiments test the hypothesis that intraperitoneal administration of polymeric nanoparticles designed to target the delivery of DNA encoding so-called suicide genes to ovarian cancer cells will effectively kill the cells, resulting in ovarian tumor regression. We will modify polymers in three ways, aiming to enhance their ability to target DNA delivery to ovarian cancer cells and to improve their resistance to inactivation by serum. One approach will be to pegylate polymers and conjugate them to one of two single chain variable antibody fragments (scFvs) having reactivity to proteins found on the surface of ovarian tumor cells, or to folic acid. The second approach will be to complex DNA poly(2-amino ester)-nanoparticles with scFv- or folic acid-conjugated poly(acrylic acid). The third approach will be to make combinatorial end-modifications to the structure of poly(2-amino ester)s. We will use a high-throughput cell-based transfection assay to identify the modified polymers imparting the highest degree of serum resistance and DNA delivery. We will then test the effectiveness of selected polymer formulations in three in vivo mouse models: a transgenic model for ovarian cancer, a sygeneic mouse/tumor cell model, and a human tumor cell xenograft model. In addition to targeting DNA delivery to ovarian cancer cells, we aim to target gene expression using ovarian-specific promoter sequences. We will use non-invasive imaging technologies (bioluminescence and microCT) to assess longitudinally the response of tumors to the nanoparticle-delivers DT-A therapy. In addition, we will determine the effect of this therapy on life span and determine whether the therapy results in non-specific toxicity. There are currently no effective therapies for advanced-stage ovarian cancer patients. Our expectation is that the innovative use of nanoparticles to target delivery of suicide genes to ovarian cancer cells, combined with a strategy for targeting gene expression to these cells, will lead to an effective treatment for this deadly disease. While we focus here on the development of a new therapy for ovarian cancer, this study will help establish the utility of nanoparticles for gene therapy and pave the way for their broader application for treating additional types of cancer and other diseases. Project Narrative: Poly(2-amino ester)s is cationic, biodegradable polymers that show great promise as non-viral vectors for the delivery of therapeutic DNA to cancer cells. There are currently no effective therapies for advanced-stage ovarian cancer patients that either do not respond to initial therapy or those with recurrent disease. The purpose of this study is to introduce modifications to poly(2-amino ester)s that result in efficient, targeted nanoparticle-delivery of DNA encoding suicide genes to ovarian tumor cells following intraperitoneal administration. Targeted nanotherapy, used alone or as an adjuvant therapy, should lead to a more effective treatment for patients with metastatic ovarian cancer.