Targeted nanoparticle gene therapy for lung cancer

描述(由申请人提供)：项目摘要Savara公司正在研究一种变革性纳米核传递技术，作为治疗肺癌的一流候选基因。由于肺癌的发病率和死亡率非常高，迫切需要一种副作用较少的有效的肺癌治疗方法。基因治疗虽然有希望，但在临床上仍然不成功，主要是由于治疗基因在肿瘤组织中的表达不足，以及运送载体的不良反应。最近，堪萨斯大学开发了一种用于核酸输送的新型纳米颗粒技术(纳米核技术)，并独家授权给专门治疗肺部疾病的药物开发公司Savara Inc.。纳米核技术包括与DNA(或用于传递siRNA的RNA)捆绑在一起的阳离子多肽，并被钙凝聚成小纳米颗粒(75-100 nm)。利用纳米核技术，内源性细胞凋亡诱导基因(TRAIL和血管紧张素II2型受体(AT2R))在小鼠肺内获得了高水平的局部表达。在培养的几种人肺癌细胞系中，这两种基因的过表达都会导致细胞显著死亡，但对正常肺上皮细胞或成纤维细胞的影响很小。AT2R过表达还可诱导体外培养的肺癌前体细胞显著死亡。在给LLC小鼠气管内喷洒AT2R或TRAIL基因作为纳米核制剂后，基因表达至少持续了两周。对经过治疗的肺部的观察显示，肿瘤负担显著减少，没有对自然组织产生任何毒性的迹象，也没有炎症的迹象。与基于病毒载体的基因治疗不同，纳米核基因治疗预计会产生最低限度的宿主免疫反应，并且没有病毒基因相关的缺点，如基因突变或通过随机插入基因组产生癌基因。这项研究的目的是在两个不同的体内肺癌模型中，使用两个不同的候选治疗基因(AT2R和TRAIL)，提供优化形式的纳米核基因治疗方法的治疗概念验证。纳米核制剂将在气管内给药，无论有没有补充静脉给药。小鼠LLC模型中强劲的初步数据表明，在这项拟议的第一阶段研究中，成功的可能性很高。第一阶段的成功完成将使该计划能够推进到使用K-ras基因突变和烟草致癌物诱导的肺癌模型进行的疗效研究，以及在更大动物中进行的慢性安全性研究，从而为最终的翻译研究奠定坚实的基础。

DESCRIPTION (provided by applicant): Project Summary A transformational NanoNucleic delivery technology is being investigated by Savara Inc. as a promising first-in-class gene therapy candidate for lung cancer. A potent lung cancer therapy with fewer side effects is urgently needed due to the exceptionally high rates of morbidity and mortality of this particular cancer. Gene therapy, while promising, remains clinically unsuccessful, mainly due to insufficient therapeutic gene expression in cancer tissues, and adverse effects of the delivery vectors. Recently, a novel nanoparticle technology for nucleic acid delivery ("NanoNucleic" technology) was developed at the University of Kansas, and licensed exclusively to Savara Inc, a drug development company specializing in the treatment of lung diseases. The NanoNucleic technology comprises a cationic peptide bundled with DNA (or RNA for siRNA delivery), and condensed by calcium into small nanoparticles (75-100 nm). Using the NanoNucleic technology, high local expression of endogenous apoptosis inducer genes (TRAIL and angiotensin II type 2 receptor (AT2R)) was achieved in the lungs of mice. Over-expression of either gene induced marked cell death in several human lung cancer cell lines in culture, but the effect on normal lung epithelial cells or fibroblasts was minimal. AT2R over-expression also induced significant cell death in lung cancer progenitor cells in culture. After administering an intratracheal spray o AT2R or TRAIL genes as NanoNucleic formulations to LLC mice, gene expression lasted at least two weeks. Observations of the treated lungs revealed a remarkable reduction in tumor burden, without any signs of toxicity toward the native tissue, nor signs of inflammation. Unlike viral vector-based gene therapy, NanoNucleic gene therapy is expected to generate minimal host immune response and none of the viral gene- associated drawbacks such as gene mutations or the production of oncogenes via random insertion into the genome. The aim of the proposed research is to provide therapeutic proof-of- concept of an optimized form of NanoNucleic gene therapy approach using two different therapeutic gene candidates (AT2R, and TRAIL) in two different in vivo lung cancer models. NanoNucleic formulations will be administered intratracheally, with or without complementary intravenous administration. The strong preliminary data in the mouse LLC model suggest a high likelihood of success in this proposed Phase I research. Successful completion of the Phase I will enable advancement of the program into efficacy studies using K-ras gene mutation- and tobacco carcinogen-induced lung cancer models, as well as chronic safety studies in larger animals, and thereby build a solid foundation for eventual translational research.