Targeted nanoparticle gene therapy for lung cancer

描述（由申请人提供）：项目概述：Savara公司正在研究一种变革性纳米核传递技术，作为一种有前景的一流肺癌基因治疗候选药物。由于这种特殊癌症的发病率和死亡率异常高，迫切需要一种副作用少的有效肺癌治疗方法。基因治疗虽然有希望，但在临床上仍不成功，主要原因是治疗性基因在癌症组织中的表达不足，以及传递载体的不良影响。最近，堪萨斯大学开发了一种用于核酸递送的新型纳米颗粒技术（“NanoNucleic”技术），并将其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siRNA递送的RNA）捆绑的阳离子肽，并通过钙凝聚成小纳米颗粒（75-100纳米）。利用NanoNucleic技术，在小鼠肺中实现了内源性凋亡诱导基因TRAIL和血管紧张素II 2型受体（AT2R）的高表达。在培养的几种人肺癌细胞系中，两种基因的过表达均可诱导明显的细胞死亡，但对正常肺上皮细胞或成纤维细胞的影响很小。AT2R过表达在培养的肺癌祖细胞中也会引起显著的细胞死亡。在气管内喷射AT2R或TRAIL基因作为纳米核制剂后，LLC小鼠的基因表达持续至少两周。对治疗后肺部的观察显示，肿瘤负荷显著减轻，对原生组织没有任何毒性迹象，也没有炎症迹象。与基于病毒载体的基因治疗不同，纳米核基因治疗有望产生最小的宿主免疫反应，并且没有病毒基因相关的缺陷，例如基因突变或通过随机插入基因组产生致癌基因。该研究的目的是在两种不同的体内肺癌模型中使用两种不同的治疗性候选基因（AT2R和TRAIL），为一种优化形式的纳米核基因治疗方法提供治疗性概念证明。纳米核制剂将气管内给药，有或没有补充静脉给药。小鼠LLC模型中强有力的初步数据表明，这项拟议的I期研究成功的可能性很高。I期的成功完成将推动该项目进入K-ras基因突变和烟草致癌物诱导的肺癌模型的疗效研究，以及大型动物的慢性安全性研究，从而为最终的转化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.