Multi-Modal Gene Therapy for Pancreatic Cancer using Targeted Nanovectors

靶向纳米载体用于胰腺癌的多模式基因治疗 胰腺癌预后很差，部分原因是快速侵袭和转移。 为了有效地治疗晚期胰腺癌，需要有新的临床可翻译的治疗策略。虽然已经尝试了几种基因治疗策略，但主要的限制是开发安全有效的全身给药给药系统。 为了克服系统性基因传递的挑战，我们开发了新型的非浓缩明胶 基于工程化的纳米载体系统(Gen)，可以包裹质粒DNA，防止 在体循环和细胞内转运过程中降解，并在体外和体内有效地在原位人乳腺肿瘤异种移植模型中进行转染。表达的可溶性Flt-1(VEGF-R1)对人原位乳腺癌有较好的治疗作用。基于这些令人印象深刻的初步观察，我们建议使用以表皮生长因子受体(EGFR)为靶点，包裹wt-p53和sFlt-1编码质粒的长循环基因，用于胰腺癌的单一和联合基因治疗。EGFR在大约50%的胰腺癌中过度表达，是肿瘤转移和对化疗和放射治疗耐药的预测指标。 我们的假设是，wt-P53的转染会抑制肿瘤生长，诱导细胞凋亡，并提供“旁观者效应”，而表达的sFlt-1则具有抗血管生成和防止继发转移的作用。这种联合疗法使用安全的EGFR靶向基因，在胰腺癌的晚期将特别有益，没有有害的副作用。 该建议的具体目的是：(1)利用工程设计标准，制备系统性p53和sFlt-1基因递送的EGFR靶向基因；(2)评估胰腺癌(Panc-1和Capan-1)细胞的摄取、细胞毒性和转染性；(3)检测全身给药后荷瘤裸鼠的生物分布、肿瘤摄取和转染率；(4)检测皮下和原位胰腺癌裸鼠的治疗效果和防止转移的效果；以及(5)确定全身给药的急性安全性概况。这项研究的结果对于在不久的将来将这项临床可翻译的技术应用到临床为胰腺癌患者带来好处是至关重要的。

Multi-Modal Gene Therapy For Pancreatic Cancer Using Targeted Nanovectors Pancreatic cancer is associated with very poor prognosis partly due to rapid invasion and metastasis Novel clinically-translatable therapeutic strategies are necessary in order to effectively treat advanced stage pancreatic cancer. Although several gene therapy strategies have been tried, the major limitation is in the development of safe and effective delivery system for systemic administration. To overcome systemic gene delivery challenges, we have developed novel non-condensing gelatin based engineered nanovector systems (GENS) that can encapsulate plasmid DNA, protect against degradation in the systemic circulation and during intracellular transport, and efficiently transfect in vitro and in vivo in an orthotopic human breast tumor xenograft model. The expressed soluble Flt-1 (VEGF-R1) was therapeutically effective in the treatment of orthotopic human breast adenocarcinoma. Based on these impressive preliminary observations, we propose to use epidermal growth factor receptor (EGFR)-targeted long-circulating GENS encapsulated with wt-p53 and sFlt-1 encoding plasmids for single and combination gene therapy in pancreatic cancer. EGFR is over-expressed in approximately 50% pancreatic cancer and is a predictive indicator of tumor metastasis and resistance to chemo- and radio-therapy. Our hypothesis is that wt-p53 transfection will suppress tumor growth, induce apoptosis, and provide the "bystander effect", while the expressed sFlt-1 will lead to anti-angiogenic effect and prevent secondary metastasis. This combination therapy, delivered with safe EGFR-targeted GENS, will be especially beneficial in advanced stages of pancreatic cancer without the harmful side effects. The specific aims of this proposal are to: (1) formulate, using engineering design criteria, EGFR-targeted GENS for systemic p53 and sFlt-1 gene delivery; (2) evaluate uptake, cytotoxicity, and transfection in pancreatic adenocarcinoma (Panc-1 and Capan-1) cells; (3) examine the biodistribution, tumor uptake, and transfection in pancreatic adenocarcinoma-bearing nude mice upon systemic administration; (4) examine the therapeutic efficacy and prevention of metastasis in subcutaneous and orthotopic pancreatic adenocarcinoma-bearing nude mice, and (5) determine acute safety profile of systemically administered GENS. The results from this study are critical in order to adapt this clinically-translatable technology into the clinic for benefit to pancreatic cancer patients in the near future.