RNA Therapeutics for Pancreatic Cancer

胰腺癌的 RNA 治疗

基本信息

批准号：
8531680
负责人：
Rebekah White
金额：
$ 15.22万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-08-17 至 2015-07-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): The vast majority of patients with pancreatic cancer are not cured by resection alone. Standard therapies are associated with low response rates and modest improvements in survival, and there is a dire need for more effective therapies. Aptamers are a class of therapeutic nucleic acid (RNA or DNA) molecules, which specifically bind to existing target proteins. Aptamers are generated by an iterative screening process of large combinatorial libraries that can be modified for nuclease resistance. Aptamers can have direct therapeutic effects mediated by binding their protein targets. In addition, aptamers that bind to cell surface receptors can be internalized by cells expressing those receptors and be utilized to deliver other therapeutic cargo. Our global hypothesis is that aptamers that bind targets over-expressed on pancreatic cancer cells relative to normal cells can be used to selectively deliver cytotoxic cargo, such as small interfering RNAs (siRNAs) or chemotherapeutic agents, to pancreatic cancer cells. We have 2 specific aims: Specific Aim #1: To utilize selection strategies against complex targets to identify new pancreatic cancer targets. The ideal target for aptamer-mediated delivery is one that is highly expressed on the surface of all pancreatic cancers, efficiently internalized, and not expressed on the surface of normal cells. Selection strategies utilizing complex targets such as whole cancer cells or tumor tissue in vivo allow the aptamers to choose their own targets. This aim includes in vitro selection against whole pancreatic cancer cells as well as in vivo selection against pancreatic cancer xenografts and genetically engineered mouse models of pancreatic cancer. We will characterize selected aptamers by identifying their specific protein and cellular targets. This aim therefore has the potential to simultaneously identify novel targets and the agents to mediate delivery to them. Aptamers that are internalized by pancreatic cancer cells will be further evaluated in Aim #2. Specific Aim #2: To utilize aptamers that is internalized by pancreatic cancer cells for specific delivery of siRNAs and other therapeutic cargo. We have preliminary data demonstrating that a RNA aptamer that binds EGFR and a DNA aptamer that binds nucleolin are internalized by pancreatic cancer cells. In parallel with the identification of new aptamers in Aim #1, we will utilize these extant aptamers to optimize constructs for delivery of K-ras siRNAs and gemcitabine polymers into cells. Then, we will use aptamers discovered in Aim #1 with the cargo technology gained in the first part of Aim #2 to formulate more specific and effective constructs to deliver K-ras siRNAs and gemcitabine polymers into pancreatic cancer cells in vitro and in vivo.

描述（由申请人提供）：绝大多数胰腺癌患者不能仅通过切除来治愈。标准疗法与低反应率和生存的适度改善有关，并且需要更有效的疗法。适体是一类治疗性核酸（RNA或DNA）分子，该核酸（RNA或DNA）分子特别结合了现有的靶蛋白。适体是通过大型组合文库的迭代筛选过程产生的，该过程可用于耐核酸酶耐药性。适体可以通过结合其蛋白质靶标介导的直接治疗作用。另外，可以通过表达这些受体并被用来提供其他治疗性货物的细胞来内部化与细胞表面受体结合的适体。我们的全球假设是，相对于正常细胞，对胰腺癌细胞过表达的靶标的适体可用于选择性地输送细胞毒性货物，例如小型干扰RNA（siRNA）或化学治疗剂，与胰腺癌细胞。我们有2个特定目标：特定目标＃1：利用针对复杂靶标的选择策略来识别新的胰腺癌靶标。适体介导的递送的理想目标是在所有胰腺癌的表面上高度表达，有效地内部化，并且在正常细胞表面上未表达。利用整个癌细胞或体内肿瘤组织等复杂靶标的选择策略使适体可以选择自己的靶标。该目标包括针对整个胰腺癌细胞的体外选择以及针对胰腺癌异种移植物的体内选择以及胰腺癌的基因工程小鼠模型。我们将通过识别其特定蛋白质和细胞靶标来表征选定的适体。因此，该目标有可能同时识别新的目标和代理，以调节向其传递。在AIM 2中将进一步评估由胰腺癌细胞内化的适体。特定目的＃2：利用胰腺癌细胞内化的适体来特异性地递送siRNA和其他治疗货物。我们的初步数据表明，结合EGFR的RNA适体和结合核仁蛋白结合的DNA适体由胰腺癌细胞内化。与AIM＃1中新的适体的鉴定并行，我们将利用这些现存的适体优化用于将K-RAS siRNA和吉西他滨聚合物传递到细胞中的构造。然后，我们将使用在AIM＃1中发现的适合学家，AIM＃2的第一部分获得了货物技术，以制定更具体和有效的结构，以在体外和体内输送K-Ras siRNA和Gemcitabine聚合物将其输送到胰腺癌细胞中。