RNA Therapeutics for Pancreatic Cancer

胰腺癌的 RNA 治疗

• 批准号: 8321494
• 负责人: Rebekah White
• 金额: $ 15.26万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 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
• 来源: https://reporter.nih.gov/project-details/8321494
• 关键词: Binding; Cell Surface Receptors; Cells; Complex; DNA; Data; Disease; Distant; Drug Formulations; Epidermal Growth Factor Receptor; Excision; Genetically Engineered Mouse; In Vitro; Learning; Libraries; Malignant neoplasm of pancreas; Mediating; Normal Cell; Nucleic Acids; Operative Surgical Procedures; Patients; Polymers; Process; Proteins; RNA; Radiation; Regional Disease; Relative (related person); Research; Resistance; Screening procedure; Small Interfering RNA; Surface; Technology; Testing; Therapeutic; Therapeutic Effect; Time; TimeLine; Tumor Tissue; Unresectable; Xenograft procedure; advanced disease; aptamer; cancer cell; cellular targeting; chemotherapeutic agent; chemotherapy; combinatorial; cytotoxic; effective therapy; gemcitabine; improved; in vivo; irradiation; mouse model; novel; nuclease; nucleolin; pancreatic cancer cells; prostate stem cell antigen; receptor; response; tumor

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(申请人提供)：绝大多数胰腺癌患者不能仅靠切除治愈。标准疗法与低应答率和适度改善存活率有关，迫切需要更有效的疗法。适配子是一类治疗性核酸(RNA或DNA)分子，能与现有的靶蛋白特异性结合。适配子是通过迭代筛选大的组合文库而产生的，这些组合文库可以被修饰以抵抗核酸酶。适配子可以通过结合它们的蛋白靶标来发挥直接的治疗作用。此外，与细胞表面受体结合的适体可以被表达这些受体的细胞内化，并被用来运送其他治疗货物。我们的全球假设是，与正常细胞相比，与胰腺癌细胞过度表达的靶点结合的适体可以用来选择性地将细胞毒物质，如小干扰RNA(SiRNAs)或化疗药物，输送到胰腺癌细胞。我们有两个特定的目标：特定的目标1：利用针对复杂靶点的选择策略来识别新的胰腺癌靶点。适配子介导的理想靶点是一种在所有胰腺癌表面高表达、高效内化而在正常细胞表面不表达的靶点。利用体内整个癌细胞或肿瘤组织等复杂靶点的选择策略允许适体选择自己的靶点。这一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瘤和胰腺癌基因工程小鼠模型的体内选择。我们将通过确定其特定的蛋白质和细胞靶标来鉴定选定的适配子。因此，这一目标有可能同时确定新的目标和调停给它们的药物。被胰腺癌细胞内化的适配子将在目标2中进一步评估。具体目标2：利用由胰腺癌细胞内化的适配子来特定地运送siRNA和其他治疗货物。我们有初步数据表明，与EGFR结合的RNA适配子和与核仁素结合的DNA适配子被胰腺癌细胞内化。在AIM#1中鉴定新的适配子的同时，我们将利用这些现有的适配子来优化K-ras siRNA和吉西他滨聚合物进入细胞的结构。然后，我们将使用在AIM#1中发现的适配子和在AIM#2第一部分中获得的Cargo技术来构建更特异和有效的构建体，将K-ras siRNA和吉西他滨聚合物输送到体外和体内的胰腺癌细胞中。