Developing Small Molecules to Potentiate RNA Interference

描述（由申请人提供）：sirna是合成的约21个碱基对的双链寡核苷酸。当应用于细胞时，sirna可以有效地特异性地沉默它们的靶基因，称为RNA干扰（RNAi）。RNAi已成为功能基因组学研究的重要工具，并成为一类潜在的人类治疗分子。然而，几乎每家siRNA药物公司都遇到了一些障碍，主要是人体试验所需的高剂量siRNA，这带来了潜在的副作用，以及siRNA分子的脱靶效应。后者被认为可以通过巧妙设计siRNA分子来解决。目前还没有解决前者的办法。为了解决与siRNA治疗相关的这些困难，我们已经确定了一种rnai增强子，它可以提高siRNA的疗效，降低所需的siRNA剂量，并延长其沉默效果。如果开发成功，这些增强剂可以作为siRNA药物的辅助治疗。老年性黄斑变性（AMD）是黄斑细胞退化的一种疾病，导致视力模糊，最终失明。老年性黄斑变性是50岁以上人群失明的主要原因，在美国每年有20万新病例报告。迄今为止，已经开发了两种用于治疗AMD的sirna。因此，目前的siRNA候选药物对AMD的完全疗效可能尚未实现。在这个I期STTR提案中，我们将在小鼠模型中研究RNAi-E是否可以增强siRNA治疗AMD的疗效，这将为RNAi-E可以与siRNA药物一起作为辅助治疗提供原则性论证。我们将确定rnai增强化合物（RNAi-E）的最佳浓度，以在体外系统中增强化学修饰的siRNA分子，并确定RNAi-E在体内增强siRNA功效的可行性。该项目的第二阶段将需要IND支持配方、药代动力学和毒理学研究，将主要化合物推进人体临床试验。如果这些研究取得成功，这将是sirna作为治疗试剂的一大进步。

DESCRIPTION (provided by applicant): SiRNAs are synthetic double-stranded oligonucleotides of ~21 base pairs. When applied to cells, siRNAs can effectively and specifically silence their target genes, called RNA interference (RNAi). RNAi has become attractive tool for functional genomics and a potential class of molecules for human therapeutics. However, almost every siRNA drug company encounters several hurdles, mainly the high dose of siRNA needed for human trials with which come potential side effects, and off-target effects of siRNA molecules. The latter is believed to be resolvable by clever design of siRNA molecules. There are no solutions for the former at the moment. To address these difficulties associated with siRNA therapy, we have identified an RNAi-enhancer that can raise siRNA efficacy, lower the required siRNA dose, and prolong its silencing effect. If successfully developed, these enhancers could be used as an adjuvant therapy with siRNA drugs. Age-related macular degeneration (AMD) is a condition in which cells of the macula lutea degenerate, resulting in blurred vision and ultimately blindness. AMD is the leading cause of blindness in people over age 50, with 200,000 new cases reported annually in US. To date, two siRNAs have been developed for the treatment of AMD. As a result, the full efficacy of current siRNA drug candidates for AMD may not yet be achieved. In this Phase I STTR proposal, we will examine whether RNAi-E can enhance the efficacy of siRNAs to treat AMD in a mouse model, which will provide the proof-of-principle demonstration that RNAi-E could be used as an adjuvant therapy along with siRNA drugs. We will determine the optimal concentration of an RNAi-enhancing compound (RNAi-E) to potentiate chemically modified siRNA molecules in an in vitro system and determine the feasibility of RNAi-E for enhancing siRNA efficacy in vivo. Phase II of this project will entail IND enabling formulation, pharmacokinetics and toxicology studies that advance the leading compound(s) into human clinical trials. If these studies are successful, this would be a major stride toward the improvement of siRNAs for use as therapeutic reagents.