Identification of Therapeutic Small Molecules for Myotonic Dystrophy Type 1

描述(申请人提供)：强直性肌营养不良症(DM1)是人类最常见的成人起病肌营养不良症。目前，还没有治愈DM1和相关疾病的药物，也没有FDA批准的药物。DM1是一种常染色体显性遗传病，由DMPK基因3‘端非翻译区CTG重复序列扩增引起。这一缺陷导致编码扩展的CUG重复序列(CUGexp)的突变DMPK RNAs的表达，形成大的核内RNA-蛋白质复合体或焦点。CUGexp RNA的表达导致RNA剪接异常，这反过来又与DM1病理的关键特征的发展有关。我们假设，在DM1细胞中降解或分散CUGexp RNA的小分子可以重建正常的剪接模式，并逆转DM1的病理。为了验证这一假设，我们开发了一种初级HTS和一种次级HIT验证试验，以识别选择性改变DMPK CUGexp RNA生物学的小分子，而不影响正常的DMPK转录本。我们的内部资料库是使用强大的机器学习化学信息学平台开发的，由40,000个高度多样化的小分子组成，代表了数百万种化合物的资料库。从2,500种化合物的筛选中获得的初步结果表明，我们的策略允许快速识别在患者细胞和DM1小鼠模型中成功逆转DM1病理的有效分子。为了共同努力确定一组有效的先导化合物，可以开发成治疗DM1的鸡尾酒，我们提出了以下目标：目标1.实施一次HTS和二次HIT验证试验，从我们的内部文库中筛选20,000个分子。目的2.在三级DM1患者的基于细胞的分析中测试HITS，以确定逆转五种关键细胞DM1表型的高度有效的先导。铅的选择性、毒性和协同作用将同时进行衡量。目的3.对先导化合物的化学结构进行反复精炼，以优化其药理性质并建立构效关系。

DESCRIPTION (provided by applicant): Myotonic dystrophy (DM1) is the most common adult onset muscular dystrophy in humans. Currently, there is no cure or an FDA approved drug for DM1 and related diseases. DM1 is an autosomal dominant disorder resulting from the expansion of a CTG-repeat sequence in the 3' untranslated region of the DMPK gene. This defect results in the expression of mutant DMPK RNAs encoding expanded CUG repeats (CUGexp) that form large intra nuclear RNA-protein complexes or foci. Expression of CUGexp RNAs leads to abnormal RNA splicing, which in turn has been linked to the development of key features of DM1 pathology. We hypothesize that small molecules that degrade or disperse CUGexp RNAs in DM1 cells can re-establish normal splice patterns and reverse DM1 pathology. To test this hypothesis, we have developed a primary HTS and a secondary hit validation assay to identify small-molecules that selectively alter the biology of DMPK CUGexp RNAs without affecting the normal DMPK transcripts. Our in house library was developed using a robust machine learning chemoinformatics platform and consists of 40,000 highly diverse small-molecules representing a library of several million compounds. Preliminary results obtained from a screen of 2,500 compounds demonstrate that our strategy allows the rapid identification of potent molecules that successfully reverse DM1 pathology in both patient cells and DM1 mouse models. In a concerted effort to identify a set of potent lead compounds that can be developed as a therapeutic cocktail for DM1 we propose the following Aims: Aim 1. Implement primary HTS and the secondary hit validation assay to screen 20,000 molecules from our in-house library. Aim 2. Test hits in tertiary DM1 patient cell-based assays to identify highly potent leads that reverse five key cellular DM1 phenotypes. Selectivity, toxicity and synergy of leads will be measured in parallel. Aim 3. The chemical structure of lead compounds will be reiteratively refined to optimize pharmacological properties and establish structure-activity relationships.