Human Stem Cells for Toxicity Screening(RMI)

描述(由申请人提供)： 人类基因组序列的完成，在阐明疾病分子机制方面的最新进展，以及组合化学、高通量筛选和“基因组”技术的出现，为发现新的治疗药物提供了前所未有的机会。然而，许多候选药物由于在人体上的疗效不佳、不良的药效学特性、不可接受的不良反应和主要的不可预测的毒性而失败。目前的非临床安全性评估成本高、耗时长、使用大量试剂且涉及大量动物，这使得在药物开发流程的早期评估大量新化学实体(NCEs)的毒性是不切实际的。此外，典型的毒性研究无法可靠地预测人体潜在的安全问题，这是代价高昂的临床试验磨损的主要原因。因此，需要新的经济方法来有效地确定吸收、分布、代谢、排泄和毒性(ADMET)，这些方法可以更早地整合到药物开发流程中，以便识别在临床试验中更有可能成功的NCEs。这项高风险和高影响的提案将确立成人肝和肾干细胞作为受体介导的毒性的体外高通量模型的实用性。将研究雌激素、过氧化物酶体增殖物激活、芳香烃和孕烷X受体介导的活性，以比较评估成人肝和肾干细胞对活体诱导的啮齿动物效应的反应。使用同源人、小鼠和大鼠基因芯片的剂量和时间依赖的基因表达谱将与传统的(例如组织病理学、细胞增殖、临床化学)、分子(例如染色质免疫沉淀)和计算方法(例如反应元件搜索)相结合来阐明保守和分歧的反应。所有数据将在DBZACH(http://dbzach.fst.msu.edu))中管理，这是一个符合MIAME的模块化毒素基因组支持关系数据库。通过使用先进的统计方法(如遗传算法/偏最小二乘框架)，通过计算整合这些不同的数据，重建调控路径和网络，并进行比较研究，以确定假定的基于机制的跨物种保守生物标记物，这些标记物可用于高通量筛选，并可预测体内人类毒性。一旦得到验证，这些成体干细胞模型和基于机械的生物标记物可以用于优化、排序和优先考虑新的先导化合物。此外，该提案还将开发计算工具，以改进药物发现和开发过程中的知识管理和决策。

DESCRIPTION (provided by applicant): Completion of the human genome sequence, recent advances in elucidating the molecular mechanisms of disease, and the emergence of combinatorial chemistry, high-throughput screening and "omic" technologies have provided unprecedented opportunities to discover new therapeutic agents. However, many candidate agents are failing due to poor efficacy in humans, unfavorable pharmacodynamic properties, unacceptable adverse effects, and major unpredicted toxicities. Current nonclinical safety assessments are costly, time consuming, utilize large amounts of agent and involve significant numbers of animals, making it impractical to evaluate the toxicity of large numbers of new chemical entities (NCEs) early in the drug development pipeline. Moreover, typical toxicity studies fail to reliably predict potential safety problems in humans, a leading cause of costly clinical trial attrition. Consequently, new economical approaches to efficiently determine the absorption, distribution, metabolism, excretion and toxicity (ADMET) are required that can be integrated earlier in the drug development pipeline in order to identify NCEs that have a greater likelihood of success in clinical trials. This high-risk and high-impact proposal will establish the utility of adult human liver and kidney stem cells as in vitro high-throughput models for receptor-mediated toxicity. Estrogen, peroxisome proliferator-activated, aryl hydrocarbon and pregnane X receptor mediated activities will be investigated to comparatively assess adult human liver and kidney stem cell responses to in vivo elicited rodent effects. Dose- and time-dependent gene expression profiling using orthologous human, mouse and rat cDNA microarrays will be used in conjunction with traditional (e.g. histopathology, cell proliferation, clinical chemistry), molecular (e.g. chromatin immunoprecipitation) and computational approaches (e.g. response element searches) to elucidate conserved and divergent responses. All data will be managed within dbZach (http://dbzach.fst.msu.edu) a MIAME-compliant modular toxicogenomic supportive relational database. Regulatory pathways and networks will be reconstructed by computationally integrating this disparate data using advanced statistical approaches (e.g. genetic algorithm/partial least squares framework) and comparatively examined in order to identify putative mechanistically-based cross-species conserved biomarkers that are amendable to high throughput screening, and predictive of in vivo human toxicity. Once validated, these adult stem cell models and mechanistically-based biomarkers could be employed in optimizing, ranking and prioritizing new lead compounds. Moreover, this proposal will also develop computational tools that will improve knowledge management and decision-making during drug discovery and development.