Expansion of Post-natal Human Stem Cells For A Pre-Clinical Dystrophy Model

描述（由申请人提供）： 干细胞治疗多种疾病的发展是在广泛的生物医学领域工作的研究人员的目标。随着对干细胞基础生物学的理解不断取得进展，通过追求临床前模型来保持对这些细胞的治疗应用的关注是很重要的。我们实验室的成员已经确定了一个小鼠肌肉来源的干细胞群体，表现出增强的能力，在肌肉萎缩症模型中再生骨骼肌。将该细胞群移植到小鼠的骨骼肌中导致比成肌细胞移植疗法显著更有效的再生（就营养不良肌肉内再生肌营养不良蛋白阳性肌纤维的数量而言），成肌细胞移植疗法一直是美国和加拿大的人类临床试验的焦点。我们假设，分离和移植更有效的干细胞，如人肌源性干细胞（huMDSC）或人脐带血干细胞，将改善肌营养不良症细胞治疗的结果。我们建议在这里使用临床前模型来测试我们的能力，以扩大人类肌肉来源的细胞群，以达到治疗细胞剂量（质量干细胞）和再生骨骼肌。细胞治疗方法的主要目标是1）产生临床相关数量的（质量或稳健的）huMDSC，2）维持其干细胞表型，3）防止其体外转化/了解其局限性。这些因素结合在一起，将通过维持其有效的表型来增加健壮干细胞的数量。在本提案的具体目标1中，我们将扩增huMDSC和脐带血干细胞群，以确定增殖极限，测量扩增动力学，并预测临床扩增时间。在特定目标2中，我们将评价扩增群体中与体外老化相关的任何转化指征。我们将通过分析分子标记和多能性来测试持续的自我更新。最重要的是，我们将检查细胞的染色体畸变，细胞周期控制的丧失和衰老。我们将进行体内实验，以测试持续的再生效率和肿瘤生长。这些目标将建立标准测试，通过这些测试来评估临床前环境中的任何干细胞群，并将提供对干细胞和癌症干细胞之间可能联系的基本见解。

DESCRIPTION (provided by applicant): The development of stem cell therapy for numerous diseases is the goal of researchers working in a wide range of biomedical fields. As progress toward understanding the basic biology of stem cells continues to be made, it is important to maintain a focus on therapeutic applications of these cells by pursuing preclinical models. Members of our laboratory have identified a mouse muscle-derived stem cell population that exhibits an enhanced ability to regenerate skeletal muscle in a muscular dystrophy model. Transplantation of this cell population into the skeletal muscle of mice results in significantly more efficient regeneration (in terms of number of regenerating dystrophin positive myofibers within dystrophic muscle) than does myoblast transplantation therapy, which has been the focus of human clinical trials in both the United States and Canada. We hypothesize that the isolation and transplantation of more potent stem cells such as human muscle-derived stem cells (huMDSCs) or human cord blood stem cells will improve the outcome of cell therapy for muscular dystrophy. We propose here to use a preclinical model to test our ability both to expand human muscle-derived cell populations to achieve therapeutic cell doses (of quality stem cells) and to regenerate skeletal muscle. The primary goals of the cell therapy approach are 1) to generate clinically relevant numbers of (quality or robust) huMDSCs, 2) to maintain their stem cell phenotype, and 3) to prevent their in vitro transformation/ understand their limits. Together these things will increase the quantity of the robust stem cells by maintaining their potent phenotype. In Specific Aim 1 of this proposal, we will expand huMDSC and cord blood stem cell populations to identify the proliferative limits, measure expansion kinetics, and predict clinical expansion time. In Specific Aim 2, we will evaluate the expanded populations for any indication of transformation associated with in vitro aging. We will test for continued self-renewal by assaying molecular markers and multipotency. Most importantly, we will examine the cells for chromosomal aberrations, loss of cell cycle controls, and senescence. We will perform in vivo experiments to test for continued regeneration efficiency and neoplastic growth. These aims will establish standard tests by which to assess any stem cell population in a preclinical setting and will provide basic insight into the possible link between stem cells and cancer stem cells.