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从事广泛生物医学领域的研究人员的目标。随着对干细胞基本生物学的理解继续取得进展，通过寻求临床前模型来保持对这些细胞的治疗应用的关注是重要的。我们实验室的成员已经确定了一种小鼠肌肉来源的干细胞群体，在肌肉营养不良模型中表现出增强的再生骨骼肌的能力。将这种细胞群移植到小鼠的骨骼肌中，再生效率(就营养不良肌肉中再生的dystrophin阳性肌纤维数量而言)明显高于成肌细胞移植疗法，后者一直是美国和加拿大人类临床试验的重点。我们假设，分离和移植更强大的干细胞，如人肌源性干细胞(HuMDSCs)或人脐血干细胞将改善肌营养不良症的细胞治疗结果。在这里，我们建议使用临床前模型来测试我们的能力，既扩大人类肌肉来源的细胞群，以达到治疗细胞剂量(高质量的干细胞)，又再生骨骼肌。细胞治疗方法的主要目标是1)产生临床上相关数量的(质量或健壮的)huMDSCs，2)保持其干细胞表型，以及3)防止其体外转化/了解其限制。总而言之，这些东西将通过保持强大的表型来增加强壮干细胞的数量。在这项建议的具体目标1中，我们将扩大huMDSC和脐带血干细胞种群，以确定增殖极限，测量扩增动力学，并预测临床扩增时间。在特定的目标2中，我们将评估扩大的种群是否有任何与体外老化相关的转化迹象。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异常、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体，并将提供对干细胞和癌症干细胞之间可能联系的基本洞察。

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.