Modeling chromosome 7 loss in Myelodysplasia-iPSCs

描述(申请人提供)：骨髓增生异常综合征(MDS)是一种克隆性血液学疾病，特征是无效的造血，有发展为骨髓衰竭或急性白血病的倾向。尽管其发病率相对较高，但对其发病机制知之甚少，其治疗仍以姑息治疗为主。这在很大程度上是由于缺乏良好的动物模型，以及原代MDS细胞体外培养的挑战。7号染色体全部或部分丢失[del(7/7q)]是MDS中一种反复出现的细胞遗传学异常，与不良预后有关，强烈表明一个或多个关键基因-迄今仍难以捉摸-驻留在7q染色体上。随着人类多能干细胞(HPSC)研究的最新突破-直接重编程和新的基因工程技术-通过精确地将基因组元件破坏到其同源基因组和细胞环境中的同源基因组和细胞环境中的反向遗传学-到目前为止对人类基因组来说是不可想象的-现在已经成为一个现实的前景。我们的目标是利用我们和其他人开发的尖端重编程和基因工程技术来建立一个新的基于hPSC的模型，以研究骨髓发育不良的细胞、分子和遗传学发病机制。在初步研究中，我们从患者骨髓细胞中获得了染色体7q缺失的MDS-IPSC系，并发现它们概括了潜在的与疾病相关的表型：细胞增殖和造血分化受损。在这项拟议的研究中，我们计划通过重新编程和染色体工程来获得额外的del(7q)-以及等基因的正常IPSCs，并表征它们在未分化状态和造血分化后的表型。为了确定在MDS发病机制中起作用的基因，我们将对位于染色体7q的候选基因进行筛选，以挽救我们的del(7q)-hPSCs的增殖。这些研究利用强大的新技术，将为骨髓发育不良的研究提供新的有价值的资源，深入了解受影响的细胞过程和分子途径，并有可能确定在MDS、骨髓衰竭和白血病前期发病机制中的关键基因。好了！

DESCRIPTION (provided by applicant): Myelodysplastic syndromes (MDS) are clonal hematologic disorders characterized by ineffective hematopoiesis and a propensity for progression to bone marrow (BM) failure or acute leukemia. Despite their relatively high incidence, very little is known about their pathogenesis and their treatment remains mainly palliative. This is largely due to the unavailability of good animal models and the challenges of the ex vivo culture of primary MDS cells. Loss of the entire or part of chromosome 7 [del(7/7q)] is a recurrent cytogenetic abnormality in MDS, associated with unfavorable prognosis, strongly suggesting that one or more critical genes - that so far remain elusive - reside in chromosome 7q. With recent breakthroughs in human pluripotent stem cell (hPSC) research - direct reprogramming and new genetic engineering technologies - reverse genetics in an isogenic setting by precise disruption of genomic elements into their cognate genomic and cellular context - hitherto unthinkable for the human genome - are now a realistic prospect. Our goal is to harness cutting-edge reprogramming and genetic engineering technologies that we and others have developed to establish a novel hPSC-based model to study the cellular, molecular and genetic pathogenesis of myelodysplasia. In preliminary studies, we have derived MDS-iPSC lines with chromosome 7q deletions from patient BM cells and found that they recapitulate potential disease- associated phenotypes: impaired cell proliferation and hematopoietic differentiation. In the proposed study we plan to derive additional del(7q)- as well as isogenic karyotypically normal iPSCs, through reprogramming and chromosome engineering, and characterize their phenotype in the undifferentiated state and following hematopoietic differentiation. To identify genes with a role in MDS pathogenesis, we will perform a screen of candidate genes residing in chromosome 7q for rescue of proliferation in our del(7q)- hPSCs. These studies, using powerful new technologies, will provide a novel valuable resource for the study of myelodysplasia, generate insights into the cellular processes and molecular pathways affected and potentially identify critical genes in the pathogenesis of MDS, bone marrow failure and preleukemia, in general. !