Modeling chromosome 7 loss in Myelodysplasia-iPSCs

描述（由申请人提供）：骨髓增生异常综合征（MDS）是一种克隆性血液学疾病，其特征是无效造血和进展为骨髓（BM）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，其治疗主要是姑息性的。这在很大程度上是由于良好的动物模型的不可用性和原代MDS细胞的离体培养的挑战。7号染色体[del（7/7 q）]的全部或部分缺失是MDS中的复发性细胞遗传学异常，与不利的预后相关，强烈表明一个或多个关键基因-迄今为止仍然难以捉摸-存在于染色体7 q中。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-通过精确破坏基因组元件进入其同源基因组和细胞背景的等基因环境中的反向遗传学-迄今为止对于人类基因组是不可想象的-现在是一个现实的前景。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，建立一种新的基于hPSC的模型，以研究骨髓增生异常的细胞，分子和遗传发病机制。在初步研究中，我们已经从患者BM细胞中衍生出具有染色体7 q缺失的MDS-iPSC系，并且发现它们概括了潜在的疾病相关表型：受损的细胞增殖和造血分化。在拟议的研究中，我们计划通过重编程和染色体工程来获得额外的del（7 q）-以及同基因核型正常的iPSC，并表征其在未分化状态和造血分化后的表型。为了鉴定在MDS发病机制中起作用的基因，我们将进行位于染色体7 q中的候选基因的筛选以拯救我们的del（7 q）-hPSC中的增殖。这些研究，使用强大的新技术，将提供一个新的有价值的资源，骨髓增生异常的研究，产生的细胞过程和分子途径的影响，并可能确定关键基因的发病机制MDS，骨髓衰竭和白血病前期，一般的见解。!

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. !