Ye Zhaohui, Liu Cyndi F, Lanikova Lucie, Dowey Sarah N, He Chaoxia, Huang Xiaosong, Brodsky Robert A, Spivak Jerry L, Prchal Josef T, Cheng Linzhao
Division of Hematology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Stem Cell Program, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Stem Cells. 2014 Jan;32(1):269-78. doi: 10.1002/stem.1545.
Disease-specific induced pluripotent stem cells (iPSCs) provide an unprecedented opportunity to establish novel disease models and accelerate drug development using distinct tissue target cells generated from isogenic iPSC lines with and without disease-causing mutations. To realize the potential of iPSCs in modeling acquired diseases which are usually heterogeneous, we have generated multiple iPSC lines including two lines that are JAK2-wild-type and four lines homozygous for JAK2-V617F somatic mutation from a single polycythemia vera (PV) patient blood. In vitro differentiation of the same patient-derived iPSC lines have demonstrated the differential contributions of their parental hematopoietic clones to the abnormal erythropoiesis including the formation of endogenous erythroid colonies. This iPSC approach thus may provide unique and valuable insights into the genetic events responsible for disease development. To examine the potential of iPSCs in drug testing, we generated isogenic hematopoietic progenitors and erythroblasts from the same iPSC lines derived from PV patients and normal donors. Their response to three clinical JAK inhibitors, INCB018424 (Ruxolitinib), TG101348 (SAR302503), and the more recent CYT387 was evaluated. All three drugs similarly inhibited erythropoiesis from normal and PV iPSC lines containing the wild-type JAK2 genotype, as well as those containing a homozygous or heterozygous JAK2-V617F activating mutation that showed increased erythropoiesis without a JAK inhibitor. However, the JAK inhibitors had less inhibitory effect on the self-renewal of CD34+ hematopoietic progenitors. The iPSC-mediated disease modeling thus underlies the ineffectiveness of the current JAK inhibitors and provides a modeling system to develop better targeted therapies for the JAK2 mutated hematopoiesis.
疾病特异性诱导多能干细胞（iPSC）提供了前所未有的机会，可利用从具有和不具有致病突变的同基因iPSC系产生的不同组织靶细胞来建立新型疾病模型并加速药物开发。为了实现iPSC在模拟通常具有异质性的获得性疾病方面的潜力，我们从一名真性红细胞增多症（PV）患者的血液中生成了多个iPSC系，包括两个JAK2野生型系和四个JAK2-V617F体细胞突变纯合的系。同一患者来源的iPSC系的体外分化已证明其亲本造血克隆对异常红细胞生成的不同贡献，包括内源性红系集落的形成。因此，这种iPSC方法可能为导致疾病发展的遗传事件提供独特而有价值的见解。为了研究iPSC在药物测试中的潜力，我们从PV患者和正常供体来源的相同iPSC系中生成了同基因造血祖细胞和成红细胞。评估了它们对三种临床JAK抑制剂INCB018424（鲁索替尼）、TG101348（SAR302503）和最新的CYT387的反应。所有三种药物同样抑制了来自含有野生型JAK2基因型的正常和PV iPSC系以及含有纯合或杂合JAK2-V617F激活突变的系的红细胞生成，这些系在没有JAK抑制剂的情况下红细胞生成增加。然而，JAK抑制剂对CD34+造血祖细胞的自我更新抑制作用较小。因此，iPSC介导的疾病建模揭示了当前JAK抑制剂的无效性，并提供了一个建模系统来开发针对JAK2突变造血的更好的靶向治疗方法。
