Khan Naeem, Hills Robert K, Knapper Steve, Steadman Lora, Qureshi Ushna, Rector Jerrald L, Bradbury Charlotte, Russell Nigel H, Vyas Paresh, Burnett Alan K, Grimwade David, Hole Paul S, Freeman Sylvie D
Department of Clinical Immunology, Institute of Immunology and Immunotherapy, University of Birmingham, Edgbaston, Birmingham, United Kingdom.
Department of Haematology, Cardiff University School of Medicine, University Hospital Wales, Cardiff, United Kingdom.
PLoS One. 2016 Sep 26;11(9):e0163291. doi: 10.1371/journal.pone.0163291. eCollection 2016.
In acute myeloid leukemia (AML) quiescence and low oxidative state, linked to BCL2 mitochondrial regulation, endow leukemic stem cells (LSC) with treatment-resistance. LSC in CD34+ and more mature CD34- AML have heterogeneous immunophenotypes overlapping with normal stem/progenitor cells (SPC) but may be differentiated by functional markers. We therefore investigated the oxidative/reactive oxygen species (ROS) profile, its relationship with cell-cycle/BCL2 for normal SPC, and whether altered in AML and myelodysplasia (MDS). In control BM (n = 24), ROS levels were highest in granulocyte-macrophage progenitors (GMP) and CD34- myeloid precursors but megakaryocyte-erythroid progenitors had equivalent levels to CD34+CD38low immature-SPC although they were ki67high. BCL2 upregulation was specific to GMPs. This profile was also observed for CD34+SPC in MDS-without-excess-blasts (MDS-noEB, n = 12). Erythroid CD34- precursors were, however, abnormally ROS-high in MDS-noEB, potentially linking oxidative stress to cell loss. In pre-treatment AML (n = 93) and MDS-with-excess-blasts (MDS-RAEB) (n = 14), immunophenotypic mature-SPC had similar ROS levels to co-existing immature-SPC. However ROS levels varied between AMLs; Flt3ITD+/NPM1wild-type CD34+SPC had higher ROS than NPM1mutated CD34+ or CD34- SPC. An aberrant ki67lowBCL2high immunophenotype was observed in CD34+AML (most prominent in Flt3ITD AMLs) but also in CD34- AMLs and MDS-RAEB, suggesting a shared redox/pro-survival adaptation. Some patients had BCL2 overexpression in CD34+ ROS-high as well as ROS-low fractions which may be indicative of poor early response to standard chemotherapy. Thus normal SPC subsets have distinct ROS, cell-cycle, BCL2 profiles that in AML /MDS-RAEB are decoupled from maturation. The combined profile of these functional properties in AML subpopulations may be relevant to differential treatment resistance.
在急性髓系白血病(AML)中,与BCL2线粒体调节相关的静止状态和低氧化状态赋予白血病干细胞(LSC)治疗抗性。CD34+和更成熟的CD34- AML中的LSC具有与正常干/祖细胞(SPC)重叠的异质性免疫表型,但可通过功能标志物进行区分。因此,我们研究了正常SPC的氧化/活性氧(ROS)谱、其与细胞周期/BCL2的关系,以及在AML和骨髓增生异常综合征(MDS)中是否发生改变。在对照骨髓(n = 24)中,粒细胞-巨噬细胞祖细胞(GMP)和CD34-髓系前体细胞中的ROS水平最高,但巨核细胞-红系祖细胞的ROS水平与CD34+CD38low未成熟SPC相当,尽管它们的ki67高。BCL2上调是GMP特有的。在无过多原始细胞的MDS(MDS-noEB,n = 12)中的CD34+SPC中也观察到了这种情况。然而,在MDS-noEB中,红系CD34-前体细胞的ROS异常高,这可能将氧化应激与细胞丢失联系起来。在预处理的AML(n = 93)和有过多原始细胞的MDS(MDS-RAEB)(n = 14)中,免疫表型成熟SPC的ROS水平与共存的未成熟SPC相似。然而,AML之间的ROS水平有所不同;Flt3ITD+/NPM1野生型CD34+SPC的ROS高于NPM1突变的CD34+或CD34- SPC。在CD34+AML(在Flt3ITD AML中最为突出)以及CD34- AML和MDS-RAEB中观察到异常的ki67低BCL2高免疫表型,表明存在共同的氧化还原/促生存适应性。一些患者在CD34+ROS高以及ROS低的细胞亚群中均有BCL2过表达,这可能表明对标准化疗的早期反应较差。因此,正常SPC亚群具有不同的ROS、细胞周期、BCL2谱,在AML /MDS-RAEB中这些谱与成熟过程解耦。AML亚群中这些功能特性的综合谱可能与不同的治疗抗性相关。