Hyperglycemia mediated myeloproliferative disease

项目总结/摘要 糖尿病（DM）是癌症发展的一个强有力的危险因素。然而，尚不清楚糖尿病是否也是一种风险 用于将前白血病干细胞（pre-LSC）转化为成熟白血病（如急性骨髓性白血病）的因子 白血病（AML）、慢性粒单核细胞白血病（CMML）或重度骨髓增生性肿瘤 （MPN）.为此，对超过2万个外周血（PB）细胞进行广泛的全外显子组测序 对血液学表型检测的人进行了160个基因的检测， 在白血病中突变发现的两个最突变的基因是表观遗传调节因子：10 - 11易位 甲基胞嘧啶双加氧酶2（TET 2）和DNA胞嘧啶甲基转移酶3A（DNMT 3A）。值得注意的是，这两个 MPN和AML患者的基因突变频率非常高。重要的是， 表明糖尿病患者比非糖尿病患者更容易发生这些突变。然而，在这方面， 我们对话语标记语在MPN中的致病作用的理解存在很大的知识差距， 白血病发生使用Tet 2功能丧失（Tet 2-/-）的鼠模型的研究表明，Tet 2缺陷型小鼠中， 造血干细胞（HSCs）具有异常的整体5-羟甲基胞嘧啶（5-hmC）水平和局部5-hmC水平 负责HSC自我更新的基因中的hmC水平。此外，Tet 2-/-HSC显示出竞争性的细胞毒性。 造血干细胞在造血干细胞中具有优于正常HSC的优势（即克隆造血），但不会发展为AML。此外，委员会认为， Tet 2单倍不足（Tet 2 +/-）小鼠仅在年老时表现出这些表型的较温和形式， 这表明Tet 2是一种假定的肿瘤抑制因子。我们发现Tet 2缺陷小鼠表现出 对急性炎症的持续反应和老年的未感染Tet 2-/-小鼠显示一系列 编码天然免疫/促炎途径组分的基因，包括S100 A8/9、TLR 4、NFκB1 和IL-6随着糖尿病患者发生慢性炎症并增加S100 A8/A9的表达， 这一建议的中心假设是，携带单一遗传病变的糖尿病个体， 在HSC中的TET 2（在没有任何血液恶性肿瘤的情况下）将更容易发展为严重的 MPN和/或骨髓性白血病，部分归因于过度活跃的促炎细胞因子信号级联或正向调节。 喂养正信号环和部分高血糖（HG）诱导5-hmC进一步全面降低 在携带Tet 2损失的前LSC中的水平，从而模拟缺乏所有形式的泰特的前LSC。的确， Tet 2突变小鼠糖尿病模型（Ins 2秋田/+），我们的初步数据表明，糖尿病 Tet 2单倍不足的小鼠（Ins 2Akita/+; Tet 2 +/-）逐渐发展成致死性AML/重度MPN。重要的是， 用抗炎分子治疗暴露于急性炎症攻击的Tet 2-/-小鼠， APX 3330逆转了这种表型。基于这些初步结果，我们假设进行性DM 作为将前LSC和/或克隆造血转化为血红素恶性肿瘤的重要风险因素 以年龄依赖的方式。

PROJECT SUMMARY/ABSTRACT Diabetes mellitus (DM) is a strong risk factor for cancer development. However, it is unclear if DM is also a risk factor for transforming pre-leukemic stem cells (pre-LSCs) into full-blown leukemia such as acute myeloid leukemia (AML), chronic myelomonocytic leukemia (CMML) or severe form of myeloproliferative neoplasm (MPN). To this end, extensive whole exome sequencing on peripheral blood (PB) cells of more than 20 thousand persons who were unselected for hematologic phenotypes were examined for 160 genes that are recurrently mutated in leukemia. Two most mutated genes found were epigenetic regulators: Ten eleven translocation methylcytosine dioxygenase 2 (TET2) and DNA cytosine-methyltransferase 3A (DNMT3A). Notably, both these genes are mutated at very high frequency in patients with MPNs and AML. Importantly, epidemiological findings demonstrate that persons with DM are more likely to have these mutations than those without DM. However, there is a significant gap in knowledge regarding our understanding of DMs causative role in MPN and leukemogenesis. Studies using murine models of loss of Tet2 function (Tet2-/-) show that Tet2-deficient hematopoietic stem cells (HSCs) have abnormal global 5-hydroxymethylcytosine (5-hmC) levels and local 5- hmC levels in genes responsible for self-renewal of HSCs. In addition, Tet2-/- HSCs show a competitive advantage (i.e. clonal hematopoiesis) over normal HSCs but do not progress to AML development. Moreover, mice with haplo-insufficiency of Tet2 (Tet2+/-) manifest milder form of these phenotypes only when aged, indicating that Tet2 functions as a putative tumor suppressor. We discovered that Tet2-deficient mice manifest a sustained response to acute inflammation and aged naïve Tet2-/- mice show elevated expression of a series of genes encoding the innate immune/pro-inflammatory pathway components including S100A8/9, TLR4, NFκB1 and IL-6. As patients with DM develop chronic inflammation and have increased expression of S100A8/A9, the central hypothesis of this proposal is that diabetic individuals that carry a single genetic lesion in the form of TET2 in their HSCs (in absence of any hematologic malignancies), will be more susceptible to developing severe MPN and/or myeloid leukemia, in part to an overactive pro-inflammatory cytokine signaling cascade or a forward feeding positive signaling loop and in part to hyperglycemia (HG) induced further global reduction in 5-hmC levels in pre-LSCs bearing loss of Tet2, thus mimicking pre-LSCs lacking all forms of TET. Indeed, by introducing Tet2 mutation into a murine model of diabetes (Ins2Akita/+), our preliminary data demonstrate that the diabetic mice haploinsufficient for Tet2 (Ins2Akita/+;Tet2+/-) progressively develop lethal AML/severe MPN. Importantly, treatment of Tet2-/- mice exposed to an acute inflammatory challenge with an anti-inflammatory molecule, APX3330, reverses this phenotype. Based on these preliminary results, we hypothesize that progressive DM acts as a significant risk factor for transforming pre-LSCs and/or clonal hematopoiesis into heme malignancies in an age-dependent manner.