U2AF1 Mutations in Chinese Patients with Acute Myeloid Leukemia and Myelodysplastic Syndrome

Somatic mutations of U2AF1 gene have recently been identified in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). In this study, we analyzed the frequency and clinical impact of U2AF1 mutations in a cohort of 452 Chinese patients with myeloid neoplasms. Mutations in U2AF1 were found in 2.5% (7/275) of AML and 6.3% (6/96) of MDS patients, but in none of 81 CML. All mutations were heterozygous missense mutations affecting codon S34 or Q157. There was no significant association of U2AF1 mutation with blood parameters, FAB subtypes, karyotypes and other gene mutations in AML. The overall survival (OS) of AML patients with U2AF1 mutation (median 3 months) was shorter than those without mutation (median 7 months) (P = 0.035). No difference in the OS was observed between MDS patients with and without U2AF1 mutations. Our data show that U2AF1 mutation is a recurrent event at a low frequency in AML and MDS.     

急性白血病基因突变与多步骤发病机制和临床相关性

急性髓细胞白血病(AML)是一组在发病机制和临床行为方面差异较大的疾病.在急性早幼粒细胞白血病中(APL),PML-RARα是APL的关键驱动(driver)突变,具有显性负的调控作用,影响髓系分化、凋亡和DNA复制和修复,其特殊结构使其成为全反式维甲酸和三氧化二砷的靶标.随着第二代测序技术的发展,在AML中发现了一些新的基因突变,其中DNA甲基转移酶3A(DNMT3A)突变是与表观遗传学相关的、与AML较差预后有关的基因事件.在1185例AML的基因分析中,研究发现与表观遗传学相关的第Ⅲ类突变与老年、高WBC及较差的临床预后有关.AML的发病是多步骤的,涉及不同通路上不同分子事件的相互作用,目前认为影响转录因子和信号传导通路的分子事件相互作用是AML完全发病的重要模式之一.     

Prognostic Significance of KIT Mutations in Core-Binding Factor Acute Myeloid Leukemia: A Systematic Review and Meta-Analysis

The prognostic significance of KIT mutations in core-binding factor acute myeloid leukemia (CBF-AML), including inv(16) and t(8;21) AML, is uncertain. We performed a systematic review and meta-analysis of the effect of KIT mutations on the complete remission (CR) and relapse rates and overall survival (OS) of CBF-AML. PubMed, Embase, Web of Science, and the Cochrane Library were searched and relevant studies were included. Negative effect was indicated on relapse risk of CBF-AML (RR [relative risk], 1.43; 95%CI [confidence interval], 1.20–1.70) and t(8;21) AML (RR, 1.70; 95% CI, 1.31–2.21), not on OS of CBF-AML (RR, 1.09; 95% CI, 0.97–1.23), CR (OR [odds ratio], 0.95; 95% CI, 0.52–1.74), relapse risk (RR, 1.12; 95% CI, 0.90–1.41) or OS (RR, 1.03; 95% CI, 0.90–1.18) of inv(16) AML. Subgroup analysis of t(8,21) AML showed negative effect of KIT mutations on CR (OR, 2.03; 95%CI: 1.02–4.05), relapse risk (RR, 1.89; 95%CI: 1.51–2.37) and OS (RR, 2.26; 95%CI: 1.35–3,78) of non-Caucasians, not on CR (OR, 0.61; 95%CI: 0.19–1.95) or OS (RR, 1.12; 95%CI: 0.90–1.40) of Caucasians. This study indicates KIT mutations in CBF-AML to be included in the initial routine diagnostic workup and stratification system of t(8,21) AML. Prospective large-scale clinical trials are warranted to evaluate these findings.     

Driver Mutations in Acute Myeloid Leukemia with Inversion of Chromosome 16

Molecular Biology - Certain subtypes of acute myeloid leukemia occur as a result of the cooperation of several events these are, the formation of fusion genes as a result of chromosomal...     

Leukemic Stem Cell Frequency: A Strong Biomarker for Clinical Outcome in Acute Myeloid Leukemia

Introduction

Treatment failure in acute myeloid leukemia is probably caused by the presence of leukemia initiating cells, also referred to as leukemic stem cells, at diagnosis and their persistence after therapy. Specific identification of leukemia stem cells and their discrimination from normal hematopoietic stem cells would greatly contribute to risk stratification and could predict possible relapses.

Results

For identification of leukemic stem cells, we developed flow cytometric methods using leukemic stem cell associated markers and newly-defined (light scatter) aberrancies. The nature of the putative leukemic stem cells and normal hematopoietic stem cells, present in the same patient''s bone marrow, was demonstrated in eight patients by the presence or absence of molecular aberrancies and/or leukemic engraftment in NOD-SCID IL-2Rγ-/- mice. At diagnosis (n = 88), the frequency of the thus defined neoplastic part of CD34+CD38- putative stem cell compartment had a strong prognostic impact, while the neoplastic parts of the CD34+CD38+ and CD34- putative stem cell compartments had no prognostic impact at all. After different courses of therapy, higher percentages of neoplastic CD34+CD38- cells in complete remission strongly correlated with shorter patient survival (n = 91). Moreover, combining neoplastic CD34+CD38- frequencies with frequencies of minimal residual disease cells (n = 91), which reflect the total neoplastic burden, revealed four patient groups with different survival.

Conclusion and Perspective

Discrimination between putative leukemia stem cells and normal hematopoietic stem cells in this large-scale study allowed to demonstrate the clinical importance of putative CD34+CD38- leukemia stem cells in AML. Moreover, it offers new opportunities for the development of therapies directed against leukemia stem cells, that would spare normal hematopoietic stem cells, and, moreover, enables in vivo and ex vivo screening for potential efficacy and toxicity of new therapies.     

成人急性髓性白血病SOCS-1基因及其甲基化的研究

目的：通过检测成人急性髓性白血病中SOCS．1基因表达水平及其甲基化水平,研究其在白血病发病中的作用。方法：运用甲基化特异性PCR（Methylation specificPCR,MSP）方法,对24例急性髓性白血病患者和4株白血病细胞株（Jurkat、Raji、U937、NALM17）,进行SOCS-1基因甲基化水平的研究;同时运用Real—timePCR法定量分析SOCS—1基因表达水平。以10例健康人为正常对照组。结果：24例成人急性髓性白血病患者中,15例有SOCS-1基因甲基化（62．5％）,而正常对照组无SOCS-1基因甲基化（0％）,二者有显著差异（P〈0．05）;SOCS-1基因甲基化组与无SOCS-1基因甲基化组相比较,其SOCS—1基因相对表达量明显减少（P口0．05）;与患者临床病理特征相结合比较,发现SOCS-1基因的甲基化与患者年龄、性别和病程阶段无相关。4株白血病细胞株中,Jurkat和U937表现有SOCS—1甲基化（50％）,Raji和NALM17无SOCS—1甲基化,前者SOCS-1基因表达量较后者也明显降低（P〈0．05）。结论：SOCS—1基因在成人急性髓性白血病中甲基化水平明显增高,且SOCS-1基因甲基化后表达水平受到抑制,提示SOCS-1基因及其甲基化在急性髓性白血病的发生发展中可能具有一定作用。     

成人急性髓性白血病SOCS-1 基因及其甲基化的研究

目的:通过检测成人急性髓性白血病中SOCS-1基因表达水平及其甲基化水平,研究其在白血病发病中的作用。方法:运用甲基化特异性PCR(Methylation specific PCR,MSP)方法,对24例急性髓性白血病患者和4株白血病细胞株(Jurkat、Raji、U 937、NALM 17),进行SOCS-1基因甲基化水平的研究;同时运用Real-time PCR法定量分析SOCS-1基因表达水平。以10例健康人为正常对照组。结果:24例成人急性髓性白血病患者中,15例有SOCS-1基因甲基化(62.5%),而正常对照组无SOCS-1基因甲基化(0%),二者有显著差异(P<0.05);SOCS-1基因甲基化组与无SOCS-1基因甲基化组相比较,其SOCS-1基因相对表达量明显减少(P﹤0.05);与患者临床病理特征相结合比较,发现SOCS-1基因的甲基化与患者年龄、性别和病程阶段无相关。4株白血病细胞株中,Jurkat和U 937表现有SOCS-1甲基化(50%),Raji和NALM 17无SOCS-1甲基化,前者SOCS-1基因表达量较后者也明显降低(P<0.05)。结论:SOCS-1基因在成人急性髓性白血病中甲基化水平明显增高,且SOCS-1基因甲基化后表达水平受到抑制,提示SOCS-1基因及其甲基化在急性髓性白血病的发生发展中可能具有一定作用。     

Mutations in DNA Methyltransferase (DNMT3A) Observed in Acute Myeloid Leukemia Patients Disrupt Processive Methylation

DNA methylation is a key regulator of gene expression and changes in DNA methylation occur early in tumorigenesis. Mutations in the de novo DNA methyltransferase gene, DNMT3A, frequently occur in adult acute myeloid leukemia patients with poor prognoses. Most of the mutations occur within the dimer or tetramer interface, including Arg-882. We have identified that the most prevalent mutation, R882H, and three additional mutants along the tetramer interface disrupt tetramerization. The processive methylation of multiple CpG sites is disrupted when tetramerization is eliminated. Our results provide a possible mechanism that accounts for how DNMT3A mutations may contribute to oncogenesis and its progression.     

减低剂量去甲氧柔红霉素联合阿糖胞苷方案治疗老年急性髓细胞白血病的临床研究

目的:探讨减低剂量去甲柔红霉素联合阿糖胞苷(IA)方案治疗老年急性髓细胞白血病(AML)患者的疗效。方法:收集我院老年急性髓细胞白血病患者62例,随机分成减低剂量IA治疗组和标准剂量IA对照组,两组均实施3+7治疗方案。治疗2个疗程,比较两组不良反应和临床疗效。结果:减低剂量IA治疗组总CR率和CCR率分别为75.0%和66.7%;标准剂量IA对照组总CR率和CCR率分别为50.0%和33.3%。减低剂量IA治疗组总生存期25+月较标准剂量IA对照组生存期23+月延长。结论:对于老年急性髓细胞白血病患者,减低剂量IA治疗方案的CR率和CCR率与标准剂量IA治疗方案相比具有明显疗效优势。     

基于生物信息学分析SCHIP1在急性髓系白血病中的表达及其临床意义

通过数据挖掘和生物信息学分析手段,探讨施旺膜蛋白相互作用因子1(schwannomin interacting protein 1,SCHIP1)基因在急性髓系白血病患者中的表达情况及其临床意义。首先,对Oncomine数据库中收录的所有急性髓系白血病(acute myloid leukaemia,AML)数据集进行荟萃分析,筛选出目标基因SCHIP1并进一步分析其在AML病人中的表达变化。随后,从GEO数据库中下载含生存信息的AML数据集源文件,分析SCHIP1表达对疾病的预后作用。另外,利用TCGA数据库对SCHIP1的表达情况进行亚组分析及与FLT3基因突变、PML/RARα融合基因和RAS活化等高危因素进行相关性分析。最后,利用GEPIA2工具验证SCHIP1的表达情况、预后意义及与FLT3、PML基因表达的相关性。结果发现Oncomine数据库中收录了44个AML数据集,总计共3534个样本数据。其中5个数据集共1188个样本包含“Cancer vs.Normal”的mRNA表达数据,对其进行荟萃分析显示SCHIP1位于显著高表达分子的第17位。生存分析显示,SCHIP1表达量与AML患者总体生存率呈负相关。亚组分析显示SCHIP1在M0/M1/M2中较M3/M6中表达更高,但与年龄、性别和种族无关。另外,相关性研究分析显示SCHIP1与FLT3基因突变弱相关,但与PML/RARα融合基因和RAS活化等高危因素无显著相关性。这些结果表明SCHIP1在急性髓系白血病中高表达,且其高表达与患者的生存预后呈显著负相关。因此,SCHIP1可作为疾病的预后生物标志物,并有望成为AML的精准治疗靶点。     

Breakthrough Invasive Fungal Infections in Patients with Acute Myeloid Leukemia

Mycopathologia - We sought to determine the occurrence, risk factors, effect of antifungal prophylaxis, and outcomes of invasive fungal infections (IFIs) in patients with acute myeloid leukemia...     

凋亡抑制蛋白XIAP 在急性髓系白血病和淋巴瘤骨髓组织中 的表达及意义

目的:研究凋亡抑制蛋白(XIAP)在白血病及淋巴瘤骨髓活检组织中的表达及意义。方法:采用免疫组织化学法检测10例急性髓系白血病,13例淋巴瘤,9例非恶性血液病患者骨髓活检组织中XIAP的表达水平。结果:XIAP蛋白在急性髓系白血病、淋巴瘤骨髓活检组织中的阳性表达积分均高于非恶性血液病,差异均有统计学意义(P<0.05)。结论:XIAP的表达水平与白血病及淋巴瘤的发生发展有一定关联,可能与其抑制肿瘤细胞的凋亡有关。     

Selenium and Glutathione Peroxidase Status in Adult Egyptian Patients with Acute Myeloid Leukemia

This study was undertaken to evaluate selenium (Se) and glutathione peroxidase (GPX) status in patients with newly diagnosed acute myeloid leukemia (AML) before and after induction therapy. Twenty-five patients with newly diagnosed AML and 15 healthy age- and sex-matched control subjects were included in this study. Serum Se level by the graphite furnace atomic absorption spectrometric technique and GPX activity by an adaptation of Beutler method was performed for the patients before and after receiving the induction therapy. Serum Se level was significantly lower in patients with AML versus control subjects (63.1?±?8.8 versus 77?±?8.8 µg/L before therapy with a P value <0.01 and 69?±?6.8 versus 77?±?8.8 µg/L after therapy with a P value <0.01).GPX activity was significantly lower in patients with AML versus control subjects (1.6?±?0.4 versus 3.4?±?0.7 µ/g protein pretreatment with a P value <0.01and 1.9?±?0.6 versus 3.4?±?0.7 µ/g protein post induction treatment with P value <0.01).Se level and GPX activity significantly increased in AML patients after treatment. Patients who accomplished complete remission after induction harbored significantly higher Se levels than resistant patients before and after treatment. There was no significant correlation between serum Se level and GPX activity. Decreased Se level and reduced GPX activity in AML patients support the association of carcinogenesis and subnormal Se states.     

Clinical and Prognostic Implications of Roundabout 4 (Robo4) in Adult Patients with Acute Myeloid Leukemia

Background

Robo4 is involved in hematopoietic stem/progenitor cell homeostasis and essential for tumor angiogenesis. Expression of Robo4 was recently found in solid tumors and leukemia stem cells. However, the clinical implications of Robo4 expression in patients with acute myeloid leukemia (AML) remain unclear.

Methods

We investigated the clinical and prognostic relevance of mRNA expression of Robo4 in bone marrow (BM) mononuclear cells from 218 adult patients with de novo AML. We also performed immunohistochemical staining to assess the Robo4 protein expression in the BM biopsy specimens from 30 selected AML patients in the cohort.

Results

Higher Robo4 expression was closely associated with lower white blood cell counts, expression of HLA-DR, CD13, CD34 and CD56 on leukemia cells, t(8;21) and ASXL1 mutation, but negatively correlated with t(15;17) and CEBPA mutation. Compared to patients with lower Robo4 expression, those with higher expression had significantly shorter disease-free survival (DFS) and overall survival (OS). This result was confirmed in an independent validation cohort. Furthermore, multivariate analyses showed that higher Robo4 expression was an independent poor prognostic factor for DFS and OS in total cohort and patients with intermediate-risk cytogenetics, irrespective of age, WBC count, karyotype, and mutation status of NPM1/FLT3-ITD, and CEBPA.

Conclusions

BM Robo4 expression can serve as a new biomarker to predict clinical outcomes in AML patients and Robo4 may serve as a potential therapeutic target in patients with higher Robo4 expression.     

敲低EDAG加强NPM1蛋白的降解并增加AML病人对药物的敏感性

Nucleophosmin (NPM1或B23.1)是在细胞核内广泛表达的蛋白磷酸酶,在多方面发挥重要作用,如核糖体合成、中心体复制、细胞周期控制、细胞增殖及转化．NPM1是急性粒细胞白血病(acute myeloid leukemia, AML)中最常见的突变基因之一．红系分化相关基因(erythroid differentiation associated gene, EDAG)是在造血组织特异表达的基因,在造血细胞的增殖与谱系分化调节方面发挥重要作用．在AML病人中,高表达的EDAG与较差的预后相关联．我们前期研究结果显示,EDAG与NPM1相结合并调节NPM1稳定性,但在AML病人体内EDAG与NPM1的关系,及EDAG与NPM突变体(NPMc⁺)的关系尚未明确．在本文中发现：在AML病人骨髓CD34⁺细胞中,敲低EDAG表达导致NPM1蛋白稳定性降低并提高了对柔红霉素的敏感性;EDAG虽不与突变体NPMc⁺相互作用,但在蛋白出核抑制剂(leptomycin B, LMB)作用下,过表达EDAG提高NPMc⁺蛋白稳定性;表达突变NPMc⁺的AML病人与表达NPM1蛋白的病人相比,其骨髓CD34⁺细胞对柔红霉素具有更高的敏感性,且敲低EDAG能微弱提高其敏感性．上述结果表明,EDAG在AML病人药物治疗中发挥的可能作用以及NPMc⁺ “逃脱”,使EDAG无法保护其稳定性,这提示了在AML病人药物治疗过程中EDAG的潜在作用,同时也提示,携带NPMc⁺蛋白的AML患者具有较好预后,可能与NPMc⁺蛋白“逃脱”出EDAG对其稳定性的保护有关．     

High Risk of Hepatitis B Reactivation among Patients with Acute Myeloid Leukemia

BackgroundHepatitis B virus (HBV) infections are common and associated with significant morbidity and mortality in cancer patients. However, the incidence and risk factors of HBV reactivation in patients with acute myeloid leukemia (AML) are rarely investigated.MethodsAML patients followed-up at the National Taiwan University Hospital between 2006 and 2012 were analyzed. The clinical characteristics and laboratory data were retrospectively reviewed.ResultsFour hundred and ninety patients comprising 265 men and 225 women were studied. The median age was 52 years (range, 18 - 94). Chronic HBV carriage was documented at the time of leukemia diagnosis in 57 (11.6%) patients. Forty-six (80.7%) of the 57 HBV carriers received prophylaxis with anti-HBV agents. Sixteen HBV carriers (28.1%) developed hepatitis B reactivation during or after chemotherapy, including 7 patients who had discontinued antiviral therapy. The incidence of hepatitis B reactivation among AML patients with HBV carriage was 9.5 per 100 person-years. Prophylaxis with anti-HBV agents significantly decreased the risk of hepatitis B reactivation among HBV carriers (13% vs. 61%, p<0.001). Four (2.8%) of 142 patients with initial positive anti-HBsAb and anti-HBcAb experienced hepatitis B reactivation and lost their protective anti-HBsAb. Multivariate analysis revealed that diabetes mellitus (p=0.008, odds ratio (OR) = 2.841, 95% confident interval (CI): 0.985-8.193) and carriage of HBsAg (p<0.001, OR=36.878, 95% CI: 11.770-115.547) were independent risk factors for hepatitis B reactivation in AML patients.ConclusionsHepatitis B reactivation is not uncommon in the HBsAg positive AML patients. Prophylaxis with anti-HBV agent significantly decreased the risk of hepatitis B reactivation.