急性白血病中自噬分子机制的研究现状

自噬在维持细胞能量平衡、适应细胞应激、去除老化损伤细胞器、调节机体免疫功能等机制中发挥重要作用。自噬参与正常造血干细胞(HSC)的增殖、分化, 在恶性造血中也具有重要作用, 同时与急性白血病(AL)的发生、发展相关。笔者从基因及蛋白质合成层面, 对正常造血、急性髓细胞白血病(AML)和急性淋巴细胞白血病(ALL)中自噬的研究现状进行阐述, 旨在为AL患者的靶向治疗提供新思路。     

髓系/NK细胞急性白血病6例分析

髓系／NK细胞急性白血病起源于髓系和NK共同的前体细胞,发病率低,约占急性髓系白血病（AML）5％左右。骨髓形态与急性早幼粒细胞白血病（APL）相似,故易误诊为CD56＋APL,特别是在尚未开展细胞遗传学、分子生物学的医院。为更好的认识及处理该病,现将2003／2007年收治的6例髓系／NK细胞急性白血病患者资料进行总结分析。     

急性髓细胞白血病淋巴系分化抗原的表达

目的探讨急性髓细胞白血病(AML)淋巴系分化抗原表达的情况和意义。方法分析120例AML免疫组化结果,观察其临床表现和治疗经过。结果伴淋巴系分化抗原表达的AML(LY+AML)占AML总数的30.0%,其完全缓解率较不伴淋巴系分化抗原表达的AML(LY-AML)低,CD56阳性的AML易发生髓外浸润。结论急性髓细胞白血病可表达个别淋巴系分化抗原,细胞免疫组化有助于急性白血病的正确诊断,对判断预后有一定的帮助。     

髓系肉瘤11例临床分析

髓系肉瘤是由髓系前体细胞在骨髓外部位形成的实体性肿瘤,大多由急性髓系白血病(AML)原始细胞髓外浸润所形成,也可发生在AML发病之前,作为AML的先兆表现,但有少部分病例可始终不进展为急性白血病.     

CD123靶向抑制剂治疗急性髓细胞白血病的研究新进展

急性髓细胞白血病(AML)是常见的成年人白血病之一。虽然AML的标准治疗方案可以使大多数初诊患者获得完全缓解(CR),但是其复发率高,并且复发后易对原化疗药物产生耐药。目前,AML患者的5年总体生存(OS)率仅约为25%,亟需寻找更为有效的治疗方法。CD123在白血病干细胞(LSC)及多种白血病细胞表面高表达,与AML...     

微小RNA与急性白血病

急性白血病包括急性髓系白血病(AML)和急性淋巴细胞白血病(ALL),起源于髓系及淋系分化或具有多系分化潜能的干细胞[1-2].成人以AML多见,儿童则以ALL多见.     

青蒿素及其衍生物抗急性髓系白血病作用的研究进展

青蒿素及其衍生物是一类具有多种生物活性的天然药物,目前已发现其不仅具有显著的抗疟疾作用,还具有强大的抗急性髓系白血病（AML）作用。青蒿素及其衍生物通过促进活性氧（ROS）的生成、诱导细胞自噬、下调抗凋亡蛋白髓系白血病1(MCL-1)和B淋巴细胞瘤-2基因（BCL-2）、激活同源性磷酸酶-张力蛋白（PTEN）/蛋白激酶B(AKT)途径等多种方式发挥抗AML作用。AML是一种血液系统恶性肿瘤,具有高缓解率、易复发、预后差的特点。目前AML临床一线治疗方案已经数十年没有改变,急需找到一种新的治疗方案改善预后。本文就近些年青蒿素及其衍生物抗AML作用的研究进展做出综述,以期能为AML新的治疗方案提供思路和方向。     

急性白血病流式细胞术免疫分型的特点及临床意义

目的探讨急性白血病流式细胞术免疫分型的特点及临床意义。方法 100例急性白血病,采用流式细胞术进行急性白血病免疫表型检测。结果①用特异性抗体将急性淋巴系白血病分为T细胞系列急性淋巴细胞白血病(T-ALL)和B细胞系急性淋巴细胞白血病(B-ALL)。②用特异性抗体使急性髓细胞白血病(AML)的分型更明确。③发现急性淋巴细胞白血病(ALL)中伴髓系抗原表达(My-ALL)、AML中伴淋系抗原表达(Ly AML)和混合型白血病。结论免疫学分型能反映白血病细胞的特征,提高了诊断的准确性。     

老年急性髓系白血病细胞遗传学的预后意义

老年急性髓系白血病(acute myeloid leukemia,AML)约占成人AML的半数以上,其治疗缓解率低、生存时间短,预后非常差。近年来,人们逐渐认识到细胞遗传学在AML中的重要意义,根据细胞遗传学可以对白血病进行诊断分型、预后分层和治疗指导,但目前关于细胞遗传学对老年AML的预后影响的研究相对较少,本文就细胞遗传学在老年AML中的预后意义做一综述。     

AML1-ETO融合蛋白的研究进展

急性髓系白血病中AML1-ETO融合蛋白被认为是一种预后良好的细胞和分子遗传学异常,但若伴有其他分子学异常,如KIT、FLT3、AML1-ETO9a剪接变体等更易致白血病生成,且影响预后.AML1-ETO能抑制GATA-1乙酰化,从而抑制红系分化、AML1-ETO对其靶基因的影响以及冬凌草、格列卫靶向治疗已成为目前研究的热点.     

嵌合抗原受体修饰T细胞治疗急性髓细胞白血病的研究进展

急性髓细胞白血病(AML)是一种常见的血液系统恶性肿瘤,临床治疗以传统化疗方案为主,该病复发率高,且预后差.近年,应用嵌合抗原受体修饰T细胞(CAR-T)治疗血液系统恶性肿瘤的研究,尤其是采用CD19 CAR-T治疗B细胞恶性肿瘤,取得了快速发展.多项研究结果表明,CAR-T在AML治疗中,也展现出良好的发展前景.笔者拟就嵌合抗原受体(CAR)的结构、CAR-T治疗AML的研究进展,以及CAR-T免疫疗法的局限性进行综述.     

The intersection of genetic and chemical genomic screens identifies GSK-3α as a target in human acute myeloid leukemia

Acute myeloid leukemia (AML) is the most common form of acute leukemia in adults. Long-term survival of patients with AML has changed little over the past decade, necessitating the identification and validation of new AML targets. Integration of genomic approaches with small-molecule and genetically based high-throughput screening holds the promise of improved discovery of candidate targets for cancer therapy. Here, we identified a role for glycogen synthase kinase 3α (GSK-3α) in AML by performing 2 independent small-molecule library screens and an shRNA screen for perturbations that induced a differentiation expression signature in AML cells. GSK-3 is a serine-threonine kinase involved in diverse cellular processes, including differentiation, signal transduction, cell cycle regulation, and proliferation. We demonstrated that specific loss of GSK-3α induced differentiation in AML by multiple measurements, including induction of gene expression signatures, morphological changes, and cell surface markers consistent with myeloid maturation. GSK-3α-specific suppression also led to impaired growth and proliferation in vitro, induction of apoptosis, loss of colony formation in methylcellulose, and anti-AML activity in vivo. Although the role of GSK-3β has been well studied in cancer development, these studies support a role for GSK-3α in AML.     

141例儿童急性髓系白血病的疗效及预后相关因素分析

目的评价初治儿童急性髓系白血病(AML)的疗效及探讨除急性早幼粒细胞白血病(APL)外的 AML 的预后相关因素。方法 141例18岁以下 AML 患者分成 APL 组(A 组,51例)和除APL 外的 AML 组(B 组,90例)进行回顾性研究分析。采用 Kaplan-Meier 曲线评估患者的无事件生存(EFS)率、无病生存(DFS)率和总生存(OS)率,Cox 回归模型评估预后因素。结果 B 组1个疗程完全缓解(CR)率为54.4%(49例),总缓解率为76.7%。5年累积 EFS 率、DFS 率和 OS 率分别为(28.4±9.0)%、(28.39±8.96)%和(35.5±6.3)%;A 组5年累积 EFS 率、DFS 率和 OS 率分别为(81.5±5.7)%、(94.3±4.0)%和(81.4±5.7)%:全部141例 AML 患儿5年累积 DFS 率和5年累积OS 率分别为(56.9±6.3)%和(53.3±4.8)%。B 组病例经多因素分析表明,初诊时骨髓白血病细胞比例较高和≥2个疗程达 CR 以及巩固治疗6个疗程以下是影响患者预后的危险因素(P 值均<0.05)。结论儿童 APL 预后良好。其他儿童 AML 中,初诊时骨髓原始细胞比例低和1个疗程达CR 以及巩固治疗6个疗程以上者预后较优;儿童 M_(2h)/t(8;21)与除 APL 以外的其他亚型相比没有显示预后良好的趋势;降低复发是改善儿童 AML 预后的关键。     

微小RNA在急性髓细胞白血病中的研究进展

微小RNA(miRNA)是一类长度约为22个核苷酸残基的非编码RNA,在细胞分化、增殖、凋亡等方面都有重要作用.近年来,miRNA已成为相关研究的热点,并且其与多种癌症的关系已经得到证实.研究结果表明,miRNA的异常表达与急性髓细胞性白血病(AML)密切相关.笔者就miRNA在AML中的最新研究进展进行综述.     

急性髓系白血病中MN1基因的研究进展

MN1基因编码转录共激活因子,在某些急性髓系白血病（AML）中高表达。MN1在正常核型AML患者中的高表达与预后差和生存时间短相关;在全部inv（16）AML中高表达,其高表达在非M3的AML中被认为与对维甲酸的耐药有关。本文就MN1基因的结构和作用机制、MN1-TEL与急性髓系白血病,MN1与正常核型AML,MN1与inv（16）AML,MN1与维甲酸耐药等作一综述。     

Transcription factor RUNX1 promotes survival of acute myeloid leukemia cells

RUNX1 is generally considered a tumor suppressor in myeloid neoplasms. Inactivating RUNX1 mutations have frequently been found in patients with myelodysplastic syndrome (MDS) and cytogenetically normal acute myeloid leukemia (AML). However, no somatic RUNX1 alteration was found in AMLs with leukemogenic fusion proteins, such as core-binding factor (CBF) leukemia and MLL fusion leukemia, raising the possibility that RUNX1 could actually promote the growth of these leukemia cells. Using normal human cord blood cells and those expressing leukemogenic fusion proteins, we discovered a dual role of RUNX1 in myeloid leukemogenesis. RUNX1 overexpression inhibited the growth of normal cord blood cells by inducing myeloid differentiation, whereas a certain level of RUNX1 activity was required for the growth of AML1-ETO and MLL-AF9 cells. Using a mouse genetic model, we also showed that the combined loss of Runx1/Cbfb inhibited leukemia development induced by MLL-AF9. RUNX2 could compensate for the loss of RUNX1. The survival effect of RUNX1 was mediated by BCL2 in MLL fusion leukemia. Our study unveiled an unexpected prosurvival role for RUNX1 in myeloid leukemogenesis. Inhibiting RUNX1 activity rather than enhancing it could be a promising therapeutic strategy for AMLs with leukemogenic fusion proteins.     

Histamine dihydrochloride and low-dose interleukin-2 as post-consolidation immunotherapy in acute myeloid leukemia

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. Although most patients achieve complete remission (CR) after chemotherapy, the majority suffer from subsequent leukemic relapse, which is associated with poor long-term survival. Thus, new therapies to maintain CR are highly warranted. After the completion of chemotherapy, AML patients have a minimal burden of leukemic cells, which are reportedly susceptible to cytotoxic lymphocytes such as NK cells and T cells. A therapy that boosts the function of these effector cells therefore has the potential to eradicate the malignant clone in AML and prevent relapse, Here, we briefly review the literature on the role of the immune system in AML and introduce the rationale for the use of histamine dihydrochloride (HDC) in conjuction with low-dose IL-2 as relapse-preventive immunotherapy for this disease.     

Targeting of mTOR is associated with decreased growth and decreased VEGF expression in acute myeloid leukaemia cells

Background  The mammalian target of rapamycin (mTOR) has recently been implicated in leukaemic cell growth, tumour-associated angiogenesis and expression of vascular endothelial growth factor (VEGF). We examined whether mTOR plays a role as regulator of growth and VEGF-expression in acute myeloid leukaemia (AML). Three mTOR-targeting drugs, rapamycin, everolimus (RAD001) and CCI-779, were applied. The effects of these drugs on growth, survival, apoptosis and VEGF expression in primary AML cells and various AML cell lines were examined.
Materials and methods  Growth of AML cells and AML-derived cell lines was assessed by ³H-thymidine incorporation, survival was examined by light- and electron microscopy, by Tunel assay and by AnnexinV-staining, and the expression of VEGF by Northern blotting, RT-PCR and ELISA.
Results  Rapamycin was found to counteract growth in the AML cell lines U937 and KG1a as well as in primary AML cells in 14/18 patients examined. The effects of rapamycin and its derivatives were dose-dependent (IC₅₀: 10 pM–100 nM). It was also found that exposure to mTOR-targeting drugs resulted in apoptosis and in decreased expression of VEGF in leukaemic cells.
Conclusions  mTOR-targeting drugs exert antileukaemic effects on AML cells in vitro through multiple actions, including direct inhibition of proliferation, induction of apoptosis and suppression of VEGF. Based on this study and other studies, mTOR can be regarded as a potential drug target in AML.     

mTORC1 is essential for leukemia propagation but not stem cell self-renewal

Although dysregulation of mTOR complex 1 (mTORC1) promotes leukemogenesis, how mTORC1 affects established leukemia is unclear. We investigated the role of mTORC1 in mouse hematopoiesis using a mouse model of conditional deletion of Raptor, an essential component of mTORC1. Raptor deficiency impaired granulocyte and B cell development but did not alter survival or proliferation of hematopoietic progenitor cells. In a mouse model of acute myeloid leukemia (AML), Raptor deficiency significantly suppressed leukemia progression by causing apoptosis of differentiated, but not undifferentiated, leukemia cells. mTORC1 did not control cell cycle or cell growth in undifferentiated AML cells in vivo. Transplantation of Raptor-deficient undifferentiated AML cells in a limiting dilution revealed that mTORC1 is essential for leukemia initiation. Strikingly, a subset of AML cells with undifferentiated phenotypes survived long-term in the absence of mTORC1 activity. We further demonstrated that the reactivation of mTORC1 in those cells restored their leukemia-initiating capacity. Thus, AML cells lacking mTORC1 activity can self-renew as AML stem cells. Our findings provide mechanistic insight into how residual tumor cells circumvent anticancer therapies and drive tumor recurrence.     

组蛋白去乙酰化酶抑制剂与AML1-ETO阳性急性髓细胞白血病的研究进展

第8号与第21号染色体发生易位,t(8;21) (q22;q22)可使位于第21号染色体的急性髓细胞白血病(AML)1基因与位于第8号染色体的ETO基因融合,形成AML1-ETO融合基因.AML1-ETO能够募集mSin3/N-CoR/ SMART/HDAC共抑制复合物至AML1靶基因的启动子区,使白细胞介素(IL)-3、粒-巨噬细胞集落刺激因子(GM-CSF)等与造血干细胞分化有关的基因及抑癌基因失活,进而导致白血病发生.组蛋白去乙酰化酶抑制剂(HDACI)通过组蛋白乙酰化、染色质重塑,可使AML1-ETO目的基因恢复表达、降解AML1-ETO融合蛋白等发挥抗白血病作用,同时选择性作用于AML1-ETO阳性细胞.目前,HDACI与DNA去甲基化药物、糖皮质激素类药物、热休克蛋白(HSP)-90抑制剂及三氧化二砷(ATO)联合应用治疗AML1-ETO阳性AML还在探索阶段.笔者拟就HDACI对AML1-ETO融合蛋白及其目的基因的作用,以及HDACI联合用药在AML1-ETO阳性AML治疗方面的作用机制进行综述.