Numerous genetic abnormalities which can not be identified by cytogenetic detection (e.g., gene mutations, gene expression abnormalities) have been gradually found, which means that the further molecular classification of AML (acute myeloid leukemia) with distinctive prognosis have arrived. For example, mutations of the transcription factor (CCAAT enhancer binding factor alpha, C/EBPalpha) or nucleophosmin-1 (NPM1) may predict better prognosis, whereas partial tandem duplications of the MLL gene (MLL-PTD), internal tandem duplications of FLT3 (FLT3-ITD) or mutations of WT1 gene confer worse prognosis. This review focuses on the features and relationship of these genetic abnormalities, as well as their influence on the prognosis of AML.
Humans ; Leukemia, Myeloid, Acute ; diagnosis ; genetics ; Prognosis

Acute myeloid leukemia (AML) is a group of diseases with a conspicuous heterogeneity. Following the development of cytogenetics, multiple reproducible chromosome aberrations have been discovered in AML, many of which not only are diagnostic markers for specific AML subtypes but also significant prognostic factors for determining complete remission (CR), relapse risk, and overall survival (OS). However, with the foundation of available chromosome analysis, a large group of acute myeloid leukemia (AML) patients, 40% to 49% of adults and 25% of children had not been found abnormality of chromosome karyotype under microscope. These so-called cytogenetically normal acute myeloid leukemia (CN-AML) patients have usually been classified in an intermediate-risk prognostic category. Nevertheless, the outcome of the CN-AML patients are varied in clinical studies, likely because there exist diverse gene mutations in these patients according to recent researches. Those mutations at the molecular level, on basis of which AML could be further classified, are significantly associated with CN-AML patients and offer potential targets for specific therapeutic studies. The review focuses on research advances abroad in this field including gene mutations suggesting bad prognosis such as FMS-related tyrosine kinase 3 gene mutation, Baalc gene and ETS-related gene hyperexpression, Wilms' tumor gene mutation and other gene mutations as well as gene mutations suggesting good prognosis such as nucleophosmin gene mutation, mixed lineage leukemia-partial tandem duplication, CCAAT/enhancer-binding protein α gene mutation.
Cytogenetics ; Humans ; Karyotyping ; Leukemia, Myeloid, Acute ; diagnosis ; genetics ; Prognosis

Acute myeloid leukemia (AML) is a rare type of childhood acute leukemia, which has a worse prognosis than childhood acute lymphoblastic leukemia. Over the past decade, significant progress has been made in the treatment of childhood AML and the 5-year event-free survival rate may be as high as 70% in developed countries. This survival improvement is largely attributable to risk-stratified treatments, therapies tailored to individual patients based on the biological characteristics of the disease, and continuously improving supportive care. An accurate diagnosis is the prerequisite for risk stratification, prognostic evaluation and therapeutic decision making. How to reduce early mortality and thus improve overall survival, how to implement appropriate supportive treatment to reduce treatment-associated complications, and how to reduce treatment-related mortality are the key to the improvement of therapies for childhood acute myeloid leukemia.
Child ; Humans ; Leukemia, Myeloid, Acute ; diagnosis ; drug therapy ; genetics ; mortality ; Leukemia, Promyelocytic, Acute ; drug therapy ; genetics

UNLABELLEDThis study was aimed to explore the value of detecting the expression levels of MLL-AF9 (mixed lineage leukemia, MLL) fusion gene during the treatment of acute myeloid leukemia (AML) by real-time fluorescence quantitative PCR (RQ-PCR), and to evaluate its prognostic significance in monitoring minimal residual disease (MRD). The expression levels of 11 patients with MLL-AF9 fusion gene positive were detected precisely by RQ-PCR during the treatment in order to analyze the correlation of detection results with clinical manifestations. The results showed that the expression levels of MLL-AF9 fusion gene in patients at initial diagnosis were 1.3%-55.28%.

RESULTSobtained from 5 patients who received chemotherapy alone during the interval between first and second courses of chemotherapy indicated that 2 patients with <0.1% of MLL-AF9 fusion gene expression levels all achieved hematologic complete remission and survived, while the remaining 3 patients with ≥ 0.1% of MLL-AF9 fusion gene did not achieve hematologic complete remission and only 1 case survived. Moreover, results obtained from 6 transplant patients within a month before the transplantation suggested that 4 of them with < 0.1% of MLL-AF9 fusion gene expression levels survived without relapses, while the remaining 2 patients with ≥ 0.1% of MLL-AF9 fusion gene expression levels relapsed and died. Besides, MLL-AF9 fusion gene expression levels were ≥ 0.1% within one month before the morphological relapse of bone marrow in 2 recurrent patients. It is concluded that the detecting the expression level of MLL-AF9 fusion gene by RQ-PCR is an effective and accurate method to quantify and monitor the MRD level of MLL-AF9 gene positive AML patients and may be used for early detecting molecular relapse of AML.

Humans ; Leukemia, Myeloid, Acute ; diagnosis ; genetics ; Myeloid-Lymphoid Leukemia Protein ; genetics ; Neoplasm, Residual ; genetics ; Oncogene Proteins, Fusion ; genetics ; Prognosis ; Real-Time Polymerase Chain Reaction ; methods

OBJECTIVETo evaluate the effects of DNMT3A gene mutation on prognosis of patients with acute myeloid leukemia (AML) by a meta-analysis.

METHODSMethods of Cochrane systematic review was followed by 7 databases,including PubMed, Embase, Ovid, CNKI, CBM, WanFang Data and VIP, were searched for peer-reviewed articles related to DNMT3A gene mutations and prognosis of patients with AML.Then manual retrieval was applied into literature references. After the evaluation of quality and extract of clinical trialliterature data, Stata 11.0 was employed to perform meta-analysis.

RESULTSSeven randomized controlled trials involving 1493 cases were included in the meta-analysis. The prognosis of patients with DNMT3A mutations and without DNMT3A mutations was compared. There was no statistically significant difference in complete remission(CR) rate (OR=1.034, 95%CI: 0.596~1.796, P=0.905 between two groups, but the overall survival (OS（HR=1.990, 95%CI: 1.463~2.510, P=0.000 and disease free survival (DFS) (HR= 2.840, 95%CI: 1.063~4.613, P=0.002) of patients without DNMT3A mutations were longer than those with DNMT3A mutation.

CONCLUSIONDNMT3A gene mutation is an independent risk factor of poor prognosis of patients with acute myeloid leukemia.

DNA (Cytosine-5-)-Methyltransferases ; genetics ; Humans ; Leukemia, Myeloid, Acute ; diagnosis ; genetics ; Mutation ; Prognosis ; Risk Factors

The study was purposed to investigate the significance of id4 gene promoter methylation in monitoring AML patients with complete remission (CR). Methylation specific-PCR (MS-PCR) were used to detect the status of promoter methylation of id4 gene in bone marrow samples from AML patients with CR who had accepted induction with DA or IA and 4 to 5 consolidation chemotherapy with Ara-C. The results showed that in the all 32 patients, 15 were found to show id4 promoter methylation and 7 out of the 15 were found relapsed or tendency to relapse in the following-up period. While all the 17 patients with id4 unmethylation were still in their CR status in the same period. In conclusion, id4 promoter methylation might be a predictor for relapse of AML patients with CR in certain degree.
DNA Methylation ; Humans ; Inhibitor of Differentiation Proteins ; genetics ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; Neoplasm, Residual ; diagnosis ; genetics ; Promoter Regions, Genetic ; genetics

OBJECTIVETo optimize pre-coated multiple-probe fluorescence in situ hybridization (FISH) to improve its efficiency in cytogenetic diagnosis of acute leukemia.

METHODSThe original multiple-probe FISH techniques were optimized by adjusting the cell density and adding a process of protease digestion. Cytogenetic anomalies were detected in 141 patients with acute lymphocytic leukemia (ALL) or acute myeloid leukemia/ myelodysplastic syndromes (AML/MDS) using the modified technique, and 35 of the patients were also examined using the original technique. The successful detection rate and positive site detection rate were compared between the modified and original techniques.

RESULTSModification of the pre-coated multiple-probe FISH technique resulted in an significant increase of the successful detection rate (from 85.3% to 100%) and the positive site detection rate (from 5.1% to 8.6%) in ALL patients; in AML/MDS patients, the successful detection rate was significantly improved from 67.4% to 99.8% and the positive site detection rate from 3.5% to 6.0% (P<0.01).

CONCLUSIONThe modified pre-coated multiple-probe FISH technique can significantly increase the diagnostic efficiency of cytogenetic abnormalities in leukemic patients.

Chromosome Aberrations ; Humans ; In Situ Hybridization, Fluorescence ; methods ; Karyotyping ; Leukemia, Myeloid, Acute ; diagnosis ; genetics ; Myelodysplastic Syndromes ; diagnosis ; genetics

This study was aimed to investigate the relationship between expression of CD200 antigen and clinical characteristics in AML patients and to analyse the value of CD200 in evaluation of AML prognosis. The CD200 and immunophenotypes were detected by flow cytometry, the chromosome karyotypes were determined by R banding, the FISH was used to measure the AML1/ETO, PML/RARa and inv(16), and PCR technique was used to detect the fusion genes AML1/ETO and PML/RARα. The results showed that the positive rate of CD200 antigen expression in 54 patients was 57.4% (31/54), the CD200 antigen expression between sex and age of patients was no significant different (P > 0.05). There was significant difference of CD200 expression between CD34 and CD117 (P < 0.05), but the difference of CD200 expression in chromosome karyotypes was no significant difference(P > 0.05). Moreover, there was significant difference of CD200 expression in CD34 and CD117 of CBF positive AML patients (P < 0.05). It is concluded that the CD200 antigen expression in AML may associate with a poor prognosis of patients.
Antigens, CD ; immunology ; Chromosome Banding ; Humans ; Immunophenotyping ; Karyotyping ; Leukemia, Myeloid, Acute ; diagnosis ; genetics ; immunology ; Oncogene Proteins, Fusion ; Prognosis

Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Bone Marrow Transplantation ; Cytarabine ; administration & dosage ; Humans ; Leukemia, Myeloid, Acute ; diagnosis ; genetics ; therapy ; Prognosis

OBJECTIVETo explore the heterogeneous subclones in acute myeloid leukemia (AML) with t(8;21) by quantitative multicolor- fluorescence in situ hybridization (QM-FISH), and to figure out whether there is putative ancestral relationship among different subclones.

METHODSBacterial artificial chromosomes (BAC) clones that contain the targeted genes including AML1, ETO, WT1, p27 and c-kit were searched in the data base UCSC Genome Bioinformatics. Multicolor FISH probes were prepared by linking fluorescein labeled dUTP or dCTP to targeted genes by nick translation. Bone marrow mononuclear cells from t (8;21) AML patients are dropped on to the wet surface of glass slides after hypotonic treatment and fixation. After hybridization, the fluorescence signals were captured by Zeiss fluorescence microscope. The copy number of AML1, ETO, WT1, p27, c- kit and the AML1-ETO fusion gene in AML1-ETO positive cells was counted. The cells with same signals were defined as a subclone. Various subclones were recorded and their proportions were calculated, and their evolutionary relationship was deduced. The subclones in matched primary and relapsed samples were compared, the evolution of dominant clones were figured out and the genomic abnormality that is associated with relapse and drug resistance were speculated.

RESULTSIn this study, 36 primary AML with t(8;21) cases and 1 relapsed case paired with the primary case were detected. In these 36 primary cases, 4 cases (11.1%) acquired additional AML1-ETO fusion signal, 3(8.3%) had additional AML1 signal, 4(11.1%) had additional ETO signal, 20(55.6%) had additional WT1 signal, 15(41.7%) had additional p27 signal and 14(38.9%) had additional c-kit signal. In addition, 10(27.8%) displayed AML1 signal deletion, and such an aberration represents statistic significance in male patients. It seems that male patients usually accompany AML1 signal deletion. Of 36 cases, 28(77.8 %) harbored at least 2 subclones (ranged from 2 to 10). According to the genetic signature of subclones, we can assemble a putative ancestral tree, and the genetic architecture is linear or branching. In particular, the clonal architecture of the relapsed sample exhibited significant clonal evolution compared to its paired sample at diagnosis, including proportion changes in dominant clone, subclone disappearance and appearance of new dominant clones.

CONCLUSIONGenomic abnormality is very diverse in t(8;21) AML. Subclones have linear or complex branching evolutionary histories, and clonal architecture is dynamic.

Chromosomes, Human, Pair 21 ; Chromosomes, Human, Pair 8 ; Humans ; In Situ Hybridization, Fluorescence ; Leukemia, Myeloid, Acute ; diagnosis ; genetics ; Male ; Translocation, Genetic