Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023467 (acute myeloid leukemia)
 35,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acute myeloid leukaemia (AML) is a major haematopoietic malignancy characterized by the proliferation of a malignant clone of myeloid progenitor cells. A reciprocal translocation, t(8;21)(q22;q22), observed in the leukaemic cells of approximately 40% of patients with the M2 subtype of AML disrupts both the AML1 (CBFA2) gene on chromosome 21 and the ETO (MTG8) gene on chromosome 8 (refs 3-5). A chimaeric protein is synthesized from one of the derivative chromosomes that contains the N terminus of the AML1 transcription factor, including its DNA-binding domain, fused to most of ETO, a protein of unknown function. We generated mice that mimic human t(8;21) with a "knock-in' strategy. Mice heterozygous for an AML1-ETO allele (AML1-ETO/+) die in midgestation from haemorrhaging in the central nervous system and exhibit a severe block in fetal liver haematopoiesis. This phenotype is very similar to that resulting from homozygous disruption of the AML1 (Cbfa2) or Cbfb genes, indicating that AML1-ETO blocks normal AML1 function. However, yolk sac cells from AML1-ETO/+ mice differentiated into macrophages in haematopoietic colony forming unit (CFU) assays, unlike Cbfa2-/- or Cbfb-/-cells, which form no colonies in vitro. This indicates that AML1-ETO may have other functions besides blocking wild-type AML1, a property that may be important in leukaemogenesis.
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PMID:Embryonic lethality and impairment of haematopoiesis in mice heterozygous for an AML1-ETO fusion gene. 905 47

Autologous peripheral blood stem cell transplantation (PBSCT) is replacing autologous bone marrow transplantation (BMT) in the treatment of leukemia. One of the potential advantages of autologous PBSCT is the possibility that peripheral blood stem cells (PBSC) are less likely to be contaminated by leukemic cells than bone marrow grafts. However, the major problem still remains the high incidence of leukemic relapse following autologous PBSCT, which may be caused by the reinfusion of PBSC contaminated by leukemic cells. Recently, we have developed a quantitative assay using competitive reverse transcriptase polymerase chain reaction that estimates the number of AML1/ETO transcripts in t(8;21) acute myelogenous leukemia (AML), in order to determine the degree of leukemic cell contamination in PBSC harvests, and to monitor minimal residual disease (MRD) quantitatively in patients with t(8;21) AML. Our data indicate that although PBSC harvests collected after consolidation chemotherapy are contaminated by leukemic cells, the degree of leukemic cell contamination decreases with repeated cycles of chemotherapy. Furthermore, the MRD in PBSC harvests is less than in the corresponding bone marrow obtained on the day of the PBSC collection. There appears to be no relationship between the number of AML1/ETO transcripts found in the infused PBSC harvests and the incidence of leukemic relapse following autologous PBSCT in our study. However, a substantial decrease of AML1/ETO transcripts was seen following autologous PBSCT. Thus, the quantitative analysis of AML1/ETO transcripts may be clinically useful in patients with t(8;21) AML.
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PMID:Significance of quantitative analysis of AML1/ETO transcripts in peripheral blood stem cells from t(8;21) acute myelogenous leukemia. 913 Jun 15

In order to design the best construct for therapeutic hammerhead ribozymes against AML1-MTG8, the t(8;21)-associated fusion mRNA of acute myeloid leukemia, we synthesized DNA/RNA chimeric ribozymes directed to the area adjacent to the fusion point between AML1 and MTG8. Catalytic efficiency and fusion gene specificity of ribozymes were examined by kinetic studies of the cleavage reactions of AML1-MTG8, AML1, and MTG8 RNAs transcribed in vitro. Ribozyme 2 (Rz2) specifically cleaved AML1-MTG8 RNA at three nucleotides downstream of the fusion junction with high efficiency. The highest cleavage efficiency was achieved by Rz4.3, which targeted non-contiguous sequences and cleaved at 19 nucleotides downstream of the fusion junction. Rz4.3 also cleaved MTG8 RNA but the cleavage efficiency was three orders of magnitude lower than that for AML1-MTG8 RNA. Therefore, Rz4.3 and Rz2 are the proper ribozymes for in vivo application to modulate gene expression of the AML1-MTG8.
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PMID:In vitro catalytic activities of DNA/RNA chimeric hammerhead ribozymes against AML1-MTG8 mRNA, a fused gene transcript in acute myeloid leukemia with t(8;21). 915 Aug 86

Karyotyping with fluorescence in situ hybridization (FISH) is reported in two rare cases of AML-M2 FAB. In the first case FISH analysis confirmed the presence of a t(7;11)(p15:p15) translocation in a complex karyotype that also showed an unbalanced translocation involving the other chromosome 7, a rare rearrangement between chromosomes 9 and 20, and four or five copies of a small marker derived from chromosome 9. In the second case whole chromosome painting with probes for chromosomes 8, 14, and 21 revealed the presence of a masked t(8;21) translocation in which one chromosome 14 was involved in a newly discovered rearrangement, i.e., t(8;14;21)(q22-q24;q11;q22). Moreover , double color FISH using ETO-CDR P1 probe and a cosmid for the 5' part of AML-1 on chromosome 21 showed a two color signal on the 8q-, suggesting a recombination between ETO and AML 1. Molecular cytogenetics overcomes limitation of chromosome banding in the interpretation of complex rearrangements.
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PMID:Identification of chromosome changes in acute myeloid leukemia (AML-M2) by molecular cytogenetics. 916 32

Cases of secondary acute myeloid leukemia (AML) occurring after treatment for an Ewing's sarcoma are uncommon. Therapy-related AML with t(8;21) translocation is an entity which has been well characterized. A case of AML-2 with t(8;21) and t(3;15) occurring 4 years after treatment for an Ewing's sarcoma with cyclophosphamide, doxorubicin, vincristine, dactinomycin, and radiotherapy, is reported. Autologous bone marrow transplantation was performed during second remission, 23 months after diagnosis. Reverse transcriptase polymerase chain reaction of the AML1/ETO fusion gene product was performed in order to monitor the quality of the remission. The patient currently remains in remission 24 months after the bone marrow transplantation.
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PMID:Therapy-related acute myeloid leukemia with t(8;21) in a child with previous Ewing's sarcoma. 918 Sep 15

MTG8 is a counterpart gene of AML1 in acute myeloid leukemia with t(8:21) translocation. Most of the coding region of the MTG8 is fused with AML1 runt domain. In normal tissues, the MTG8 is highly expressed in brain, but not in hematopoietic tissues. MTG8 may be important in leukemogenesis as well as in AML1 truncation. The function of MTG8 is assumed to be as a transcription factor, because it possesses several features common to transcription factors; putative zinc finger motifs, serine/threonine/proline-rich sequences and a region similar to TAF110. In this paper, we report on the protein properties of the MTG8.
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PMID:Significance of MTG8 in leukemogenesis. 920 71

The (8;21)(q22;q22) translocation, reported in 40% of M2-subtype acute myeloid leukemias (AMLs), is the second-most frequently observed example of a nonrandom genetic alteration associated with AML. Juxtaposition of the AML1 gene on chromosome 21 to the ETO gene on chromosome 8 fuses the NH2-terminal portion of AML1 to near-full length ETO, creating AML1/ETO. Previous work has been focused on perturbation of AML1 gene function by the chimeric fusion protein as a mechanism of leukemogenesis. Here, we demonstrate that ETO itself has transforming properties. Ectopic ETO expression in NIH/3T3 cells led to foci of transformation and colony growth in soft agar. ETO-expressing cells grew to higher saturation densities and induced tumors following injection into irradiated and splenectomized nude mice. Our data suggests that ETO may play an important role in the leukemic transforming potential of the AML1/ETO fusion protein.
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PMID:Transformation properties of the ETO gene, fusion partner in t(8:21) leukemias. 923 Feb 7

This review briefly summarizes literature considered noteworthy in the field of adult acute leukemia published during 1996. Does intensity remains a controversial issue in both acute myelogenous and lymphoblastic leukemia. The most convincing data showing efficacy of high dose fractionated chemotherapy was presented in patients with Burkitt's lymphoma/leukemia; the remainder of clinical studies failed to show a definitive advantage to high-dose therapy. Numerous studies addressed the role of the multidrug resistant phenotype and, at least in adult disease, demonstrated that the presence of this particular phenotype was a poor prognostic indicator. In the pediatric population, the significance of multidrug resistance expression appeared less clear. Discrepancies between protein expression and function were also evaluated in clinical samples and outcomes reported in large clinical series. Among the most interesting scientific investigations were those focused on the molecular mechanisms involved in the specific translocations t(15;17) and t(8;21) in acute myelogenous leukemia and t(12;21) in acute lymphoblastic leukemia. The genes PML and AML1, and ETO were examined in normal hematopoietic progenitors and their fusions proteins, PML/RAR alpha and AML1/ETO, measured in patients in clinical remission, and important data were presented concerning these proteins and measurement of minimal residual disease. Provocative data were also presented suggesting that retinoic acid may induce synthesis of a protein that selectively degrades PML/RAR alpha, and that interferons may regulate PML/RAR alpha expression.
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PMID:Recent advances in the treatment of acute leukemia. 926 53

A novel variant translocation t(8;20)(q22;p13) detected by karyotype analysis of bone marrow cells using R- and G-banding techniques, is reported in a case of M2-acute myeloid leukaemia (AML). The leukaemic cells were indistinguishable morphologically from that of M2-AML with t(8;21)translocation. RT-PCR revealed no AML1/ETO fusion transcript, but the wild-type ETO-3' was expressed in the bone marrow cells suggesting that t(8;20) is a true simple variant translocation of t(8;21), and that a fusion gene consisting of ETO and an unidentified gene located in band 20p13 may exist in our case. Further study is required to clarify the entity of the assumed fusion gene.
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PMID:t(8;20)(q22;p13): a novel variant translocation of t(8;21) in acute myeloblastic leukaemia. 933 32

We have investigated a case of acute myelocytic leukaemia derived from myelodysplastic syndrome (MDS-AML) with an 8;21 translocation. In this case the AML1/MTG8 (ETO) fusion transcript was not detected by reverse transcriptase-polymerase chain reaction (RT-PCR), and the rearrangement of the AML1 gene locus was not detected by Southern blot nor pulse field gel electrophoresis (PFGE) analyses using specific probes for the AML1 gene. Fluorescence in-situ hybridization (FISH) study using cosmid probes for 21q22 revealed that the breakpoint of 21q22 was telomeric to the AML1 gene locus and centromeric from D21S259, 351, 3421 loci. This is the first report concerning the t(8;21)(q22;q22) carrying AMLs (de novo AML, MDS-AML and therapy-related AML) to show that the breakpoint at 21q22 is located outside the AML1 gene locus. It is also noteworthy that the cell-surface antigen expression pattern of the bone marrow (BM) blasts was changed from CD7+ CD2+ CD13+ CD33+ CD19- CD11b+ CD14+ CD36+ to CD7- CD2- CD13+ CD19+ CD11b- CD14- CD33+ CD34+ CD36- CD56+ during leukaemic progression, and the pattern in leukaemic phase was similar to the characteristic phenotype of de novo AML cases with t(8;21), when the AML1/MTG8 fusion transcripts are always detected by RT-PCR.
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PMID:Genetic analysis of 8;21 chromosomal translocation without AML1 gene involvement in MDS-AML. 940 Oct 77


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