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)

The expression of the myeloperoxidase (MPO) gene was studied, by means of Northern blot analysis in 14 cases of acute myeloid leukemia (AML), 11 cases of chronic myeloid leukemia (CML), and 6 cases of CML blast crisis, and in HL60 cells before and after induction of terminal differentiation with retinoic acid (RA), phorbol esters (TPA), or vitamin D. The expression of a panel of cell cycle-related genes, namely C-MYC, histone H3, ornithine decarboxylase, P53, vimentin, and calcyclin, was also studied in the same cell populations. Our results indicate that: (a) MPO gene expression (steady state mRNA levels) is strictly confined to the first stages of myeloid differentiation, reaching its peak at the promyelocyte stage and becoming undetectable in mature granulocytes and monocytes; (b) cells devoid of any detectable MPO enzymatic activity such as leukemic basophils have a high content of MPO mRNA; and (c) MPO gene expression is not related to the growth activity of the cell population. Finally, our results show that the pattern of expression of growth-regulated genes in the neoplastic myeloid disorders AML, CML, and CML blast crisis is remarkably different.
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PMID:Expression of the myeloperoxidase gene in acute and chronic myeloid leukemias: relationship to the expression of cell cycle-related genes. 254

Acute leukemia was diagnosed in 62 adults and children over a recent 13-month period. Using light microscopy, cytochemical profiles, surface markers, and cytogenetics, 25 cases were classified as acute myeloid leukemia (AML) and 32 as acute lymphoblastic leukemia (ALL). The remaining 5 cases of de novo acute leukemia were unclassifiable. The routine cytochemical battery used on these 62 cases included: myeloperoxidase, sudan black B, nonspecific esterase, and periodic acid-Schiff (PAS). Flow markers utilized were: T3, T4, T5, T8, T10, T11, B1, B4, kappa, lambda, Ia, CALLA, Mo1, Mo2, My4, My7, My8, and My9. TdT was performed by immunoperoxidase and ELISA methods. The five unclassified cases were cytochemically negative and expressed no B- or T-cell-specific antigens, or TdT positivity. The morphologic differential diagnosis was between FAB L-2 and M-1. Karyotypic abnormalities involving chromosomes 3 and 7 were suggestive of myeloid origin in 2 of 4 patients studied. Flow cytometry demonstrated My7 on greater than 50% of blasts from two cases. Myeloperoxidase ultracytochemistry showed reaction product in small primary granules of blasts from all 5 cases. Positive cells contained only 1-2 granules/cell profile. The number of positive cells per case was in the range 10-20%. We conclude from this study that ultracytochemistry is very useful in providing definitive diagnosis and accurate subclassification of some AML FAB M-1 cases, particularly when light microscopic cytochemistry, cytogenetics, and flow cytometric markers are noncontributory. We propose to designate these acute "unclassified" leukemias as AML FAB M-1 "microgranular" type.
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PMID:Acute myeloid leukemia, FAB M-1 microgranular variant: a multiparameter study. 254 66

We reported a 68-year-old woman with acute nonlymphocytic leukemia, in whom the leukemia transformed from poorly differentiated myeloperoxidase (MPO)-negative type into myelomonocytic type during the observation without chemotherapy. Hematological findings on admission revealed a leukocyte count of 3,500/microliters with 48% blasts and a platelet count of 9.2 x 10(4)/microliters. Bone marrow aspiration showed 68.2% infiltration of blasts negative for MPO. Sudan black B and esterase stains. By electron microscopy MPO was detected in the endoplasmic reticulum and nucleoenvelope of the blasts. Large vacuole-like granules were MPO-negative. She was observed without administration of any antileukemic agent or an immunopotentiator. The leukocyte count rose gradually, in association with increases in the relative and absolute counts of mature neutrophils and monocytic cells, and the platelet count. Twenty-six months after the initial diagnosis, a blood examination showed a leukocyte count of 74,300/microliters with 20.5% mature neutrophils and 15.5% monocytic and a platelet count of 31.4 x 10(4)/microliters. Cytological, cytochemical, ultrastructural and immunological studies of the bone marrow cells showed features compatible with acute myelomonocytic leukemia (FAB M4). This case is unusual in respect that poorly differentiated ANLL transformed spontaneously into moderately differentiated ANLL.
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PMID:[Spontaneous differentiation from myeloperoxidase-negative acute nonlymphocytic leukemia to acute myelomonocytic leukemia]. 255 92

Auer rods are cytoplasmic inclusions found only in the leukaemic cells of some cases of acute myeloid leukaemia (AML). The ultrastructure of Auer rods is different in different sub-types of the disease and it is suggested here that this may be a consequence of the Auer rods consisting of different crystalline forms of the enzyme myeloperoxidase. There is statistical evidence to indicate that patients with Auer rods have a more favourable prognosis than those without. It is proposed that an investigation of the factors that determine the form, if any, of the crystallisation of myeloperoxidase will lead to a better understanding of the molecular events underlying the different types of AML. In the long term this may in turn lead to a therapeutic advance.
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PMID:Auer rods and myeloperoxidase: an approach for investigating changes at the molecular level in acute myeloid leukaemia (AML). 255 30

The relationship between cell features by light microscopy and therapeutic outcome of 72 patients with acute myeloblastic leukemia (FAB M1) were investigated. The patients were divided into two groups according to myeloperoxidase-(MPO) positive percentage of blast cells, namely a low (less than 50%) and high (greater than 50%) MPO group. No remarkable morphological difference of blast cells between these two groups was observed. The 38 patients with low MPO showed a significantly lower complete response rate (CR) (52.6%) than the 34 patients with high MPO (85.3%) (p = 0.003) that included 10 CAE-positive patients and 2 ANAE-positive CAE-negative patients. The low MPO group included 5 CAE-positive patients with granulocyte dysplasia and 7 additional patients with alpha naphthyl acetate esterase (ANAE) positivity who were chloroacetate esterase (CAE) negative. Low positivity of blast cells may be due to a defective enzyme expression in the former but also may be a reflection of 'monocytic' aberrant expression in the latter. The low MPO group in M1 with this heterogeneous population is less likely to achieve CR with chemotherapy, while the high MPO group with a higher CR rate suggests a more pure entity within the myeloblastic leukemias referred to as M1. After further refinement by eliminating 24 cases that were 'esterase positive' (ANAE and/or CAE), the results were still the same, suggesting that the more immature blast populations were in the low MPO group.
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PMID:Prognostic significance of myeloperoxidase positivity of blast cells in acute myeloblastic leukemia without maturation (FAB: M1): an ECOG study. 256 Jul 75

Since myeloperoxidase (MPO) is considered to be a critical marker of differentiating acute myelogenous leukemia (AML) from acute lymphocytic leukemia (ALL), the analysis of MPO gene expression may provide further insight into the leukemia classification and the lineage fidelity of leukemia cells. By Northern blot hybridization using full-length MPO cDNA as a probe, approximately 66% of AML cells (3/4 M1 cases, 2/4 M2 cases, 15/15 M3 cases, 11/15 M4 cases, and 2/12 M5 cases) were found to express MPO mRNAs, whereas none of 18 ALL cases did. MPO mRNA was detectable when AML cells contained at least 10% peroxidase-positive cells. APL (M3) cells expressed high levels of mRNA in accordance with heavy staining for peroxidase.
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PMID:Myeloperoxidase gene expression in acute leukemias. 256 Aug 87

During the course of differentiation of early human myeloid cells toward monocytes and granulocytes, cell surface expression of the cell adhesion molecule, CD11b/CD18 (Mo1) increases dramatically and expression of myeloperoxidase (MPO), a bacteriocidal enzyme, decreases markedly. Using the inducible promyelocytic cell line HL-60 as a model, we studied the mRNA expression of these genes. Differentiation of these cells along both a monocytic and a granulocytic pathway demonstrated that the mRNA levels of the two subunits of CD11b/CD18 increased in a pattern temporally and quantitatively similar to the increase in cell surface expression of this heterodimer. In contrast, the expression of MPO mRNA decreased in a temporal and quantitative pattern similar to the known decrease in MPO protein during differentiation, suggesting that regulation of these myeloid-specific proteins may occur at the level of mRNA expression. These findings have important implications with regard to the nature of the block in differentiation in acute nonlymphocytic leukemia and the regulation of myeloid gene expression.
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PMID:Differential expression of CD11b/CD18 (Mo1) and myeloperoxidase genes during myeloid differentiation. 256 20

Mo5 is a 94-kd protein antigen expressed by human peripheral blood monocytes, neutrophils, and by all bone marrow myeloperoxidase-positive myeloid precursors (promyelocytes, myelocytes, metamyelocytes, and bands). Mo5 is borne by the malignant cells of 74% of patients (N = 27) with acute monocytic leukemia (French-American-British [FAB] group M4, M5), and 50% of patients (N = 38) with acute granulocytic leukemia (FAB M1, M2, and M3). Nonmyeloid cells in peripheral blood and bone marrow are Mo5-negative. The surface expression of Mo5 by myeloid cells is modulated by several experimental conditions: Exposure of neutrophils to calcium ionophore (1 mumol/L, 37 degrees C, ten minutes) under conditions resulting in degranulation of specific granules produces a three- to fourfold increase in the plasma membrane density of Mo5 antigen. This suggests that, in neutrophils, there is an intracellular pool of Mo5 antigen, which may be associated with specific granules, and that granule-associated Mo5 is translocated to the plasma membrane upon degranulation. Conversely, incubation of monocytes, neutrophils, U-937, and Mo5-positive leukemia cells in medium containing anti-Mo5 monoclonal antibody results in a significant decrease in surface Mo5 expression. This loss of surface Mo5 is a rapid, temperature-dependent process (occurring within 30 minutes at 37 degrees C) that is produced by divalent anti-Mo5 immunoglobulin [F(ab')2 but not F(ab)]. After down-modulation, Mo5 is reexpressed by monocytes within 48 hours. Mo5 is therefore a human myelomonocytic differentiation antigen whose expression is modulated up or down depending on the nature of extracellular stimuli.
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PMID:The modulated expression of Mo5, a human myelomonocytic plasma membrane antigen. 257 92

A near-tetraploid clone was observed at the 5th relapse in a 34 year-old female with acute granulocytic leukemia. She was referred to Hiroshima University Hospital presenting with palpitation in May 1978. On admission she had a WBC count of 2,900/microliters with 31.5% blasts, platelet count of 2.4 x 10(4)/microliters and hemoglobin of 2.8 g/dl. A bone marrow aspirate showed hypercellular with 88.5% blasts. Most of them were weakly positive for peroxidase reaction. Occasional Auer rod and/or fine azurophilic granules were observed. DCMP therapy (daunorubicin, cytosine arabinoside, 6-mercaptopurine, and prednisone) was started and the first complete remission was achieved in August 1978. Afterward, the 5th relapse occurred in August 1986 and several kinds of drugs were given without effects. She died 8 years and 9 months after the diagnosis. Karyotype prior to treatment showed a normal diploidy without tetraploid mitoses. However, cells with near-tetraploid (mode: 91) were observed predominantly on the 5th relapse sample and almost all mitoses were occupied with near-tetraploidy at the terminal stage. Results of serial cytogenetic and hematologic study showed a close correlation between the incidence of near-tetraploid mitoses and that of very large blast cells. The significance of tetraploidy in previously reported 44 cases including our case was discussed.
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PMID:[Acute granulocytic leukemia with near-tetraploid chromosome constitution appearing in the late stage of the disease with survival of almost 9 years]. 267 39

A spontaneous complete remission of 5 month's duration was observed in a 70 year-old man with acute myeloblastic leukemia complicated with severe pneumonia. The remission occurred after severe pancytopenia. He was treated only with antibiotics and blood transfusions. On admission, the leukocyte count was 6.4 x 10(3)/microliters with 98% myeloblasts. The hemoglobin level was 9.9 g/dl and platelet count was 1.5 x 10(4)/microliters. Marrow aspirate was hypercellular with 98.5% myeloblasts, which weakly showed Ia like antigen and myeloid related antigen. On relapse after five weeks' complete remission, leukemic cells were more immature, peroxidase negative and showed no surface markers. Chromosomal abnormalities were detected. During remission induction therapy he died of severe bacterial and fungal sepsis. Such cases of spontaneous complete remission have been rarely reported, previous adult cases were summarized and the role of etiologic factors were discussed.
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PMID:[Spontaneous complete remission in a 70 year-old man with acute myeloblastic leukemia with severe pneumonia]. 268 8


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