Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A transplantable myelogenous leukemia of an inbred Wistar/Furth rat has been established in tissue culture and cloned. The resulting transplantable leukemia line demonstrates in vitro doubling time of 20 hr, colony-forming efficiency of 5% in liquid and methylcellulos-containing medium, and a saturation density of 3.0 x 106 cells/sq cm in liquid medium. Following intraperitoneal inoculation, newborn rats developed solid tumors, ascities, and leukemia with ld50 of5 x 103 cells and mean latency of 60 days. The tumor cell morphology was consistent with that of acute myelogenous leukemia. Histochemical staining for myeloid enzymes revealed no evidence of myeloperoxidase, esterase, or leukocyte alkaline phosphatase; however, fluorescent antibody staining for lysozyme was markedly positive. Serum, urine, and ascitic fluid from rats with transplanted leukemia also contained elevated levels of lysozyme. There was no detectable type-CRNA virus production by this cell line after as long as 100 days in vitro. This inbred rat myelogenous leukemia should provide a useful model for studies of chemotherapy and immunoltherapy of human acute myelogenous leukemia.
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PMID:Acute myelogenous leukemia of the Wistar/Furth rat: establishment of a continuous tissue culture line producing lysozyme in vitro and in vivo. 4 87

Granule formation was investigated in differentiating neutrophils of a patient with acute myelogenous leukemia (AML) by means of the combined techniques of electron microscopy and peroxidase cytochemistry. Two important pathologic features were observed: first, an abnormal concentration and packaging of peroxidase into Auer rods in leukemic promyelocytes, and second, the presence of Auer rods surrounded by single-unit membranes in some mature polymorphonuclear leukocytes (PMN). An additional unexpected finding was the discovery of two distinct populations of PMN circulating concurrently; a minor (less than 5%) normal one that contained both peroxidase-positive azurophilic and peroxidase-negative specific granules and a major abnormal one characterized by the absence of specific granules. None of these abnormalities was observed during the two remissions of this patient's disease. During relapse a "hiatus leukemicus" occurred, which also revealed two populations of cells, a majority population of leukemic blasts, and a minority population of a few normal PMN. These findings documented several developmental abnormalities in the differentiating cells of myelogenous leukemia and also suggested that concurrent normal and abnormal populations of PMN may be a helpful diagnostic feature of a leukemic process.
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PMID:Abnormalities in granule formation in acute myelogenous leukemia. 6 55

Rat chloroma cells have been propagated in permanent suspension cultures and are grown in Dulbecco's modified Eagle's medium with 10% fetal calf serum and 2.5% horse serum. Several lines have been established; the one of longest duration, Mia C51, has been maintained for over 18 months and has undergone over 100 transfers. Mia C51 cells have a doubling time of 12 hr and maintain many of the properties of the parent tumor, including the characteristic greenish color with high myeloperoxidase activity, an an aneuploid chromosomal pattern, and intact tumorigenicity. They will uniformly produce greenish chloroma tumors when injected into newborn rats. Electron microscopic examination of chloroma tumors and the cultured cells derived from them reveal the presence of extracellular mature and immature type C virus particles morphologically typical of oncornaviruses. Chloroma cells obtained from tumors that lost their alkaline phosphatase activity after repeated transfer regain full activity in culture. Studies using the antigen-antibody crossed electrophoresis indicate that the loss of alkaline phosphatase activity represents a true decrease in alkaline phosphatase protein, which is restored under culture conditions. The availability of a permanent chloroma cell line in culture that maintains the biological properties of the parent tumor provides a useful model for the study of myeloid leukemia.
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PMID:Characteristics of rat carcinoma in culture. 16 71

The morphology, cytochemistry, metabolism, and bactericidal function of neutrophilic polymorphonuclear leukocytes (PMN) from a patient with subacute myelogenous leukemia were evaluated. The patient's mature PMN were deficient in granules and staining reactivity for myeloperoxidase (MPO) and alkaline phosphatase (LAP). These cells killed Staphylococcus aureus in an abnormal pattern when they were challenged with various increasing multiples of bacteria per neutrophil. At a low ratio of challenge (1.25 bacteria per neutrophil) the MPO-LAP-deficient PMN killed only 18 +/- 6 per cent (mean +/- 1 S.D.) (normal, 79 +/- 7) of the initial bacterial inoculum. As the PMN were challenged with higher ratios of bacteria per cell, the bactericidal effectiveness of the hypogranular PMN improved. At a 50:1 ratio the patient's cells killed within the normal range (28 +/- 10 per cent vs. normal of 48 +/- [mean +/- 1 S.D.]). Although rates of glucose oxidation and oxygen consumption by patient or control PMN stimulated with comparable ratios of heat-killed bacteria were the same, only minimal metabolic enhancement was produced in the MPO-LAP-deficient PMN by lower ratios. In contrast, higher ratios produced a marked increase in both of these metabolic activities indicating a major metabolic response to multiple ingestions by the patient's PMN. These observations may reflect the activation of compensatory microbicidal mechanisms available to the MPO-LAP-deficient PMN only when challenged by large multiples of bacteria.
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PMID:Abnormal pattern of bactericidal activity of neutrophils deficient in granules, myeloperoxidase, and alkaline phosphatase. 18 7

The mouse myeloid leukemia cell line (M1) is known to differentiate in vitro into macrophages and granulocytes upon treatment with various inducers including mouse ascitic fluid. Changes of cell surface proteins during differentiation of M1 cells were analyzed by the lactoperoxidase-catalyzed radioiodination method and SDS-polyacrylamide slab gel electrophoresis. Treatment of the cells with ascitic fluid changed the electrophoretic pattern of the iodinated proteins, the prominent change being the appearance of a new protein with a molecular weight of 180 000 (P180). Iodinated P180 was also detected in normal macrophages in granulocytes, which are similar to differentiated M1 cells. This protein was metabolically labeled with L-[14C]fucose, increasing with the period of the treatment. P180 was not expressed on ascitic fluid-treatment of a resistant clone of M1 cells that could not be induced to differentiate. These results indicate that P180 is a glycoprotein that is exposed on the outer surface of differentiated M1 cells, and that its expression is associated with differentiation of the cells. P180 was solubilized from 125I-labeled macrophages with detergents bound to concanavalin A-Sepharose. This suggests that P180 is one of the receptors for concanavalin A. Therefore, P180 may contribute partly to the increases in agglutinability by concanavalin A and in the number of concanavalin A binding sites on the surface of M1 cells, which are known to be associated with differentiation of M1 cells.
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PMID:Differentiation-associated changes in membrane proteins of mouse myeloid leukemia cells. 29 Mar 96

Three lines of rat leukemia, DBLA-1, -6, and -9, were studied serologically by complement-dependent cytotoxicity test. DBLA-1, -6, and -9 were killed by anti-lymphocyte sera, anti-Thy-1.1 sera, and rabbit anti-rat brain sera absorbed with AKR/J brain. However, anti-T and anti-B lymphocyte sera had no cytotoxic effect on DBLA-1, -6, and -9. Furthermore, DBLA-6 and -9 did not absorb the cytotoxic activity of anti-T serum on thymocytes, while DBLA-1 slightly absorbed the cytotoxic activity. These results indicate that DBLA-1, -6, and -9 are of lymphoid origin and possess rat Thy-1 antigens, but lack mature T-lymphocyte antigens. On the other hand, peroxidase-positive myelogenous leukemia L1005 failed to react with any of the antisera used.
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PMID:Serological characterization of rat leukemia lines, DBLA-1, -6, and -9. 31 51

The Fc-receptor of normal human leukocytes, of CLL-cells, and of hematopoietic cell lines was demonstrated with soluble peroxidase-anti-peroxidase (PAP) complexes. In about 9% of normal lymphocytes an almost continuous, strong labeling of the cell membrane was established. Some of these lymphocytes were characterized by a peculiar uniform fine structure. The percentage of PAP-labeled monocytes was in the range of 25%, neutrophils nearly 100%, eosinophils 0%, CLL-cells 10%. Labeled portions of the membrane were interiorized from monocytes. The lymphoid cell-line Daudi established from a Burkitt's lymphoma appeared almost negative, the cell line K562 established from a myeloid leukemia in 75% of the cells strongly positive. PAP-labeling was not influenced by preincubation with trypsine or with neuraminidase; it was negative when PAP-F(ab)2 was used. Results of PAP-labeling were not always in agreement with EA-rosettes or with agg-Ig.
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PMID:Demonstration of the Fc-receptor of blood cells by soluble peroxidase-anti-peroxidase (PAP) complexes. 35 Mar 18

Methylation and DNase I-hypersensitive sites of the myeloperoxidase gene in human myeloid leukemia HL-60 cells were studied by Southern blot hybridization using the myeloperoxidase gene probes. Digestion of DNA with a methylation-sensitive restriction endonuclease indicated that a CpG in the CCGG sequence located 3.53 kbp upstream of the myeloperoxidase gene was unmethylated in HL-60 cells expressing the gene, whereas it was methylated in K562 cells and human placenta not expressing the gene. The site in HL-60 cells remained unmethylated after retinoic acid- or 12-O-tetradecanoyl-phorbol-13-acetate-induced differentiation that arrests myeloperoxidase synthesis. Digestion of isolated nuclei with various amounts of DNase I indicated that four DNase I-hypersensitive sites were in an upstream region of the myeloperoxidase gene in HL-60 cells and three sites were within the gene. In retinoic acid-induced cells, the bands of the hypersensitive site near the 5' side of the gene and that in the first intron became weak, while that of the site in the fifth intron became strong. The bands of these hypersensitive sites were weak in K562 cells. The implications of these changes in tissue-specific expression and developmental down-regulation of the myeloperoxidase gene are discussed.
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PMID:Undermethylation and DNase I hypersensitivity of myeloperoxidase gene in HL-60 cells before and after differentiation. 130 85

Myeloperoxidase (MPO) is a heme-containing glycoprotein found in the primary granules (or azurophilic granules) of human polymorphonuclear leukocytes. In the present study, cultured myeloid leukemia HL-60 cells were exposed for 0-72 h to 250 microM 4,6-dioxoheptanoic acid (succinylacetone, SA), a specific inhibitor of heme biosynthesis, and the effects were evaluated using ultrastructural, immunochemical, and cytochemical methods. En bloc peroxidase staining of glutaraldehyde-fixed cells was accomplished with a 30-min exposure to 3,3'-diaminobenzidine (DAB) tetrahydrochloride. Ultrastructural examination revealed that peroxidase reactivity in the endoplasmic reticulum (ER) was relatively unchanged for 8 h and decreased between 12 and 24 h; however, ER lacked DAB-reactive peroxidase at 48-72 h. Peroxidase reactivity in the ER reappeared within 4 h after removal of SA. Seventy-two hours after exposure to SA the number of condensed cytoplasmic granules stained with DAB was significantly decreased, and many of the granules had a "target" appearance with a central DAB-reactive dense core. Staining of mitochondria was observed with overnight exposure to DAB and persisted in HL-60 cells treated 72 h with SA. Mitochondrial and nuclear morphology appeared unaltered. Immunostaining of MPO in thin sections of paraformaldehyde/glutaraldehyde-fixed unosmicated HL-60 cells, embedded in Lowicryl K4M, was accomplished with sequential exposure to an affinity-purified monospecific rabbit antibody to HL-60-MPO and protein A conjugated to 5- or 10-nm colloidal gold. Compared to untreated control HL-60 cells, cells exposed to SA for 48 h exhibited comparable to increased immunoreactive MPO in the ER, despite the absence of heme-dependent peroxidase reactivity. The data indicate that SA inhibits formation of enzymatically active MPO and that in the presence of SA, the ER contains a form(s) of MPO that lacks enzymatic reactivity.
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PMID:Ultrastructural, immunochemical, and cytochemical study of myeloperoxidase in myeloid leukemia HL-60 cells following treatment with succinylacetone, an inhibitor of heme biosynthesis. 132 Oct 53

A newly established human monocytic cell line, SKM-1, showed strong expression of myeloperoxidase mRNA, to the same extent as in HL-60 cells. We studied the cell morphology and myeloperoxidase expression of this cell line, which was established from a patient with myelodysplastic syndrome who had an abnormal chromosome on the upstream region of 17p13. Electron micrographs showed the cells to have a fragile and irregular cell surface. SKM-1 cells were peroxidase-positive. About 60% of myeloperoxidase (MPO) was released to the culture fluid from SKM-1 cells but only a few percent of MPO was released from HL-60 cells into the culture fluid. The predominant mRNA size of SKM-1 myeloperoxidase was 3.3 kb although there was a smaller size as well. Fluorescent in situ hybridization of MPO mRNA showed strong staining in 5% to 10% of SKM-1 cells and of bone marrow cells from patients with myelogenous leukemia, while all cells from HL-60 were positive.
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PMID:The monocytic cell line SKM-1 strongly expresses the myeloperoxidase gene. 133 56


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