Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The processing and intracellular transport of lactoferrin of the neutrophil specific granules was investigated by biosynthetic labeling with (14C)leucine of bone marrow cells from healthy individuals and patients with chronic myeloid leukemia. Lactoferrin was precipitated with antilactoferrin serum and the immunoprecipitates were analyzed by sodium dodecyl sulfate (SDS), polyacrylamide gel electrophoresis (PAGE) followed by fluorography. In contrast to myeloperoxidase of azurophil granules, lactoferrin was not synthesized as a larger precursor, and it was not found to be phosphorylated. The transfer to granules of newly synthesized lactoferrin was demonstrated in pulse-chase labeling experiments followed by centrifugation of cell homogenate in a Percoll gradient. Monensin, which exchanges protons for Na+ and NH4+ cation, blocked the transfer completely, indicating a need for acidification mechanisms. Unlike myeloperoxidase, newly synthesized lactoferrin rapidly became resistant to endoglycosidase H, indicating a transport through the medial and transcisternae of the Golgi apparatus with conversion of "high mannose" to "complex" oligosaccharide side chains. Intracellular transfer of some major neutrophil azurophil and specific granule constituents is obviously regulated differently. Lactoferrin seems to be processed like proteins destined for secretion, while myeloperoxidase is processed more or less like lysosomal enzymes.
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PMID:Biosynthesis and processing of lactoferrin in bone marrow cells, a comparison with processing of myeloperoxidase. 282 14

Successful postembedding immunolabelling for electron microscopy is sometimes difficult to achieve. We propose that light microscopy can be used (1) to detect quickly processing steps which have an adverse effect on the tissue antigenicity and (2) to check the specific reactivity of the immunogold detecting system normally employed at the ultrastructural level. The individual steps of fixation, dehydration and embedding were tested for their ability to preserve antigenicity by light microscopic peroxidase--anti-peroxidase cytochemistry. Steps that severely reduced antigenicity were replaced by less destructive alternatives compatible with reasonable ultrastructural preservation. The specific reactivity of the immunogold detecting system was assessed by using the light microscopic immunogold-silver staining method. We studied the antigen lactoferrin in human neutrophilic granulocytes from patients with chronic myeloid leukaemia. We obtained strong immunolabelling of specific granules and good ultrastructural preservation using routine methods at room temperature. For lactoferrin the method of choice was to fix in 3% paraformaldehyde/0.1% glutaraldehyde followed by 1% OsO4, dehydrate in 70% ethanol, embed in LR White resin and polymerize at 40 degrees C for 40 h. These conditions may not be suitable for all antigens and we emphasize that for each new antigen a similar study should be carried out.
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PMID:Use of light microscopic immunotechniques in selecting preparation conditions and immunoprobes for ultrastructural immunolabelling of lactoferrin. 322 Jul 93

Cell-associated lactoferrin (Lf) was analyzed using a new method involving cell permeabilization, indirect immunofluorescence staining, and flow cytometry. Statistical techniques to evaluate the results for percentage of positive cells, relative fluorescence and homogeneity of Lf distribution were also devised. Most normal adult neutrophils (97.1 +/- 0.3% (SEM), range 92.7-99.6%, n = 41) had brilliant fluorescence homogeneously distributed among the cells. There was significantly greater homogeneity of neutrophil Lf distribution in post-menopausal than pre-menopausal females. In chronic myelogenous leukemia (n = 13) and cord blood (n = 7), fractions of Lf-positive neutrophils were decreased (77.3 +/- 7.5%, range 13.3-96.3%; 71.4 +/- 9.3, range 32.0-95.6%, respectively). Normal monocyte-rich isolates had moderate fluorescence (28.7 +/- 3.6%, range 9.3-76.8%, n = 22). Among blood lymphocyte-rich preparations, 13.1 +/- 1.3% of cells had weak positivity (range 4.9-26.6%, n = 19); monoclonal B and T lymphocytes had similar parameters. No other cells had detectable Lf. Our results were significantly correlated with those obtained manually (r = 0.98, P less than 0.001), and are consistent with Lf quantity and distribution determined using other methods.
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PMID:Assessment of total immunoreactive lactoferrin in hematopoietic cells using flow cytometry. 328 Jun 85

We have developed a technique that permits evaluation and semi-quantification of iron-binding function in mature neutrophils. Neutrophil iron-binding reactivity (NFeBR) visualized using the iron nitrilotriacetate-acid ferrocyanide technique was rated 0 to 5+ in 100 segmented cells; the ratings were totaled to yield a score (NFeBRS). Males and post-menopausal females had significantly higher NFeBRS than pre-menopausal females. Neonates had low values, and a homogeneous distribution of NFeBR among neutrophils. In pregnancy and acute infection, NFeBRS were significantly increased. In a patient with congenital lactoferrin (Lf) deficiency, the NFeBRS was very low. In Ph1-positive chronic myelogenous leukemia, 13 of 17 patients had low NFeBRS due to decreased NFeBR, which was heterogeneously distributed among mature neutrophils. By ultrastructural analysis of mature neutrophils in two such patients, the stain deposits in FeBR-positive granules were of normal intensity, but the numbers of positive granules were decreased in many cells. NFeBRS were also low in 12 of 23 patients with other myeloproliferative disorders, and in seven of 15 patients with acute non-lymphoblastic leukemia, but in only seven of 63 patients with other neoplasms. NFeBRS were significantly correlated (p less than 0.008) with values of neutrophil Lf content quantified by immunologic assays in a wide variety of conditions and over a broad range of values. These results augment observations of neutrophil Lf made using immunological methods.
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PMID:Iron-binding reactivity in mature neutrophils: relative cell content quantification by cytochemical scoring. 336 50

Inhibitory activity in extract from human blood granulocytes was tested on granulocyte-macrophage colony formation in vitro. The inhibition depended on the type of serum used. With mouse BMC and FCS in the cultures, extract corresponding to 2.5 X 10(4) granulocytes/ml reduced the colony number by 35%, and extract from 2 X 10(5) cells caused maximal inhibition (80-90%). With HS and mouse BMC the colony number was reduced by only 11-12%, but stronger inhibition (55%) was observed when the serum concentration was reduced. With both types of sera the total cell number per culture plate was reduced relatively more than the colony number. Human GM-CFC were as sensitive as mouse GM-CFC, and extract from CML granulocytes inhibited less (p less than 0.01) than extract from normal cells. Biochemical studies indicated that the inhibitor is a protein with a molecular weight of 30-60,000. Lactoferrin, a putative inhibitor of CSF production, did not inhibit spontaneous or CSF-induced colony formation in these studies.
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PMID:Colony inhibiting factor in mature granulocytes from normal individuals and patients with chronic myeloid leukemia. 347 14

A solid-phase, one-step radioimmunoassay was developed for the determination of plasma lactoferrin concentration. The detection limit of the assay is 150 micrograms/l. Leakage of cellular lactoferrin was minimal when EDTA was used as anticoagulant, while results obtained from serum and from heparinized plasma were not reproducible. The plasma lactoferrin concentration of 35 female and 44 male healthy adults was measured in order to determine normal values. The geometric mean of lactoferrin levels in men is about 10% higher than in women: 483 (200-1500) micrograms/l in men and 446 (200-870) micrograms/l in women. Patients with acute and chronic leukaemias were also studied. In 38 patients with chronic myeloid leukaemia plasma lactoferrin levels were increased by three times while the neutrophil count was ten times higher than normal. Normal lactoferrin concentrations were measured in plasma samples from 15 patients with chronic lymphocytic leukaemia in incomplete remission while no detectable lactoferrin was found in samples from those in relapse (10 patients). In the untreated patients or those in relapse (19 cases) of both acute lymphocytic and myeloid leukaemias, plasma lactoferrin concentrations were undetectable while they seemed to return to normal during remission (3 cases). The data obtained indicate that the determination of plasma lactoferrin concentration might play an important role in facilitating the assessment of total blood granulocyte pool (TBGP).
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PMID:Plasma lactoferrin levels in leukaemias. 347 35

Lactoferrin is a major constituent of polymorphonuclear leukocyte granules and is present in mature neutrophils but not in blasts or promyelocytes. We have isolated a cDNA probe for lactoferrin and used it to study the synthesis of lactoferrin mRNA by normal and leukemic granulocyte precursors. The probe pHL-41 has been subcloned in phage m13 and characterized by restriction endonuclease analysis and nucleic acid sequencing. pHL-41 contains approximately 40% of the coding sequence of the lactoferrin gene. The 3' untranslated region includes a stop codon and a possible polyadenylation signal. There is a greater than 98% agreement between the cDNA-deduced amino acid sequence and that determined by analysis of the protein. Myeloid cells from normal bone marrow and circulating leukocytes from patients with chronic granulocytic leukemia contain lactoferrin mRNA transcripts that are indistinguishable in size and relative quantity. The human promyelocytic leukemia cell line HL-60 contains no lactoferrin mRNA. Induction of monocytic or granulocytic differentiation fails to induce the synthesis of detectable lactoferrin message. Similarly, studies with the human myeloblastic leukemia cell line PLB-985 reveal the inability of these cells to produce lactoferrin mRNA even under conditions that bring about morphologically demonstrable granulocytic differentiation. These data suggest that granulocytic differentiation in the leukemic cell lines is incomplete or defective. The presence of lactoferrin may play a role in the orderly expression of the genetic program leading to the development of the normal mature granulocyte.
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PMID:Isolation of lactoferrin cDNA from a human myeloid library and expression of mRNA during normal and leukemic myelopoiesis. 347

We examined the synthesis of lactoferrin, an iron binding protein that, among hematopoietic cells, is restricted to secondary granules of polymorphonuclear leukocytes. Lactoferrin biosynthesis was absent from leukemic myeloblasts and promyelocytes but abundant in normal bone marrow and both the bone marrow and peripheral blood of patients with chronic myelogenous leukemia (CGL) if the samples contained substantial numbers of myelocytes and metamyelocytes. Lactoferrin was present in the steady state in normal or CGL bands and polymorphonuclear leukocytes, but no lactoferrin biosynthesis was detectable in these samples. Taken together, these results suggest that lactoferrin accumulation begins with the onset of biosynthesis at the myelocyte stage and is largely complete by the beginning of the band stage of maturation. HL-60 cells, a permanent promyelocytic leukemia cell line, synthesized no lactoferrin. Translation of messenger RNA in Xenopus laevis oocytes revealed that mRNA from patients with chronic myelogenous leukemia and abundant myelocytes and metamyelocytes directed the synthesis of readily detectable amounts of lactoferrin, whereas HL-60 cells contained no translatable lactoferrin mRNA. We thus hypothesize that lactoferrin is a useful marker of gene expression restricted to the terminal stages of granulocyte maturation. Biosynthesis of this protein appears to be mediated by appearance of translatable mRNA at the myelocyte stage, coincident with development of secondary granules. Absence of lactoferrin production by HL-60 cells is due to absence of translatable lactoferrin mRNA, either because of lineage infidelity of these transformed cells or because of arrest before the developmental stage at which secondary granules appear.
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PMID:Lactoferrin biosynthesis during granulocytopoiesis. 659

In the process of evaluating roles for purified preparations of lactoferrin, transferrin and acidic isoferritins in the regulation of myelopoiesis, it was found that: (1) values reported for lactoferrin in the serum and plasma of normal donors are in most cases an over-estimation, (2) lactoferrin suppresses the production/release of granulocyte-macrophage colony stimulatory factors (GM-CSF) from monocytes in the absence of T-lymphocytes and also suppresses the production/release of acidic isoferritin-inhibitory activity from monocytes, (3) lactoferrin, transferrin and acidic isoferritins act on their specific target cells which express Ia-like antigens, (4) lactoferrin and transferrin act in vivo to suppress rebound myelopoiesis in mice recovering from sublethal dosages of Cytoxan, with preliminary observations suggesting that lactoferrin has a greater apparent effect on the bone marrow and transferrin has a greater apparent effect on the spleen, (5) active lactoferrin derives from Fc receptor positive subpopulations of PMN from patients with CML as well as from normal donors, but the percentage of Fc receptor containing PMN is lower in CML, as is the amount of active lactoferrin found in their PMN, and (6) lactoferrin, transferrin and acidic isoferritins suppress the colony formation of U937 clonogenic cells, with lactoferrin and transferrin decreasing the release of growth factors from U937 cells which are needed to stimulate U937 colony formation, and lactoferrin and acidic isoferritins suppress the colony formation of WEHI-3 cells, with lactoferrin decreasing the release of growth factors from WEHI-3 cells which are needed to stimulate WEHI-3 colony formation. Speculation on the potential usefulness of these iron binding glycoproteins to control of disease progression is given in the discussion.
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PMID:Lactoferrin, transferrin and acidic isoferritins: regulatory molecules with potential therapeutic value in leukemia. 660 37

The death-associated protein kinase 2 (DAPK2) belongs to a family of Ca(2+)/calmodulin-regulated serine/threonine kinases involved in apoptosis. During investigation of candidate genes operative in granulopoiesis, we identified DAPK2 as highly expressed. Subsequent investigations demonstrated particularly high DAPK2 expression in normal granulocytes compared with monocytes/macrophages and CD34(+) progenitor cells. Moreover, significantly increased DAPK2 mRNA levels were seen when cord blood CD34(+) cells were induced to differentiate toward neutrophils in tissue culture. In addition, all-trans retinoic acid (ATRA)-induced neutrophil differentiation of two leukemic cell lines, NB4 and U937, revealed significantly higher DAPK2 mRNA expression paralleled by protein induction. In contrast, during differentiation of CD34(+) and U937 cells toward monocytes/macrophages, DAPK2 mRNA levels remained low. In primary leukemia, low expression of DAPK2 was seen in acute myeloid leukemia samples, whereas chronic myeloid leukemia samples in chronic phase showed intermediate expression levels. Lentiviral vector-mediated expression of DAPK2 in NB4 cells enhanced, whereas small interfering RNA-mediated DAPK2 knockdown reduced ATRA-induced granulocytic differentiation, as evidenced by morphology and neutrophil stage-specific maturation genes, such as CD11b, G-CSF receptor, C/EBPepsilon, and lactoferrin. In summary, our findings implicate a role for DAPK2 in granulocyte maturation.
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PMID:The death-associated protein kinase 2 is up-regulated during normal myeloid differentiation and enhances neutrophil maturation in myeloid leukemic cells. 1734 2


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