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 functional capacities of granulocytes in patients with chronic granulocytic leukemia are still a subject of controversy, probably due to the heterogeneity of the abnormalities observed from patient to patient. For a better definition of these abnormalities, 14 patients with untreated chronic granulocytic leukemia were studied. The patients were divided into three groups on the basis of the functional activities of their phagocytosing granulocytes. In four patients (group I), the granulocytes were normal in respect to particle ingestion, nitroblue tetrazolium (NBT)-stimulated reduction, cyanide-insensitive oxygen (O2) consumption, superoxide anion (O2-)-stimulated production, hydrogen peroxide (H2O2) production, and iodination. They also had a normal myeloperoxidase (MPO) content. In four patients (group III), the granulocytes were significantly defective in all of these activities. In the six remaining patients (group II), all the initial metabolic steps of the phagocytosing granulocytes (ingestion, NBT reduction, O2 consumption, O2-production, H2O2 production) were normal, as were the MPO content of the granulocytes, while iodination was strikingly decreased. These metabolic features suggested a degranulation defect which was observed ultrastructurally in the only patient studied among these six. The phagocytosing granulocytes of this patient did not degranulate and no deposits of MPO activity were seen in the phagosomes.
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PMID:Metabolic activity of phagocytosing granulocytes in chronic granulocytic leukemia: ultrastructural observation of a degranulation defect. 19 42

Human granulocyte catalase (hydrogen peroxide:hydrogen peroxide oxidoreductase, EC 1.11.1.6) was purified from chronic myeloid leukemia cells. The purification procedure included heat precipitation, ammonium sulphate fractionation, DEAE-Sephadex chromatography, gel chromatography on Sephadex G-200 and isoelectric focusing with an approximate yield of 30% and a 1000-fold purification. The molecular weight of the subunit obtained by sodium dodecyl sulphate electrophoresis was 65 800. So20,w was 11.6 +/- 0.24. The pH-optimum was 6.6-6.7 and the spectrum showed a major peak at 405 nm and shoulders at 500, 540 and 625 nm typical for catalase. The electrophoretic mobility was towards the anode at pH 8.6 and identical to normal granulocyte and erythrocyte catalase. These three species of catalase gave the reaction of identity on immunodiffusion and crossed immunoelectrophoresis. The content of catalase and its activity of isolated granulocytes were approximately identical in normal and chronic myeloid leukemia granulocytes while the specific activity of leukemic catalase was higher than normal. No difference in catalase content was found between mature and immature leukemic granulocytes.
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PMID:Purification of human granulocyte catalase in chronic myeloid leukemia. 40 30

Several conditions for the immunoperoxidase staining on terminal deoxynucleotidyl transferase (TdT) were surveyed in leukemic cells. Fixation of the slides in methanol containing 0.03% hydrogen peroxide for 30 min obliterated endogenous peroxidase completely. Pretreatment of the slides with normal goat serum diminished nonspecific staining effectively. Replacement of rabbit anti-TdT serum with non-immune rabbit IgG gave negative staining in the slides from TdT+ cases. The presence or the absence of TdT and % TdT+ cells determined by this method were in concordance with those assessed by immunofluorescence (IF) or by biochemical assay. Therefore, the immunoperoxidase staining provides an easy and dependable method to survey TdT by bright-field microscopy. The peroxidase+ small granules were detected in the nucleus of the blasts from TdT+ ALL cases. However, in two of four cases with CML in blast crisis peroxidase+ granules were distributed in the cytoplasm as well as in the nucleus. This finding suggests that blasts of some CML cases in blast crisis have phenotypic characteristics similar to some population of TdT+ cells in thymocytes.
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PMID:Detection of terminal deoxynucleotidyl transferase (TdT)-positive leukemia cells by an immunoperoxidase staining. 637 13

The first 10 bone marrow transplantations (BMT), 6 of the allogenic (allo-BMT) and 4 autologous (auto-BMT) were performed from February to June 1994 in Byelarus Center for Bone Marrow Transplantation. Two of the patients were experiencing the first complete remission of acute lymphoblastic leukemia (ALL), one of them - the first ALL recurrence, three patients with acute myeloblastic leukemia had the first complete remission, four patients had a chronic phase of chronic myeloid leukemia. In auto-BMT bone marrow (BM) was stored in liquid hydrogen after programmed freezer. An average yield of nucleated cells (NC) after taking and separation of allo-BM made up 3.0 x 10(8) cell/kg and 2.7 x 10(8) cell/kg in auto-BMT. After thawing of BM NC yield reached 1.5 x 10(8) cell/kg (0.8-2.3) x 10(8) cell/kg. CFU concentrations persisted at 24.7 x 10(4) (5.0-40.4) x 10(4) cell/kg body weight. The mean duration of leukocyte, neutrophil and platelet rise to the levels of over 1.0 x 10(9)/l, 0.5 x 10(9)/l, 20 x 10(9) cell/l, respectively, and the last time red cells were transfused were 23 (19-33), 23 (19-31), 22 (9-51), 4.5 (0-19), respectively. One ALL (first complete remission) patient died on day 52 after allo BMT of severe hepatic venous-occlusive disease. The other ALL patient (the first relapse) developed another relapse on day 112 after BMT. The rest 8 patients are in satisfactory condition.
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PMID:[First results of bone marrow transplantation in acute and chronic leukemia at the Byelarus Center for Bone Marrow Transplantation]. 759 68

We have isolated signal transduction inhibitors of low molecular weight from microorganisms and plants. Since inducers of differentiation and apoptosis may be developed as new anticancer agents, we have studied induction of differentiation and apoptosis in neoplastic cells by our signal transduction inhibitors. Aristeromycin isolated as an Abl function inhibitor induced erythroid differentiation in human CML K562 cells. Aristeromycin may induce differentiation by inhibition of methylating reactions in the cell. We isolated dephostatin from Streptomyces as a tyrosine phosphatase inhibitor, and synthesized its stable analogue, 3,4-dephostatin. The stable analogue, 3,4-dephostatin, potentiated NGF-induced morphological differentiation in rat pheochromocytoma PC12h cells, possibly by inhibition of tyrosine dephosphorylation of MAPK. Erbstatin, a tyrosine kinase inhibitor, induced morphological apoptosis and internucleosomal DNA fragmentation in mouse leukemia L1210 and human SCLC cells. Erbstatin was shown to induce apoptosis by hydrogen peroxide formation. Thus, these signal transduction inhibitors appear to be useful tools for the mechanistic study of cellular differentiation and apoptosis.
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PMID:Induction of cellular differentiation and apoptosis by signal transduction inhibitors. 938 83

Peroxyacetyl nitrate (PAN), an ubiquitous air pollutant, induced apoptosis in human leukemia HL-60, human chronic myelogenous leukemia K-562, and mouse monocyte-macrophage RAW 264.7 cell lines. In the HL 60 cells, characteristic apoptosis morphology could be observed 4 h after the cells were treated with 50 microM PAN. Exposure of HL-60 cells to increasing concentrations of PAN (from 1 microM to 100 microM) confirmed the concentration dependence of apoptosis as evidenced by DNA fragmentation in HL-60 cells, chromatin condensation by acridine-orange staining, and the appearance of the DNA apoptotic peak in flow cytometry. During apoptosis in HL-60 cells, 3-nitrotyrosine and 3,5-dinitrotyrosine were detected by high-performance liquid chromatography and liquid chromatography-mass spectrometry-mass spectrometry. We hypothesized that PAN might induce cell death in human leukemia cells by releasing peroxynitrite and other reactive oxygen species (ROS) such as superoxide and hydrogen peroxide. Moreover, exogenous superoxide dismutase promoted PAN-induced apoptosis, and in contrast, a combination of superoxide dismutase and catalase suppressed this apoptosis. We also hypothesize that the generation of ROS during PAN-induced apoptosis in HL-60 cells could activate stress-activated protein kinase/jun N-terminal kinase activity. The formation of H2O2 produced from the dismutation of PAN-elicited superoxide anion contributed to the apoptotic mechanism in HL-60 cells through ROS pathways. These findings suggested that induction of apoptosis by the air pollutant PAN might occur as a result of the release of ROS.
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PMID:Peroxyacetyl nitrate-induced apoptosis through generation of reactive oxygen species in HL-60 cells. 1041 Nov 46

The BCR/ABL oncogene causes chronic myelogenous leukemia, a myeloproliferative disorder characterized by clonal expansion of hematopoietic progenitor cells and myeloid cells. It is shown here that transformation of the hematopoietic cell lines Ba/F3, 32Dcl3, and MO7e with BCR/ABL results in an increase in reactive oxygen species (ROS) compared with quiescent, untransformed cells. The increase in ROS was directly due to BCR/ABL because it was blocked by the ABL-specific tyrosine kinase inhibitor STI571. Oxidative stress through ROS is believed to have many biochemical effects, including the potential ability to inhibit protein-tyrosine phosphatases (PTPases). To understand the significance of increased production of ROS, a model system was established in which hydrogen peroxide (H(2)O(2)) was added to untransformed cells to mimic the increase in ROS induced constitutively by BCR/ABL. H(2)O(2) substantially reduced total cellular PTPase activity to a degree approximately equivalent to that of pervanadate, a well known PTPase inhibitor. Further, stimulation of untransformed cells with H(2)O(2) or pervanadate increased tyrosine phosphorylation of each of the most prominent known substrates of BCR/ABL, including c-ABL, c-CBL, SHC, and SHP-2. Treatment of the BCR/ABL-expressing cell line MO7/p210 with the reducing agents pyrrolidine dithiocarbamate or N-acetylcysteine reduced the accumulation of ROS and also decreased tyrosine phosphorylation of cellular proteins. Further, treatment of MO7e cells with H(2)O(2) or pervanadate increased the tyrosine kinase activity of c-ABL. Drugs that alter ROS metabolism or reactivate PTPases may antagonize BCR/ABL transformation.
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PMID:The BCR/ABL tyrosine kinase induces production of reactive oxygen species in hematopoietic cells. 1083 15

Engagement of the receptor for advanced glycation end products (RAGE) by products of nonenzymatic glycation/oxidation triggers the generation of reactive oxygen species (ROS), thereby altering gene expression. Because dissection of the precise events by which ROS are generated via RAGE is relevant to the pathogenesis of complications in AGE-related disorders, such as diabetes and renal failure, we tested the hypothesis that activation of NADPH oxidase contributed, at least in part, to enhancing oxidant stress via RAGE. Here we show that incubation of human endothelial cells with AGEs on the surface of diabetic red blood cells, or specific AGEs, (carboxymethyl)lysine (CML)-modified adducts, prompted intracellular generation of hydrogen peroxide, cell surface expression of vascular cell adhesion molecule-1, and generation of tissue factor in a manner suppressed by treatment with diphenyliodonium, but not by inhibitors of nitric oxide. Consistent with an important role for NADPH oxidase, although macrophages derived from wild-type mice expressed enhanced levels of tissue factor upon stimulation with AGE, macrophages derived from mice deficient in a central subunit of NADPH oxidase, gp91phox, failed to display enhanced tissue factor in the presence of AGE. These findings underscore a central role of NADPH oxidase in AGE-RAGE-mediated generation of ROS and provide a mechanism for altered gene expression in AGE-related disorders.
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PMID:Activation of NADPH oxidase by AGE links oxidant stress to altered gene expression via RAGE. 1128 50

Clinical studies with the Abl tyrosine kinase inhibitor STI-571 in chronic myeloid leukemia demonstrate that many patients with advanced stage disease respond initially but then relapse. Through biochemical and molecular analysis of clinical material, we find that drug resistance is associated with the reactivation of BCR-ABL signal transduction in all cases examined. In six of nine patients, resistance was associated with a single amino acid substitution in a threonine residue of the Abl kinase domain known to form a critical hydrogen bond with the drug. This substitution of threonine with isoleucine was sufficient to confer STI-571 resistance in a reconstitution experiment. In three patients, resistance was associated with progressive BCR-ABL gene amplification. These studies provide evidence that genetically complex cancers retain dependence on an initial oncogenic event and suggest a strategy for identifying inhibitors of STI-571 resistance.
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PMID:Clinical resistance to STI-571 cancer therapy caused by BCR-ABL gene mutation or amplification. 1156 95

Normal aerobic metabolism is associated with the production of reactive oxygen species (ROS) and, consequently, the induction of apoptosis and necrosis. The cell death response to oxidative stress is thought to contribute to aging, neurological degeneration, and other disorders. ROS-induced apoptosis and necrosis involves activation of the cytoplasmic c-Abl tyrosine kinase and thereby signaling to mitochondria. Herein, we show that STI571, an inhibitor of Bcr-Abl in chronic myelogenous leukemia, blocks activation of c-Abl in the response of mouse embryo fibroblasts and human U-937 myeloid leukemia cells to hydrogen peroxide (H(2)O(2)). Immunofluorescence microscopy and subcellular fractionation studies demonstrate that STI571 decreases H(2)O(2)-induced targeting of c-Abl to mitochondria in the two cell types by 59 to 85%. The results also show that STI571 attenuates H(2)O(2)-induced loss of the mitochondrial transmembrane potential. In concert with these effects, STI571 inhibits the death response to H(2)O(2) exposure by 40 to 80% depending on the cell type. These findings indicate that inhibition of c-Abl signaling by STI571 attenuates mitochondrial dysfunction and cell death in the cellular response to oxidative stress.
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PMID:Abrogation of the cell death response to oxidative stress by the c-Abl tyrosine kinase inhibitor STI571. 1252 98


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