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

Arginine-rich and lysine-rich histones were extracted from various cytologic types of leukemic blasts and from preparations rich in normal monocytes. On polyacrylamide disc electrophoresis, the patterns of normal monocyte histones closely resembled those found in acute histiomonocytic leukemia (Schilling type). The electrophoretic patterns of histones obtained from leukemic blasts in acute myelomonocytic leukemia (Naegeli type) were similar to those found in both acute myelobastic leukemia and chronic granulocytic leukemia. The results support the concept that acute myelomonocytic leukemia may be closely related to, or a variant of, acute myeloblastic leukemia, and that acute histiomonocytic leukemia is most probably a monocytic rather than a myeloblastic disorder. In addition to accepted morphologic and enzymatic criteria, the present studies suggest that differences in histone patterns might be useful in further distinguishing between histiomonocytic, myeloblastic, and myelomonocytic leukemias.
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PMID:Histone abnormalities in adult acute leukemias. 105 65

IL-8 and its structural analogs derived from blood platelets have been proposed as stimuli of IgE-independent basophil activation. In order to clarify the mechanism of action of these peptides, we examined the effects of pure IL-8, connective tissue-activating peptide III (CTAP-III), neutrophil-activating peptide 2 (NAP-2), and platelet factor 4 (PF-4) on blood basophils with and without pretreatment by IL-3, which modulates mediator release. After pretreatment with IL-3, significant histamine release was observed with 10(-8) M and 10(-7) M IL-8 and 10(-7) M NAP-2, but not with the other peptides. At higher concentrations (10(-6) M), however, all IL-8 analogs, as well as the unrelated cationic peptides poly-D-lysine, histone VS, and lysozyme, induced histamine release to variable degrees. Binding and competition studies with [125I]IL-8 revealed specific IL-8R on basophils from a patient with chronic myelogenous leukemia and normal individuals. From 3500 to 9600 receptors with a mean Kd value of 0.15 nM were found on average per chronic myelogenous leukemia and normal basophil, respectively. NAP-2 weakly competed for IL-8 binding. IL-8 and, to a lesser extent, NAP-2 led to a transient rise of cytosolic free calcium concentration ([Ca2+]i), which was independent of a preexposure to IL-3. IL-8 prevented the [Ca2+]i rise induced by NAP-2, but did not influence [Ca2+]i responses to other agonists, e.g. C5a, C3a, or platelet-activating factor. IL-8 induced [Ca2+]i changes and histamine release in IL-3-primed basophils were pertussis toxin sensitive. CTAP-III or PF-4 did not compete for IL-8 binding, did not induce [Ca2+]i changes, and did not influence the [Ca2+]i response to IL-8 and NAP-2. This study shows that IL-8 and NAP-2 activate human basophils by a receptor-mediated mechanism similar to that operating in neutrophils. At high concentrations histamine release can also be induced by cationic peptides by a mechanism that does not involve the IL-8R, and probably depends on cationic interactions.
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PMID:Activation of human basophils through the IL-8 receptor. 138 21

The membrane protein kinase C (PKC) content was found to be higher in erythrocytes form patients suffering from chronic myelogenous leukemia (CML) compared to normal erythrocytes. PKC activity was also higher in the cytosol and after translocation to the membrane, as assessed by histone phosphorylation. The increased PKC activity in CML erythrocytes was associated with abnormal phosphorylation of protein 4.1. Since phosphorylation-dephosphorylation mechanisms are likely candidates for controlling membrane protein associations, the altered PKC activity may be one of the factors responsible for altered thermal sensitivity and mechanical stability of CML erythrocytes.
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PMID:Altered erythrocyte protein kinase C activity and membrane protein phosphorylation in chronic myelogenous leukemia. 201 93

Human myeloid cell nuclear differentiating antigen (MNDA) is a Mr 55,000 non-histone basic nuclear protein expressed in myeloid leukemia cell lines that are at late stages of differentiation (HL-60 and U937) and in normal granulocytes and monocytes, but is not present in lymphoid cells or in other human cells and tissues tested. Affinity purified monospecific polyclonal antibodies and rat monoclonal antibodies have been developed for the immunocytochemical detection of MNDA. Using these antibodies, we surveyed 21 cases of acute leukemia classified by French-American-British (FAB) Group criteria, two cases of biphenotypic acute leukemia and one case of blast crisis of chronic granulocytic leukemia for the presence of MNDA. The most intense staining reactions were present in the nuclei of two cases of acute promyelocytic (FAB M3) leukemia. MNDA was not detected in three of five cases of acute myeloblastic leukemia without maturation (FAB M1). The remaining two cases of the M1 category showed weak to moderate staining. No staining reaction was seen in acute lymphocytic leukemia (ALL), biphenotypic leukemia or the lymphoid blast crisis of chronic granulocytic leukemia. Variable staining reactions were demonstrated in the remaining cases. These data suggest that the presence of MNDA is correlated with myeloid and monocytic differentiation in acute leukemia, being strongly expressed in M3 type, often not detected in M1 leukemia and absent in ALL.
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PMID:Expression of human myeloid cell nuclear differentiation antigen (MNDA) in acute leukemias. 225 28

The pattern of protein kinase activity in leukemic cells from patients with chronic myelocytic leukemia, acute myeloblastic leukemia, acute monocytic leukemia, chronic lymphocytic leukemia, and acute lymphoblastic leukemia was studied and compared with normal peripheral blood granulocytes and lymphocytes. Our data showed that: (a) histone kinase activity was slightly lower in leukemic cells than in normal cells, whereas casein kinase activity was 2- to 3-fold higher in leukemic cells; (b) cyclic adenosine 3':5'-monophosphate stimulated 1.4- to 1.6-fold histone kinase activity of both normal and leukemic cells, whereas it did not stimulate casein kinase activity; (c) the ratio of histone kinase activities to casein kinase activities correlated directly with the maturation of the white blood cells; and (d) histone and casein kinase activities of extracts from normal and leukemic cells behaved similarly on chromatography on phosphocellulose and casein/Sepharose 4B. These results suggest that the increase in casein kinase activity is not due to the appearance of a new type of casein kinase but to an increase of the casein kinases 1 and 2 present in normal cells.
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PMID:Cyclic adenosine 3':5'-monophosphate-dependent and -independent protein kinases in human leukemic cells. 629 19

Here we demonstrate that treatment with SAHA (suberoylanilide hydroxamic acid), a known inhibitor of histone deacetylases (HDACs), alone induced p21 and/or p27 expressions but decreased the mRNA and protein levels of Bcr-Abl, which was associated with apoptosis of Bcr-Abl-expressing K562 and LAMA-84 cells. Cotreatment with SAHA and imatinib (Gleevec) caused more down-regulation of the levels and auto-tyrosine phosphorylation of Bcr-Abl and apoptosis of these cell types, as compared with treatment with either agent alone (P <.05). This finding was also associated with a greater decline in the levels of phospho-AKT and Bcl-x(L). Significantly, treatment with SAHA also down-regulated Bcr-Abl levels and induced apoptosis of CD34(+) leukemia blast progenitor cells derived from patients who had developed progressive blast crisis (BC) of chronic myelocytic leukemia (CML) while receiving therapy with imatinib. Taken together, these findings indicate that cotreatment with SAHA enhances the cytotoxic effects of imatinib and may have activity against imatinib-refractory CML-BC.
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PMID:Cotreatment with the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) enhances imatinib-induced apoptosis of Bcr-Abl-positive human acute leukemia cells. 1244 42

Reactive carbonyl species (RCS) are potent mediators of cellular carbonyl stress originating from endogenous chemical processes such as lipid peroxidation and glycation. Skin deterioration as observed in photoaging and diabetes has been linked to accumulative protein damage from glycation, but the effects of carbonyl stress on skin cell genomic integrity are ill defined. In this study, the genotoxic effects of acute carbonyl stress on HaCaT keratinocytes and CF3 fibroblasts were assessed. Administration of the alpha-dicarbonyl compounds glyoxal and methylglyoxal as physiologically relevant RCS inhibited skin cell proliferation, led to intra-cellular protein glycation as evidenced by the accumulation of N(epsilon)-(carboxymethyl)-L-lysine (CML) in histones, and caused extensive DNA strand cleavage as assessed by the comet assay. These effects were prevented by treatment with the carbonyl scavenger D-penicillamine. Both glyoxal and methylglyoxal damaged DNA in intact cells. Glyoxal caused DNA strand breaks while methylglyoxal produced extensive DNA-protein cross-linking as evidenced by pronounced nuclear condensation and total suppression of comet formation. Glycation by glyoxal and methylglyoxal resulted in histone cross-linking in vitro and induced oxygen-dependent cleavage of plasmid DNA, which was partly suppressed by the hydroxyl scavenger mannitol. We suggest that a chemical mechanism of cellular DNA damage by carbonyl stress occurs in which histone glycoxidation is followed by reactive oxygen induced DNA stand breaks. The genotoxic potential of RCS in cultured skin cells and its suppression by a carbonyl scavenger as described in this study have implications for skin damage and carcinogenesis and its prevention by agents selective for carbonyl stress.
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PMID:DNA damage by carbonyl stress in human skin cells. 1251 11

Treatment with LAQ824 (Novartis Pharmaceutical, Inc.), a cinnamyl hydroxamic acid analogue inhibitor of histone deacetylases, depleted the mRNA and protein expression of Bcr-Abl in human chronic myeloid leukemia blast crisis (CML-BC) cells. Exposure to LAQ824 induced the expression of the cell cycle-dependent kinase inhibitors p21 and p27 and caused cell cycle G(1)-phase accumulation and apoptosis of CML-BC cells. LAQ824 also induced acetylation of heat shock protein 90. This inhibited the chaperone association of Bcr-Abl with heat shock protein 90, thereby promoting the proteasomal degradation of Bcr-Abl. Cotreatment with LAQ824 increased imatinib mesylate-induced apoptosis of CML-BC cells. Additionally, LAQ824 down-regulated the levels of mutant Bcr-Abl possessing the T315I point mutation, as well as induced apoptosis of imatinib-refractory primary CML-BC cells. Therefore, LAQ824 may be a promising therapeutic agent in the treatment of imatinib-sensitive or -refractory human leukemia.
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PMID:Histone deacetylase inhibitor LAQ824 both lowers expression and promotes proteasomal degradation of Bcr-Abl and induces apoptosis of imatinib mesylate-sensitive or -refractory chronic myelogenous leukemia-blast crisis cells. 1294 44

We show that common heterochromatin antigenic protein markers [HP1alpha, -beta, -gamma and mono-, di-, and trimethylated histone H3 lysine 9 (H3K9)], although present in human blood progenitor CD34+ cells, differentiated lymphocytes, and monocytes, are absent in neutrophil granulocytes and to large extent, in eosinophils. Monomethylated and in particular, dimethylated H3K9 are present to variable degrees in the granulocytes of chronic myeloid leukemia (CML) patients, without being accompanied by HP1 proteins. In patients with an acute phase of CML and in acute myeloid leukemia patients, strong methylation of H3K9 and all isoforms of HP1 are detected. In chronic forms of CML, no strong correlations among the level of histone methylation, disease progression, and modality of treatment were observed. Histone methylation was found even in "cured" patients without Philadelphia chromosome (Ph) resulting from +(9;22)(q34;q11) BCR/ABL translocation, suggesting an incomplete process of developmentally regulated chromatin remodeling in the granulocytes of these patients. Similarly, reprogramming of leukemia HL-60 cells to terminal differentiation by retinoic acid does not eliminate H3K9 methylation and the presence of HP1 isoforms from differentiated granulocytes. Thus, our study shows for the first time that histone H3 methylation may be changed dramatically during normal cell differentiation. The residual histone H3 methylation in myeloid leukemia cells suggests an incomplete chromatin condensation that may be linked to the leukemia cell proliferation and may be important for the prognosis of disease treatment and relapse.
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PMID:Methylation of histones in myeloid leukemias as a potential marker of granulocyte abnormalities. 1550 73

Expression of BCR-ABL is the leading cause of chronic myelogenous leukemia. In chronic myelogenous leukemia cells, c-Abl expression is silenced by promoter methylation. In addition, the level of c-Abl needs to be tightly and constantly regulated due to its cytotoxicity and its rapid degradation after activation. Yet the regulation of c-Abl expression remains unclear. In an effort to gain better understanding of c-Abl function, we performed a glutathione S-transferase-Abl pull-down screen and identified TopBP1, a topoisomerase IIbeta-binding protein that contains Brca1 C-terminal motifs and has been implicated in DNA damage response. Their physical interaction was verified by in vitro and in vivo assays with TopBP1 found as a substrate of Abl proteins. TopBP1 could repress the expression of c-Abl at both mRNA and protein levels. Reporter assays indicate that TopBP1 directly repressed the promoter activity of c-Abl. Furthermore, TopBP1 repressed expression of c-Abl through a novel mechanism that involved histone deacetylation and DNA methylation. This transcriptional repression was inhibited by c-Abl in a kinase-dependent manner. The dual antagonistic interplay between c-Abl and TopBP1 may also provide a mechanism for fine-tuning of c-Abl levels.
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PMID:Identification of TopBP1 as a c-Abl-interacting protein and a repressor for c-Abl expression. 1596 88


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