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)

Neutrophil granulocytes are the most important white blood cells in the combat of non-viral infections. Circumstantial evidence indicates that neutrophils in addition modulate the inflammatory process. Production of neutrophils takes place in the bone marrow, and mature cells egress to the circulation. Neutrophils emigrate following activation from the vessels into the tissues (chemotaxis). During this process neutrophils generate reactive oxygen species (respiratory burst) and mobilize intracellular compartments (degranulation). By degranulation, neutrophils exercise influence on nearby cells or bacteria by extracellular release of intragranular proteins (exocytosis), and intensify plasma membrane-related processes, such as chemotaxis and respiratory burst, by translocation of membrane-bound proteins to the surface (upregulation). Ultimately, microorganisms may be killed intracellularly following engulfment (phagocytosis). The thesis presents results of protein-chemical analysis of human neutrophils, based on studies of intact cells and subcellular structures (subcellular fractionation). By fractionation, azurophil granules and specific granules can be disunited from each other and from plasma membrane and secretory vesicles. Only partial separation of plasma membrane and secretory vesicles can be obtained. Subcellular structures are identified by markers, e.g. vitamin B12 binding protein for specific granules, and latent alkaline phosphatase for secretory vesicles. The studies demonstrated tetranectin in neutrophils, localized exclusively in the secretory vesicles. Tetranectin was released by incubation of neutrophils in the presence of weak, inflammatory stimuli and paralleled the upregulation of alkaline phosphatase, but preceded degranulation of specific granules. Alkaline phosphatase has previously been employed as a plasma membrane marker. A novel ELISA for HLA class I antigen was introduced as a new plasma membrane marker. Results obtained by this assay showed upregulation of alkaline phosphatase occurring without a concurrent redistribution of HLA antigen. This indicates that the two proteins are localized in separate compartments. Upregulation of alkaline phosphatase induced by weak stimuli, however, paralleled the translocation of cytochrome b559, anticipated to be the terminal component in the respiratory burst, and known to be localized primarily in the specific granules. The present studies indicate that 15% of cytochrome b is localized in the secretory vesicles. An ELISA was established for quantitation of beta 2-microglobulin, the light chain of HLA class I antigens. The concentration of beta 2-microglobulin in plasma from patients with chronic myeloid leukaemia was found to correlate with the concentration of vitamin B12 binding protein.4+ Measurements in neutrophils demonstrated 65% of the total content of beta 2-microglobulin to be localized in the specific granules, and 20% to be present in secretory vesicles.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Human neutrophil structure and function with special reference to cytochrome b559 and beta 2-microglobulin. 849 95

Urinary neopterin levels, blood dihydropteridine reductase activity as well as other frequently used clinical parameters were evaluated in 110 patients suffering from various types of lymphomas and leukemias. Among them neopterin was detected as the most sensitive marker representing the severity of malignancy (p<0.00001). All patients with active diseases had significantly raised urinary neopterin levels compared to those in remission and healthy controls. Of 69 patients with active disease 66 (96%) were above the upper limit seen in healthy subjects. In addition, the highest neopterin excretion was found in patients with active chronic myeloid leukemia (1469+/-479 micromol/mol creatinine n=16). In contrast, only 1 of 41 patients in stable responsive disease and remission (2.4%) had increased urinary neopterin levels above the upper limit. Dihydropteridine reductase (DHPR) activities were also detected in all patients and control groups. In active disease slightly reduced (DHPR) activities were evident (3.42+/-0.37 for controls, 2.92+/-0.39 in active disease and 3.28+/-0.42 nmol red cytochrome C/min/5 mm diameter disc in remission patients). However in patients under medication this was strengthened. This data also suggest that DHPR activity can be effected by chemotherapy. The results of the present study support the fact that urinary neopterin levels may be an useful and reliable early prognostic marker for neoplasia when used together with other prognostic indicators. Our data also suggest that reductions in DHPR activities may also be an underlying cause for the neurological disorders that are commonly seen in patients with haematological malignancies.
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PMID:Dihydropteridine reductase activity and neopterin levels in leukemias and lymphomas: is there any correlation between these two parameters? 1070 61

Apaf-1 protein deficiency occurs in human leukaemic blasts and confers resistance to cytochrome-c-dependent apoptosis. Demethylation treatment with 5-aza-2'-deoxycytidine (5aza2dc) increased the sensitivity of the K562 leukaemic cell line to UV light-induced apoptosis in association with increased Apaf-1 protein levels. There was no correlation between Apaf-1 protein expression and Apaf-1 mRNA levels after the demethylation treatment. Methylation-specific polymerase chain reaction was used to show that the methylation can occur within the Apaf-1 promoter region in leukaemic blasts. Apaf-1 DNA methylation was demonstrated in acute myeloid leukaemia, chronic myeloid leukaemia and acute lymphoid leukaemia, suggesting that it is not specific to a particular leukaemia subtype. Apaf-1 protein expression did not correlate with Apaf-1 mRNA levels in human leukaemic blasts. Some leukaemic cells expressed high levels of Apaf-1 mRNA but low levels of Apaf-1 protein. This study suggests that Apaf-1 DNA promoter methylation might contribute to the inactivation of Apaf-1 expression. However, Apaf-1 protein levels might also be controlled at post-transcription level.
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PMID:Role of DNA methylation in the suppression of Apaf-1 protein in human leukaemia. 1254 66

The inhibition by imatinib of the cytochrome p450 3A4 isoenzyme may reduce the CYP3A4-mediated metabolic clearance of clinically important coadministered drugs. The main purpose of this study was to evaluate the effect of the coadministration of imatinib on the pharmacokinetics of simvastatin, a probe CYP3A4 substrate. In total, 20 patients with chronic myeloid leukaemia received an oral dose of 40 mg of simvastatin on study day 1. On study days 2-7, each patient received 400 mg of imatinib once daily orally and on study day 8, 400 mg imatinib together with 40 mg of simvastatin was given. Blood levels of simvastatin were measured predose and for 24 h postdose on study days 1 and 8. Two additional blood samples were taken for imatinib pharmacokinetic (PK) assessment on day 8 before, and 24 h after, imatinib administration. Imatinib increased the mean maximum concentration (C(max)) value of simvastatin two-fold and the area under concentration-time curve (AUC ((0-inf))) value 3.5-fold (P<0.001) compared with simvastatin alone. There was a statistically significant decrease in total-body clearance of drug from the plasma (CL/F) with a mean reduction of 70% for simvastatin (P<0.001): the mean half-life of simvastatin was prolonged from 1.4-2.7 h when given together with imatinib. No changes in imatinib PK parameters were found when given concomitantly with simvastatin. In conclusion, the coadministration of imatinib at steady state with 40 mg simvastatin increases the exposure (C(max) and AUCs) of simvastatin significantly (P<0.001) by two-three-fold. Caution is therefore required when administering imatinib with CYP3A4 substrates with a narrow therapeutic window. The coadministration of simvastatin with imatinib (400 mg) was well tolerated and no major safety findings were reported in this study.
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PMID:Effects of imatinib mesylate (STI571, Glivec) on the pharmacokinetics of simvastatin, a cytochrome p450 3A4 substrate, in patients with chronic myeloid leukaemia. 1461 92

The purpose of study was to explore the possible functions of Bcl-xL in the glucosamine sulfate-induced apoptosis of chronic myeloid leukemia K562 cells. Light microscopy and Wright-Giemsa staining were used to investigate the morphologic evidences for apoptosis of K562 cells induced by glucosamine sulfate (GS); immunofluorescence was used to observe the translocation of cathepsin D and cytochrome C during the apoptosis; Western blot was performed to detect the expression of Bcl-xL, Bid, Bax in K562 cells treated by GS. The results showed that many vacuoles were observed in the cytoplasma of the K562 cells treated by GS; fluorescent signals of cathepsin D and cytochrome were fransformed from granules to disperse form by using immunofluorescence; the expression of Bcl-xL was found down-regulated in K562 cells treated by GS, but not in the cells pre-treated with pepstatin A; the significant changes were not detected in expression of Bax and Bid protein before or after apoptosis. It is concluded that Bcl-xL protein may mediate relationship between cathepsin D and mitochondia pathway, Cathepsin D may play an important role in the GS inducing apoptosis of K562 cells through downregulation of Bcl-xL expression.
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PMID:[Role of Bcl-xL in the cathepsin D-associated apoptosis of K562 cells]. 1597 24

Imatinib is a specific and potent inhibitor of the BCR-ABL tyrosine kinase. Several clinical trials have demonstrated the efficacy of imatinib in chronic myeloid leukemia. Adverse cutaneous reactions induced by imatinib are frequent and may be dose related. We report a case of an unusual pustular eruption in a patient with chronic myeloid leukemia, who received high doses imatinib for blast crisis and later voriconazole for invasive pulmonary aspergillosis. At the time of his skin eruption, elevated plasma levels of imatinib were recorded. Imatinib is primarily metabolized by the cytochrome CYP3A4. Voriconazole is a cytochrome CYP3A4 inhibitor and can lead to high plasma levels of imatinib. This case suggests that severe drug reactions to imatinib may be related not only to imatinib doses, but also to elevated plasma drug levels resulting from pharmacokinetic interactions. The monitoring of imatinib plasma levels may be of help for identifying patients at risk for severe toxicity.
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PMID:Severe pustular eruption associated with imatinib and voriconazole in a patient with chronic myeloid leukemia. 1628 35

Chronic myeloid leukemia (CML) is characterized by the presence of chimeric protein BCR-ABL associated with high tyrosine kinase (TK) activity, which leads to cell tumorogenicity, resistance to apoptosis, and differentiation. Gossypol is a natural polyphenolic compound isolated from cottonseed and has antiproliferative activity in a variety of cancer cell lines. (-)Gossypol is proved the potent component. Here we examined the growth inhibitory effect of (-)gossypol and its combination with imatinib in K562 cells. (-)Gossypol inhibited cell growth, promoted apoptosis, induced DeltaPsim loss, and cytochrome C release. Furthermore, (-)gossypol had a synergistic inhibitory effect on growth in K562 cells when combined with imatinib. Enhanced apoptosis, cytochrome C release, and caspase 3 cleavage as well as noticeable decrease of Mcl-1 and Bcl-XL were observed in K562 cells treated with both (-)gossypol and imatinib. These results suggest that (-)gossypol induced apoptosis in K562 cells through a mitochondria pathway and that the combination of imatinib and (-)gossypol might be an effective treatment for CML.
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PMID:(-)Gossypol and its combination with imatinib induce apoptosis in human chronic myeloid leukemic cells. 1792 90

This study was aimed to investigate the role of mitochondria pathway in signal transduction of chronic myeloid leukemia (CML). After bcr3/abl2 antisense oligodeoxynucleotide (ASO) was introduced into CML cell line K562 cells by liposomal transfection, the cell viability was detected by MTT assay, the cell apoptosis was determined by flow cytometry (FCM), the mitochondrial membrane potential (DeltaPsi) was labeled by Rhodamine 123 and examined by FCM, and the expression of mitochondrial apoptosis signal transduction pathway related proteins cytochrome C was analyzed by Western blot. The results showed that after K562 cells were exposed to 2 micromol/L of bcr3/abl2 ASO for 24 hours, bcr3/abl2 ASO significantly inhibited cell viability with inhibitory rate of 65.7%, induced the apoptosis of K562 cell line with apoptotic rate of 16.9%, and decreased mitochondrial Deltapsi of K562 cells with the reducing rate of 38.33%, enhanced the expression of cytochrome C with increase of optical density value from 2.33 +/- 0.3 to 4.78 +/- 0.1 by laser photometric scanning. It is concluded that mitochondria pathway plays an important role in signal transduction of chronic myeloid leukemia by directing apoptotic signal transduction.
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PMID:[Role of mitochondria pathway in signal transduction of chronic myeloid leukemia]. 1937 50

In comparison with four tumor cell lines and three non transformed cell types, chronic myeloid leukemia K562 cells were selectively sensitive to proliferation inhibition by the oxoindole derivative XJW20, as determined by the MTT assay. Further investigation revealed that XJW20 selectively induced G2/M arrest and apoptosis in K562 cells. At the molecular level, XJW20-induced G2/M arrest was accompanied by up-regulation of cyclin B1 and phospho (p)-Cdc25C (Ser216) and down-regulation of CDK1. There is no change in the expression of CDK2. The increased apoptotic activity by XJW20 was characterized by an increase in reactive oxygen species (ROS) generation, the mitochondrial transmembrane potential (DeltaPsi(m)) dissipation, cytochrome C releasing, apoptotic nuclei (AO/EB double staining) and nuclei condensation (DAPI-staining). The down-regulation of phosphorylated ERK was also found in XJW20-treated K562 cells. These molecular events induced by XJW20 may provide insight into the mechanism of action that led to growth arrest and apoptosis.
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PMID:XJW20, a novel oxoindole derivative, induces G2/M arrest and apoptosis selectively in K562 leukemia cell line. 1988 35

Objectives. Using apocynin (inhibitor of NADPH oxidase), and Mitoquinol 10 nitrate (MitoQ; mitochondrial-targeted antioxidant), we addressed the importance of mitochondria versus NADPH oxidase-derived ROS in glucose-induced apoptosis of pericytes. Methods. NADPH oxidase was localised using Western blot analysis and cytochrome C reduction assay. Apoptosis was detected by measuring caspase-3 activity. Intracellular glucose concentration, ROS formation and Nepsilon-(carboxymethyl) lysine (CML) content were measured using Amplex Red assay kit, dihydroethidium (DHE), and competitive immunoabsorbant enzyme-linked assay (ELISA), respectively. Results. NADPH oxidase was localised in the cytoplasm of pericytes suggesting ROS production within intracellular compartments. High glucose (25 mM) significantly increased apoptosis, intracellular glucose concentration, and CML content. Apoptosis was associated with increased gp91phox expression, activity of NADPH oxidase, and intracellular ROS production. Apocynin and not MitoQ significantly blunted the generation of ROS, formation of intracellular CML and apoptosis. Conclusions. NADPH oxidase and not mitochondria-derived ROS is responsible for the accelerated apoptosis of pericytes in diabetic retinopathy.
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PMID:NADPH Oxidase versus Mitochondria-Derived ROS in Glucose-Induced Apoptosis of Pericytes in Early Diabetic Retinopathy. 2065 59


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