Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present paper we present data on the synthesis, crystal structure and biological activity of bis(dipyridamole) tetrachloroplatinate(II).dipyridamole.dihydrate, [dpmH]2 PtCl4.dpm.2H2O. The crystals are Triclinic P1 with a = 11.490(2) A, b = 13.630(2) A, c = 15.81(1) A, a = 100.97(2) degrees, beta = 100.89(3) degrees, gamma = 112.35(1) degrees, Z = 1, M = 1885.9, Dx = 1.46 g/cm3, MoK alpha (lambda = 0.71069 A), mu = 0.0184 mm-1, R = 4.4%, Rw = 5.0%, 3231 (1 > 2 sigma (I)). The structure is stabilized by a hydrogen-bonding network. It was observed that although dpm alone is not able to alter the electrophoretic mobility of pUC8 DNA forms, the synthesized Pt-dpm compound substantially modifies the DNA conformation since it significantly alters the electrophoretic mobility of nicked and closed circular forms of pUC8 DNA. However, the alteration in mobility of pUC8 DNA induced by this compound upon binding is lower than that induced by cis-DDP. The analysis of the antiproliferative activity of the Pt-dpm salt against MDA-MB 468 (breast carcinoma) and HL-60 (leukemia) human cancer cells showed that this compound has ID50 values of 0.87 microM and 0.65 microM, respectively. Interestingly, it was found out that although the dpm molecule does not present any significant antiproliferative activity, the ID50 values of Pt-dpm are about 3-fold and 7-fold lower than those of cis-DDP and K2PtCl4, respectively. Altogether the biological data suggest that in Pt-dpm a synergic effect between cation and anion is produced.
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PMID:Synthesis, crystal structure, and biological activity of a Pt-dipyridamole salt. 784 86

We characterize here an arachidonic acid (AA)-derived metabolite previously found to have an adjuvant effect in phytohemagglutinin-induced mitogenesis of lymphocytes from mothers of newborn babies and from immunodeficient infants. We named the metabolite 'compound 4' due to its position in a thin-layer chromatography system developed for isolation of eicosanoids. The compound was originally found to be produced by peripheral blood mononuclear leukocytes and the T cell leukemia line Jurcat after long-term (18-24 h) incubation with [1-14C]AA. Compound 4 is also produced by lymphocytes, monocytes, platelets, thrombocytes, cultured fibroblasts and various types of malignant cell lines. We purified this metabolite by means of high pressure liquid chromatography with synchronous detection of radioactivity and measurement of ultraviolet-light absorption at 278 nm. Proton nuclear magnetic resonance spectroscopy and mass spectrometry with electron impact techniques demonstrated that compound 4 is not an eicosanoid, but is identical to p-acetamidobenzoic acid (PACBA). The cells synthesize PACBA from p-aminobenzoic acid and a two-carbon residue from AA.
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PMID:Identification of a substance, previously shown to enhance mitogenesis of human lymphocytes, as the acetamide of p-aminobenzoic acid. 791 14

We have previously reported that polymorphonuclear granulocyte (PMN) chemiluminescence (CL) and superoxide anion production are abnormally low in patients with polycythaemia vera (PV) after simulation with n-formyl-methionyl-leucyl-phenylalanine (fMLP), but normal when elicited by phorbol myristate acetate (PMA). This study documents that both fMLP and PMA induced CL was normal in PMN from patients with chronic myelogenous leukaemia (CML) and essential thrombocythaemia (ET). Furthermore, we monitored intracellular hydrogen peroxide (H2O2) production in PMN and monocytes from patients with PV, CML and ET by flow cytometry. H2O2 production in resting and PMA-stimulated cells was normal in all diseases. So also was fMLP induced H2O2 generation in ET PMN and monocytes. In contrast, fMLP-induced H2O2 production was significantly lower both in PV PMN (1.8 +/- 0.7 mean fluorescence intensity units in PV compared to 8.4 +/- 3.4 in healthy controls; P < 0.02), and in PV monocytes (0.3 +/- 0.5 compared to 2.5 +/- 0.7 in controls; P < 0.02). A less pronounced reduction of fMLP stimulated H2O2 production was noted in CML PMN (3.8 +/- 3.1 compared to 8.4 +/- 3.4 in controls; P < 0.05), and monocytes (1.3 +/- 0.6 compared to 2.5 +/- 0.7 in controls; P < 0.05). The reduction of H2O2 generation in PV and CML PMN was not attributed to subpopulations of less responsive cells. However, one ET and one CML patient showed a subpopulation of less responsive PMN. Thus intracellular H2O2 (as well as extracellular release of superoxide ions) is reduced in fMLP-stimulated PV PMN and monocytes but normal after PMA stimulation, a phenomenon that is not consistently found in other myeloproliferative disorders.
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PMID:Studies of neutrophil and monocyte oxidative responses in polycythaemia vera and related myeloproliferative disorders. 799 85

HL-60-R, a multi-drug-resistant (MDR) subclone of the human leukemia cell line HL-60, was selected in continuous culture in doxorubicin (DOX) in the absence of mutagenic agents. When compared to the parent line HL-60, HL-60-R showed greater relative resistance to vinblastine than to etoposide, or to the selecting agent DOX. Co-exposure to verapamil, a known modulator of MDR, partially increased its sensitivity to DOX and vinblastine. The HL-60-R cell line stained positively with the P-glycoprotein-specific monoclonal antibody (MAb), C219, whereas the HL-60 parent was negative. Southern analysis showed 32-fold amplification of the mdrI gene in HL-60-R, whereas slot-blot analysis demonstrated 70-fold over-expression of the specific mdrI message in HL-60-R compared to HL-60. Northern blot analysis revealed the presence of 2 species of messenger RNA of sizes 5.1 kb and 4.5 kb. No transcripts were detectable in the parent. Flow cytometric analysis showed significantly reduced cellular retention of DOX as well as rapid efflux from the drug-resistant cell line. HL-60-R proved to be nearly 4 times more resistant to hydrogen peroxide than its parent, and 1,000 times more resistant to inhibition of cellular glutathione synthesis by D,L-buthionine sulfoximine (BSO). Verapamil modulated DOX resistance in HL-60-R incompletely but, in the presence of glutathione depletion, nearly completely reversed DOX resistance. Elevated levels of glutathione and glutathione-peroxidase activity were demonstrated, thereby implicating enhanced activity of the glutathione/glutathione-peroxidase cycle as an additional basis for its resistance to DOX. These findings suggest that an enhanced capacity for detoxifying oxyradicals may contribute to anthracycline resistance in acute leukemia.
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PMID:P-glycoprotein and alterations in the glutathione/glutathione-peroxidase cycle underlie doxorubicin resistance in HL-60-R, a subclone of the HL-60 human leukemia cell line. 809 91

By reaction of K2PtCl4 with spermidine we have synthesized two tris-platinum covalent compounds of formula (PtI2)3(sper)2 and (PtCl2)3(sper)2, one ionic compound of formula (sperH3)2(PtCl4)3, and another one of a covalent nature of formula (PtCl2sperH)2 (PtCl4) having a partially protonated spermidine residue. Treatment of the tris-platinum compounds with hydrogen peroxide and hydrochloric acid led to the production of two compounds of formula cis-trans-cis-(PtIVCl2(OH)2)3(sper)2 and cis-(PtIVCl4)3(sper)2, respectively. All of them have been characterized by IR and 1H MNR spectroscopy and tested for their ability to interact with pUC8 plasmid DNA by the use of UV, CD, and electrophoretic techniques. The results suggest that all of these compounds modify the secondary structure of the double helix. We observed that the alteration in electrophoretic mobility of nicked and closed circular forms of DNA induced by the Pt(II) complexes is higher than that induced by the Pt(IV) complexes. The synthesized compounds were also assayed for antitumor activity in vitro against breast (MDA-MB468) and leukemia (HL-60) tumor cells. Only three of these complexes may be regarded as potential antitumor agents, since their ID50 values are lower than 10 micrograms/ml.
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PMID:Platinum (II) and (IV) spermidine complexes. Synthesis, characterization, and biological studies. 813 54

A series of novel water-soluble amine platinum (II) tellurate complexes of the type (A)Pt(II) [TeO2(OH)4], where A = 1,2-diaminocyclohexane (DACH), 1,1-bis(aminomethyl)cyclohexane (AMCH), ethylenediamine (en), or cyclopentylamine (cpa), were prepared either by the reaction of amineplatinum (II) sulfate with barium tellurate or by a direct reaction of (A)Pt(OH)2 with telluric acid. Oxidation of the amine platinum(II) tellurate produced amine platinum(IV) tellurate (A)Pt(IV)trans(Z) [TeO2(OH)4] complexes, where Z = OH or Cl, following oxidation with hydrogen peroxide or with chlorine gas, respectively. Complexes were characterized by elemental analysis, and IR and 195Pt NMR spectroscopy. Against i.p. murine leukemia cells in vivo, some of the complexes displayed good antitumor activity when administered intraperitoneally (i.p.) on days 1, 5, and 9 at their optimal doses. Pt(II) complexes containing R,R-DACH, S,S-DACH, R,R-S,S-DACH, or AMCH produced %T/C of 147 to 288 whereas cis-DACH, en, and cpa complexes were inactive. In the Pt(IV) series, the R,R-DACH complex with axial Cl was highly active (%T/C = 371, 40% cures) compared with the complex with axial OH (%T/C = 135).
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PMID:Synthesis, characterization, and antitumor activity of amine platinum(II) and (IV) tellurate complexes. 816 8

In this study, we measured hydrogen peroxide (H2O2) release as one of the functions of mature eosinophils, and utilized it as a quantitative index. We demonstrated that 1) the human eosinophilic leukemia cell line, EoL-1, did not release H2O2 when stimulated with phorbol myristate acetate (PMA), but after culturing with tumor necrosis factor (TNF) and interferon-gamma (IFN-gamma) it acquired the ability to release H2O2; 2) the ability to release H2O2 was time dependent and reached a peak after 4 days of culture; 3) administration of TGF-beta or GM-CSF, with TNF and IFN-gamma enhanced the PMA-induced release of H2O2 from EoL-1. To examine the potential relationship between c-myc gene expression and induction of the ability to release H2O2, Northern analysis of c-myc gene expression in EoL-1 cocultured with TNF and IFN-gamma was performed. The results showed that the c-myc gene was spontaneously expressed in EoL-1, and the level of c-myc mRNA was markedly reduced after the cells were cocultured with TNF and IFN-gamma, suggesting that the decrease of the c-myc mRNA level is closely associated with induction of the ability to release H2O2.
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PMID:The effect of cytokines on the differentiation of an eosinophilic leukemia cell line (EoL-1) is associated with down regulation of c-myc gene expression. 836 80

The evaluation of the influence of different environmental carcinogenic factors requires interdisciplinary cooperation. Related studies include epidemiological surveys and air, water and soil, chemical, toxicological, and microbiological analyses, supplemented by experimental verification of suspected ecological pathogens and cofactors. A balance of carcinogens and protective agents in the external environment and in the human body is recommended for an ecologically oriented prevention. Toxicological control of the food chain using modern technology (Proton-induced X-ray emission (PIXE), nuclear activation analysis, and induced coupled plasma) should be integrated with microanalyses at the cellular level (by X-ray scanning electron microscopy, nuclear magnetic response, PIXE, and spontaneous and delayed chemiluminescence for balance of free-radicals and their scavengers). A pilot cross-disciplinary study conducted in the area of a "cluster" of human neoplasms and cattle leukemia, in comparison with control villages in Poland, showed an excess in Pb, Hg, Ni, Rb, K, Mn, Cr, and Zn, accompanied by a nutritional deficiency in Mg, Ca, Fe, Co, and Se in the food chain of the "cluster." The living and breeding houses in this area were significantly more contaminated with the toxicogenic molds Aspergillus flavus and Penicillium meleagrinum and by nitrate and nitrite in the drinking water. Our experiments showed that selenium deficiency stimulated the growth of fungi and some bacteria and increased the immunosuppressive and teratogenic effects of aflatoxin B1. New methods of protection of the indoor environment against microbiological contamination and laser-related biotechnology for nutritional prevention of selenium deficiency and associated risk of neoplasms have been introduced. Primary prevention requires a large scale application of highly sensitive methods for early detection of risk factors in the environment, food, water, and at the personal level, as well as education of the society and an integrated common corrective action.
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PMID:Environmental risk factors of cancer and their primary prevention. 845 68

Protein tyrosine phosphatases (PTPases) play an important role in regulating cell growth and transformation. We report that the antitumor agent gallium nitrate is a potent inhibitor (concentration producing 50% inhibition, 2-6 microM) of detergent-solubilized cellular membrane PTPase from Jurkat human T-cell leukemia cells and HT-29 human colon cancer cells. This is the first report of a selective, small molecule drug inhibitor of PTPase. Gallium nitrate did not inhibit CD45, a PTPase found in the membranes of hemopoietic lineage cells such as Jurkat cells. Studies with gallium nitrate and a series of gallium-containing analogues revealed no correlation between growth-inhibitory activity in Jurkat and HT-29 cells and the ability to inhibit detergent-solubilized PTPase. Gallium nitrate and most of the gallium analogues penetrate poorly into cells. In contrast, a gallium-hydrogen peroxide complex inhibits DNA synthesis in Jurkat cells and induces the accumulation of phosphotyrosines on multiple intracellular proteins in this cell line. Gallium-hydrogen peroxide complex and gallium nitrate have similar inhibitory activity toward detergent-soluble PTPase. This is a new mechanism of action for gallium nitrate but it is not known if the inhibition of PTPase is related to the antitumor activity of gallium nitrate.
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PMID:Inhibition of protein tyrosine phosphatase by the antitumor agent gallium nitrate. 846 6

The relationship between chromatin structure and endonuclease sensitivity was investigated. The cells used in this study were a) human myelogenous leukemic cell lines (HL-60, ML-I, U-937, THP-I) (Group I), which produced internucleosomal DNA cleavage, and b) human T-cell leukemia (MOLT-4), erythroleukemia (K562), glioblastoma (T98G, U87MG) and glioma (KG-1-C) cell lines (Group II), which produced no internucleosomal DNA cleavage, upon treatment with various apoptosis-inducing agents. When the nuclei, isolated from these cells were digested with micrococcal nuclease, chromatin DNA was cleaved into oligonucleosomal units. Although sensitivity to micrococcal nuclease considerably differed from cell to cell, Group I cells were generally more sensitive to micrococcal nuclease digestion than Group II cells. Similar sensitivity to DNase I was observed in both groups of cells. Acid-urea polyacrylamide gel electrophoresis of histone fractions from control and apoptosing HL-60 cells (induced either by hydrogen peroxide or UV irradiation) revealed no significant change in the relative composition of five major histones, indicating the absence of selective degradation of histone HI, but rather the nonspecific degradation of many nuclear proteins. These data suggest a difference in a chromatin structure between Group I and II cells, which might result in the selective production of internucleosomal DNA cleavage only in Group I cells.
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PMID:Chromatin structure and endonuclease sensitivity in human leukemic cell lines. 870 41


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