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Query: UMLS:C0023418 (
leukemia
)
93,477
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Chromophore modification of the anthracenediones related to mitoxantrone in an attempt to provide agents with diminished or no cardiotoxicity has resulted in a novel class of DNA binders, the anthrapyrazoles. Selected biochemistry, electrochemistry and tumour biology were carried out for a series of compounds possessing the same upper and lower side chains but with varying A-ring hydroxylation patterns. The anthrapyrazoles bind strongly to DNA, are selective and potent inhibitors of DNA synthesis and cause the formation of single-strand breaks in DNA. They also induced far less (20-200-fold) superoxide dismutase-sensitive
oxygen
consumption than doxorubicin in the rat liver microsomal system, a property that may be indicative of reduced cardiotoxicity. This result is in accord with their polarographic properties in which the anthrapyrazoles show a much greater resistance to reduction (E'1/2 = -0.983- -1.085 V) relative to daunorubicin (E'1/2 = -0.625 V) and mitoxantrone (E'1/2 = -0.775 V). The anthrapyrazoles demonstrate high levels of activity against a broad range of murine tumours in vivo including the P388
leukaemia
and mammary adenocarcinoma 16c lines detailed in this study.
...
PMID:Design, biochemical pharmacology, electrochemistry and tumour biology of anti-tumour anthrapyrazoles. 245 96
In order to synthesize bifunctional antitumor compounds, the interactions of adriamycin with metallocene dichlorides, Cp2MCl2, where M = Zr, Ti, V, have been studied. Using absorption, fluorescence, and circular dichroism measurements, we have shown that adriamycin is able to coordinate to the three metal ions. The interaction of Cp2ZrCl2 and Cp2VCl2 with adriamycin leads to compounds of 1:2 metal:drug stoichiometry, whereas the interaction of Cp2TiCl2 with adriamycin leads to two types of compounds of 1:2 and 1:1 stoichiometry. The Zr-adriamycin complex, which is unable to dissociate, even at a pH lower than 1, does not display antitumor activity against P-388
leukemia
. However Ti-adriamycin complexes, which are more susceptible to dissociation in acidic media, exhibit antitumor activity that compares with that of the free drug. These complexes, unlike adriamycin, do not catalyze the flow of electrons from NADH to molecular
oxygen
through NADH dehydrogenase. In addition, the presence of metal ions promote the binding of the drug to DNA and erythrocyte ghosts.
...
PMID:Bifunctional antitumor compounds: interaction of adriamycin with metallocene dichlorides. 253 37
Myeloperoxidase (MPO) is a heme containing enzyme involved in the
oxygen
-dependent microbicidal activity of human polymorphonuclear leukocytes (PMN). Complete hereditary and acquired MPO deficiencies are defined as lack of peroxidase activity in PMN. Using this criterion, we studied a patient with complete hereditary MPO deficiency, and a MPO deficient variant cell line of HL-60 (HL-60-A7), which we used as a model for acquired MPO deficiency. Western blot analysis showed complete absence of mature and precursor protein of MPO both in PMN from the patient and in HL-60-A7 cells. PMN from both parents had one half of normal levels of these proteins. To study further the molecular basis of this defect, we isolated an intron specific probe for MPO and used it and a cDNA probe. Both normal human bone marrow cells and the promyelocytic HL-60
leukemia
cells contained MPO mRNA species of 2.8, 3.3, approximately 4, and greater than 8 kilobase (kb). The transcripts of greater than 8 and approximately 4 kb contained sequences hybridizing to a probe specific for intron 7 of the MPO gene. Bone marrow cells of the MPO deficient patient contained two species of heterogeneous nuclear (hn) RNA of greater than 8 and approximately 4 kb, but only trace amounts of the normal sized 3.3 kb MPO mRNA and undetectable 2.8 kb MPO mRNA. HL-60-A7 cells contained both greater than 8 and approximately 4 kb hnRNA, but only small amounts of normal sized 2.8 kb MPO mRNA and undetectable levels of the 3.3 kb mRNA. Southern blot analyses revealed no gross alteration of the MPO gene in both cases. Our results suggest that a pretranslational defect is one mechanism leading to MPO deficiency.
...
PMID:Evidence for a pretranslational defect in hereditary and acquired myeloperoxidase deficiency. 254 Aug 60
P388
leukemia
sublines were isolated from
leukemia
-cell-bearing CD2F1 mice that had been treated in vivo with increasing amounts of diaziquone (AZQ). The sublines isolated for in vitro studies were AZQ19 and AZQ30 which corresponded to the 19th and 30th in vivo passages, respectively. The AZQ19 subline displayed a very low degree of resistance to AZQ (1.5-fold), whereas the AZQ30 subline was sensitive. Both sublines, however, had much higher degrees of resistance to Adriamycin than to AZQ (24-fold for AZQ30 cells and 10-fold for AZQ19 cells). Both cell lines were also more resistant to actinomycin D, colchicine, and vincristine than to AZQ. The AZQ19 line was resistant to the alkylator thio-TEPA to the same degree that it was to AZQ, but the AZQ30 line was sensitive to thio-TEPA. On the other hand, AZQ30 cells were resistant to hydrogen peroxide with a very low degree of resistance (1.27-fold, P less than 0.05), whereas the AZQ19 line was sensitive. Drug accumulation experiments indicated that AZQ-resistant cells differed from the parental line in that they did not accumulate Adriamycin or vinblastine. In the case of AZQ, however, resistant and parental lines accumulated the same amounts of exchangeable AZQ. Using the immunoblotting technique, no P-glycoprotein was found in resistant cells. The resistant lines consumed
oxygen
at greater rates than the parental line.
Oxygen
consumption (Mean +/- SD) in sensitive cells was 2.0 +/- 0.4% O2 consumed/min, whereas in resistant cells it was nearly 3.1 +/- 0.6% O2 consumed/min. The increase in
oxygen
consumption with drug resistance was statistically significant (P less than 0.01). The kinetics of production of hydroxyl free radicals and of AZQ free radicals were faster in the resistant lines reflecting, in essence, their increased
oxygen
consumption. It appears that the two sublines analyzed here show resistance mechanisms that may have been elicited by the two distinct chemical constituents of AZQ. Therefore, in the AZQ19-resistant line, the alkylating aspect of AZQ was emphasized, whereas in the AZQ30 line, the quinone and, thus, free radical aspect was emphasized. This is consistent with AZQ30 cells being sensitive to the alkylator thio-TEPA and resistant to hydrogen peroxide, and the AZQ19 line being resistant to thio-TEPA and sensitive to hydrogen peroxide. In addition, the AZQ30 cell line was relatively more resistant than the AZQ19 line to Adriamycin.
...
PMID:In vitro multidrug resistance of P388 murine leukemia selected for resistance to diaziquone. 257 72
The title coordination compound has been synthesized by the reaction of HLaEDTA.7H2O with (formula; see text) in ethanol aqueous solution. The single crystal has grown from aqueous solution and has been characterized by IR, TG-DTA, X-ray powder diffraction, molar conductance, UV and 1H-NMR. The determination of its crystal and molecular structure shows that it crystallizes in space group P21/n with lattice parameters: a = 14.735A, b = 29.335A, c = 16.409A, beta = 99.24 degrees, v = 7009.30A3, z = 4, F(000) = 3488, molecular weight M = 1756.90, Dc = 1.665g/cm3. It has been refined by the full matrix least squares method to final discrepancy factor R = 0.096. The anion [La2(EDTA)2(H2O)4]2- turns out to be a dimer, in which each of the two EDTA4- ions is coordinated to a La3+ ion with five of its six coordinating sites and the remaining sixth one--the
oxygen
atom of carboxylis bridged to two La3+ ions, thus forming a parallelogrammic four-membered ring La2O2. The nine coordinations about each metal are completed by two water molecules. The average bond length is 2.560 A for La-O and 2.833A for La-N. Approximately, the dimer belongs to point group Ci with the centre of inversion at the centre of La2O2 parallelogram. The antitumor activity of the coordination compound was studied by observing its effect on the incorporation of 3H-TdR into DNA of
leukemia
(L7712) cells in vitro. The degree of inhibition reached 83.9% after exposing 2 X 10(5) cells per millilitre to 4 X 10(-5) mol/L of the compound for 24 h, being higher than those of its precursors.
...
PMID:Study on some biologically active coordination compounds of metal ions (I)--Synthesis, characterization, structure and antitumor activity of complex of 3,6-di-(dimethylamino)-dibenzopyriodonium lanthanum EDTA. 261 Aug 65
The relation between the lifetimes of the triplet states of various porphyrins and their photosensitizing effects on the photodynamic therapy (PDT) of tumor has been examined. Diethylene-triamine pentaacetic acid ester of 4-[1-(2-hydroxy-ethyloxy)ethyl]-2-vinyl deuteroporphyrin-IX gallium (III) complex (Ga-DP), zinc (II) complex (Zn-DP), and manganese (III) complex (Mn-DP) and Photofrin II (PII) are used as the photosensitizer. The triplet lifetimes have been measured for the samples adsorbed on filter paper (FP) and found to be 57 ms (Ga-DP), 26 ms (Zn-DP), less than or equal to 10 microseconds (Mn-DP) and 9 ms (PII). The phosphorescence of Ga-DP in tumor-bearing golden hamsters are measured both in tumor tissue and in liver. They show bi-exponential decay with the lifetimes of about 5 and 20 ms. From the values, the generation rate, kct[3O2], of singlet molecular
oxygen
in living animal tissue may be estimated to be an order of 10(2) s-1. The PDT effects have been quantitatively investigated for in vitro experiments; upon irradiation the growth inhibitions of mouse p388
leukemia
cells are obtained as a function of concentration of Ga-DP, Zn-DP, Mn-DP and PII. The experimental results indicate that the PDT effects depend essentially on the triplet lifetimes of the photosensitizers.
...
PMID:Critical importance of the triplet lifetime of photosensitizer in photodynamic therapy of tumor. 278 Aug 23
Changes in the production of reactive
oxygen
species and total superoxide dismutase activity have been observed during differentiation of some hematopoietic cells. We therefore investigated whether the steady-state level and rate of transcription of superoxide dismutase-1 (SOD-1) mRNA change during terminal differentiation of the human
leukemia
cell lines THP-1, HEL, and HL-60 into macrophages and/or granulocytes, respectively. Macrophage differentiation is accompanied by a gradual decrease in both the transcription rate (10x) and the steady-state level (6x) of SOD-1 mRNA. No decrease was observed after treatment with the diacylglycerol analog 1,2 dioctanol-rac-glycerol (di-C8), which like phorbol 12-myristate 13-acetate also activates protein kinase C but does not induce differentiation at the concentration used. The same decrease in SOD-1 mRNA level was observed when HL-60 cells were induced to differentiate into granulocytes by treatment with dimethylsulfoxide. These data suggest that a decrease in SOD-1 mRNA to almost undetectable levels accompanies differentiation of macrophages and granulocytes.
...
PMID:Loss of copper-zinc superoxide dismutase gene expression in differentiated cells of myelo-monocytic origin. 279 Feb 4
Myristoyl-CoA:protein N-myristoyltransferase (NMT; EC 2.3.1.97) catalyzes the cotranslational linkage of myristate to the N-terminal glycine residues of several cellular, viral, and oncoproteins. We have recently synthesized a series of sulfur- and
oxygen
-substituted analogs of myristic acid that are similar in length to the 14:0 fatty acid yet have hydrophobicities equivalent to dodecanoate or decanoate. Previous in vitro enzyme assays and metabolic labeling studies indicate that some of these analogs are excellent substrates for NMT and are incorporated into subsets of cellular N-myristoyl proteins. Their sequence-specific incorporation probably arises from cooperative interactions between the acyl CoA and peptide binding sites of NMT. The human immunodeficiency virus 1 (HIV-1) and Moloney murine
leukemia
virus (MoMLV) depend on myristoylation of gag polyprotein precursors for assembly. We have tested four analogs--12-methoxydodecanoic acid, 10-propoxydecanoic acid, 5-octyloxypentanoic acid, and 11-ethylthioundecanoic acid--for their ability to block replication of these retroviruses. All reduce HIV-1 replication when incubated with CD4+ H9 cells for 10 days at 10-100 microM. 12-Methoxydodecanoic acid is most effective, producing a concentration-dependent decrease in (i) reverse transcriptase activity (to levels that were 5-10% of control at 20-40 microM), (ii) p24 levels, and (iii) syncytia formation. This degree of inhibition of HIV-1 replication is equivalent to that seen with 5 microM 3'-azido-3'-deoxythymidine and is accomplished without apparent toxicity, as measured by cell viability, protein, and nucleic acid synthesis. 5-Octyloxypentanoic acid inhibits MoMLV assembly in a dose-dependent fashion without accompanying cellular toxicity, while 12-methoxydodecanoic acid has no effect. These data suggest that the use of cellular NMT activity to deliver analogs of myristate with altered physical-chemical properties to proteins that undergo this cotranslational modification may represent an effective anti-viral therapeutic strategy as well as a way to investigate the role of covalently bound fatty acid in viral assembly.
...
PMID:Replication of human immunodeficiency virus 1 and Moloney murine leukemia virus is inhibited by different heteroatom-containing analogs of myristic acid. 281 17
Varicella-zoster virus (VZV) is a cause of serious pneumonias in immunosuppressed patients. Although there are reports of residual lung changes in adults following VZV pneumonia, no previous studies of lung function in children following this infection have been done. We studied 11 patients (median age 11 years) who had had VZV pneumonia 1 to 16 years previously. All patients had a primary diagnosis of acute lymphocytic leukemia. Pneumonia was mild in most of the patients: Three had only radiographic evidence of pneumonia and required no supplemental
oxygen
, and seven required an FiO2 less than or equal to 0.4 for intervals for up to 11 days. One patient had severe pneumonia and required major ventilatory support. Three patients (27%) had significant restrictive defects on follow-up, with total lung capacity 62-69% predicted; and a fourth was abnormal at 1 month follow-up but normal at 16 months. No obstructive defects were noted, although RV/TLC ratios were elevated in three patients and volume of isoflow increased in three. Single breath diffusing capacity was reduced in two patients, but gas exchange was normal in all. No residual radiographic changes were present except in the patient who had severe pneumonia and increased lung markings at 2 months follow-up. All three patients with restrictive changes had other infections before or following VZV, including Pneumocystis carinii pneumonia in two and recurrent, nonspecific pneumonias in the third. We conclude that VZV pneumonia had minimal residual effects on lung function in children with
leukemia
.
...
PMID:Pulmonary function following varicella-zoster pneumonia in children with leukemia. 282 72
Two melanotic human melanoma cell lines, IRE 1 and IRE 2, and the lymphoma- and
leukaemia
-derived cell lines Raji and K 562, were exposed to different concentrations (from 5 X 10(-3) M to 10(-5) M) of phenols, both substrates (s) and non-substrates (ns) of tyrosinase, in the presence or absence of the
oxygen
-radical-scavenger enzymes superoxide dismutase, catalase and peroxidase. Monophenols were tyrosine (s), 4-hydroxyanisole (s) and butylated hydroxyanisole (ns); diphenols were L-3,4-dihydroxyphenylalanine (s), dopamine (3,4-dihydroxyphenethylamine) (s), terbutylcatechol (s), hydroquinone (s) and resorcinol (ns); triphenols were 6-hydroxydopa (3,4,6-trihydroxyphenylalanine) (s) and methyl gallate (s). Triphenols and o- and p-diphenols underwent complete oxidation in culture medium within 24 h of incubation and were significantly more toxic than monophenols and the m-diphenol resorcinol, which, under the same cultural conditions, were much more stable. No significant differences in percentage survival were found among the different cell lines for each drug tested. The major component of toxicity up to 24 h of di- and tri-phenols is due to toxic
oxygen
species acting outside the cells and not to cellular uptake of these phenols as such. In fact the addition of
oxygen
-radical-scavenger enzymes significantly (P less than 0.01) decreased the adverse effect of these drugs on all cell lines. The lower toxicity of monophenols and resorcinol as compared with that of di- and tri-phenols is due, in our opinion, to the fact that they are less oxidized under the conditions existing in the culture medium, and therefore do not produce sufficient levels of
oxygen
radicals. For these compounds, a primary intracellular action has to be taken into account to explain their cytotoxicity.
...
PMID:Comparative cytotoxicity of phenols in vitro. 282 25
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