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)

Studies are described on the interrelationships between divalent metals, dNTP's and PPi in determining the properties of complementary DNA (cDNA) product from the in vitro reverse transcriptase reaction with detergent-treated Moloney murine leukemia virus. In spite of the several-fold greater amount of cDNA product with Mn2+ than with Mg2+, net yield of high-molecular-weight cDNA was much greater with Mg2+ thant with Mn2+. This held true, as well, for the reactions containing excess dNTP or dNTP plus PPi, both of which (as has been reported for Mg2+) promote synthesis of high-molecular-weight cDNA product. Hif total dNTP concentration remained important for maximum high-molecular-weight product with Mg2+ and was not replaced by simply providing dNTP in excess over Mg2+. Under the conditions tested here, addition of PPi did not further increase cDNA product size with Mg2+ when compared with dNTP in excess over Mg2+. Extent of degradation of the RNA template during the incubations was correlated with the size of cDNA product.
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PMID:Optimal conditions for synthesis of long complementary DNA product with Moloney murine leukemia virus. 9 Jan 69

An RNA-directed DNA polymerase was purified from a cell line derived from a radiation-induced lymphoma in NIH Swiss mice which produced non-infectious type C virus particles. The enzyme was isolated from a high speed particulate fraction which bands at a density of 1.16--1.19 g/ml in a sucrose gradient, and purified by successive chromatography on DEAE-cellulose, phosphocellulose and hydroxyapatite. The purified DNA polymerase has a molecular weight of 68 000, a pH optimum of 7.5, a KCl optimum of 50 mM, and a Mn2+ optimum of 0.25 mM. It prefers (dT)15 . (A)n to (dT)15 . (dA)n as the primer template and transcribes the poly(C) strand of (dG)15 .(C)n and (dG)15 . (OMeC)n. It transcribes heteropolymeric regions of avian myeloblastosis virus 70 S RNA, and is inhibited by antiserum to Rauscher murine leukemia virus DNA polymerase. Comparison of the properties of DNA polymerase purified from radiation-induced lymphoma cells with the DNA polymerase purified from non-defective murine type C RNA tumor viruses shows that the mouse lymphoma enzyme is both biochemically and immunologically related to murine leukemia virus DNA polymerases.
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PMID:Characterization of an RNA-directed DNA-polymerase from a cell line derived from a radiation-induced lymphoma in mice. 9 May 22

The new antiviral substance phosphonoformate (PFA) has been tested in a cell-free system for its effect on reverse transcriptases from an avian retrovirus (avian myeloblastosis virus, AMV) and from mammalian retroviruses (Rauscher leukaemia virus, RMuLV; bovine leukaemia virus; baboon endogenous virus; simian sarcoma virus; visna virus). The observed inhibitory effect of PFA has been compared with that of a structurally related substance, phosphonoacetate (PAA). Phosphonoformate, at a concentration of 100 microM, reduced the activities of all the above mentioned polymerases by 90% when (rA)n.(dT)10 was used as a template/primer. The dose-response curves for AMV and RMuLV polymerases primed with (rA)n.(dT)10 showed PFA to be a 1000-fold more active than PAA; the RMuLV polymerase activity was reduced to 50% after incubation with 0.7 microM-PFA and 0.7 mM-PAA, respectively. There was no difference in PFA inhibition of virus-associated and purified reverse transcriptase activity. Results with various synthetic templates showed that both the RNA- and the DNA-dependent polymerase activities of reverse transcriptase were inhibited by PFA. The endogenous polymerase activity of AMV was inhibited to 50% at 100 microM-PFA, while PAA had no effect. The PFA inhibition was dependent on whether Mg2+ or Mn2+ was used as divalent cation in the assay. Phosphonoformate arrested DNA synthesis immediately after being added to the assay system. The mechanism of inhibition of the AMV polymerase was non-competitive with respect to substrate and template and the apparent inhibition constants were 16 microM and 9 microM, respectively.
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PMID:Phosphonoformate inhibits reverse transcriptase. 9 44

Analogues of cis-dichlorodiammineplatinum(II) were prepared in which substituted pyridines (A), 1-(4-aminobenzylidene)indene (B), or DL-3,5,3'5'-tetraoxo-1,2-dipiperazinopropane (ICRF-159) was used in place of ammonia, and in some cases platinum(IV) or palladium(II) was used in place of the platinum(II). Both platinum complexes with ICRF-159 were active against leukemia 1210, but none of the others produced significant life extension following a single ip dose of 400 mg/kg. Attempts to prepare complexes of ICRF-159 with Zn(II), Mn(II), and Cr(III) were unsuccessful, but there were indications of complex formation with CuCl2 and with NiCl2.
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PMID:Platinum and palladium derivatives for chemotherapy studies. 45 9

Multiple forms of RNA polymerases (I, II and III) from murine leukemia L1210 cells are solubilized, purified and characterized. Heterogeneity of RNA polymerases I and III is revealed by chromatography on DEAE-Sephadex and Phosphocellulose (P-11). The properties of these forms such as peculiarities of transcription of native and denaturated DNA, metal ion dependence (Mg2+, Mn2+ and (NH4)2SO4) and alpha-amanitin sensitivity resemble those reported for other mammalian RNA polymerases. The level of RNA polymerase I of leukemia L1210 cells increase approximately ten-fold relative to its level in some organs of healthy mice.
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PMID:[RNA-polymerase of murine leukemia L1210 cells]. 62 42

The per-capita intakes of zinc, cadmium, copper and of chromium were estimated from food consumption data in 28 countries and were found to correlate directly with the age-corrected mortalities from cancers of intestine, prostate, breast, leukemia, skin and of other organs, suggesting that the anticarcinogenic effect of selenium is counteracted by other trace elements. Similarly calculated dietary intakes of manganese are inversely correlated, particularly with the mortalities from cancer of pancreas, an organ normally known to contain high concentrations of this element. Arsenic intakes correlate inversely with the male lung cancer mortalities. A number of other direct and inverse associations were observed which suggest that trace elements in the human diet may hav both benign and adverse effects on tumor development. The zinc concentrations in whole blood collected from healthy donors in the U.S. correlate directly with regional mortalities from cancers of intestine, breast and of other sites. The origin of these associations is discussed primarily in terms of the seleium-antagonistic effect of zinc and of some of the other elements considered. Results of animal experiments and of other studies are cited which support hypotheses that link human cancer development to possible deficiencies or excesses in the dietary trace element intakes.
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PMID:Cancer mortality correlation studies--IV: associations with dietary intakes and blood levels of certain trace elements, notably Se-antagonists. 85 92

The RNA polymerase activities from the nuclei of the spleen of uninfected and Rauscher murine leukemia virus-infected NIH Swiss mice were resolved by DEAE-cellulose column chromatography, and their properties were compared. The RNA polymerase activities from infected and uninfected spleens were the same with respect to column elution profiles, optimum requirements for various salts, ratios of activities with Mn2+ and Mg2+, sedimentation values, and response to most templates. With the exception of minor differences in activities with certain DNA templates, the significance of which is not clear, no qualitative differences in the enzymes from these two sources were found, but an increase in the specific activity of the alpha-amanitin sensitive enzyme, RNA polymerase II, was found in the leukemic spleen. These preliminary results suggest that there may be no novel RNA polymerase induced by Rauscher murine luekemia virus-infection, and they are in keeping with the interpretation that the viral DNA genome is transcribed by a host RNA polymerase.
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PMID:Deoxyribonucleic acid-dependent ribonucleic acid polymerases from spleen of uninfected and Rauscher murine leukemia virus-infected NIH Swiss mice.? 112 31

A cell line (BsT) established from neoplastic embryonal tissues of the platyfish (Xiphophorus maculatus) released spontaneously retrovirus-like particles. The particles have a buoyant density of 1.16 g/ml, a mean diameter of 100 nm and the morphology of immature retroviruses. The particle-associated proteins p70, p65, and p28 react with an antiserum directed against the major internal feline leukemia virus structural protein p27. The particles are associated with a reverse transcriptase. The purified enzyme has a molecular weight of about 70 kDa and prefers the template primers poly(rA):oligo(dT), poly(dC):oligo(dG), and poly(rC):oligo(dG) in the presence of Mn2+. The enzyme activity is inhibited by antibodies directed against the reverse transcriptase of feline leukemia virus and simian sarcoma virus. The particles contain a ribonucleic acid of about 70 S. In an endogenous reverse transcriptase reaction nucleic acids in the range of 0.2 to 0.4 kb were synthesized. In Northern blots with these nucleic acids as probe, three transcripts of about 8.5, 4.2, and 1.5 kb were detected in BsT cells. Southern blot analysis with the same probe demonstrates related sequences in the DNA of BsT cells and the platyfish and swordtail (Xiphophorus helleri). Hybridization experiments with the LTR-gag region of the feline leukemia virus show homologous sequences in the Xiphophorus genome.
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PMID:Isolation and characterization of a retrovirus from the fish genus Xiphophorus. 137 84

We measured the serum levels of manganese-superoxide dismutase (Mn-SOD) in acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL). Serum Mn-SOD level for normal subjects was 94.1 +/- 23.5 ng/ml (mean +/- S.D.), the levels for AML and ALL patients were 159.6 +/- 77.1 ng/ml and 154.4 +/- 77.0 ng/ml, respectively. The serum Mn-SOD levels were unrelated to individual intracellular Mn-SOD levels, but correlated well with serum lactate dehydrogenase values. Regression of the leukemia was accompanied by decrease in the serum level of Mn-SOD. Serum Mn-SOD may thus serve as a measure of the activity of the disease.
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PMID:Elevated serum manganese superoxide dismutase in acute leukemias. 159 65

Reverse transcriptase (RT) transcribes viral RNA into DNA to be integrated into the host genome. To study epidemiological aspects of human leukemias and lymphomas which are known to express retroviruses, clinical specimens in this report were assayed for divalent cation-dependent viral-specific RT. The assay was carried out with cells solubilized with a detergent to release RT enzyme. RT was purified with poly(U)-Sepharose which fixed all DNA polymerases and assayed with 4 synthetic homopolymers, oligonucleotide primed-templates, poly(rA)-oligo(dT)12-18 or poly(dA)-oligo(dT)12-18 with Mg2+, poly(rC)-oligo(dG)12-18 or poly(rCm)-oligo(dG)12-18 with Mn2+ as divalent cation and [methyl-3H]thymidine 5'-triphosphate or deoxy[8-3H]guanosine 5-triphosphate respectively. Radioactivity incorporation of the precipitate allows quantitation of RT activity. One Hodgkin's disease, one out of 2 B lymphomas, one out of 2 T lymphomas, eight out of 12 leukemias were found to be positive for RT activity as well as acquired immunodeficiency syndrome (AIDS) patients, known to express RT. The obtained RT activity in hematological malignancies was found to be comparable to positive controls such as RT enzymes purified from avian myeloblastosis and Moloney murine leukemia viruses.
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PMID:Presence of reverse transcriptase in human leukemias and lymphomas. 170 70


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