Browsing by Subject "DNA Topoisomerases, Type II"
Now showing items 1-20 of 20
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Altered Phosphorylation, Biosynthesis and Degradation of the 170 kDa Isoform of Topoisomerase II in Amsacrine-Resistant Human Leukemia Cells
(1993)Resistance to amsacrine in HL-60/AMSA is 50-100 fold compared to the parental HL-60/S cells. Synthesis and phosphorylation of topoisomerase II (TOPO II) were 2-3 fold lower in HL-60/AMSA compared to HL-60/S cells metabolically ...
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Attenuation of drug-stimulated topoisomerase II-DNA cleavable complex formation in wild-type HL-60 cells treated with an intracellular calcium buffer is correlated with decreased cytotoxicity and site-specific hypophosphorylation of topoisomerase IIα
(1998)Topoisomerase II (topo II), an essential enzyme for cell viability, is also the target for clinically important anti-neoplastic agents that stimulate topo II-mediated DNA scission. The role of alterations in topo IIα ...
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Commitment to erythroid differentiation in mouse erythroleukemia cells is controlled by alterations in topoisomerase IIα phosphorylation
(1996)To explore the program of cell differentiation in Friend murine erythroleukemia (MEL) cells, we used three clonal variants: phorbol 12- myristate 13-acetate (PMA)-hypersensitive TS-19-101, PMA-resistant TR19-9, and ...
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The Dietary Anticancer Agent Ellagic Acid is a Potent Inhibitor of DNA Topoisomerases in Vitro
(1995)Ellagic acid and 12 related agents have been tested for their ability to inhibit the activities of human DNA topoisomerase (topo) I and IL Using specific in vitro assays, we found ellagic acid and flavellagic acid to be ...
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The effect of topoisomerase inhibitors on the expression of differentiation markers and cell cycle progression in human K-562 leukemia cells
(1992)Treatment of human K-562-J leukemia cells for 1 h with the topoisomerase II-reactive drugs VP-16, VM-26, or mAMSA resulted in a dose-dependent inhibition of proliferation and in an increase in the percentage of cells ...
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Flavonoids as DNA topoisomerase antagonists and poisons: Structure-activity relationships
(1995)Selected flavonoids were tested for their ability to inhibit the catalytic activity of DNA topoisomerase (topo) I and II. Myricetin, quercetin, fisetin, and morin were found to inhibit both enzymes, while phloretin, ...
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Genistein induces apoptosis and topoisomerase II-mediated DNA breakage in colon cancer cells
(2000)The present study was undertaken to determine if (a) genistein induces topo II-mediated DNA damage in HT-29 colon cancer cells
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Induction of Differentiation and DNA Strand Breakage in Human HL-60 and K-562 Leukemia Cells by Genistein
(1990)Genistein, an in vitro inhibitor of topoisomerase II and tyrosine kinases, suppressed growth and induced differentiation in HL-205 cells, a clonal population of the human promyelocytic HL-60 leukemia cells, and in K-562-J ...
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Inhibition of N-methyl-N-nitrosourea-induced mammary tumors in rats by the soybean isoflavones
(1996)Soy-based diets, rich in the isoflavones genistein and daidzein, are thought to protect against breast and prostate cancer. Soy-based diets, rich in the isoflavones genistein and daidzein, are thought to protect against ...
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Inhibition of topoisomerase IIα activity in CHO K1 cells by 2- [(aminopropyl)amino]ethanethiol (WR-1065)
(1994)The aminothiol 2-[(aminopropyl)amino]ethanethiol (WR-1065) is the active thiol of the clinically studied radioprotective agent S-2-(3- aminopropylamino)ethylphosphorothioic acid (WR-2721). WR-1065 is an effective radiation ...
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Involvement of host DNA gyrase in growth of bacteriophage T5
(1986)Bacteriophage T5 did not grow at the nonpermissive temperature of 42°C in Escherichia coli carrying a temperature-sensitive mutation in gyrB [gyrB(Ts)], but it did grow in gyrA(Ts) mutants at 42°C. These findings indicate ...
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Isolation of isoflavones from soy-based fermentations of the erythromycin-producing bacterium Saccharopolyspora erythraea
(1997)A search for an abundant and economical source of isoflavones, particularly genistein, led to the discovery that the erythromycin-producing organism Saccharopolyspora erythraea also produces this promising new cancer-prevention ...
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A novel use for the comet assay: Detection of topoisomerase II inhibitors
(2000)Background: The simple and quick comet assay can quantitatively detect DNA cleavage in cells. This study aimed to determine whether the comet assay could be used to detect topoisomerase (topo) II inhibitors. Materials and ...
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Novobiocin- and Phorbol-12-myristate-13-acetate-induced Differentiation of Human Leukemia Cells Associated with a Reduction in Topoisomerase II Activity
(1989)Studies were conducted to determine the possible involvement of DNA topoisomerase II (Topo II) in the induction of differentiation in two human promyelocytic HL-60 leukemia cell variants that are either susceptible or ...
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Phenoxodiol (2H-1-benzopyran-7-0,1,3-(4-hydroxyphenyl)), a novel isoflavone derivative, inhibits DNA topoisomerase II by stabilizing the cleavable complex
(2002)Cancer therapeutic drugs that inhibit DNA topoisomerase (topo) II by stabilizing the cleavable complex are collectively known as topo II poisons. Phenoxodiol is a synthetic derivative of the plant isoflavone daidzein and ...
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Resistance to etoposide in human leukemia HL-60 cells: Reduction in drug-induced DNA cleavage associated with hypophosphorylation of topoisomerase II phosphopeptides
(1996)Tumor cell resistance to anthracyclines and epipodophyllotoxins can be due to reduced drug accumulation and/or alterations in the activity of topoisomerase II (TOPO II). HL-60 cells selected in 0.05 μg/ml doxorubicin (DOX) ...
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Selection of cancer chemopreventive agents based on inhibition of topoisomerase II activity
(2000)The present study was undertaken to determine if in vitro inhibition of one or both of the two most dominant mammalian DNA topoisomerases (topos) is common among chemopreventive agents. To determine if an agent was a topo ...
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Topologically constrained domains of supercoiled DNA in eukaryotic cells
(1997)The size of supercoiled, topologically constrained DNA domains within the squamous carcinoma cell line SQ-20B were determined by direct comparison with a panel of irradiated supercoiled plasmid DNAs. Loss of supercoiling ...
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WR-1065, an active metabolite of the cytoprotector amifostine, affects phosphorylation of topoisomerase IIα leading to changes in enzyme activity and cell cycle progression in CHO AA8 cells
(1997)The effects of WR-1065 (2-((aminopropyl)amino)ethanethiol) on cell cycle progression, topoisomerase (topo) IIα activity, and topo IIα phosphorylation in Chinese hamster ovary (CHO) cells have been investigated. Exposure ...