70 resultados para ADRIAMYCIN


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We have previously observed that breast cancer cell lines could exhibit either epithelial or fibroblastic phenotypes as reflected by their morphologies and intermediate filament protein expression (C. L. Sommers, D. Walker-Jones, S. E. Heckford, P. Worland, E. Valverius, R. Clark, M. Stampfer, and E. P. Gelmann, Cancer Res., 49: 4258-4263, 1989). Fibroblastoid, vimentin-expressing breast cancer cell lines are more invasive in vitro and in vivo (E. W. Thompson, S. Paik, N. Brunner, C. L. Sommers, G. Zugmaier, R. Clarke, T. B. Shima, J. Torri, S. Donahue, M. E. Lippman, G. R. Martin, and R. B. Dickson, J. Cell. Physiol., 150: 534-544, 1992). We hypothesized that a breast cancer cell with an epithelial phenotype could undergo a transition to a fibroblastic phenotype, possibly resulting in more invasive capacity. We now show that two Adriamycin-resistant MCF-7 cell lines and a vinblastine-resistant ZR-75-B cell line have undergone such a transition. Adriamycin-resistant MCF-7 cells express vimentin, have diminished keratin 19 expression, have lost cell adhesion molecule uvomorulin expression, and have reduced formation of desmosomes and tight junctions as determined by reduced immunodetection of their components desmoplakins I and II and zonula occludens (ZO)-1. Other MCF-7 cell lines selected for resistance to vinblastine and to Adriamycin and verapamil did not have these characteristics, indicating that drug selection does not invariably cause these phenotypic changes. In addition, to determine if vimentin expression in MCF-7 cells alone could manifest a fibroblastic phenotype, we transfected the full-length human vimentin complementary DNA into MCF-7 cells. Although vimentin expression was achieved in MCF-7 cells, it did not affect the phenotype of the cells in terms of the distribution of keratins, desmoplakins I and II, ZO-1, or uvomorulin or in terms of in vitro invasiveness. We conclude that vimentin expression is a marker for a fibroblastic and invasive phenotype in breast cancer cells but does not by itself give rise to this phenotype.

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Treatment of rats with Adriamycin caused an increase in the incorporation into hepatic cholesterol of [1-14C] acetate, but not of [2-14C] mevalonate. The step affected was found to be 3-hydroxy-3-methylglutaryl CoA reductase whose activity in the liver microsomes increased in Adriamycin-treated animals, but was inhibited when the drug was added in the assay medium. Also, the concentration of ubiquinone in the liver and of cholesterol in the plasma increased.

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The antitumour antibiotic, adriamycin, inhibited oxidative phosphorylation in freshly prepared mitochondria from the heart, liver and kidney of the rat. It abolished respiratory control and stimulated ATPase activity. Sccinate oxidation by heart mitochondria was extremely sensitive to the drug when hexokinase was present in the reaction medium. The sensitive site has been identified to lie in the region between the succinate dehydrogenase flavoprotein and ubiquinone of the respiratory chain.

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The inhibitory action of the anticancer antibiotic, Adriamycin, on succinate-dependent oxidative phosphorylation in heart mitochondria was markedly potentiated by the presence of hexokinase in the reaction medium. This 'hexokinase effect' was not observed in the oxidation of NAD+-linked substrates, or when liver or kidney mitochondria were used in place of heart mitochondria. These results offer a biochemical explanation for the extreme cardiac toxicity of the drug.

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Adriamycin (Doxorubicin) stimulates NADH oxidase activity in liver plasma membrane, but does not cause NADH oxidase activity to appear where it is not initially present, as in erythrocyte membrane. NADH dehydrogenase from rat liver and erythrocyte plasma membranes shows similar adriamycin effects with other electron acceptors. Both NADH ferricyanide reductase and vanadate-stimulated NADH oxidation are inhibited by adriamycin, as is a cyanide insensitive ascorbate oxidase activity, whereas NADH cytochrome c reductase is not affected. The effects may contribute to the growth inhibitory (control) and/or deleterious effects of adriamycin. It is clear that adriamycin effects on the plasma membrane dehydrogenase involve more than a simple catalysis of superoxide formation.

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Immunoliposomes were prepared using the antibody raised against the avian myeloblastosis virus envelope glycoprotein, gp80. Adriamycin was encapsulated into immunoliposomes. More drug was delivered into target cells when the drug encapsulated in immunoliposomes was incubated with the cells. The drug encapsulated in immunoliposomes was able to inhibit the RNA synthesis twice more than free drug in the virus-transformed myeloblasts. Pre-treatment of cells with ammonium chloride, reversed the effect of drug encapsulated in immunoliposomes. The drugs encapsulated in immunoliposomes had marginal effect on the RNA synthesis of non-target cells, the yolk sac cells. Colony formation by virus-transformed cells and focus formation by virus-infected yolk sac cells was inhibited significantly by the drug encapsulated in immunoliposomes.

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Immunoliposomes were prepared using rabbit anti-AMV gp80 IgG for the targeted chemotherapy of avian myeloblastosis virus infection. Adriamycin was encapsulated into immunoliposomes and used for in vivo studies. Comparative pharmacokinetics of free drug, drug encapsulated in free liposomes and of drug encapsulated in immunoliposomes in the virus-infected cells revealed that (i) the drug encapsulated in liposomes was cleared from the plasma slowly, and (ii) the drug encapsulated in immunoliposomes accumulated in the target tissue, the bone marrow, 5- and 8.5-fold more than the drug encapsulated in free liposomes and free drug, respectively. The drug encapsulated in immunoliposomes inactivated the virus and exhibited more chemotherapeutic efficacy as compared to controls when injected up to 24 h post-infection. However, when injected 48 h post-infection the drug encapsulated in immunoliposomes did not offer any protection against the virus infection. There is no detectable antibody response against immunoliposomes in the infected animals.

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Water is an integral part of DNA, and the conserved water molecules at the binding sites can modulate drug binding to DNA or protein. We report here that anthracycline antitumor antibiotics, adriamycin (AM) and daunomycin (DM), binding to DNA is accompanied by different hydration changes, with AM binding resulting in the uptake of about twice as many water molecules as DM. These results indicate that water is playing an important role in drug binding to DNA.

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Transcriptome analysis using microarray technology represents a powerful unbiased approach for delineating pathogenic mechanisms in disease. Here molecular mechanisms of renal tubulointerstitial fibrosis (TIF) were probed by monitoring changes in the renal transcriptome in a glomerular disease-dependent model of TIF ( adriamycin nephropathy) using Affymetrix (mu74av2) microarray coupled with sequential primary biological function-focused and secondary

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We explored the role of angiotensin II and vasopressin in the maintenance of blood pressure during the nephrotic syndrome of adriamycin-induced nephropathy in rats. All 91 rats treated with adriamycin developed chronic renal failure with nephrotic syndrome, which was more pronounced in the normotensive rats than the 35% who became hypertensive. Angiotensin II blockade with DuP 753 produced a significantly greater hypotensive response in both the adriamycin-hypertensive (-16+/-3 mmHg) and adriamycin-normotensive (-14+/-5 mmHg) groups than the saline-treated controls (-5+/-1 mm Hg, P<.05). Vasopressin blockade with either a V1V2 inhibitor or a selective V-1 inhibitor produced a hypotensive response in adriamycin-hypertensive rats only (by -16+/-4 and -17+/-2 mm Hg, respectively, P<.01), although the nonselective vasopressin inhibitor produced similar fluid loss and body weight reduction in all three groups. The data suggest that in adriamycin-induced nephropathy with nephrotic syndrome, angiotensin II contributes to blood pressure maintenance in both hypertensive and normotensive animals, whereas the presser action of vasopressin contributes to elevated blood pressure in hypertensive animals only.

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Adriamycin, a commonly used antineoplastic antibiotic, induces glomerular lesions in rats, resulting in persistent proteinuria and glomerulosclerosis. We studied the effects of dietary protein and of an angiotensin I converting enzyme inhibitor on the progression of this nephropathy and the evolution of the histological lesions, as well as mesangial macromolecule flow. Adriamycin nephropathy was induced by injecting a single iv dose of adriamycin (3 mg/kg body weight) into the tail vein of male Wistar rats (weight, 180-200 g). In Experiment I animals with adriamycin-induced nephropathy were fed diets containing 6% (Low-Protein Diet Group = LPDG), 20% (Normal-Protein Diet Group = NPDG) and 40% (High-protein Diet Group = HPDG) protein and were observed for 30 weeks. In Experiment II the rats with adriamycin nephropathy were divided into 2 groups: ADR, that received adriamycin alone, and ADR-ENA, that received adriamycin plus enalapril, an angiotensin I converting enzyme inhibitor. The animals were sacrificed after a 24-week observation period. Six hours before sacrifice the animals were injected with I-131-ferritin and the amount of I-131-ferritin in the glomeruli was measured. In Experiment III, renal histology was performed 4, 8 and 16 weeks after adriamycin injection. At the end of Experiment I the tubulointerstitial lesion index was 2 for LPDG, 8 for NPDG, and 7.5 for HPDG (P<0.05); the frequency of glomerulosclerosis was 19 +/- 6.1% in LPDG, 42.6 +/- 6% in NPDG, and 54 +/- 9% in HPDG (P<0.05); and proteinuria was 61.1 +/- 25 mg/24 h in LPDG, 218.7 +/- 27.5 mg/24 h in NPDG, and 324.5 +/- 64.8 mg/24 h in HPDG (P<0.05). In Experiment II, at sacrifice, 24-h proteinuria was 189 +/- 16.1 mg in ADR, and 216 +/- 26.1 mg in ADR-ENA (P>0.05); the tubulointerstitial lesion index was 5 for ADR, and 5 for ADR-ENA (P>0.05); the frequency of glomerulosclerosis was 40 +/- 5.2% in ADR and 44 +/- 6% in ADR-ENA (P>0.05); the amount of I-131-ferritin in the mesangium was 214.26 +/- 22.71 cpm/mg protein in ADR and 253.77 +/- 69.72 cpm/mg protein in ADR-ENA (P>0.05). In Experiment III, sequential histological analysis revealed an acute tubulointerstitial cellular infiltrate at week 4, which was decreased at week 8. Tubular casts and dilatation were first seen at week 8 and increased at week 16 when few glomerular lesions were found. The results suggest that the tubulointerstitial lesions may play a role in the development of glomerulosclerosis in adriamycin-induced nephropathy.