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Jose M Villalba - One of the best experts on this subject based on the ideXlab platform.
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Dicoumarol impairs mitochondrial electron transport and pyrimidine biosynthesis in human myeloid leukemia hl 60 cells
Biochemical Pharmacology, 2007Co-Authors: David Gonzalezaragon, Julia Ariza, Jose M VillalbaAbstract:Dicoumarol, a competitive inhibitor of NAD(P)H:quinone oxidoreductase 1 (NQO1), increases intracellular superoxide and affects cell growth of tumor cells. This work was set to establish a mechanistic link between Dicoumarol, superoxide and cell cycle alterations in HL-60 cells. Using ES936, a mechanism-based irreversible inhibitor of NQO1, we demonstrate that NQO1 inhibition is not a major factor involved in superoxide boost. Mitochondrial Complexes II, III and IV were directly inhibited by Dicoumarol. Succinate, which inhibits superoxide generation by reversed electron flow in Complex II, significantly decreased superoxide boost in Dicoumarol-treated cells and in isolated mitochondria incubated with Dicoumarol and decylubiquinol. Superoxide generation in cells was strongly potentiated by blocking the quinone site of Complex II with thenoyltrifluoroacetone, supporting the involvement of cytochrome b560 to drive electrons for increasing superoxide. Simultaneous inhibition of the mitochondrial chain upstream ubiquinone and displacement of succinate from the Complex II active site is proposed as a major mechanism to explain how Dicoumarol increases superoxide in HL-60 cells. Dicoumarol-treated cells accumulated in S phase due to the impairment of pyrimidine biosynthesis at dihydroorotate dehydrogenase step because blockade was overcome by addition of exogenous uridine or orotate, but not by dihydroorotate. We demonstrate for the first time that Dicoumarol inhibits mitochondrial electron transport, induces superoxide release by reversed electron flow in Complex II, and inhibits pyrimidines biosynthesis. These actions must be taken into account when considering Dicoumarol effects on cells.
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Dicoumarol relieves serum withdrawal induced g0 1 blockade in hl 60 cells through a superoxide dependent mechanism
Biochemical Pharmacology, 2005Co-Authors: Rosario I. Bello, Guillermo Lopezlluch, Plácido Navas, Nathalie Forthoffer, Consuelo Gomezdiaz, Maria Del Carmen Cordobapedregosa, Jose M VillalbaAbstract:Abstract This work was set to study how Dicoumarol affects the cell cycle in human myeloid leukemia HL-60 cells. Cells were accumulated in G 0/1 after serum deprivation. However, when cells were treated with 5 μM Dicoumarol in serum-free medium, a significant increment in the number of cells in S-phase was observed. Inhibition of G 0/1 blockade was confirmed by the increase of thymidine incorporation, the phosphorylation of retinoblastoma protein, and the promotion of cell growth in long-term treatments in the absence of serum. Dicoumarol treatment increased superoxide levels, but did not affect peroxide. Increase of cellular superoxide was essential for inhibition of G 0/1 blockade, since scavenging this reactive species with a cell-permeable form of SOD and the SOD mimetics 2-amino-3,5-dibromo- N -[ trans -4-hydroxycyclohexyl]benzylamine (ambroxol, 100 μM) and copper[II]diisopropyl salicylate (CuDIPS, 10 μM) completely abolished the effect of Dicoumarol. However, N -acetyl-cysteine, overexpression of Bcl-2 or a cell-permeable form of catalase were not effective. 5-Methoxy-1,2-dimethyl-3-[(4-nitrophenol)methyl]-indole-4,7-dione (ES936), a mechanism-based irreversible inhibitor of NAD(P)H:quinone oxidoreductase 1 (NQO1), did not promote S phase entry, and Dicoumarol still inhibited G 0/1 blockade in the presence of ES936. We demonstrate that Dicoumarol inhibits the normal blockade in G 0/1 in HL-60 cells through a mechanism involving superoxide, but this effect is not dependent solely on the inhibition of the NQO1 catalytic activity. Our results send a precautionary message about use of Dicoumarol to elucidate cellular processes involving oxidoreductases.
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Dicoumarol relieves serum withdrawal-induced G0/1 blockade in HL-60 cells through a superoxide-dependent mechanism.
Biochemical pharmacology, 2005Co-Authors: Rosario I. Bello, Guillermo López-lluch, Plácido Navas, Consuelo Gómez-díaz, Nathalie Forthoffer, María Del Carmen Córdoba-pedregosa, Jose M VillalbaAbstract:Abstract This work was set to study how Dicoumarol affects the cell cycle in human myeloid leukemia HL-60 cells. Cells were accumulated in G 0/1 after serum deprivation. However, when cells were treated with 5 μM Dicoumarol in serum-free medium, a significant increment in the number of cells in S-phase was observed. Inhibition of G 0/1 blockade was confirmed by the increase of thymidine incorporation, the phosphorylation of retinoblastoma protein, and the promotion of cell growth in long-term treatments in the absence of serum. Dicoumarol treatment increased superoxide levels, but did not affect peroxide. Increase of cellular superoxide was essential for inhibition of G 0/1 blockade, since scavenging this reactive species with a cell-permeable form of SOD and the SOD mimetics 2-amino-3,5-dibromo- N -[ trans -4-hydroxycyclohexyl]benzylamine (ambroxol, 100 μM) and copper[II]diisopropyl salicylate (CuDIPS, 10 μM) completely abolished the effect of Dicoumarol. However, N -acetyl-cysteine, overexpression of Bcl-2 or a cell-permeable form of catalase were not effective. 5-Methoxy-1,2-dimethyl-3-[(4-nitrophenol)methyl]-indole-4,7-dione (ES936), a mechanism-based irreversible inhibitor of NAD(P)H:quinone oxidoreductase 1 (NQO1), did not promote S phase entry, and Dicoumarol still inhibited G 0/1 blockade in the presence of ES936. We demonstrate that Dicoumarol inhibits the normal blockade in G 0/1 in HL-60 cells through a mechanism involving superoxide, but this effect is not dependent solely on the inhibition of the NQO1 catalytic activity. Our results send a precautionary message about use of Dicoumarol to elucidate cellular processes involving oxidoreductases.
Sadia Rehman - One of the best experts on this subject based on the ideXlab platform.
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theoretical and structural studies of a stable dinuclear sodium complex of Dicoumarol 3 3 pyridin 3 ylmethanediyl bis 4 hydroxy 2h chromen 2 one
Journal of Molecular Structure, 2020Co-Authors: Muhammad Ikram, Sadia Rehman, Afzal Khan, Ayub Jadoon, Mutasem Omar SinnokrotAbstract:Abstract The synthesis of a Dicoumarol derivative (C24H15NO6) is reported via fusing 4-hydroxycoumarin with 3-pyridinecarboxaldehyde. The sodium derivative [Na2(C24H14NO6)2(MeOH)2(H2O)2] was synthesized by treating sodium methoxide with the Dicoumarol ligand (C24H15NO6). The resulting dinuclear sodium complex was structurally characterized using various spectroscopic and analytical techniques including 1H, 13C{1H}-NMR, high resolution ESI-MS(+), infrared spectroscopy, elemental and single crystal diffraction analyses. The molecular structure of [Na2(C24H14NO6)2(MeOH)2(H2O)2] exhibits coordination of methanol, water and Dicoumarol. B3LYP calculations were carried out to optimize the theoretical structural parameters and theoretical 1H and 13C NMR spectra for comparison with the respective experimental data which are well correlated.
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Theoretical and structural studies of a stable dinuclear sodium complex of Dicoumarol - 3,3′-(pyridin-3-ylmethanediyl)bis(4‑hydroxy-2H-chromen-2-one)
Journal of Molecular Structure, 2020Co-Authors: Muhammad Ikram, Sadia Rehman, Afzal Khan, Ayub Jadoon, Mutasem Omar SinnokrotAbstract:Abstract The synthesis of a Dicoumarol derivative (C24H15NO6) is reported via fusing 4-hydroxycoumarin with 3-pyridinecarboxaldehyde. The sodium derivative [Na2(C24H14NO6)2(MeOH)2(H2O)2] was synthesized by treating sodium methoxide with the Dicoumarol ligand (C24H15NO6). The resulting dinuclear sodium complex was structurally characterized using various spectroscopic and analytical techniques including 1H, 13C{1H}-NMR, high resolution ESI-MS(+), infrared spectroscopy, elemental and single crystal diffraction analyses. The molecular structure of [Na2(C24H14NO6)2(MeOH)2(H2O)2] exhibits coordination of methanol, water and Dicoumarol. B3LYP calculations were carried out to optimize the theoretical structural parameters and theoretical 1H and 13C NMR spectra for comparison with the respective experimental data which are well correlated.
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Synthesis of New Dicoumarol Based Zinc Compounds and their Invitro Antimicrobial Studies
Journal of the Mexican Chemical Society, 2017Co-Authors: Sadia Rehman, Muhammad Ikram, Fazle SubhanAbstract:The Dicoumarol derivatives were reacted with Zn (II) salt yielding the complexes (1-10) where metal centre was seen to be coordinated with Dicoumarols through hydroxyl and carbonyl sites of attachments. All the synthesized compounds were studied spectroscopically using 1 H, 13 C{ 1 H}-NMR, infrared spectroscopic method, and analytically using ES (+,-) -MS, elemental analyses and conductance studies. The combined NMR and mass spectral data suggested the attachment of two ligands to the zinc (II) centre. Hydroxyl site is deprotonated and take part in charge neutraliza- tion of metal center. The synthesized zinc based Dicoumarol com- pounds were screened for antimicrobial activities against Gram negative bacteria Escherichia coli, Salmonella typhus, Agrobacterium tumefaciens, Erwinia carotovora, Pseudomonas aeruginosa, Klebsiella pneumoniae, Gram positive bacteria Staphylococcus aureus, Bacillus subtilis, Bacillus atrophaeus and fungal Strain Candida albicans. All the compounds shown exceptional antimicrobial and antifungal activities.
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new Dicoumarol sodium compound crystal structure theoretical study and tumoricidal activity against osteoblast cancer cells
Chemistry Central Journal, 2013Co-Authors: Sadia Rehman, Muhammad Ikram, Ajmal Khan, Soyoung Min, Effat Azad, Thomas S Hofer, K H Mok, Robert J Baker, Alexander J BlakeAbstract:Enormous interest had been paid to the coordination chemistry of alkali and alkaline metal ions because of their role inside body viz; their Li+/Na+ exchange inside the cell lead to different diseases like neuropathy, hypertension, microalbuminuria, cardiac and vascular hypertrophy, obesity, and insulin resistance. It has been presumed that alkali metal ions (whether Na+ or K+) coordinated to chelating ligands can cross the hydrophobic cell membrane easily and can function effectively for depolarizing the ion difference. This unique function was utilized for bacterial cell death in which K+ has been found coordinated valinomycin (antibiotic). Distinct sodium adduct (1) with Dicoumarol ligand, 4-Hydroxy-3-[(4-hydroxy-2-oxo-4a,8a-dihydro-2H-chromen-3-yl)-phenyl-methyl]-chromen-2-one (L) is isolated from the saturated solution of sodium methoxide. Single crystal X-ray diffraction studies of the adduct reveals that sodium is in the form of cation attached to a methoxide, methanol and a Dicoumarol ligand where carbonyl functional groups of the coumarin derivative are acting as bridges. The sodium compound (1) is also characterized by IR, 1H-NMR, and 13C{1H}-NMR spectroscopic techniques. The composition is confirmed by elemental analysis. DFT study for 1 has been carried out using B3LYP/6-13G calculations which shown the theoretical confirmation of the various bond lengths and bond angles. Both the compounds were studied subsequently for the U2OS tumoricidal activity and it was found that L has LD50 value of 200 μM whereas the sodium analog cytotoxicity did not drop down below 60%. A sodium analogue (1) with medicinally important Dicoumarol ligand (L) has been reported. The crystal structure and DFT study confirm the formation of cationic sodium compound with Dicoumarol. The ligand was found more active than the sodium analog attributed to the instability of 1 in solution state. Coumarin compound with sodium was observed to be less cytotoxic than the ligand, its LD50 value never dropped below 60%.
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Synthesis, Characterization And Biological Evaluation Of Transition Metal Complexes Of Modified Coumarins
2013Co-Authors: Sadia RehmanAbstract:Dicoumarol compounds (L1-L10) derived after the condensation of various aldehydes with 4-hydroxycoumarin were studied elaborately.The compounds, L1, L3, L5, L8, L9 and L10 were found to be bearing Dicoumarol whereas compounds L2, L4, L6 and L7 were assigned dichromone structures, based on the absence and presence of intermolecular hydrogen bonding, respectively.The condensation behaviour was found to be altering only incase when aldehydes having hydroxyl group, substituted at ortho position, was present as a substrate.A mixture of Dicoumarol (L3 & L10) as minor and new class of coumarin compounds called translactonized compounds (L11 & L12) as a major product was produced in that case.The translactonized products (L11 & L12) were studied in detail for their structural features using spectroanalytical techniques and single crystal diffraction studies for L11 only.The Dicoumarol and dichromone structures of compounds L1-L10 were studied for their complexation behavior.These compounds were reacted with Zn (II) salt yielding the complexes (1-10) where metal centre was seen to be coordinated with Dicoumarols through hydroxyl and carbonyl sites of attachments.All the Dicoumarol ligands, L1-L10, were seen to be monoanionic in nature. A novel class of sodium derivatives (11-20) was also produced after reacting sodium methoxide with Dicoumarols (L1-L10). All the synthesized compounds were studied spectroscopically using 1H, 13C{1H}, 23Na-NMR (only in case of 11-20 compouds) infrared spectroscopic method, and analytically using ES(+,-)-MS, elemental analyses and conductance studies.Apart from it Dicoumarol compound like L6 was also studied by single crystal diffraction after recrystallizing the ligand from concentrated solution of L6 in DMF in Pc space group.Sodium compounds like 16 and 18 were recrystallized from concentrated methanol in P21/n space groups.The combined NMR and mass spectral data suggested the attachment of two ligands to the zinc and sodium centers respectively.Hydroxyl site is deprotonated and take part in charge neutralization of metal center in the former while the carbonyl sites of attachments were exploited leaving the hydroxyl sites intact in latter.Lactonic oxygen was also found to be coordinating to the sodium center producing the unusal products.Bone cancer is one of the uprising concerns for the scientist, therefore, all these compounds were studied in vitro for their osteoblast sarcomysis against U2OS cancerous cells.The compounds L1-L10 were found very active whereas the compound L11 was found most active compound of all the synthesized coumarin derivatives.All Zinc compounds were found active, except 4 and 9.The metal complex 3, was more active than the neat ligand.Similarly reasonable activity was seen for 6 and 10 metal complexes.The metal complex 8, showed the LD50 value which never dropped beyond 55%. All the sodium compounds due to the unstable nature in solution state were found less active.Apart from it all the synthesized compounds were studied for their antimicrobial activities against pathogenic microbes including Gram positive bacteria Bacillus atrophaeus, Bacillus subtilis, Staphylococcus aureus, Gram negative bacteria Klebsiella pneumoniae, Salmonella typhus Pseudomonas aeruginosa, Escherichia coli, Agrobacterium tumefaciens, Erwinia carotovora, fungal Strain Candida albican.These compounds depicted very good results particularly those derived from salicyldehyde, while rest of the compounds were moderately active against the tested microbes. Part IIDicoumarols, derived from aldehydes with ortho hydroxy substitution, were successfully cyclized by Sn(n-Bu)3Cl in THF as a reaction medium.Catalytic cycle revealed the formation of HO-Sn-O=C cyclic intermediate which is rearranged and isomerized to the cyclic lactone.N-butane was released by Sn(n-Bu)3Cl leaving behind Sn(n-Bu)2(OH)Cl keeping the catalytic route continued unless the other two butyl attached to tin were also consumed.The final product after cyclization of L3 was also studied using single crystal diffraction studies.The cyclized products were identified by NMR and high resolution mass spectrometric analyses
Plácido Navas - One of the best experts on this subject based on the ideXlab platform.
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Dicoumarol down regulates human pttg1 securin mrna expression through inhibition of hsp90
Molecular Cancer Therapeutics, 2008Co-Authors: Agustin Hernandez, Juan A Bernal, Guillermo Lopezlluch, Plácido Navas, Jose Antonio PintortoroAbstract:Securin, the natural inhibitor of sister chromatid untimely separation, is a protooncogene overexpressed in tumors. Its protein levels correlate with malignancy and metastatic proneness. Dicoumarol, a long-established oral anticoagulant, is a new Hsp90 inhibitor that represses PTTG1/Securin gene expression and provokes apoptosis through a complex trait involving both intrinsic and extrinsic pathways. Dicoumarol activity as an Hsp90 inhibitor is confirmed by smaller levels of Hsp90 clients in treated cells and inhibition of in vivo heat shock luciferase activity recovery assays. Likewise, established Hsp90 inhibitors (17-allylamino-geldanamycin and novobiocin) repress PTTG1/Securin gene expression. Also, overexpression of human Hsp90 in yeast makes them hypersensitive to Dicoumarol. Both apoptosis and PTTG1/Securin gene repression exerted by Dicoumarol in cancer cells are independent of three of the most important signaling pathways affected by Hsp90 inhibition: nuclear factor-κB, p53, or Akt/protein kinase B signaling pathways. However, effects on PTTG1/Securin could be partially ascribed to inhibition of the Ras/Raf/extracellular signal-regulated kinase pathway. Overall, we show that expression of PTTG1/Securin gene is Hsp90 dependent and that Dicoumarol is a bona fide Hsp90 inhibitor. These findings are important to understand the mode of action of Hsp90 inhibitors, mechanisms of action of Dicoumarol, and Securin overexpression in tumors. [Mol Cancer Ther 2008;7(3):474–82]
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Dicoumarol down-regulates human PTTG1/Securin mRNA expression through inhibition of Hsp90.
Molecular Cancer Therapeutics, 2008Co-Authors: Agustin Hernandez, Juan A Bernal, Guillermo López-lluch, Plácido Navas, José Antonio Pintor-toroAbstract:Securin, the natural inhibitor of sister chromatid untimely separation, is a protooncogene overexpressed in tumors. Its protein levels correlate with malignancy and metastatic proneness. Dicoumarol, a long-established oral anticoagulant, is a new Hsp90 inhibitor that represses PTTG1/Securin gene expression and provokes apoptosis through a complex trait involving both intrinsic and extrinsic pathways. Dicoumarol activity as an Hsp90 inhibitor is confirmed by smaller levels of Hsp90 clients in treated cells and inhibition of in vivo heat shock luciferase activity recovery assays. Likewise, established Hsp90 inhibitors (17-allylamino-geldanamycin and novobiocin) repress PTTG1/Securin gene expression. Also, overexpression of human Hsp90 in yeast makes them hypersensitive to Dicoumarol. Both apoptosis and PTTG1/Securin gene repression exerted by Dicoumarol in cancer cells are independent of three of the most important signaling pathways affected by Hsp90 inhibition: nuclear factor-κB, p53, or Akt/protein kinase B signaling pathways. However, effects on PTTG1/Securin could be partially ascribed to inhibition of the Ras/Raf/extracellular signal-regulated kinase pathway. Overall, we show that expression of PTTG1/Securin gene is Hsp90 dependent and that Dicoumarol is a bona fide Hsp90 inhibitor. These findings are important to understand the mode of action of Hsp90 inhibitors, mechanisms of action of Dicoumarol, and Securin overexpression in tumors. [Mol Cancer Ther 2008;7(3):474–82]
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Dicoumarol relieves serum withdrawal induced g0 1 blockade in hl 60 cells through a superoxide dependent mechanism
Biochemical Pharmacology, 2005Co-Authors: Rosario I. Bello, Guillermo Lopezlluch, Plácido Navas, Nathalie Forthoffer, Consuelo Gomezdiaz, Maria Del Carmen Cordobapedregosa, Jose M VillalbaAbstract:Abstract This work was set to study how Dicoumarol affects the cell cycle in human myeloid leukemia HL-60 cells. Cells were accumulated in G 0/1 after serum deprivation. However, when cells were treated with 5 μM Dicoumarol in serum-free medium, a significant increment in the number of cells in S-phase was observed. Inhibition of G 0/1 blockade was confirmed by the increase of thymidine incorporation, the phosphorylation of retinoblastoma protein, and the promotion of cell growth in long-term treatments in the absence of serum. Dicoumarol treatment increased superoxide levels, but did not affect peroxide. Increase of cellular superoxide was essential for inhibition of G 0/1 blockade, since scavenging this reactive species with a cell-permeable form of SOD and the SOD mimetics 2-amino-3,5-dibromo- N -[ trans -4-hydroxycyclohexyl]benzylamine (ambroxol, 100 μM) and copper[II]diisopropyl salicylate (CuDIPS, 10 μM) completely abolished the effect of Dicoumarol. However, N -acetyl-cysteine, overexpression of Bcl-2 or a cell-permeable form of catalase were not effective. 5-Methoxy-1,2-dimethyl-3-[(4-nitrophenol)methyl]-indole-4,7-dione (ES936), a mechanism-based irreversible inhibitor of NAD(P)H:quinone oxidoreductase 1 (NQO1), did not promote S phase entry, and Dicoumarol still inhibited G 0/1 blockade in the presence of ES936. We demonstrate that Dicoumarol inhibits the normal blockade in G 0/1 in HL-60 cells through a mechanism involving superoxide, but this effect is not dependent solely on the inhibition of the NQO1 catalytic activity. Our results send a precautionary message about use of Dicoumarol to elucidate cellular processes involving oxidoreductases.
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Dicoumarol relieves serum withdrawal-induced G0/1 blockade in HL-60 cells through a superoxide-dependent mechanism.
Biochemical pharmacology, 2005Co-Authors: Rosario I. Bello, Guillermo López-lluch, Plácido Navas, Consuelo Gómez-díaz, Nathalie Forthoffer, María Del Carmen Córdoba-pedregosa, Jose M VillalbaAbstract:Abstract This work was set to study how Dicoumarol affects the cell cycle in human myeloid leukemia HL-60 cells. Cells were accumulated in G 0/1 after serum deprivation. However, when cells were treated with 5 μM Dicoumarol in serum-free medium, a significant increment in the number of cells in S-phase was observed. Inhibition of G 0/1 blockade was confirmed by the increase of thymidine incorporation, the phosphorylation of retinoblastoma protein, and the promotion of cell growth in long-term treatments in the absence of serum. Dicoumarol treatment increased superoxide levels, but did not affect peroxide. Increase of cellular superoxide was essential for inhibition of G 0/1 blockade, since scavenging this reactive species with a cell-permeable form of SOD and the SOD mimetics 2-amino-3,5-dibromo- N -[ trans -4-hydroxycyclohexyl]benzylamine (ambroxol, 100 μM) and copper[II]diisopropyl salicylate (CuDIPS, 10 μM) completely abolished the effect of Dicoumarol. However, N -acetyl-cysteine, overexpression of Bcl-2 or a cell-permeable form of catalase were not effective. 5-Methoxy-1,2-dimethyl-3-[(4-nitrophenol)methyl]-indole-4,7-dione (ES936), a mechanism-based irreversible inhibitor of NAD(P)H:quinone oxidoreductase 1 (NQO1), did not promote S phase entry, and Dicoumarol still inhibited G 0/1 blockade in the presence of ES936. We demonstrate that Dicoumarol inhibits the normal blockade in G 0/1 in HL-60 cells through a mechanism involving superoxide, but this effect is not dependent solely on the inhibition of the NQO1 catalytic activity. Our results send a precautionary message about use of Dicoumarol to elucidate cellular processes involving oxidoreductases.
Rosario I. Bello - One of the best experts on this subject based on the ideXlab platform.
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Dicoumarol relieves serum withdrawal induced g0 1 blockade in hl 60 cells through a superoxide dependent mechanism
Biochemical Pharmacology, 2005Co-Authors: Rosario I. Bello, Guillermo Lopezlluch, Plácido Navas, Nathalie Forthoffer, Consuelo Gomezdiaz, Maria Del Carmen Cordobapedregosa, Jose M VillalbaAbstract:Abstract This work was set to study how Dicoumarol affects the cell cycle in human myeloid leukemia HL-60 cells. Cells were accumulated in G 0/1 after serum deprivation. However, when cells were treated with 5 μM Dicoumarol in serum-free medium, a significant increment in the number of cells in S-phase was observed. Inhibition of G 0/1 blockade was confirmed by the increase of thymidine incorporation, the phosphorylation of retinoblastoma protein, and the promotion of cell growth in long-term treatments in the absence of serum. Dicoumarol treatment increased superoxide levels, but did not affect peroxide. Increase of cellular superoxide was essential for inhibition of G 0/1 blockade, since scavenging this reactive species with a cell-permeable form of SOD and the SOD mimetics 2-amino-3,5-dibromo- N -[ trans -4-hydroxycyclohexyl]benzylamine (ambroxol, 100 μM) and copper[II]diisopropyl salicylate (CuDIPS, 10 μM) completely abolished the effect of Dicoumarol. However, N -acetyl-cysteine, overexpression of Bcl-2 or a cell-permeable form of catalase were not effective. 5-Methoxy-1,2-dimethyl-3-[(4-nitrophenol)methyl]-indole-4,7-dione (ES936), a mechanism-based irreversible inhibitor of NAD(P)H:quinone oxidoreductase 1 (NQO1), did not promote S phase entry, and Dicoumarol still inhibited G 0/1 blockade in the presence of ES936. We demonstrate that Dicoumarol inhibits the normal blockade in G 0/1 in HL-60 cells through a mechanism involving superoxide, but this effect is not dependent solely on the inhibition of the NQO1 catalytic activity. Our results send a precautionary message about use of Dicoumarol to elucidate cellular processes involving oxidoreductases.
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Dicoumarol relieves serum withdrawal-induced G0/1 blockade in HL-60 cells through a superoxide-dependent mechanism.
Biochemical pharmacology, 2005Co-Authors: Rosario I. Bello, Guillermo López-lluch, Plácido Navas, Consuelo Gómez-díaz, Nathalie Forthoffer, María Del Carmen Córdoba-pedregosa, Jose M VillalbaAbstract:Abstract This work was set to study how Dicoumarol affects the cell cycle in human myeloid leukemia HL-60 cells. Cells were accumulated in G 0/1 after serum deprivation. However, when cells were treated with 5 μM Dicoumarol in serum-free medium, a significant increment in the number of cells in S-phase was observed. Inhibition of G 0/1 blockade was confirmed by the increase of thymidine incorporation, the phosphorylation of retinoblastoma protein, and the promotion of cell growth in long-term treatments in the absence of serum. Dicoumarol treatment increased superoxide levels, but did not affect peroxide. Increase of cellular superoxide was essential for inhibition of G 0/1 blockade, since scavenging this reactive species with a cell-permeable form of SOD and the SOD mimetics 2-amino-3,5-dibromo- N -[ trans -4-hydroxycyclohexyl]benzylamine (ambroxol, 100 μM) and copper[II]diisopropyl salicylate (CuDIPS, 10 μM) completely abolished the effect of Dicoumarol. However, N -acetyl-cysteine, overexpression of Bcl-2 or a cell-permeable form of catalase were not effective. 5-Methoxy-1,2-dimethyl-3-[(4-nitrophenol)methyl]-indole-4,7-dione (ES936), a mechanism-based irreversible inhibitor of NAD(P)H:quinone oxidoreductase 1 (NQO1), did not promote S phase entry, and Dicoumarol still inhibited G 0/1 blockade in the presence of ES936. We demonstrate that Dicoumarol inhibits the normal blockade in G 0/1 in HL-60 cells through a mechanism involving superoxide, but this effect is not dependent solely on the inhibition of the NQO1 catalytic activity. Our results send a precautionary message about use of Dicoumarol to elucidate cellular processes involving oxidoreductases.
Osamu Ogawa - One of the best experts on this subject based on the ideXlab platform.
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Dicoumarol enhances doxorubicin-induced cytotoxicity in p53 wild-type urothelial cancer cells through p38 activation.
BJU international, 2009Co-Authors: Yoshiyuki Matsui, Jun Watanabe, Osamu Ogawa, Sentai Ding, Koji Nishizawa, Yoichiro Kajita, Kentaro Ichioka, Ryoichi Saito, Takashi Kobayashi, Hiroyuki NishiyamaAbstract:OBJECTIVE To investigate the effectiveness of a combined treatment of 3–30-methylene-bis[4-hydroxycoumarin] (Dicoumarol) with doxorubicin for the treatment of urothelial cancer, as doxorubicin is a common chemotherapeutic agent but its therapeutic efficacy is limited. MATERIALS AND METHODS The synergistic effect of Dicoumarol with chemotherapeutic agents such as cisplatin, doxorubicin and paclitaxel was evaluated in RT112 urothelial cancer cells. Then, Dicoumarol-mediated enhancement of doxorubicin-induced cytotoxicity was screened in urothelial cancer cell lines with different p53 statuses or RT112 stable transfectants with a dominant-negative mutant of p53 (p53DN). To clarify the importance of the modification of p53 function by Dicoumarol to enhance doxorubicin toxicity, the change in the p53-p21 pathway and mitogen-activated protein kinase (MAPK)-mitochondria pathway by the combined treatment were elucidated by Western blot analysis. Finally, the effect of p21 knockdown in the susceptibility to doxorubicin was examined with RT112 stable transfectants with short hairpin RNA (shRNA) of p21. RESULTS Dicoumarol significantly increased the susceptibility of RT112 cells to cisplatin and doxorubicin, but not to paclitaxel in RT112 cells. Dicoumarol (100 µm) also enhanced the cytotoxicity of doxorubicin in other bladder cancer cell lines with wild-type p53 (wt-p53; three times in 253J and 13 times in KK47), but not in those with mutant-type p53 (TCCsup, J82 and EJ) or in RT112 p53DN. The combined treatment with Dicoumarol suppressed p53/p21 induction by doxorubicin and resulted in sequential p38 MAPK activation, myeloid cell leukaemia 1 suppression and caspase cleavage. The synergistic effect of doxorubicin/Dicoumarol was suppressed by the p38 MAPK inhibitor SB202190 and, furthermore, p21 knockdown with shRNA transfection made RT112 cells six times more susceptible to doxorubicin with p38 MAPK activation. CONCLUSION These results suggest that concomitant use of Dicoumarol could enhance the cytotoxicity of doxorubicin in urothelial cancer cells with wt-p53 through the p53/p21/p38 MAPK pathways. This combined treatment may provide a new therapeutic option to overcome chemoresistance in bladder cancer.
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Dicoumarol potentiates cisplatin-induced apoptosis mediated by c-Jun N-terminal kinase in p53 wild-type urogenital cancer cell lines.
Oncogene, 2006Co-Authors: Jun Watanabe, Hiroyuki Nishiyama, Yoshiyuki Matsui, Masaaki Ito, Hiroaki Kawanishi, Toshiyuki Kamoto, Osamu OgawaAbstract:3-3′-Methylene-bis [4-hydroxycoumarin] (Dicoumarol), an inhibitor of NADPH:quinone oxidoreductase 1, has been reported to possess potential antineoplastic effects and the ability to abrogate p53 protein. In the present study, we investigated the cytotoxic effects of Dicoumarol in combination with cisplatin (CDDP), using four bladder (RT112, 253J, J82 and UMUC3) and two prostate (LNCap and PC3) cancer cell lines. Single treatment with 100 μ M Dicoumarol suppressed cell proliferation but did not induce apoptosis at 24 h in all cell lines examined. On the other hand, pretreatment with Dicoumarol enhanced cytotoxicity of CDDP in three cell lines with wild type of p53 (RT112, 253J and LNCap), but not in three other cell lines with mutant p53 or in RT112 stable transfectants with a dominant-negative mutant of p53. In RT112 and LNCap, CDDP induced p53 and p21 expression, while pretreatment of Dicoumarol suppressed induction of p53/p21 and resulted in sequential activation of c-Jun N-terminal kinase (JNK) in a time-dependent manner. Furthermore, inhibition of JNK, using SP600125, completely suppressed activity of caspases and poly-(ADP-ribose) polymerase cleavage, leading to suppression of enhancement of CDDP-mediated apoptosis by Dicoumarol. These results suggested that Dicoumarol could enhance cytotoxicity of CDDP in urogenital cancer cells with wild-type p53 through the p53/p21/JNK pathways.