The Experts below are selected from a list of 174 Experts worldwide ranked by ideXlab platform
Olivier Duval - One of the best experts on this subject based on the ideXlab platform.
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EthoxyFagaronine, a synthetic analogue of Fagaronine that inhibits vascular endothelial growth factor-1, as a new anti-angiogeneic agent
Investigational New Drugs, 2015Co-Authors: Farid Ouchani, Olivier Duval, Jeanjacques Helesbeux, Isabelle Letinois, Laurent Martiny, Albin Jeanne, Jessica Thevenard, Amandine Wahart, Emmanuelle Charpentier, Jerome DevyAbstract:Angiogenesis plays a pivotal role in tumorigenesis and also contributes to the pathogenesis of hematologic malignancies. A number of plant compounds have shown efficacy in preclinical and clinical studies and some of them possess an anti-angiogenic activity. Our present findings report anti-angiogenic activities of ethoxyFagaronine (etxfag), a synthetic derivative of Fagaronine. Once determined the non-cytotoxic concentration of etxfag, we showed that the drug inhibits VEGF-induced angiogenesis in a Matrigel™ plug assay and suppresses ex vivo sprouting from VEGF-treated aortic rings. Each feature leading to neovascularization was then investigated and results demonstrate that etxfag prevents VEGF-induced migration and tube formation in human umbilical vein endothelial cells (HUVEC). Moreover, etxfag also suppresses VEGF-induced VEGFR-2 phosphorylation and inhibits FAK phosphorylation at Y-861 as well as focal adhesion complex turnover. Beside these effects, etxfag modifies MT1-MMP localization at the endothelial cell membrane. Finally, immunoprecipitation assay revealed that etxfag decreases VEGF binding to VEGFR-2. As we previously reported that etxfag is able to prevent leukemic cell invasiveness and adhesion to fibronectin, all together our data collectively support the anti-angiogenic activities of etxfag which could represent an additional approach to current anti-cancer therapies.
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Targeting focal adhesion assembly by ethoxyFagaronine prevents lymphoblastic cell adhesion to fibronectin
Analytical Cellular Pathology, 2012Co-Authors: Farid Ouchani, Jerome Devy, Olivier Duval, Jeanjacques Helesbeux, Stéphanie Salesse, Isabelle Letinois, Anthony Rusciani, D. Gras-billart, Laurent Duca, Laurent MartinyAbstract:Background: Leukemic cell adhesion to proteins of the bone marrow microenvironment provides signals which control morphology, motility and cell survival. We described herein the ability of ethoxyFagaronine (etxfag), a soluble synthetic derivative of Fagaronine, to prevent leukemic cell adhesion to fibronectin peptide (FN/V). Methods: Phosphorylation of fak and pyk2 were evaluated by immunoblotting. Labelled proteins were localized by confocal microscopy. PI 3-kinase activity was evaluated by in vitro kinase assay. Results: Subtoxic concentration of etxfag reduced L1210 cell adhesion to FN/V dependently of 1 integrin engagement. Etxfag impaired FN-dependent formation of 1 clustering without modifying 1 expression at the cell membrane. This was accompanied by a decrease of focal adhesion number, a diminution of fak and pyk2 phosphorylation at Tyr-576, Tyr-861 and Tyr-579, respectively leading to their dissociations from 1 integrin and inhibition of PI 3-kinase activity. Etxfag also induced a cell retraction accompanied by a redistribution of phosphorylated fak and pyk2 in the perinuclear region and lipid raft relocalization. Conclusion: Through its anti-adhesive potential, etxfag, combined with conventional cytotoxic drugs could be potentially designed as a new anti-leukemic drug.
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The anti-invasive activity of synthetic alkaloid ethoxyFagaronine on L1210 leukemia cells is mediated by down-regulation of plasminogen activators and MT1-MMP expression and activity
Investigational New Drugs, 2011Co-Authors: Jerome Devy, Enguerran Vanquelef, Jeanjacques Helesbeux, Farid Ouchani, Christelle Oudot, Stéphanie Salesse, Fanja Rabenoelina, Siana Al-khara, Isabelle Letinois, Olivier DuvalAbstract:Quaternary benzo[ c ]phenanthridines such as Fagaronine are natural substances which have been reported to exhibit anticancer and anti-leukemic properties. However, the therapeutic use of these molecules is limited due to the high dose required to exhibit anti-tumor activity and subsequent toxicity. In this study, we describe the therapeutic potential of a new derivative of Fagaronine, EthoxyFagaronine (N-methyl-12-ethoxy-2hydroxy-3, 8, 9-trimethoxybenzo[c]-phenanthridiniumchlorhydrate) as an anti-leukemic agent. Cytotoxic activity and cell growth inhibition of EthoxyFagaronine (Etxfag) was tested on murine L1210 leukemia cells using trypan blue assay and MTT assay. At the concentration of 10^−7 M, Etxfag induced less than 10% of cell death. Etxfag (10^−7 M) was tested on L1210 cell invasiveness using matrigel™ precoated transwell chambers and efficiently reduces the invasive potential of L1210 cells by more than 50% as compared with untreated cells. Western blot and immunofluorescence experiments showed that Etxfag decreased both MT1-MMP expression and activation at the cell surface, decreased plasmin activity by down-regulating u-PAR and uPA expression at the cell surface and increasing PAI-1 secretion in conditioned media. The set of our findings underscore the therapeutic potential of ethoxyFagaronine as a new potential anticancer agent able to prevent leukemic cell dissemination.
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synthesis and pc3 androgen independent prostate cells antiproliferative effect of Fagaronine derivatives
Journal of Enzyme Inhibition and Medicinal Chemistry, 2007Co-Authors: Enguerran Vanquelef, Olivier Duval, Jeanjacques Helesbeux, Eric Debiton, Chantal Barthomeuf, Christian Jarry, Isabelle Forfar, Pascal RichommeAbstract:Fagaronine derivatives syntheses were optimized and their effect on PC3 androgen-independent prostate cell line was evaluated. An assessment of the lipophilicity of the benzo[c]phenanthridine derivatives was achieved at pH 7.4 and et 6.7 by determining log D.
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Synthesis and Antiviral Effect against Herpes Simplex Type 1 of 12-substituted Benzo[c]phenanthridinium Salts
Journal of Enzyme Inhibition and Medicinal Chemistry, 2004Co-Authors: Enguerran Vanquelef, M. Amoros, Joël Boustie, Michael A. Lynch, Roger D. Waigh, Olivier DuvalAbstract:The synthesis of benzo[c]phenanthridine alkaloid derivatives is described. In vitro antiviral activity against herpes simplex type 1 (HSV1) has been investigated. Contrary to the natural product Fagaronine, which did not have any activity in the HSV1 antiviral tests, four 12-alkoxy derivatives showed good activity demonstrating the importance of the 12-substitution in the structure-activity relationships.
Igor Nabiev - One of the best experts on this subject based on the ideXlab platform.
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Synthesis, biological activity and comparative analysis of DNA binding affinities and human DNA topoisomerase I inhibitory activities of novel 12-alkoxy-benzo[c]phenanthridinium salts
Bioorganic & Medicinal Chemistry Letters, 2001Co-Authors: Michael A. Lynch, Alyona Sukhanova, Jerome Devy, Olivier Duval, Roger D. Waigh, Simon P. Mackay, Igor NabievAbstract:New antitumor 12-alkoxy-benzo[c]phenanthridinium derivatives were obtained in high yields through multistep syntheses. Analysis of DNA binding and human DNA topoisomerase I inhibitory activities demonstrates that new compounds, combining 2, 6, and 12 substitutions, interact strongly with DNA and exhibit important topoisomerase I inhibition. The cytotoxicities against solid tumor cell lines are also determined and compared with those for Fagaronine and ethoxidine.
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molecular determinants of site specific inhibition of human dna topoisomerase i by Fagaronine and ethoxidine relation to dna binding
Journal of Biological Chemistry, 2000Co-Authors: Fabrice Fleury, Jeanclaude Jardillier, Alyona Sukhanova, Anatoli Ianoul, Jerome Devy, I A Kudelina, Olivier Duval, Alain J P Alix, Igor NabievAbstract:Abstract DNA topoisomerase (top) I inhibition activity of the natural alkaloid Fagaronine (NSC157995) and its new synthetic derivative ethoxidine (12-ethoxy-benzo[c]phenanthridine) has been correlated with their molecular interactions and sequence specificity within the DNA complexes. Flow linear dichroism shows that ethoxidine exhibits the same inhibition of DNA relaxation as Fagaronine at the 10-fold lower concentration. The patterns of DNA cleavage by top I show linear enhancement of CPT-dependent sites at the 0.016–50 μm concentrations of Fagaronine, whereas ethoxidine suppress both top I-specific and CPT-dependent sites. Suppression of top I-mediated cleavage by ethoxidine is found to be specific for the sites, including strand cut between A and T. Fagaronine and ethoxidine are DNA major groove intercalators. Ethoxidine intercalates DNA in A-T sequences and its 12-ethoxy-moiety (absent in Fagaronine) extends into the DNA minor groove. These findings may explain specificity of suppression by ethoxidine of the strong top I cleavage sites with the A(+1), T(−1) immediately adjacent to the strand cut. Fagaronine does not show any sequence specificity of DNA intercalation, but its highly electronegative oxygen of hydroxy group (absent in ethoxidine) is shown to be an acceptor of the hydrogen bond with the NH2 group of G base of DNA. Ability of Fagaronine to stabilize top I-mediated ternary complex is proposed to be determined by interaction of its hydroxy group with the guanine at position (+1) of the DNA cleavage site and of quaternary nitrogen interaction with top I. The model proposed provides a guidance for screening new top I-targeted drugs in terms of identification of molecular determinants responsible for their top I inhibition effects.
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molecular determinants of site specific inhibition of human dna topoisomerase i by Fagaronine and ethoxidine
2000Co-Authors: Fabrice Fleury, Jeanclaude Jardillier, Alyona Sukhanova, Anatoli Ianoul, Jerome Devy, I A Kudelina, Olivier Duval, Alain J P Alixi, Igor NabievAbstract:DNA topoisomerase (top) I inhibition activity of the natural alkaloid Fagaronine (NSC157995) and its new synthetic derivative ethoxidine (12-ethoxy-benzo[c] phenanthridine) has been correlated with their molecular interactions and sequence specificity within the DNA complexes. Flow linear dichroism shows that ethoxidine exhibits the same inhibition of DNA relaxation as Fagaronine at the 10-fold lower concentration. The patterns of DNA cleavage by top I show linear enhancement of CPT-dependent sites at the 0.016 ‐50 mM concentrations of Fagaronine, whereas ethoxidine suppress both top I-specific and CPT-dependent sites. Suppression of top I-mediated cleavage by ethoxidine is found to be specific for the sites, including strand cut between A and T. Fagaronine and ethoxidine are DNA major groove intercalators. Ethoxidine intercalates DNA in A-T sequences and its 12-ethoxy-moiety (absent in Fagaronine) extends into the DNA minor groove. These findings may explain specificity of suppression by ethoxidine of the strong top I cleavage sites with the A(11), T(21) immediately adjacent to the strand cut. Fagaronine does not show any sequence specificity of DNA intercalation, but its highly electronegative oxygen of hydroxy group (absent in ethoxidine) is shown to be an acceptor of the hydrogen bond with the NH2 group of G base of DNA. Ability of Fagaronine to stabilize top I-mediated ternary complex is proposed to be determined by interaction of its hydroxy group with the guanine at position (11) of the DNA cleavage site and of quaternary nitrogen interaction with top I. The model proposed provides a guidance for screening new top I-targeted drugs in terms of identification of molecular determinants responsible for their top I inhibition effects.
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Combined SERS and flow linear dichroism approach to monitoring the interaction of pharmaceuticals with their target
Systems and Technologies for Clinical Diagnostics and Drug Discovery II, 1999Co-Authors: Anatoli Ianoul, Jeanclaude Jardillier, Fabrice Fleury, Olivier Duval, Alain J P Alix, Igor NabievAbstract:Surface-Enhanced Raman Scattering (SERS) spectroscopy and Flow Linear Dichroism (FLD) technique have been employed to study the anticancer agent Fagaronine and its derivative ethoxidine - double inhibitors of DNA topoisomerases I and II. Cooperative use of two methods permitted (i) to determine the molecular determinants of the drug-DNA interactions; (ii) to monitor in real time the process of topo I inhibition by these anticancer agents. FLD technique allowed us to identify the mode of drug interactions with the DNA as a 'major groove intercalation' and to determine orientation of the drugs chromophores within the complexes. Using SERS spectroscopy we have determined the drugs molecular determinants interacting with the DNA. FLD was also used for real time monitoring of the process of sc DNA relaxation by topo I and of inhibition of relaxation with the pharmaceuticals. Ethoxidine was found to exhibit the same activity of inhibition of sc DNA relaxation as Fagaronine at the 10-fold less concentration. The proposed SERS-FLD combined approach demonstrates the new perspectives for screening new pharmaceuticals due to its relative simplicity and low expense, high sensitivity and selectivity, and, finally, possibility of real-time monitoring of the structure-function correlation within the series of drug derivatives.
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dna binding by Fagaronine and ethoxidine inhibitors of human dna topoisomerases i and ii probed by sers and flow linear dichroism spectroscopy
Journal of Physical Chemistry B, 1999Co-Authors: Anatoli Ianoul, Jeanclaude Jardillier, Fabrice Fleury, Olivier Duval, Roger D. Waigh, And Alain J P Alix, Igor NabievAbstract:Raman, surface-enhanced Raman scattering (SERS), and flow linear dichroism (FLD) spectroscopies were employed to study the potent anticancer agent Fagaronine (FGR, NSC 157995) and its derivative ethoxidine (ETX)sinhibitors of DNA topoisomerases (topos) I and II (Figure 1)sand their complexes with DNA. The FLD data obtained suggest that both compounds are strong major groove intercalators with stoichiometries 1 FGR/2.0 DNA bp and 1 ETX/4.0 DNA bp The SERS spectra of both compounds were recorded at the concentrations down to 10 -8 M for FGR and 10 -6 M for ETX, and the SERS-active modes were assigned by comparison of Raman and SERS spectra of the drugs following the changes induced by deuteration and pH environment. The SERS-active surface was proved not to affect the drug/DNA interactions, since the DNA binding constants calculated from the SERS experiments were found to be practically the same as those determined previously by viscosimetric measurements. The SERS study of the FGR/DNA complex showed that the OH group of FGR plays a key role in DNA binding, most probably because of formation of the H bond with DNA. Cooperative use of Raman, SERS, and FLD techniques enabled us to propose a molecular model for drug/DNA interactions. The differences in DNA binding by FGR and ETX are discussed in terms of different topoisomerases inhibitory activities of these drugs.
Jeanclaude Jardillier - One of the best experts on this subject based on the ideXlab platform.
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molecular determinants of site specific inhibition of human dna topoisomerase i by Fagaronine and ethoxidine relation to dna binding
Journal of Biological Chemistry, 2000Co-Authors: Fabrice Fleury, Jeanclaude Jardillier, Alyona Sukhanova, Anatoli Ianoul, Jerome Devy, I A Kudelina, Olivier Duval, Alain J P Alix, Igor NabievAbstract:Abstract DNA topoisomerase (top) I inhibition activity of the natural alkaloid Fagaronine (NSC157995) and its new synthetic derivative ethoxidine (12-ethoxy-benzo[c]phenanthridine) has been correlated with their molecular interactions and sequence specificity within the DNA complexes. Flow linear dichroism shows that ethoxidine exhibits the same inhibition of DNA relaxation as Fagaronine at the 10-fold lower concentration. The patterns of DNA cleavage by top I show linear enhancement of CPT-dependent sites at the 0.016–50 μm concentrations of Fagaronine, whereas ethoxidine suppress both top I-specific and CPT-dependent sites. Suppression of top I-mediated cleavage by ethoxidine is found to be specific for the sites, including strand cut between A and T. Fagaronine and ethoxidine are DNA major groove intercalators. Ethoxidine intercalates DNA in A-T sequences and its 12-ethoxy-moiety (absent in Fagaronine) extends into the DNA minor groove. These findings may explain specificity of suppression by ethoxidine of the strong top I cleavage sites with the A(+1), T(−1) immediately adjacent to the strand cut. Fagaronine does not show any sequence specificity of DNA intercalation, but its highly electronegative oxygen of hydroxy group (absent in ethoxidine) is shown to be an acceptor of the hydrogen bond with the NH2 group of G base of DNA. Ability of Fagaronine to stabilize top I-mediated ternary complex is proposed to be determined by interaction of its hydroxy group with the guanine at position (+1) of the DNA cleavage site and of quaternary nitrogen interaction with top I. The model proposed provides a guidance for screening new top I-targeted drugs in terms of identification of molecular determinants responsible for their top I inhibition effects.
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molecular determinants of site specific inhibition of human dna topoisomerase i by Fagaronine and ethoxidine
2000Co-Authors: Fabrice Fleury, Jeanclaude Jardillier, Alyona Sukhanova, Anatoli Ianoul, Jerome Devy, I A Kudelina, Olivier Duval, Alain J P Alixi, Igor NabievAbstract:DNA topoisomerase (top) I inhibition activity of the natural alkaloid Fagaronine (NSC157995) and its new synthetic derivative ethoxidine (12-ethoxy-benzo[c] phenanthridine) has been correlated with their molecular interactions and sequence specificity within the DNA complexes. Flow linear dichroism shows that ethoxidine exhibits the same inhibition of DNA relaxation as Fagaronine at the 10-fold lower concentration. The patterns of DNA cleavage by top I show linear enhancement of CPT-dependent sites at the 0.016 ‐50 mM concentrations of Fagaronine, whereas ethoxidine suppress both top I-specific and CPT-dependent sites. Suppression of top I-mediated cleavage by ethoxidine is found to be specific for the sites, including strand cut between A and T. Fagaronine and ethoxidine are DNA major groove intercalators. Ethoxidine intercalates DNA in A-T sequences and its 12-ethoxy-moiety (absent in Fagaronine) extends into the DNA minor groove. These findings may explain specificity of suppression by ethoxidine of the strong top I cleavage sites with the A(11), T(21) immediately adjacent to the strand cut. Fagaronine does not show any sequence specificity of DNA intercalation, but its highly electronegative oxygen of hydroxy group (absent in ethoxidine) is shown to be an acceptor of the hydrogen bond with the NH2 group of G base of DNA. Ability of Fagaronine to stabilize top I-mediated ternary complex is proposed to be determined by interaction of its hydroxy group with the guanine at position (11) of the DNA cleavage site and of quaternary nitrogen interaction with top I. The model proposed provides a guidance for screening new top I-targeted drugs in terms of identification of molecular determinants responsible for their top I inhibition effects.
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Combined SERS and flow linear dichroism approach to monitoring the interaction of pharmaceuticals with their target
Systems and Technologies for Clinical Diagnostics and Drug Discovery II, 1999Co-Authors: Anatoli Ianoul, Jeanclaude Jardillier, Fabrice Fleury, Olivier Duval, Alain J P Alix, Igor NabievAbstract:Surface-Enhanced Raman Scattering (SERS) spectroscopy and Flow Linear Dichroism (FLD) technique have been employed to study the anticancer agent Fagaronine and its derivative ethoxidine - double inhibitors of DNA topoisomerases I and II. Cooperative use of two methods permitted (i) to determine the molecular determinants of the drug-DNA interactions; (ii) to monitor in real time the process of topo I inhibition by these anticancer agents. FLD technique allowed us to identify the mode of drug interactions with the DNA as a 'major groove intercalation' and to determine orientation of the drugs chromophores within the complexes. Using SERS spectroscopy we have determined the drugs molecular determinants interacting with the DNA. FLD was also used for real time monitoring of the process of sc DNA relaxation by topo I and of inhibition of relaxation with the pharmaceuticals. Ethoxidine was found to exhibit the same activity of inhibition of sc DNA relaxation as Fagaronine at the 10-fold less concentration. The proposed SERS-FLD combined approach demonstrates the new perspectives for screening new pharmaceuticals due to its relative simplicity and low expense, high sensitivity and selectivity, and, finally, possibility of real-time monitoring of the structure-function correlation within the series of drug derivatives.
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dna binding by Fagaronine and ethoxidine inhibitors of human dna topoisomerases i and ii probed by sers and flow linear dichroism spectroscopy
Journal of Physical Chemistry B, 1999Co-Authors: Anatoli Ianoul, Jeanclaude Jardillier, Fabrice Fleury, Olivier Duval, Roger D. Waigh, And Alain J P Alix, Igor NabievAbstract:Raman, surface-enhanced Raman scattering (SERS), and flow linear dichroism (FLD) spectroscopies were employed to study the potent anticancer agent Fagaronine (FGR, NSC 157995) and its derivative ethoxidine (ETX)sinhibitors of DNA topoisomerases (topos) I and II (Figure 1)sand their complexes with DNA. The FLD data obtained suggest that both compounds are strong major groove intercalators with stoichiometries 1 FGR/2.0 DNA bp and 1 ETX/4.0 DNA bp The SERS spectra of both compounds were recorded at the concentrations down to 10 -8 M for FGR and 10 -6 M for ETX, and the SERS-active modes were assigned by comparison of Raman and SERS spectra of the drugs following the changes induced by deuteration and pH environment. The SERS-active surface was proved not to affect the drug/DNA interactions, since the DNA binding constants calculated from the SERS experiments were found to be practically the same as those determined previously by viscosimetric measurements. The SERS study of the FGR/DNA complex showed that the OH group of FGR plays a key role in DNA binding, most probably because of formation of the H bond with DNA. Cooperative use of Raman, SERS, and FLD techniques enabled us to propose a molecular model for drug/DNA interactions. The differences in DNA binding by FGR and ETX are discussed in terms of different topoisomerases inhibitory activities of these drugs.
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The role of sequence-specificity of DNA binding by benzo[c]phenanthiridines fagaronin and ethoxidine in their anti-topoisomerase I activity
Spectroscopy of Biological Molecules: New Directions, 1999Co-Authors: Jerome Devy, Jeanclaude Jardillier, Fabrice Fleury, Olivier Duval, Igor NabievAbstract:Antitumor benzo[c]phenanthiridines (fig. I) Fagaronine (fag), isolated from the roots of Fagarara zanthoxyloides Lam. (Rutaceae), and its derivative ethoxidine (ethox) interfere with the human DNA topoisomerase (topo) I cleavage complexes and are potent DNA intercalators [1, 2]. Our recent data show that both fag and ethox inhibit topo I but in two different mechanisms. Fag traps topo I-DNA cleavage complex being the topo I-“poison”. Ethox is a potent suppresser of DNA cleavage by topo I being a modulator of site-specific recognition of DNA by the enzyme. Both drugs are known to be typical intercalators whereas the data on their sequence-specificity are contradictory. DNA recognition and cleavage by topo I is known to be extremely sequence-specific: cleavage is processed in the sequences corresponding to the so-called “topo I-specific” sites which includes obligatory T-base in position (-1) downstream in the sequence. So, the goal of this work was to analyse molecular basis of site-specific interactions between the drugs and DNA, using different DNA sequences.
Jerome Devy - One of the best experts on this subject based on the ideXlab platform.
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EthoxyFagaronine, a synthetic analogue of Fagaronine that inhibits vascular endothelial growth factor-1, as a new anti-angiogeneic agent
Investigational New Drugs, 2015Co-Authors: Farid Ouchani, Olivier Duval, Jeanjacques Helesbeux, Isabelle Letinois, Laurent Martiny, Albin Jeanne, Jessica Thevenard, Amandine Wahart, Emmanuelle Charpentier, Jerome DevyAbstract:Angiogenesis plays a pivotal role in tumorigenesis and also contributes to the pathogenesis of hematologic malignancies. A number of plant compounds have shown efficacy in preclinical and clinical studies and some of them possess an anti-angiogenic activity. Our present findings report anti-angiogenic activities of ethoxyFagaronine (etxfag), a synthetic derivative of Fagaronine. Once determined the non-cytotoxic concentration of etxfag, we showed that the drug inhibits VEGF-induced angiogenesis in a Matrigel™ plug assay and suppresses ex vivo sprouting from VEGF-treated aortic rings. Each feature leading to neovascularization was then investigated and results demonstrate that etxfag prevents VEGF-induced migration and tube formation in human umbilical vein endothelial cells (HUVEC). Moreover, etxfag also suppresses VEGF-induced VEGFR-2 phosphorylation and inhibits FAK phosphorylation at Y-861 as well as focal adhesion complex turnover. Beside these effects, etxfag modifies MT1-MMP localization at the endothelial cell membrane. Finally, immunoprecipitation assay revealed that etxfag decreases VEGF binding to VEGFR-2. As we previously reported that etxfag is able to prevent leukemic cell invasiveness and adhesion to fibronectin, all together our data collectively support the anti-angiogenic activities of etxfag which could represent an additional approach to current anti-cancer therapies.
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Targeting focal adhesion assembly by ethoxyFagaronine prevents lymphoblastic cell adhesion to fibronectin
Analytical Cellular Pathology, 2012Co-Authors: Farid Ouchani, Jerome Devy, Olivier Duval, Jeanjacques Helesbeux, Stéphanie Salesse, Isabelle Letinois, Anthony Rusciani, D. Gras-billart, Laurent Duca, Laurent MartinyAbstract:Background: Leukemic cell adhesion to proteins of the bone marrow microenvironment provides signals which control morphology, motility and cell survival. We described herein the ability of ethoxyFagaronine (etxfag), a soluble synthetic derivative of Fagaronine, to prevent leukemic cell adhesion to fibronectin peptide (FN/V). Methods: Phosphorylation of fak and pyk2 were evaluated by immunoblotting. Labelled proteins were localized by confocal microscopy. PI 3-kinase activity was evaluated by in vitro kinase assay. Results: Subtoxic concentration of etxfag reduced L1210 cell adhesion to FN/V dependently of 1 integrin engagement. Etxfag impaired FN-dependent formation of 1 clustering without modifying 1 expression at the cell membrane. This was accompanied by a decrease of focal adhesion number, a diminution of fak and pyk2 phosphorylation at Tyr-576, Tyr-861 and Tyr-579, respectively leading to their dissociations from 1 integrin and inhibition of PI 3-kinase activity. Etxfag also induced a cell retraction accompanied by a redistribution of phosphorylated fak and pyk2 in the perinuclear region and lipid raft relocalization. Conclusion: Through its anti-adhesive potential, etxfag, combined with conventional cytotoxic drugs could be potentially designed as a new anti-leukemic drug.
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The anti-invasive activity of synthetic alkaloid ethoxyFagaronine on L1210 leukemia cells is mediated by down-regulation of plasminogen activators and MT1-MMP expression and activity
Investigational New Drugs, 2011Co-Authors: Jerome Devy, Enguerran Vanquelef, Jeanjacques Helesbeux, Farid Ouchani, Christelle Oudot, Stéphanie Salesse, Fanja Rabenoelina, Siana Al-khara, Isabelle Letinois, Olivier DuvalAbstract:Quaternary benzo[ c ]phenanthridines such as Fagaronine are natural substances which have been reported to exhibit anticancer and anti-leukemic properties. However, the therapeutic use of these molecules is limited due to the high dose required to exhibit anti-tumor activity and subsequent toxicity. In this study, we describe the therapeutic potential of a new derivative of Fagaronine, EthoxyFagaronine (N-methyl-12-ethoxy-2hydroxy-3, 8, 9-trimethoxybenzo[c]-phenanthridiniumchlorhydrate) as an anti-leukemic agent. Cytotoxic activity and cell growth inhibition of EthoxyFagaronine (Etxfag) was tested on murine L1210 leukemia cells using trypan blue assay and MTT assay. At the concentration of 10^−7 M, Etxfag induced less than 10% of cell death. Etxfag (10^−7 M) was tested on L1210 cell invasiveness using matrigel™ precoated transwell chambers and efficiently reduces the invasive potential of L1210 cells by more than 50% as compared with untreated cells. Western blot and immunofluorescence experiments showed that Etxfag decreased both MT1-MMP expression and activation at the cell surface, decreased plasmin activity by down-regulating u-PAR and uPA expression at the cell surface and increasing PAI-1 secretion in conditioned media. The set of our findings underscore the therapeutic potential of ethoxyFagaronine as a new potential anticancer agent able to prevent leukemic cell dissemination.
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Synthesis, biological activity and comparative analysis of DNA binding affinities and human DNA topoisomerase I inhibitory activities of novel 12-alkoxy-benzo[c]phenanthridinium salts
Bioorganic & Medicinal Chemistry Letters, 2001Co-Authors: Michael A. Lynch, Alyona Sukhanova, Jerome Devy, Olivier Duval, Roger D. Waigh, Simon P. Mackay, Igor NabievAbstract:New antitumor 12-alkoxy-benzo[c]phenanthridinium derivatives were obtained in high yields through multistep syntheses. Analysis of DNA binding and human DNA topoisomerase I inhibitory activities demonstrates that new compounds, combining 2, 6, and 12 substitutions, interact strongly with DNA and exhibit important topoisomerase I inhibition. The cytotoxicities against solid tumor cell lines are also determined and compared with those for Fagaronine and ethoxidine.
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molecular determinants of site specific inhibition of human dna topoisomerase i by Fagaronine and ethoxidine relation to dna binding
Journal of Biological Chemistry, 2000Co-Authors: Fabrice Fleury, Jeanclaude Jardillier, Alyona Sukhanova, Anatoli Ianoul, Jerome Devy, I A Kudelina, Olivier Duval, Alain J P Alix, Igor NabievAbstract:Abstract DNA topoisomerase (top) I inhibition activity of the natural alkaloid Fagaronine (NSC157995) and its new synthetic derivative ethoxidine (12-ethoxy-benzo[c]phenanthridine) has been correlated with their molecular interactions and sequence specificity within the DNA complexes. Flow linear dichroism shows that ethoxidine exhibits the same inhibition of DNA relaxation as Fagaronine at the 10-fold lower concentration. The patterns of DNA cleavage by top I show linear enhancement of CPT-dependent sites at the 0.016–50 μm concentrations of Fagaronine, whereas ethoxidine suppress both top I-specific and CPT-dependent sites. Suppression of top I-mediated cleavage by ethoxidine is found to be specific for the sites, including strand cut between A and T. Fagaronine and ethoxidine are DNA major groove intercalators. Ethoxidine intercalates DNA in A-T sequences and its 12-ethoxy-moiety (absent in Fagaronine) extends into the DNA minor groove. These findings may explain specificity of suppression by ethoxidine of the strong top I cleavage sites with the A(+1), T(−1) immediately adjacent to the strand cut. Fagaronine does not show any sequence specificity of DNA intercalation, but its highly electronegative oxygen of hydroxy group (absent in ethoxidine) is shown to be an acceptor of the hydrogen bond with the NH2 group of G base of DNA. Ability of Fagaronine to stabilize top I-mediated ternary complex is proposed to be determined by interaction of its hydroxy group with the guanine at position (+1) of the DNA cleavage site and of quaternary nitrogen interaction with top I. The model proposed provides a guidance for screening new top I-targeted drugs in terms of identification of molecular determinants responsible for their top I inhibition effects.
Jeanfrancois Riou - One of the best experts on this subject based on the ideXlab platform.
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the benzophenanthridine alkaloid Fagaronine induces erythroleukemic cell differentiation by gene activation
Planta Medica, 2005Co-Authors: Claude Dupont, Jeanfrancois Riou, Eric Couillerot, Catherine Caron, Reynald Gillet, Monique Zecheshanrot, Chantal TrentesauxAbstract:Fagaronine, a benzophenanthridine alkaloid from Fagara zanthoxyloides Lam. (Rutaceae), has been tested on the erythroleukemic cell line K562 in order to explain some previous results on cell differentiation. In this study we showed that Fagaronine induces a significant hemoglobinization of the human erythroleukemic cell line K562. This hemoglobin synthesis was accompanied by a strong increase of erythroid mRNA expression such as γ- and α-globin, and PBGD, an enzyme of heme synthesis. In addition, the Epo-R transcripts were also stimulated indicating that cells are engaged in a maturation process. Both transcription factors GATA-1 and NF-E2, which play an important role in the regulation of genes involved in the erythroid differentiation, were also transcriptionally up-regulated. To elucidate the possible role of GATA-1 in the FAG-induced differentiation of K562 cells, we transfected reporter constructs containing regulatory regions of erythroid genes encompassing GATA-1 binding sites. After 48 hours of treatment, FAG stimulated the EPO-R and γ-globin promoters by 2- to 3-fold and the promoter/enhancer region of GATA-1 gene by 3.2-fold. A mutation within the GATA-1 binding sites strongly decreased the promoter activation induced by FAG. Taken together, our results represent a demonstration that FAG exerts its differentiating activity by a specific activation of the regulating GATA-1 regions of genes involved in the erythroid phenotype expression.
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Synthesis and evaluation of new 6-amino- substituted benzo[c]phenanthridine derivatives
Journal of Medicinal Chemistry, 1993Co-Authors: Yves L Janin, Jeanfrancois Riou, Alain Croisy, Emile BisagniAbstract:Different 7,8,9,10-tetrahydrobenzo [c]phenanthridin-6(5H)-ones (10a-e) were prepared by using a one-pot procedure which includes the preparation of various 6- and 7-alkoxy-1-naphthylisocyanates from 1-naphthylamines and triphosgene, followed by addition of 1-N-morpholino-1-cyclohexenes, and cyclization of the resulting amides upon heating in the presence of hydrogen chloride. Subsequent aromatization, chlorination, and substitution with (dimethylamino)alkylamines, followed by a demethylation or a selective desisopropylation, allowed us to synthesize the derivatives 6a-i and 7a-h bearing a [(dimethylamino)alkyl]amino side chain at their 6-position. These compounds, ad the other analogs 5a-b, were devised to further study the structure-activity relationships in the benzo[c]phenanthridine family of antitumor alkaloids led by Fagaronine (1a) and nitidine (1b). Topoisomerases I and II cleavable complex assay and evaluation of the cytotoxicity and antitumor properties were performed. In vitro cytotoxicity (L1210 and Calc 18) shows a relationship between the cytotoxicity of these compounds and their topoisomerase poisoning properties. However, all these compounds were devoid of significant antitumor effect on the P388 murine leukemia system
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the antileukemic alkaloid Fagaronine is an inhibitor of dna topoisomerases i and ii
Biochemical Pharmacology, 1993Co-Authors: Annette K Larsen, Lucile Grondard, Jeannine Couprie, B Desoize, Leopold Comoe, Jeanclaude Jardillier, Jeanfrancois RiouAbstract:Abstract The antileukemic alkaloid, Fagaronine, is a potent differentiation inducer of various hematopoietic cell lines. We show here that Fagaronine is a DNA base-pair intercalator with a K app of 2.1 × 10 5 M −1 for calf thymus DNA. Fagaronine inhibits the catalytic activity of purified calf thymus topoisomerase I as shown by relaxation of supercoiled plasmid DNA followed by electrophoresis in neutral as well as in chloroquine-containing gels. The catalytic activity of topoisomerase I is inhibited at concentrations above 30 μM. Fagaronine also inhibits the catalytic activity of purified calf thymus topoisomerase II at concentrations above 25 μM as shown by decatenation of kinetoplast DNA. Fagaronine stabilizes the covalent DNA-enzyme reaction intermediate (the cleavable complex) between topoisomerase I and linear pBR322 DNA at concentrations up to 1 μM. Further increase of the Fagaronine concentration leads to a progressive decrease in the cleavable complex formation, which is totally inhibited at 100 μM. In contrast, up to 1 μM Fagaronine has no effect on cleavable complex formation between purified calf thymus topoisomerase II and linear pBR322 DNA, whereas cleavable complex formation is inhibited at higher concentrations. Exposure to Fagaronine results in an increase in DNA-protein complex formation in intact P388 murine leukemia cells. P388CPT5 cells, which have an altered topoisomerase I activity, are 4-fold resistant to the growth inhibitory effects of Fagaronine compared to the parental cell line. Similarly, DC-3F/9-OH-E Chinese hamster fibrosarcoma cells, which have an altered topoisomerase II activity, are about 5-fold resistant to the growth inhibitory effects of Fagaronine. We conclude that Fagaronine is an inhibitor of both DNA topoisomerase I and II and propose that this might play a role in the cytotoxic activity.
