Responsable : Fabrice FLEURY
Projets et objectifs: L’objectif de notre équipe est de comprendre les mécanismes moléculaires et biochimiques de la réparation de l’ADN, notamment par recombinaison homologue (RH), et d’explorer certaines voies de réparation impliquées dans les processus de résistance aux traitements anticancéreux.
Nous étudions en particulier Rad51, protéine clef de la RH fréquemment surexprimée dans les cellules cancéreuses et qui est à l’origine de résistance aux radio- et chimio-thérapies anticancéreuses.
Les interactions impliquant des protéines de réparation de l’ADN sont étudiées par criblage à haut débit (Puces à protéines). Leur caractérisation et leur analyse structure-fonction sont abordées par un ensemble d’outils biophysiques (disponibles via la plate-forme IMPACT) parfaitement maîtrisés par notre équipe. Les informations moléculaires ainsi extraites sont ensuite exploitées pour mieux comprendre les régulations au niveau cellulaire. Cette interface moléculaire-cellulaire est l’un des points forts qui caractérise notre équipe.
Mots-clés : biochimie, modifications post-traductionnelles, RAD51, réparation ADN
Membres
Anciens membres de l'équipe
- Brendan ALLIGAND, Doctorant
- Thomas CHABOT, Doctorant
- Alexandre DEMEYER , Doctorant
- Titouan JAUNET-LAHARY, Doctorant
- Florian LAFONT, Doctorant
- Denis VELIC, Doctorant
Projets
Publications
10 publications
Chabot, Thomas; Cheraud, Yvonnick; Fleury, Fabrice Relationships between DNA repair and RTK-mediated signaling pathways Article de journal Biochimica et Biophysica Acta (BBA) - Reviews on Cancer, p. 188495, 2020, ISSN: 0304419X. @article{Chabot2020, title = {Relationships between DNA repair and RTK-mediated signaling pathways}, author = {Thomas Chabot and Yvonnick Cheraud and Fabrice Fleury}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0304419X20302146}, doi = {10.1016/j.bbcan.2020.188495}, issn = {0304419X}, year = {2020}, date = {2020-12-01}, journal = {Biochimica et Biophysica Acta (BBA) - Reviews on Cancer}, pages = {188495}, publisher = {Elsevier}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Méresse, Sarah; Fodil, Mostefa; Fleury, Fabrice; Chénais, Benoît Fucoxanthin, a Marine-Derived Carotenoid from Brown Seaweeds and Microalgae: A Promising Bioactive Compound for Cancer Therapy Article de journal International Journal of Molecular Sciences, 21 (23), p. 9273, 2020, ISSN: 1422-0067. @article{Meresse2020, title = {Fucoxanthin, a Marine-Derived Carotenoid from Brown Seaweeds and Microalgae: A Promising Bioactive Compound for Cancer Therapy}, author = {Sarah Méresse and Mostefa Fodil and Fabrice Fleury and Benoît Chénais}, url = {https://www.mdpi.com/1422-0067/21/23/9273}, doi = {10.3390/ijms21239273}, issn = {1422-0067}, year = {2020}, date = {2020-12-01}, journal = {International Journal of Molecular Sciences}, volume = {21}, number = {23}, pages = {9273}, publisher = {Multidisciplinary Digital Publishing Institute}, abstract = {Fucoxanthin is a well-known carotenoid of the xanthophyll family, mainly produced by marine organisms such as the macroalgae of the fucus genus or microalgae such as Phaeodactylum tricornutum. Fucoxanthin has antioxidant and anti-inflammatory properties but also several anticancer effects. Fucoxanthin induces cell growth arrest, apoptosis, and/or autophagy in several cancer cell lines as well as in animal models of cancer. Fucoxanthin treatment leads to the inhibition of metastasis-related migration, invasion, epithelial–mesenchymal transition, and angiogenesis. Fucoxanthin also affects the DNA repair pathways, which could be involved in the resistance phenotype of tumor cells. Moreover, combined treatments of fucoxanthin, or its metabolite fucoxanthinol, with usual anticancer treatments can support conventional therapeutic strategies by reducing drug resistance. This review focuses on the current knowledge of fucoxanthin with its potential anticancer properties, showing that fucoxanthin could be a promising compound for cancer therapy by acting on most of the classical hallmarks of tumor cells.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Fucoxanthin is a well-known carotenoid of the xanthophyll family, mainly produced by marine organisms such as the macroalgae of the fucus genus or microalgae such as Phaeodactylum tricornutum. Fucoxanthin has antioxidant and anti-inflammatory properties but also several anticancer effects. Fucoxanthin induces cell growth arrest, apoptosis, and/or autophagy in several cancer cell lines as well as in animal models of cancer. Fucoxanthin treatment leads to the inhibition of metastasis-related migration, invasion, epithelial–mesenchymal transition, and angiogenesis. Fucoxanthin also affects the DNA repair pathways, which could be involved in the resistance phenotype of tumor cells. Moreover, combined treatments of fucoxanthin, or its metabolite fucoxanthinol, with usual anticancer treatments can support conventional therapeutic strategies by reducing drug resistance. This review focuses on the current knowledge of fucoxanthin with its potential anticancer properties, showing that fucoxanthin could be a promising compound for cancer therapy by acting on most of the classical hallmarks of tumor cells. |
Chabot, Thomas Université de Nantes, 2020, (294 pages). @phdthesis{chabot2020modulation, title = {Modulation de l'activité du Rad51 par le récepteur tyrosine kinase c-Met dans la réparation des cassures double-brin de l'ADN}, author = {Thomas Chabot}, url = {https://www.theses.fr/2020NANT1013}, year = {2020}, date = {2020-10-01}, school = {Université de Nantes}, abstract = {L'instabilité génomique due à la dérégulation des voies de réparation de l'ADN peut être à l’initiation de cancer et entraîner par la suite une résistance à la chimiothérapie et à la radiothérapie. La compréhension de ces mécanismes biologiques est donc essentielle dans la lutte contre le cancer. RAD51 est la protéine centrale de la voie de réparation des cassures double-brin de l'ADN par recombinaison homologue. Cette réparation conduit à une réparation fidèle de l'ADN. L'activité recombinase de la protéine RAD51 est finement régulée par des modifications post- traductionnelles telles que la phosphorylation. Au cours de la dernière décennie, de plus en plus d’études, suggèrent l'existence d'une relation entre les récepteurs à activité tyrosine kinases, souvent suractivés et impliqués dans l’agressivité et la prolifération cancéreuse, et la réparation de l'ADN. Parmi ces récepteurs à activité tyrosine kinases, le duo c-Met/HGF-SF est souvent muté, sur exprimé ou activé constitutivement dans de nombreux cancers et son inhibition a été montrée comme induisant une diminution de la réparation par recombinaison homologue. Au travers de cette thèse, nous montrons pour la première fois que c-Met est capable de phosphoryler la protéine RAD51 sur quatre résidus tyrosine localisés principalement dans l'interface monomère- monomère du nucléofilament de la recombinase humaine. Nous montrons l’implication de ces phosphorylations sur l’activité de RAD51 dans les différentes étapes de la recombinaison homologue. L'ensemble des résultats obtenus suggère le rôle possible de ces modifications dans la régulation de RAD51 et souligne l'importance de c-Met dans la réponse aux lésions de l'ADN.}, note = {294 pages}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } L'instabilité génomique due à la dérégulation des voies de réparation de l'ADN peut être à l’initiation de cancer et entraîner par la suite une résistance à la chimiothérapie et à la radiothérapie. La compréhension de ces mécanismes biologiques est donc essentielle dans la lutte contre le cancer. RAD51 est la protéine centrale de la voie de réparation des cassures double-brin de l'ADN par recombinaison homologue. Cette réparation conduit à une réparation fidèle de l'ADN. L'activité recombinase de la protéine RAD51 est finement régulée par des modifications post- traductionnelles telles que la phosphorylation. Au cours de la dernière décennie, de plus en plus d’études, suggèrent l'existence d'une relation entre les récepteurs à activité tyrosine kinases, souvent suractivés et impliqués dans l’agressivité et la prolifération cancéreuse, et la réparation de l'ADN. Parmi ces récepteurs à activité tyrosine kinases, le duo c-Met/HGF-SF est souvent muté, sur exprimé ou activé constitutivement dans de nombreux cancers et son inhibition a été montrée comme induisant une diminution de la réparation par recombinaison homologue. Au travers de cette thèse, nous montrons pour la première fois que c-Met est capable de phosphoryler la protéine RAD51 sur quatre résidus tyrosine localisés principalement dans l'interface monomère- monomère du nucléofilament de la recombinase humaine. Nous montrons l’implication de ces phosphorylations sur l’activité de RAD51 dans les différentes étapes de la recombinaison homologue. L'ensemble des résultats obtenus suggère le rôle possible de ces modifications dans la régulation de RAD51 et souligne l'importance de c-Met dans la réponse aux lésions de l'ADN. |
Fleury, Fabrice; Demeyer, Alexandre; Weigel, Pierre; Chenais, Benoit; Mathé, Monique; Lebreton, Jacques Disulfonate stilbenes for use in the treatment of proliferative diseases Patent WO2020104634A1, 2020. @patent{demeyer2020, title = {Disulfonate stilbenes for use in the treatment of proliferative diseases}, author = {Fabrice Fleury and Alexandre Demeyer and Pierre Weigel and Benoit Chenais and Monique Mathé and Jacques Lebreton}, url = {https://worldwide.espacenet.com/patent/search/family/064564793/publication/WO2020104634A1?q=pn%3DWO2020104634A1}, year = {2020}, date = {2020-05-28}, number = {WO2020104634A1}, abstract = {This invention relates to compounds of general formula: wherein R0A and R0B are independently selected from hydrogen and pharmaceutically acceptable cations; and RA and RB are identical and selected from amide, carbamate, sulphonamide, azido, cyano and halide. The invention also relates to a pharmaceutical composition comprising a compound according to the invention. According to an embodiment, the composition further comprises another active ingredient, especially an antineoplastic agent. The invention also relates to a compound or a composition according to the invention for use as a medicament, especially a compound or a composition for use in the treatment of a proliferative disease such as for example cancer.}, keywords = {}, pubstate = {published}, tppubtype = {patent} } This invention relates to compounds of general formula: wherein R0A and R0B are independently selected from hydrogen and pharmaceutically acceptable cations; and RA and RB are identical and selected from amide, carbamate, sulphonamide, azido, cyano and halide. The invention also relates to a pharmaceutical composition comprising a compound according to the invention. According to an embodiment, the composition further comprises another active ingredient, especially an antineoplastic agent. The invention also relates to a compound or a composition according to the invention for use as a medicament, especially a compound or a composition for use in the treatment of a proliferative disease such as for example cancer. |
Ayadi, Nizar; Lafont, Florian; Charlier, Cathy; Benhelli-Mokrani, Houda; Sokolov, Pavel; Sukhanova, Alyona; Fleury, Fabrice; Nabiev, Igor Comparative Advantages and Limitations of Quantum Dots in Protein Array Applications Chapitre d'ouvrage Quantum Dots, 2135 , p. 259–273, Springer, New York, NY, Humana, 2020. @inbook{cEQ3:ayadi_FLEURY:2020, title = {Comparative Advantages and Limitations of Quantum Dots in Protein Array Applications}, author = {Nizar Ayadi and Florian Lafont and Cathy Charlier and Houda Benhelli-Mokrani and Pavel Sokolov and Alyona Sukhanova and Fabrice Fleury and Igor Nabiev}, year = {2020}, date = {2020-04-01}, booktitle = {Quantum Dots}, volume = {2135}, pages = {259--273}, publisher = {Springer}, address = {New York, NY}, edition = {Humana}, series = {Methods in Molecular Biology}, keywords = {}, pubstate = {published}, tppubtype = {inbook} } |
Yaremenko, Ivan A; Coghi, Paolo; Prommana, Parichat; Qiu, Congling; Radulov, Peter S; Qu, Yuanqing; Belyakova, Yulia Yu; Zanforlin, Enrico; Kokorekin, Vladimir A; Wu, Yuki Yu Jun; Fleury, Fabrice; Uthaipibull, Chairat; Wong, Vincent Kam Wai; Terent'ev, Alexander O Synthetic Peroxides Promote Apoptosis of Cancer Cells by Inhibiting P-Glycoprotein ABCB5 Article de journal ChemMedChem, 15 (13), p. 1118–1127, 2020, ISSN: 18607187. @article{Yaremenko2020b, title = {Synthetic Peroxides Promote Apoptosis of Cancer Cells by Inhibiting P-Glycoprotein ABCB5}, author = {Ivan A Yaremenko and Paolo Coghi and Parichat Prommana and Congling Qiu and Peter S Radulov and Yuanqing Qu and Yulia Yu Belyakova and Enrico Zanforlin and Vladimir A Kokorekin and Yuki Yu Jun Wu and Fabrice Fleury and Chairat Uthaipibull and Vincent Kam Wai Wong and Alexander O Terent'ev}, doi = {10.1002/cmdc.202000042}, issn = {18607187}, year = {2020}, date = {2020-03-10}, journal = {ChemMedChem}, volume = {15}, number = {13}, pages = {1118--1127}, abstract = {This article discloses a new horizon for the application of peroxides in medical chemistry. Stable cyclic peroxides are demonstrated to have cytotoxic activity against cancer cells: in addition a mechanism of cytotoxic action is proposed. Synthetic bridged 1,2,4,5‐tetraoxanes and ozonides were effective against HepG2 cancer cells and some ozonides selectively targeted liver cancer cells (the selectivity indexes for compounds 11 b and 12 a are 8 and 5, respectively). In some instances, tetraoxanes and ozonides were more selective than paclitaxel, artemisinin and artenusic acid. Annexin V flow‐cytometry analysis revealed that the active ozonides 22 a and 23 a induced cell death of HepG2 by apoptosis. Further study showed that compounds 22 a and 23 a exhibited a strong inhibitory effect on P‐glycoprotein (P‐gp/ABCB5)‐overexpressing HepG2 cancer cells. ABCB5 is a key player in the multidrug‐resistant phenotype of liver cancer. Peroxides failed to demonstrate a direct correlation between oxidative potential and their biological activity. To our knowledge this is the first time that peroxide diastereoisomers have been found to show stereospecific antimalarial action against the chloroquine‐sensitive 3D7 strain of Plasmodium falciparum. Stereoisomeric ozonide 12 b is 11 times more active than stereoisomeric ozonide 12 a (IC50=5.81 vs 65.18 μm). Current findings mean that ozonides merit further investigation as potential therapeutic agents for drug‐resistant hepatocellular carcinoma.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This article discloses a new horizon for the application of peroxides in medical chemistry. Stable cyclic peroxides are demonstrated to have cytotoxic activity against cancer cells: in addition a mechanism of cytotoxic action is proposed. Synthetic bridged 1,2,4,5‐tetraoxanes and ozonides were effective against HepG2 cancer cells and some ozonides selectively targeted liver cancer cells (the selectivity indexes for compounds 11 b and 12 a are 8 and 5, respectively). In some instances, tetraoxanes and ozonides were more selective than paclitaxel, artemisinin and artenusic acid. Annexin V flow‐cytometry analysis revealed that the active ozonides 22 a and 23 a induced cell death of HepG2 by apoptosis. Further study showed that compounds 22 a and 23 a exhibited a strong inhibitory effect on P‐glycoprotein (P‐gp/ABCB5)‐overexpressing HepG2 cancer cells. ABCB5 is a key player in the multidrug‐resistant phenotype of liver cancer. Peroxides failed to demonstrate a direct correlation between oxidative potential and their biological activity. To our knowledge this is the first time that peroxide diastereoisomers have been found to show stereospecific antimalarial action against the chloroquine‐sensitive 3D7 strain of Plasmodium falciparum. Stereoisomeric ozonide 12 b is 11 times more active than stereoisomeric ozonide 12 a (IC50=5.81 vs 65.18 μm). Current findings mean that ozonides merit further investigation as potential therapeutic agents for drug‐resistant hepatocellular carcinoma. |
Aganyants, Hovsep; Weigel, Pierre; Hovhannisyan, Yeranuhi; Lecocq, Michèle; Koloyan, Haykanush; Hambardzumyan, Artur; Hovsepyan, Anichka; Hallet, Jean Noël; Sakanyan, Vehary Rational engineering of the substrate specificity of a thermostable d-hydantoinase (Dihydropyrimidinase) Article de journal High-Throughput, 9 (1), 2020, ISSN: 25715135. @article{Aganyants2020, title = {Rational engineering of the substrate specificity of a thermostable d-hydantoinase (Dihydropyrimidinase)}, author = {Hovsep Aganyants and Pierre Weigel and Yeranuhi Hovhannisyan and Michèle Lecocq and Haykanush Koloyan and Artur Hambardzumyan and Anichka Hovsepyan and Jean Noël Hallet and Vehary Sakanyan}, doi = {10.3390/ht9010005}, issn = {25715135}, year = {2020}, date = {2020-03-01}, journal = {High-Throughput}, volume = {9}, number = {1}, publisher = {MDPI AG}, abstract = {D-hydantoinases catalyze an enantioselective opening of 5-and 6-membered cyclic structures and therefore can be used for the production of optically pure precursors for biomedical applications. The thermostable D-hydantoinase from Geobacillus stearothermophilus ATCC 31783 is a manganese-dependent enzyme and exhibits low activity towards bulky hydantoin derivatives. Homology modeling with a known 3D structure (PDB code: 1K1D) allowed us to identify the amino acids to be mutated at the substrate binding site and in its immediate vicinity to modulate the substrate specificity. Both single and double substituted mutants were generated by site-directed mutagenesis at appropriate sites located inside and outside of the stereochemistry gate loops (SGL) involved in the substrate binding. Substrate specificity and kinetic constant data demonstrate that the replacement of Phe159 and Trp287 with alanine leads to an increase in the enzyme activity towards D,L-5-benzyl and D,L-5-indolylmethyl hydantoins. The length of the side chain and the hydrophobicity of substrates are essential parameters to consider when designing the substrate binding pocket for bulky hydantoins. Our data highlight that D-hydantoinase is the authentic dihydropyrimidinase involved in the pyrimidine reductive catabolic pathway in moderate thermophiles.}, keywords = {}, pubstate = {published}, tppubtype = {article} } D-hydantoinases catalyze an enantioselective opening of 5-and 6-membered cyclic structures and therefore can be used for the production of optically pure precursors for biomedical applications. The thermostable D-hydantoinase from Geobacillus stearothermophilus ATCC 31783 is a manganese-dependent enzyme and exhibits low activity towards bulky hydantoin derivatives. Homology modeling with a known 3D structure (PDB code: 1K1D) allowed us to identify the amino acids to be mutated at the substrate binding site and in its immediate vicinity to modulate the substrate specificity. Both single and double substituted mutants were generated by site-directed mutagenesis at appropriate sites located inside and outside of the stereochemistry gate loops (SGL) involved in the substrate binding. Substrate specificity and kinetic constant data demonstrate that the replacement of Phe159 and Trp287 with alanine leads to an increase in the enzyme activity towards D,L-5-benzyl and D,L-5-indolylmethyl hydantoins. The length of the side chain and the hydrophobicity of substrates are essential parameters to consider when designing the substrate binding pocket for bulky hydantoins. Our data highlight that D-hydantoinase is the authentic dihydropyrimidinase involved in the pyrimidine reductive catabolic pathway in moderate thermophiles. |
Yaremenko, Ivan A; Radulov, Peter S; Belyakova, Yulia Yu; Demina, Arina A; Fomenkov, Dmitriy I; Barsukov, Denis V; Subbotina, Irina R; Fleury, Fabrice; Terent'ev, Alexander O Chemistry - A European Journal, 26 (21), p. 4734–4751, 2020, ISSN: 15213765. @article{Yaremenko2020a, title = {Catalyst Development for the Synthesis of Ozonides and Tetraoxanes Under Heterogeneous Conditions: Disclosure of an Unprecedented Class of Fungicides for Agricultural Application}, author = {Ivan A Yaremenko and Peter S Radulov and Yulia Yu Belyakova and Arina A Demina and Dmitriy I Fomenkov and Denis V Barsukov and Irina R Subbotina and Fabrice Fleury and Alexander O Terent'ev}, doi = {10.1002/chem.201904555}, issn = {15213765}, year = {2020}, date = {2020-01-01}, journal = {Chemistry - A European Journal}, volume = {26}, number = {21}, pages = {4734--4751}, abstract = {The catalyst H3+xPMo12−x+6Mox+5O40 supported on SiO2 was developed for peroxidation of 1,3- and 1,5-diketones with hydrogen peroxide with the formation of bridged 1,2,4,5-tetraoxanes and bridged 1,2,4-trioxolanes (ozonides) with high yield based on isolated products (up to 86 and 90 %, respectively) under heterogeneous conditions. Synthesis of peroxides under heterogeneous conditions is a rare process and represents a challenge for this field of chemistry, because peroxides tend to decompose on the surface of a catalyst. A new class of antifungal agents for crop protection, that is, cyclic peroxides: bridged 1,2,4,5-tetraoxanes and bridged ozonides, was discovered. Some ozonides and tetraoxanes exhibit a very high antifungal activity and are superior to commercial fungicides, such as Triadimefon and Kresoxim-methyl. It is important to note that none of the fungicides used in agricultural chemistry contains a peroxide fragment.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The catalyst H3+xPMo12−x+6Mox+5O40 supported on SiO2 was developed for peroxidation of 1,3- and 1,5-diketones with hydrogen peroxide with the formation of bridged 1,2,4,5-tetraoxanes and bridged 1,2,4-trioxolanes (ozonides) with high yield based on isolated products (up to 86 and 90 %, respectively) under heterogeneous conditions. Synthesis of peroxides under heterogeneous conditions is a rare process and represents a challenge for this field of chemistry, because peroxides tend to decompose on the surface of a catalyst. A new class of antifungal agents for crop protection, that is, cyclic peroxides: bridged 1,2,4,5-tetraoxanes and bridged ozonides, was discovered. Some ozonides and tetraoxanes exhibit a very high antifungal activity and are superior to commercial fungicides, such as Triadimefon and Kresoxim-methyl. It is important to note that none of the fungicides used in agricultural chemistry contains a peroxide fragment. |
Lafont, Florian; Fleury, Fabrice; Benhelli-Mokrani, Houda DNA-PKcs Ser2056 auto-phosphorylation is affected by an O-GlcNAcylation/phosphorylation interplay Article de journal Biochimica et Biophysica Acta (BBA) - General Subjects, 1864 (12), p. 129705, 2020, ISSN: 0304-4165. @article{LAFONT2020129705, title = {DNA-PKcs Ser2056 auto-phosphorylation is affected by an O-GlcNAcylation/phosphorylation interplay}, author = {Florian Lafont and Fabrice Fleury and Houda Benhelli-Mokrani}, url = {http://www.sciencedirect.com/science/article/pii/S0304416520302178}, doi = {https://doi.org/10.1016/j.bbagen.2020.129705}, issn = {0304-4165}, year = {2020}, date = {2020-01-01}, journal = {Biochimica et Biophysica Acta (BBA) - General Subjects}, volume = {1864}, number = {12}, pages = {129705}, abstract = {Background DNA dependent Protein Kinase (DNA-PK) is an heterotrimeric complex regulating the Non Homologous End Joining (NHEJ) double strand break (DSB) repair pathway. The activity of its catalytic subunit (DNA-PKcs) is regulated by multiple phosphorylations, like the Ser2056 one that impacts DSB end processing and telomeres integrity. O-GlcNAcylation is a post translational modification (PTM) closely related to phosphorylation and its implication in the modulation of DNA-PKcs activity during the DNA Damage Response (DDR) is unknown. Methods Using IP techniques, and HeLa cell line, we evaluated the effect of pharmacological or siOGT mediated O-GlcNAc level modulation on DNA-PKcs O-GlcNAcylation. We used the RPA32 phosphorylation as a DNA-PKcs activity reporter substrate to evaluate the effect of O-GlcNAc modulators. Results We show here that human DNA-PKcs is an O-GlcNAc modified protein and that this new PTM is responsive to the cell O-GlcNAcylation level modulation. Our findings reveal that DNA-PKcs hypo O-GlcNAcylation affects its kinase activity and that the bleomycin-induced Ser2056 phosphorylation, is modulated by DNA-PKcs O-GlcNAcylation. Conclusions DNA-PKcs Ser2056 phosphorylation is antagonistically linked to DNA-PKcs O-GlcNAcylation level modulation. General significance Given the essential role of DNA-PKcs Ser2056 phosphorylation in the DDR, this study brings data about the role of cell O-GlcNAc level on genome integrity maintenance.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background DNA dependent Protein Kinase (DNA-PK) is an heterotrimeric complex regulating the Non Homologous End Joining (NHEJ) double strand break (DSB) repair pathway. The activity of its catalytic subunit (DNA-PKcs) is regulated by multiple phosphorylations, like the Ser2056 one that impacts DSB end processing and telomeres integrity. O-GlcNAcylation is a post translational modification (PTM) closely related to phosphorylation and its implication in the modulation of DNA-PKcs activity during the DNA Damage Response (DDR) is unknown. Methods Using IP techniques, and HeLa cell line, we evaluated the effect of pharmacological or siOGT mediated O-GlcNAc level modulation on DNA-PKcs O-GlcNAcylation. We used the RPA32 phosphorylation as a DNA-PKcs activity reporter substrate to evaluate the effect of O-GlcNAc modulators. Results We show here that human DNA-PKcs is an O-GlcNAc modified protein and that this new PTM is responsive to the cell O-GlcNAcylation level modulation. Our findings reveal that DNA-PKcs hypo O-GlcNAcylation affects its kinase activity and that the bleomycin-induced Ser2056 phosphorylation, is modulated by DNA-PKcs O-GlcNAcylation. Conclusions DNA-PKcs Ser2056 phosphorylation is antagonistically linked to DNA-PKcs O-GlcNAcylation level modulation. General significance Given the essential role of DNA-PKcs Ser2056 phosphorylation in the DDR, this study brings data about the role of cell O-GlcNAc level on genome integrity maintenance. |
Vil', Vera A; Yaremenko, Ivan A; Fomenkov, Dmitri I; Levitsky, Dmitri O; Fleury, Fabrice; Terent'ev, Alexander O Ion exchange resin-catalyzed synthesis of bridged tetraoxanes possessing in vitro cytotoxicity against HeLa cancer cells Article de journal Chemistry of Heterocyclic Compounds, 56 (6), p. 722–726, 2020, ISSN: 1573-8353. @article{Vil2020, title = {Ion exchange resin-catalyzed synthesis of bridged tetraoxanes possessing in vitro cytotoxicity against HeLa cancer cells}, author = {Vera A Vil' and Ivan A Yaremenko and Dmitri I Fomenkov and Dmitri O Levitsky and Fabrice Fleury and Alexander O Terent'ev}, url = {https://doi.org/10.1007/s10593-020-02722-4}, doi = {10.1007/s10593-020-02722-4}, issn = {1573-8353}, year = {2020}, date = {2020-01-01}, journal = {Chemistry of Heterocyclic Compounds}, volume = {56}, number = {6}, pages = {722--726}, abstract = {Bridged 1,2,4,5-tetraoxanes were prepared using available acidic ion exchange resin with high yields despite the possibility of peroxide decomposition under heterogeneous conditions. The bridged tetraoxanes demonstrated high cytotoxicity against HeLa cancer cells in vitro, which in some cases was higher than that of cisplatin, artesunate, and dihydroartemisinin.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Bridged 1,2,4,5-tetraoxanes were prepared using available acidic ion exchange resin with high yields despite the possibility of peroxide decomposition under heterogeneous conditions. The bridged tetraoxanes demonstrated high cytotoxicity against HeLa cancer cells in vitro, which in some cases was higher than that of cisplatin, artesunate, and dihydroartemisinin. |
2 publications
Velic, Denis; Charlier, Cathy; Popova, Milena; Jaunet-Lahary, Titouan; Bouchouireb, Zakaria; Henry, Sébastien; Weigel, Pierre; Masson, Jean-Yves; Laurent, Adèle D; Nabiev, Igor; Fleury, Fabrice Interactions of the Rad51 inhibitor DIDS with human and bovine serum albumins: Optical spectroscopy and isothermal calorimetry approaches Article de journal Biochimie, 167 , p. 187–197, 2019, ISSN: 0300-9084. @article{VELIC2019187, title = {Interactions of the Rad51 inhibitor DIDS with human and bovine serum albumins: Optical spectroscopy and isothermal calorimetry approaches}, author = {Denis Velic and Cathy Charlier and Milena Popova and Titouan Jaunet-Lahary and Zakaria Bouchouireb and Sébastien Henry and Pierre Weigel and Jean-Yves Masson and Adèle D Laurent and Igor Nabiev and Fabrice Fleury}, url = {http://www.sciencedirect.com/science/article/pii/S0300908419302743}, doi = {https://doi.org/10.1016/j.biochi.2019.09.016}, issn = {0300-9084}, year = {2019}, date = {2019-01-01}, journal = {Biochimie}, volume = {167}, pages = {187--197}, abstract = {Rad51 is a key protein in DNA repair by homologous recombination and an important target for development of drugs in cancer therapy. 4′-diisothiocyanostilbene-2,2′-disulfonic acid (DIDS) has been used in clinic during the past 30 years as an inhibitor of anion transporters and channels. Recently DIDS has been demonstrated to affect Rad51-mediated homologous pairing and strand exchange, key processes in homologous recombination. Consequently, DIDS has been considered as a potential revertant of radio- and chemo-resistance of cancer cells, the major causes of therapy failure. Here, we have investigated the behavior of DIDS towards serum albumins. The effects of environmental factors, primarily, solvent polarity, on DIDS stability were evaluated, and the mechanisms of interaction of DIDS with human or bovine serum albumin were analyzed using isothermal calorimetry, circular dichroism and fluorescence spectroscopies. DIDS interaction with both serum albumins have been demonstrated, and the interaction characteristics have been determined. By comparing these characteristics for several DIDS derivatives, we have identified the DIDS moiety essential for the interaction. Furthermore, site competition data indicate that human albumin has two DIDS-binding sites: a high-affinity site in the IIIA subdomain and a low-affinity one in the IB subdomain. Molecular docking has revealed the key molecular moieties of DIDS responsible for its interactions in each site and shown that the IB site can bind two ligands. These findings show that binding of DIDS to serum albumin may change the balance between the free and bound DIDS forms, thereby affecting its bioavailability and efficacy against Rad51.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Rad51 is a key protein in DNA repair by homologous recombination and an important target for development of drugs in cancer therapy. 4′-diisothiocyanostilbene-2,2′-disulfonic acid (DIDS) has been used in clinic during the past 30 years as an inhibitor of anion transporters and channels. Recently DIDS has been demonstrated to affect Rad51-mediated homologous pairing and strand exchange, key processes in homologous recombination. Consequently, DIDS has been considered as a potential revertant of radio- and chemo-resistance of cancer cells, the major causes of therapy failure. Here, we have investigated the behavior of DIDS towards serum albumins. The effects of environmental factors, primarily, solvent polarity, on DIDS stability were evaluated, and the mechanisms of interaction of DIDS with human or bovine serum albumin were analyzed using isothermal calorimetry, circular dichroism and fluorescence spectroscopies. DIDS interaction with both serum albumins have been demonstrated, and the interaction characteristics have been determined. By comparing these characteristics for several DIDS derivatives, we have identified the DIDS moiety essential for the interaction. Furthermore, site competition data indicate that human albumin has two DIDS-binding sites: a high-affinity site in the IIIA subdomain and a low-affinity one in the IB subdomain. Molecular docking has revealed the key molecular moieties of DIDS responsible for its interactions in each site and shown that the IB site can bind two ligands. These findings show that binding of DIDS to serum albumin may change the balance between the free and bound DIDS forms, thereby affecting its bioavailability and efficacy against Rad51. |
Chabot, Thomas; Defontaine, Alain; Marquis, Damien; Renodon-Corniere, Axelle; Courtois, Emmanuelle; Fleury, Fabrice; Cheraud, Yvonnick New phosphorylation sites of rad51 by c-met modulates presynaptic filament stability Article de journal Cancers, 11 (3), 2019, ISSN: 20726694. @article{Chabot2019a, title = {New phosphorylation sites of rad51 by c-met modulates presynaptic filament stability}, author = {Thomas Chabot and Alain Defontaine and Damien Marquis and Axelle Renodon-Corniere and Emmanuelle Courtois and Fabrice Fleury and Yvonnick Cheraud}, doi = {10.3390/cancers11030413}, issn = {20726694}, year = {2019}, date = {2019-01-01}, journal = {Cancers}, volume = {11}, number = {3}, abstract = {Genomic instability through deregulation of DNA repair pathways can initiate cancer and subsequently result in resistance to chemo and radiotherapy. Understanding these biological mechanisms is therefore essential to overcome cancer. RAD51 is the central protein of the Homologous Recombination (HR) DNA repair pathway, which leads to faithful DNA repair of DSBs. The recombinase activity of RAD51 requires nucleofilament formation and is regulated by post-translational modifications such as phosphorylation. In the last decade, studies have suggested the existence of a relationship between receptor tyrosine kinases (RTK) and Homologous Recombination DNA repair. Among these RTK the c-MET receptor is often overexpressed or constitutively activated in many cancer types and its inhibition induces the decrease of HR. In this study, we show for the first time that c-MET is able to phosphorylate the RAD51 protein. We demonstrate in vitro that c-MET phosphorylates four tyrosine residues localized mainly in the subunit-subunit interface of RAD51. Whereas these post-translational modifications do not affect the presynaptic filament formation, they strengthen its stability against the inhibitor effect of the BRC peptide obtained from BRCA2. Taken together, these results confirm the role of these modifications in the regulation of the BRCA2-RAD51 interaction and underline the importance of c-MET in DNA damage response.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Genomic instability through deregulation of DNA repair pathways can initiate cancer and subsequently result in resistance to chemo and radiotherapy. Understanding these biological mechanisms is therefore essential to overcome cancer. RAD51 is the central protein of the Homologous Recombination (HR) DNA repair pathway, which leads to faithful DNA repair of DSBs. The recombinase activity of RAD51 requires nucleofilament formation and is regulated by post-translational modifications such as phosphorylation. In the last decade, studies have suggested the existence of a relationship between receptor tyrosine kinases (RTK) and Homologous Recombination DNA repair. Among these RTK the c-MET receptor is often overexpressed or constitutively activated in many cancer types and its inhibition induces the decrease of HR. In this study, we show for the first time that c-MET is able to phosphorylate the RAD51 protein. We demonstrate in vitro that c-MET phosphorylates four tyrosine residues localized mainly in the subunit-subunit interface of RAD51. Whereas these post-translational modifications do not affect the presynaptic filament formation, they strengthen its stability against the inhibitor effect of the BRC peptide obtained from BRCA2. Taken together, these results confirm the role of these modifications in the regulation of the BRCA2-RAD51 interaction and underline the importance of c-MET in DNA damage response. |
4 publications
Benhelli-Mokrani, Houda; Mansuroglu, Zeyni; Chauderlier, Alban; Albaud, Benoit; Gentien, David; Sommer, Sabrina; Schirmer, Claire; Laqueuvre, Lucie; Josse, Thibaut; Buée, Luc; Lefebvre, Bruno; Galas, Marie Christine; è, Sylvie Sou; Bonnefoy, Eliette Genome-wide identification of genic and intergenic neuronal DNA regions bound by Tau protein under physiological and stress conditions Article de journal Nucleic acids research, 46 (21), p. 11405–11422, 2018, ISSN: 13624962. @article{Benhelli-Mokrani2018, title = {Genome-wide identification of genic and intergenic neuronal DNA regions bound by Tau protein under physiological and stress conditions}, author = {Houda Benhelli-Mokrani and Zeyni Mansuroglu and Alban Chauderlier and Benoit Albaud and David Gentien and Sabrina Sommer and Claire Schirmer and Lucie Laqueuvre and Thibaut Josse and Luc Buée and Bruno Lefebvre and Marie Christine Galas and Sylvie Sou{è}s and Eliette Bonnefoy}, doi = {10.1093/nar/gky929}, issn = {13624962}, year = {2018}, date = {2018-01-01}, journal = {Nucleic acids research}, volume = {46}, number = {21}, pages = {11405--11422}, abstract = {Tauopathies such as Alzheimer's Disease (AD) are neurodegenerative disorders for which there is presently no cure. They are named after the abnormal oligomerization/aggregation of the neuronal microtubule-associated Tau protein. Besides its role as a microtubule-associated protein, a DNA-binding capacity and a nuclear localization for Tau protein has been described in neurons. While questioning the potential role of Tau-DNA binding in the development of tauopathies, we have carried out a large-scale analysis of the interaction of Tau protein with the neuronal genome under physiological and heat stress conditions using the ChIP-on-chip technique that combines Chromatin ImmunoPrecipitation (ChIP) with DNA microarray (chip). Our findings show that Tau protein specifically interacts with genic and intergenic DNA sequences of primary culture of neurons with a preference for DNA regions positioned beyond the ±5000 bp range from transcription start site. An AG-rich DNA motif was found recurrently present within Tau-interacting regions and 30% of Tau-interacting regions overlapped DNA sequences coding for lncRNAs. Neurological processes affected in AD were enriched among Tau-interacting regions with in vivo gene expression assays being indicative of a transcriptional repressor role for Tau protein, which was exacerbated in neurons displaying nuclear pathological oligomerized forms of Tau protein.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Tauopathies such as Alzheimer's Disease (AD) are neurodegenerative disorders for which there is presently no cure. They are named after the abnormal oligomerization/aggregation of the neuronal microtubule-associated Tau protein. Besides its role as a microtubule-associated protein, a DNA-binding capacity and a nuclear localization for Tau protein has been described in neurons. While questioning the potential role of Tau-DNA binding in the development of tauopathies, we have carried out a large-scale analysis of the interaction of Tau protein with the neuronal genome under physiological and heat stress conditions using the ChIP-on-chip technique that combines Chromatin ImmunoPrecipitation (ChIP) with DNA microarray (chip). Our findings show that Tau protein specifically interacts with genic and intergenic DNA sequences of primary culture of neurons with a preference for DNA regions positioned beyond the ±5000 bp range from transcription start site. An AG-rich DNA motif was found recurrently present within Tau-interacting regions and 30% of Tau-interacting regions overlapped DNA sequences coding for lncRNAs. Neurological processes affected in AD were enriched among Tau-interacting regions with in vivo gene expression assays being indicative of a transcriptional repressor role for Tau protein, which was exacerbated in neurons displaying nuclear pathological oligomerized forms of Tau protein. |
Deriabin, Konstantin V; Yaremenko, Ivan A; Chislov, Mikhail V; Fleury, Fabrice; Terent'Ev, Alexander O; Islamova, Regina M Similar nature leads to improved properties: Cyclic organosilicon triperoxides as promising curing agents for liquid polysiloxanes Article de journal New Journal of Chemistry, 42 (18), p. 15006–15013, 2018, ISSN: 13699261. @article{Deriabin2018, title = {Similar nature leads to improved properties: Cyclic organosilicon triperoxides as promising curing agents for liquid polysiloxanes}, author = {Konstantin V Deriabin and Ivan A Yaremenko and Mikhail V Chislov and Fabrice Fleury and Alexander O Terent'Ev and Regina M Islamova}, doi = {10.1039/c8nj02499e}, issn = {13699261}, year = {2018}, date = {2018-01-01}, journal = {New Journal of Chemistry}, volume = {42}, number = {18}, pages = {15006--15013}, publisher = {Royal Society of Chemistry}, abstract = {Cyclic organosilicon triperoxides were found to be vinyl-selective free-radical initiators for thermal curing at 100-180 °C of vinyl-terminated polydimethylsiloxane and trimethylsilyl-terminated polymethylhydrosiloxane producing homogeneous transparent silicone rubbers with antibacterial properties. The usage of the cyclic organosilicon triperoxides as the curing agents does not require free radical inhibitors in comparison with diacyl- and dialkyl peroxides. Among the tested compounds, the peroxide with the Me-Si-Me fragment and two cyclohexane rings is a much more active curing agent (180 °C}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cyclic organosilicon triperoxides were found to be vinyl-selective free-radical initiators for thermal curing at 100-180 °C of vinyl-terminated polydimethylsiloxane and trimethylsilyl-terminated polymethylhydrosiloxane producing homogeneous transparent silicone rubbers with antibacterial properties. The usage of the cyclic organosilicon triperoxides as the curing agents does not require free radical inhibitors in comparison with diacyl- and dialkyl peroxides. Among the tested compounds, the peroxide with the Me-Si-Me fragment and two cyclohexane rings is a much more active curing agent (180 °C |
Lafont, Florian; Ayadi, Nizar; Charlier, Cathy; Weigel, Pierre; Nabiev, Igor; Benhelli-Mokrani, Houda; Fleury, Fabrice Assessment of DNA-PKcs kinase activity by quantum dot–based microarray Article de journal Scientific Reports, 8 (1), p. 1–12, 2018, ISSN: 20452322. @article{Lafont2018, title = {Assessment of DNA-PKcs kinase activity by quantum dot–based microarray}, author = {Florian Lafont and Nizar Ayadi and Cathy Charlier and Pierre Weigel and Igor Nabiev and Houda Benhelli-Mokrani and Fabrice Fleury}, doi = {10.1038/s41598-018-29256-2}, issn = {20452322}, year = {2018}, date = {2018-01-01}, journal = {Scientific Reports}, volume = {8}, number = {1}, pages = {1--12}, abstract = {Therapeutic efficacy against cancer is often based on a variety of DNA lesions, including DNA double-strand breaks (DSBs) which are repaired by homologous recombination and non-homologous end joining (NHEJ) pathways. In the past decade, the functions of the DNA repair proteins have been described as a potential mechanism of resistance in tumor cells. Therefore, the DNA repair proteins have become targets to improve the efficacy of anticancer therapy. Given the central role of DNA-PKcs in NHEJ, the therapeutic efficacy of targeting DNA-PKcs is frequently described as a strategy to prevent repair of treatment-induced DNA damage in cancer cells. The screening of a new inhibitor acting as a sensitizer requires the development of a high-throughput tool in order to identify and assess the most effective molecule. Here, we describe the elaboration of an antibody microarray dedicated to the NHEJ pathway that we used to evaluate the DNA-PKcs kinase activity in response to DNA damage. By combining a protein microarray with Quantum-Dot detection, we show that it is possible to follow the modification of phosphoproteomic cellular profiles induced by inhibitors during the response to DNA damage. Finally, we discuss the promising tool for screening kinase inhibitors and targeting DSB repair to improve cancer treatment.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Therapeutic efficacy against cancer is often based on a variety of DNA lesions, including DNA double-strand breaks (DSBs) which are repaired by homologous recombination and non-homologous end joining (NHEJ) pathways. In the past decade, the functions of the DNA repair proteins have been described as a potential mechanism of resistance in tumor cells. Therefore, the DNA repair proteins have become targets to improve the efficacy of anticancer therapy. Given the central role of DNA-PKcs in NHEJ, the therapeutic efficacy of targeting DNA-PKcs is frequently described as a strategy to prevent repair of treatment-induced DNA damage in cancer cells. The screening of a new inhibitor acting as a sensitizer requires the development of a high-throughput tool in order to identify and assess the most effective molecule. Here, we describe the elaboration of an antibody microarray dedicated to the NHEJ pathway that we used to evaluate the DNA-PKcs kinase activity in response to DNA damage. By combining a protein microarray with Quantum-Dot detection, we show that it is possible to follow the modification of phosphoproteomic cellular profiles induced by inhibitors during the response to DNA damage. Finally, we discuss the promising tool for screening kinase inhibitors and targeting DSB repair to improve cancer treatment. |
Jaunet-Lahary, Titouan; Vercauteren, Daniel P; Fleury, Fabrice; Laurent, Adèle D Computational simulations determining disulfonic stilbene derivative bioavailability within human serum albumin Article de journal Physical Chemistry Chemical Physics, 20 (26), p. 18020–18030, 2018, ISSN: 14639076. @article{Jaunet-Lahary2018, title = {Computational simulations determining disulfonic stilbene derivative bioavailability within human serum albumin}, author = {Titouan Jaunet-Lahary and Daniel P Vercauteren and Fabrice Fleury and Adèle D Laurent}, doi = {10.1039/c8cp00704g}, issn = {14639076}, year = {2018}, date = {2018-01-01}, journal = {Physical Chemistry Chemical Physics}, volume = {20}, number = {26}, pages = {18020--18030}, publisher = {Royal Society of Chemistry}, abstract = {Disulfonic stilbene (DS) derivatives are a member of the large family of compounds widely employed in medicine and biology as modulators for membrane transporters or inhibitors of a protein involved in DNA repair. They constitute interesting compounds that have not yet been investigated within the bioavailability framework. No crystallographic structures exist involving such compounds embedded in the most common drug carrier, human serum albumin (HSA). The present work studies, for the first time, the physico-chemical features driving the inclusion of three DS derivatives (amino, nitro and acetamido, named DADS, DNDS and DATDS, respectively) within the four common HSA binding sites using combined molecular docking and molecular dynamics simulations. A careful analysis of each ligand within each of the studied binding sites is carried out, highlighting specific interactions and key residues playing a role in stabilizing the ligand within each pocket. The comparison between DADS, DNDS and DATDS reveals that depending on the binding site, the conclusions are rather different. For instance, the IB binding site shows a specificity to DADS compounds while IIIA is the most favorable site for DNDS and DATDS. 2018}, keywords = {}, pubstate = {published}, tppubtype = {article} } Disulfonic stilbene (DS) derivatives are a member of the large family of compounds widely employed in medicine and biology as modulators for membrane transporters or inhibitors of a protein involved in DNA repair. They constitute interesting compounds that have not yet been investigated within the bioavailability framework. No crystallographic structures exist involving such compounds embedded in the most common drug carrier, human serum albumin (HSA). The present work studies, for the first time, the physico-chemical features driving the inclusion of three DS derivatives (amino, nitro and acetamido, named DADS, DNDS and DATDS, respectively) within the four common HSA binding sites using combined molecular docking and molecular dynamics simulations. A careful analysis of each ligand within each of the studied binding sites is carried out, highlighting specific interactions and key residues playing a role in stabilizing the ligand within each pocket. The comparison between DADS, DNDS and DATDS reveals that depending on the binding site, the conclusions are rather different. For instance, the IB binding site shows a specificity to DADS compounds while IIIA is the most favorable site for DNDS and DATDS. 2018 |
5 publications
Bosseboeuf, Adrien; Feron, Delphine; Tallet, Anne; Rossi, Cédric; Charlier, Cathy; Garderet, Laurent; Caillot, Denis; Moreau, Philippe; Cardó-Vila, Marina; Pasqualini, Renata; Arap, Wadih; Nelson, Alfreda Destea; Wilson, Bridget S; Perreault, Hélène; Piver, Eric; Weigel, Pierre; Girodon, François; Harb, Jean; Bigot-Corbel, Edith; Hermouet, Sylvie Monoclonal IgG in MGUS and multiple myeloma targets infectious pathogens Article de journal JCI Insight, 2 (19), p. 1–18, 2017, ISSN: 0021-9738. @article{Bosseboeuf2017, title = {Monoclonal IgG in MGUS and multiple myeloma targets infectious pathogens}, author = {Adrien Bosseboeuf and Delphine Feron and Anne Tallet and Cédric Rossi and Cathy Charlier and Laurent Garderet and Denis Caillot and Philippe Moreau and Marina Cardó-Vila and Renata Pasqualini and Wadih Arap and Alfreda Destea Nelson and Bridget S Wilson and Hélène Perreault and Eric Piver and Pierre Weigel and François Girodon and Jean Harb and Edith Bigot-Corbel and Sylvie Hermouet}, doi = {10.1172/jci.insight.95367}, issn = {0021-9738}, year = {2017}, date = {2017-01-01}, journal = {JCI Insight}, volume = {2}, number = {19}, pages = {1--18}, abstract = {Subsets of mature B cell neoplasms are linked to infection with intracellular pathogens such as Epstein-Barr virus (EBV), hepatitis C virus (HCV), or Helicobacter pylori. However, the association between infection and the immunoglobulin-secreting (Ig-secreting) B proliferative disorders remains largely unresolved. We investigated whether the monoclonal IgG (mc IgG) produced by patients diagnosed with monoclonal gammopathy of undetermined significance (MGUS) or multiple myeloma (MM) targets infectious pathogens. Antigen specificity of purified mc IgG from a large patient cohort (n = 244) was determined using a multiplex infectious-antigen array (MIAA), which screens for reactivity to purified antigens or lysates from 9 pathogens. Purified mc IgG from 23.4% of patients (57 of 244) specifically recognized 1 pathogen in the MIAA. EBV was the most frequent target (15.6%), with 36 of 38 mc IgGs recognizing EBV nuclear antigen-1 (EBNA-1). MM patients with EBNA-1-specific mc IgG (14.0%) showed substantially greater bone marrow plasma cell infiltration and higher β2-microglobulin and inflammation/infection-linked cytokine levels compared with other smoldering myeloma/MM patients. Five other pathogens were the targets of mc IgG: herpes virus simplex-1 (2.9%), varicella zoster virus (1.6%), cytomegalovirus (0.8%), hepatitis C virus (1.2%), and H. pylori (1.2%). We conclude that a dysregulated immune response to infection may underlie disease onset and/or progression of MGUS and MM for subsets of patients.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Subsets of mature B cell neoplasms are linked to infection with intracellular pathogens such as Epstein-Barr virus (EBV), hepatitis C virus (HCV), or Helicobacter pylori. However, the association between infection and the immunoglobulin-secreting (Ig-secreting) B proliferative disorders remains largely unresolved. We investigated whether the monoclonal IgG (mc IgG) produced by patients diagnosed with monoclonal gammopathy of undetermined significance (MGUS) or multiple myeloma (MM) targets infectious pathogens. Antigen specificity of purified mc IgG from a large patient cohort (n = 244) was determined using a multiplex infectious-antigen array (MIAA), which screens for reactivity to purified antigens or lysates from 9 pathogens. Purified mc IgG from 23.4% of patients (57 of 244) specifically recognized 1 pathogen in the MIAA. EBV was the most frequent target (15.6%), with 36 of 38 mc IgGs recognizing EBV nuclear antigen-1 (EBNA-1). MM patients with EBNA-1-specific mc IgG (14.0%) showed substantially greater bone marrow plasma cell infiltration and higher β2-microglobulin and inflammation/infection-linked cytokine levels compared with other smoldering myeloma/MM patients. Five other pathogens were the targets of mc IgG: herpes virus simplex-1 (2.9%), varicella zoster virus (1.6%), cytomegalovirus (0.8%), hepatitis C virus (1.2%), and H. pylori (1.2%). We conclude that a dysregulated immune response to infection may underlie disease onset and/or progression of MGUS and MM for subsets of patients. |
Yaremenko, Ivan A; Syroeshkin, Mikhail A; Levitsky, Dmitri O; Fleury, Fabrice; Terent'ev, Alexander O Cyclic peroxides as promising anticancer agents: in vitro cytotoxicity study of synthetic ozonides and tetraoxanes on human prostate cancer cell lines Article de journal Medicinal Chemistry Research, 26 (1), p. 170–179, 2017, ISSN: 1554-8120. @article{Yaremenko2017, title = {Cyclic peroxides as promising anticancer agents: in vitro cytotoxicity study of synthetic ozonides and tetraoxanes on human prostate cancer cell lines}, author = {Ivan A Yaremenko and Mikhail A Syroeshkin and Dmitri O Levitsky and Fabrice Fleury and Alexander O Terent'ev}, url = {https://doi.org/10.1007/s00044-016-1736-2}, doi = {10.1007/s00044-016-1736-2}, issn = {1554-8120}, year = {2017}, date = {2017-01-01}, journal = {Medicinal Chemistry Research}, volume = {26}, number = {1}, pages = {170--179}, abstract = {Synthetic ozonides and tetraoxanes were shown to have high cytotoxicity in vitro when tested on androgen-independent prostate cancer cell lines DU145 and PC3, which is in some cases was higher than that of doxorubicin, cisplatin, etoposide, artemisinin, and artesunate. Activity of ozonide stereoisomers differs from each other. This difference in activity and absence of correlation between activity of stereoisomers and their oxidative properties allow us to suggest existence of a quite specific mechanism of cytotoxicity of these endoperoxides different from a traditional mechanism based mainly on oxidative properties of peroxides.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Synthetic ozonides and tetraoxanes were shown to have high cytotoxicity in vitro when tested on androgen-independent prostate cancer cell lines DU145 and PC3, which is in some cases was higher than that of doxorubicin, cisplatin, etoposide, artemisinin, and artesunate. Activity of ozonide stereoisomers differs from each other. This difference in activity and absence of correlation between activity of stereoisomers and their oxidative properties allow us to suggest existence of a quite specific mechanism of cytotoxicity of these endoperoxides different from a traditional mechanism based mainly on oxidative properties of peroxides. |
Levitsky, Dmitri O; Gloriozova, Tatyana A; Poroikov, Vladimir V; Valery, M ANABOLIC CYANOSTEROIDS AND THEIR BIOLOGICAL ACTIVITIES – A BRIEF REVIEW Article de journal 6 (12), p. 127–151, 2017, ISBN: 2017121061. @article{Levitsky2017, title = {ANABOLIC CYANOSTEROIDS AND THEIR BIOLOGICAL ACTIVITIES – A BRIEF REVIEW}, author = {Dmitri O Levitsky and Tatyana A Gloriozova and Vladimir V Poroikov and M Valery}, doi = {10.20959/wjpps201712-10618}, isbn = {2017121061}, year = {2017}, date = {2017-01-01}, volume = {6}, number = {12}, pages = {127--151}, abstract = {The present review describes the biological activities of synthetic anabolic cyanosteroids. More than forty biologically active compounds have shown confirmed anti-tumour, anti-inflammatory, antiviral and other activities. The structures and reported and predicted activities of synthetic cyanosteroids are available. With the computer programme PASS and based on structure–activity relationships (SAR), some additional activities are also predicted, which point towards new possible applications of these lipids. This review emphasizes the role of cyanosteroids as an important source and potential leads for drug discovery and they are of great interest to chemists, physicians, biologists, pharmacologists and the pharmaceutical industry. KEYWORDS:}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present review describes the biological activities of synthetic anabolic cyanosteroids. More than forty biologically active compounds have shown confirmed anti-tumour, anti-inflammatory, antiviral and other activities. The structures and reported and predicted activities of synthetic cyanosteroids are available. With the computer programme PASS and based on structure–activity relationships (SAR), some additional activities are also predicted, which point towards new possible applications of these lipids. This review emphasizes the role of cyanosteroids as an important source and potential leads for drug discovery and they are of great interest to chemists, physicians, biologists, pharmacologists and the pharmaceutical industry. KEYWORDS: |
Faucon, Adrien; Benhelli-Mokrani, Houda; Fleury, Fabrice; Dutertre, Stéphanie; Tramier, Marc; Boucard, Joanna; Lartigue, Lénaïc; Nedellec, Steven; Hulin, Philippe; Ishow, Eléna Bioconjugated fluorescent organic nanoparticles targeting EGFR-overexpressing cancer cells Article de journal Nanoscale, 9 (45), p. 18094–18106, 2017, ISSN: 20403372. @article{Faucon2017, title = {Bioconjugated fluorescent organic nanoparticles targeting EGFR-overexpressing cancer cells}, author = {Adrien Faucon and Houda Benhelli-Mokrani and Fabrice Fleury and Stéphanie Dutertre and Marc Tramier and Joanna Boucard and Lénaïc Lartigue and Steven Nedellec and Philippe Hulin and Eléna Ishow}, doi = {10.1039/c7nr06533g}, issn = {20403372}, year = {2017}, date = {2017-01-01}, journal = {Nanoscale}, volume = {9}, number = {45}, pages = {18094--18106}, publisher = {Royal Society of Chemistry}, abstract = {The field of optical bioimaging has considerably flourished with the advent of sophisticated microscopy techniques and ultra-bright fluorescent tools. Fluorescent organic nanoparticles (FONs) have thus recently appeared as very attractive labels for their high payload, absence of cytotoxicity and eventual biodegradation. Nevertheless, their bioconjugation to target specific receptors with high imaging contrast is scarcely performed. Moreover, assessing the reality of bioconjugation represents high challenges given the sub-nanomolar concentrations resulting from the commonly adopted nanoprecipitation fabrication process. Here, we describe how the combination of a magnetic shell allows us to easily generate red-emitting FONs conjugated with the epidermal growth factor ligand (EGF), a small protein promoting cancer cell proliferation by activating the EGF receptor (EGFR) pathway. Dual color fluorescence correlation spectroscopy combined with immunofluorescence is originally harnessed in its time trace mode to unambiguously demonstrate covalent attachment between the FON and EGF at sub-nanomolar concentrations. Strong asymmetric clustering of EGF-conjugated FONs is observed at the membrane of MDA-MB-468 human breast cancer cells overexpressing EGF receptors using super-resolution fluorescence microscopy. Such high recruitment of EGF-conjugated FONs is attributed to their EGF multivalency (4.7 EGF per FON) which enables efficient EGFR activation and subsequent phosphorylation. The large hydrodynamic diameter (DH ∼ 301 nm) of EGF-conjugated FONs prevents immediate engulfment of the sequestered receptors, which provides very bright and localized spots in less than 30 minutes. The reported bioconjugated nanoassemblies could thus serve as ultra-bright probes of breast cancer cells with EGFR-overexpression that is often associated with poor prognosis.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The field of optical bioimaging has considerably flourished with the advent of sophisticated microscopy techniques and ultra-bright fluorescent tools. Fluorescent organic nanoparticles (FONs) have thus recently appeared as very attractive labels for their high payload, absence of cytotoxicity and eventual biodegradation. Nevertheless, their bioconjugation to target specific receptors with high imaging contrast is scarcely performed. Moreover, assessing the reality of bioconjugation represents high challenges given the sub-nanomolar concentrations resulting from the commonly adopted nanoprecipitation fabrication process. Here, we describe how the combination of a magnetic shell allows us to easily generate red-emitting FONs conjugated with the epidermal growth factor ligand (EGF), a small protein promoting cancer cell proliferation by activating the EGF receptor (EGFR) pathway. Dual color fluorescence correlation spectroscopy combined with immunofluorescence is originally harnessed in its time trace mode to unambiguously demonstrate covalent attachment between the FON and EGF at sub-nanomolar concentrations. Strong asymmetric clustering of EGF-conjugated FONs is observed at the membrane of MDA-MB-468 human breast cancer cells overexpressing EGF receptors using super-resolution fluorescence microscopy. Such high recruitment of EGF-conjugated FONs is attributed to their EGF multivalency (4.7 EGF per FON) which enables efficient EGFR activation and subsequent phosphorylation. The large hydrodynamic diameter (DH ∼ 301 nm) of EGF-conjugated FONs prevents immediate engulfment of the sequestered receptors, which provides very bright and localized spots in less than 30 minutes. The reported bioconjugated nanoassemblies could thus serve as ultra-bright probes of breast cancer cells with EGFR-overexpression that is often associated with poor prognosis. |
Alligand, Brendan; Le Breton, Magali ; Marquis, Damien; Vallette, François; Fleury, Fabrice Functional effects of diphosphomimetic mutations at cAbl-mediated phosphorylation sites on Rad51 recombinase activity Article de journal Biochimie, 139 , p. 115–124, 2017, ISSN: 61831638. @article{Alligand2017, title = {Functional effects of diphosphomimetic mutations at cAbl-mediated phosphorylation sites on Rad51 recombinase activity}, author = {Brendan Alligand and Magali {Le Breton} and Damien Marquis and François Vallette and Fabrice Fleury}, url = {http://dx.doi.org/10.1016/j.biochi.2017.05.020}, doi = {10.1016/j.biochi.2017.05.020}, issn = {61831638}, year = {2017}, date = {2017-01-01}, journal = {Biochimie}, volume = {139}, pages = {115--124}, publisher = {Elsevier Ltd}, abstract = {Homologous Recombination enables faithful repair of the deleterious double strand breaks of DNA. This pathway relies on Rad51 to catalyze homologous DNA strand exchange. Rad51 is known to be phosphorylated in a sequential manner on Y315 and then on Y54, but the effect of such phosphorylation on Rad51 function remains poorly understood. We have developed a phosphomimetic model in order to study all the phosphorylation states. With the purified phosphomimetic proteins we performed in vitro assays to determine the activity of Rad51. Here we demonstrate the inhibitory effect of the double phosphomimetic mutant and suggest that it may be due to a defect in nucleofilament formation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Homologous Recombination enables faithful repair of the deleterious double strand breaks of DNA. This pathway relies on Rad51 to catalyze homologous DNA strand exchange. Rad51 is known to be phosphorylated in a sequential manner on Y315 and then on Y54, but the effect of such phosphorylation on Rad51 function remains poorly understood. We have developed a phosphomimetic model in order to study all the phosphorylation states. With the purified phosphomimetic proteins we performed in vitro assays to determine the activity of Rad51. Here we demonstrate the inhibitory effect of the double phosphomimetic mutant and suggest that it may be due to a defect in nucleofilament formation. |
9 publications
Silva, Viviane A O; Lafont, Florian; Benhelli-Mokrani, Houda; Le Breton, Magali ; Hulin, Philippe; Chabot, Thomas; ç, Fran; Sakanyan, Vehary; Fleury, Fabrice Rapid diminution in the level and activity of DNA-dependent protein kinase in cancer cells by a reactive nitro-benzoxadiazole compound Article de journal International Journal of Molecular Sciences, 17 (5), 2016, ISSN: 14220067. @article{Silva2016, title = {Rapid diminution in the level and activity of DNA-dependent protein kinase in cancer cells by a reactive nitro-benzoxadiazole compound}, author = {Viviane A O Silva and Florian Lafont and Houda Benhelli-Mokrani and Magali {Le Breton} and Philippe Hulin and Thomas Chabot and Fran{ç}ois Paris and Vehary Sakanyan and Fabrice Fleury}, doi = {10.3390/ijms17050703}, issn = {14220067}, year = {2016}, date = {2016-05-01}, journal = {International Journal of Molecular Sciences}, volume = {17}, number = {5}, publisher = {MDPI AG}, abstract = {The expression and activity of DNA-dependent protein kinase (DNA-PK) is related to DNA repair status in the response of cells to exogenous and endogenous factors. Recent studies indicate that Epidermal Growth Factor Receptor (EGFR) is involved in modulating DNA-PK. It has been shown that a compound 4-nitro-7-[(1-oxidopyridin-2-yl)sulfanyl]-2,1,3-benzoxadiazole (NSC), bearing a nitro-benzoxadiazole (NBD) scaffold, enhances tyrosine phosphorylation of EGFR and triggers downstream signaling pathways. Here, we studied the behavior of DNA-PK and other DNA repair proteins in prostate cancer cells exposed to compound NSC. We showed that both the expression and activity of DNA-PKcs (catalytic subunit of DNA-PK) rapidly decreased upon exposure of cells to the compound. The decline in DNA-PKcs was associated with enhanced protein ubiquitination, indicating the activation of cellular proteasome. However, pretreatment of cells with thioglycerol abolished the action of compound NSC and restored the level of DNA-PKcs. Moreover, the decreased level of DNA-PKcs was associated with the production of intracellular hydrogen peroxide by stable dimeric forms of Cu/Zn SOD1 induced by NSC. Our findings indicate that reactive oxygen species and electrophilic intermediates, generated and accumulated during the redox transformation of NBD compounds, are primarily responsible for the rapid modulation of DNA-PKcs functions in cancer cells.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The expression and activity of DNA-dependent protein kinase (DNA-PK) is related to DNA repair status in the response of cells to exogenous and endogenous factors. Recent studies indicate that Epidermal Growth Factor Receptor (EGFR) is involved in modulating DNA-PK. It has been shown that a compound 4-nitro-7-[(1-oxidopyridin-2-yl)sulfanyl]-2,1,3-benzoxadiazole (NSC), bearing a nitro-benzoxadiazole (NBD) scaffold, enhances tyrosine phosphorylation of EGFR and triggers downstream signaling pathways. Here, we studied the behavior of DNA-PK and other DNA repair proteins in prostate cancer cells exposed to compound NSC. We showed that both the expression and activity of DNA-PKcs (catalytic subunit of DNA-PK) rapidly decreased upon exposure of cells to the compound. The decline in DNA-PKcs was associated with enhanced protein ubiquitination, indicating the activation of cellular proteasome. However, pretreatment of cells with thioglycerol abolished the action of compound NSC and restored the level of DNA-PKcs. Moreover, the decreased level of DNA-PKcs was associated with the production of intracellular hydrogen peroxide by stable dimeric forms of Cu/Zn SOD1 induced by NSC. Our findings indicate that reactive oxygen species and electrophilic intermediates, generated and accumulated during the redox transformation of NBD compounds, are primarily responsible for the rapid modulation of DNA-PKcs functions in cancer cells. |
Krylov, Igor B; Kompanets, Mykhailo O; Novikova, Katerina V; Opeida, Iosip O; Kushch, Olga V; Shelimov, Boris N; Nikishin, Gennady I; Levitsky, Dmitri O; Terent'ev, Alexander O Well-Known Mediators of Selective Oxidation with Unknown Electronic Structure: Metal-Free Generation and EPR Study of Imide-N-oxyl Radicals Article de journal Journal of Physical Chemistry A, 120 (1), p. 68–73, 2016, ISSN: 15205215. @article{Krylov2016, title = {Well-Known Mediators of Selective Oxidation with Unknown Electronic Structure: Metal-Free Generation and EPR Study of Imide-N-oxyl Radicals}, author = {Igor B Krylov and Mykhailo O Kompanets and Katerina V Novikova and Iosip O Opeida and Olga V Kushch and Boris N Shelimov and Gennady I Nikishin and Dmitri O Levitsky and Alexander O Terent'ev}, doi = {10.1021/acs.jpca.5b10722}, issn = {15205215}, year = {2016}, date = {2016-01-01}, journal = {Journal of Physical Chemistry A}, volume = {120}, number = {1}, pages = {68--73}, abstract = {Nitroxyl radicals are widely used in chemistry, materials sciences, and biology. Imide-N-oxyl radicals are subclass of unique nitroxyl radicals that proved to be useful catalysts and mediators of selective oxidation and CH-functionalization. An efficient metal-free method was developed for the generation of imide-N-oxyl radicals from N-hydroxyimides at room temperature by the reaction with (diacetoxyiodo)benzene. The method allows for the production of high concentrations of free radicals and provides high resolution of their EPR spectra exhibiting the superhyperfine structure from benzene ring protons distant from the radical center. An analysis of the spectra shows that, regardless of the electronic effects of the substituents in the benzene ring, the superhyperfine coupling constant of an unpaired electron with the distant protons at positions 4 and 5 of the aromatic system is substantially greater than that with the protons at positions 3 and 6 that are closer to the N-oxyl radical center. This is indicative of an unusual character of the spin density distribution of the unpaired electron in substituted phthalimide-N-oxyl radicals. Understanding of the nature of the electron density distribution in imide-N-oxyl radicals may be useful for the development of commercial mediators of oxidation based on N-hydroxyimides.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Nitroxyl radicals are widely used in chemistry, materials sciences, and biology. Imide-N-oxyl radicals are subclass of unique nitroxyl radicals that proved to be useful catalysts and mediators of selective oxidation and CH-functionalization. An efficient metal-free method was developed for the generation of imide-N-oxyl radicals from N-hydroxyimides at room temperature by the reaction with (diacetoxyiodo)benzene. The method allows for the production of high concentrations of free radicals and provides high resolution of their EPR spectra exhibiting the superhyperfine structure from benzene ring protons distant from the radical center. An analysis of the spectra shows that, regardless of the electronic effects of the substituents in the benzene ring, the superhyperfine coupling constant of an unpaired electron with the distant protons at positions 4 and 5 of the aromatic system is substantially greater than that with the protons at positions 3 and 6 that are closer to the N-oxyl radical center. This is indicative of an unusual character of the spin density distribution of the unpaired electron in substituted phthalimide-N-oxyl radicals. Understanding of the nature of the electron density distribution in imide-N-oxyl radicals may be useful for the development of commercial mediators of oxidation based on N-hydroxyimides. |
Mansuroglu, Zeyni; Benhelli-Mokrani, Houda; Marcato, Vasco; Sultan, Audrey; Violet, Marie; Chauderlier, Alban; Delattre, Lucie; Loyens, Anne; Talahari, Smail; Bégard, Séverine; Nesslany, Fabrice; Colin, Morvane; Souès, Sylvie; Lefebvre, Bruno; Buée, Luc; Galas, Marie Christine; Bonnefoy, Eliette Loss of Tau protein affects the structure, transcription and repair of neuronal pericentromeric heterochromatin Article de journal Scientific Reports, 6 (September), p. 1–16, 2016, ISSN: 20452322. @article{Mansuroglu2016, title = {Loss of Tau protein affects the structure, transcription and repair of neuronal pericentromeric heterochromatin}, author = {Zeyni Mansuroglu and Houda Benhelli-Mokrani and Vasco Marcato and Audrey Sultan and Marie Violet and Alban Chauderlier and Lucie Delattre and Anne Loyens and Smail Talahari and Séverine Bégard and Fabrice Nesslany and Morvane Colin and Sylvie Souès and Bruno Lefebvre and Luc Buée and Marie Christine Galas and Eliette Bonnefoy}, doi = {10.1038/srep33047}, issn = {20452322}, year = {2016}, date = {2016-01-01}, journal = {Scientific Reports}, volume = {6}, number = {September}, pages = {1--16}, publisher = {Nature Publishing Group}, abstract = {Pericentromeric heterochromatin (PCH) gives rise to highly dense chromatin sub-structures rich in the epigenetic mark corresponding to the trimethylated form of lysine 9 of histone H3 (H3K9me3) and in heterochromatin protein 1α (HP1α), which regulate genome expression and stability. We demonstrate that Tau, a protein involved in a number of neurodegenerative diseases including Alzheimer's disease (AD), binds to and localizes within or next to neuronal PCH in primary neuronal cultures from wild-type mice. Concomitantly, we show that the clustered distribution of H3K9me3 and HP1α, two hallmarks of PCH, is disrupted in neurons from Tau-deficient mice (KOTau). Such altered distribution of H3K9me3 that could be rescued by overexpressing nuclear Tau protein was also observed in neurons from AD brains. Moreover, the expression of PCH non-coding RNAs, involved in PCH organization, was disrupted in KOTau neurons that displayed an abnormal accumulation of stress-induced PCH DNA breaks. Altogether, our results demonstrate a new physiological function of Tau in directly regulating neuronal PCH integrity that appears disrupted in AD neurons.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Pericentromeric heterochromatin (PCH) gives rise to highly dense chromatin sub-structures rich in the epigenetic mark corresponding to the trimethylated form of lysine 9 of histone H3 (H3K9me3) and in heterochromatin protein 1α (HP1α), which regulate genome expression and stability. We demonstrate that Tau, a protein involved in a number of neurodegenerative diseases including Alzheimer's disease (AD), binds to and localizes within or next to neuronal PCH in primary neuronal cultures from wild-type mice. Concomitantly, we show that the clustered distribution of H3K9me3 and HP1α, two hallmarks of PCH, is disrupted in neurons from Tau-deficient mice (KOTau). Such altered distribution of H3K9me3 that could be rescued by overexpressing nuclear Tau protein was also observed in neurons from AD brains. Moreover, the expression of PCH non-coding RNAs, involved in PCH organization, was disrupted in KOTau neurons that displayed an abnormal accumulation of stress-induced PCH DNA breaks. Altogether, our results demonstrate a new physiological function of Tau in directly regulating neuronal PCH integrity that appears disrupted in AD neurons. |
Jaunet-Lahary, Titouan; Goupille, Anaïs; Jacquemin, Denis; Fleury, Fabrice; Graton, Jérôme; Laurent, Adèle D A Joint Theoretical and Experimental Study of the Behavior of the DIDS Inhibitor and its Derivatives Article de journal ChemPhysChem, 3 , p. 2434–2445, 2016, ISSN: 14397641. @article{Jaunet-Lahary2016, title = {A Joint Theoretical and Experimental Study of the Behavior of the DIDS Inhibitor and its Derivatives}, author = {Titouan Jaunet-Lahary and Anaïs Goupille and Denis Jacquemin and Fabrice Fleury and Jérôme Graton and Adèle D Laurent}, doi = {10.1002/cphc.201600107}, issn = {14397641}, year = {2016}, date = {2016-01-01}, journal = {ChemPhysChem}, volume = {3}, pages = {2434--2445}, abstract = {4,4′-Diisothiocyanostilbene-2,2′-disulfonic acid (DIDS) is a well-known ion-exchange inhibitor targeting cardiac functions and indirectly impeding both radio- and chemo-resistance. A joint computational and experimental study is presented to provide deeper insights into DIDS and other members of this family of compounds. To this end, we applied state-of-the-art density functional theory (DFT) and time-dependent DFT methods, in addition to measuring the optical properties. The experimental data show that such compounds are highly sensitive to their environment and that the optical properties change within as little time as 7 h. However, the optical properties of DIDS are similar in various acidic/basic environments, which were confirmed by pKa computations on both cis and trans isomers. The protonation analysis also highlights that the singly protonated form of DIDS behaves like a proton sponge compound. The experimentally observed redshift that can be seen when going from water to DMSO was reproduced solely by using the solvation model based on density, although the polarization continuum model and implicit/explicit hybrid schemes were also tested. The characteristic broadening of the absorption peak in water and the vibronic fine structure in DMSO were also reproduced thanks to vibronic coupling simulations associated with the solvent reorganization energy. For other stilbene derivatives, a correlation is found between the maximum absorption wavelength and the Hammett parameters.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 4,4′-Diisothiocyanostilbene-2,2′-disulfonic acid (DIDS) is a well-known ion-exchange inhibitor targeting cardiac functions and indirectly impeding both radio- and chemo-resistance. A joint computational and experimental study is presented to provide deeper insights into DIDS and other members of this family of compounds. To this end, we applied state-of-the-art density functional theory (DFT) and time-dependent DFT methods, in addition to measuring the optical properties. The experimental data show that such compounds are highly sensitive to their environment and that the optical properties change within as little time as 7 h. However, the optical properties of DIDS are similar in various acidic/basic environments, which were confirmed by pKa computations on both cis and trans isomers. The protonation analysis also highlights that the singly protonated form of DIDS behaves like a proton sponge compound. The experimentally observed redshift that can be seen when going from water to DMSO was reproduced solely by using the solvation model based on density, although the polarization continuum model and implicit/explicit hybrid schemes were also tested. The characteristic broadening of the absorption peak in water and the vibronic fine structure in DMSO were also reproduced thanks to vibronic coupling simulations associated with the solvent reorganization energy. For other stilbene derivatives, a correlation is found between the maximum absorption wavelength and the Hammett parameters. |
Terent'Ev, Alexander O; Pastukhova, Zhanna Yu; Yaremenko, Ivan A; Novikov, Roman A; Demchuk, Dmitry V; Bruk, Lev G; Levitsky, Dmitri O; Fleury, Fabrice; Nikishin, Gennady I Selective transformation of tricyclic peroxides with pronounced antischistosomal activity into 2-hydroxy-1,5-diketones using iron (II) salts Article de journal Tetrahedron, 72 (24), p. 3421–3426, 2016, ISSN: 14645416. @article{TerentEv2016, title = {Selective transformation of tricyclic peroxides with pronounced antischistosomal activity into 2-hydroxy-1,5-diketones using iron (II) salts}, author = {Alexander O Terent'Ev and Zhanna Yu Pastukhova and Ivan A Yaremenko and Roman A Novikov and Dmitry V Demchuk and Lev G Bruk and Dmitri O Levitsky and Fabrice Fleury and Gennady I Nikishin}, url = {http://dx.doi.org/10.1016/j.tet.2016.04.054}, doi = {10.1016/j.tet.2016.04.054}, issn = {14645416}, year = {2016}, date = {2016-01-01}, journal = {Tetrahedron}, volume = {72}, number = {24}, pages = {3421--3426}, publisher = {Elsevier Ltd}, abstract = {The present work deals with selective transformations of peroxides into organic compounds via the cleavage of the O-O bond using variable valence metals. A selective transformation of tricyclic peroxides promoted by Fe2+ salts was discovered. This selective transformation is unexpected for compounds with structural features which allow diverse decomposition pathways. 2-Hydroxy-1,5-diketones are prepared in yields up to 92% in the reactions of tricyclic peroxides with FeSO4, Fe(ClO4)2, or FeCl2. This is a new preparative method for the synthesis of 1,5-diketones. 2-Hydroxy-1,5-diketones in CDCl3 at 25 °C exist mainly in the open-chain form of the hydroxyketone over the cyclic hemiacetal. The results of this work can be of interest to understand the mechanism of the antiparasitic action of peroxides.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present work deals with selective transformations of peroxides into organic compounds via the cleavage of the O-O bond using variable valence metals. A selective transformation of tricyclic peroxides promoted by Fe2+ salts was discovered. This selective transformation is unexpected for compounds with structural features which allow diverse decomposition pathways. 2-Hydroxy-1,5-diketones are prepared in yields up to 92% in the reactions of tricyclic peroxides with FeSO4, Fe(ClO4)2, or FeCl2. This is a new preparative method for the synthesis of 1,5-diketones. 2-Hydroxy-1,5-diketones in CDCl3 at 25 °C exist mainly in the open-chain form of the hydroxyketone over the cyclic hemiacetal. The results of this work can be of interest to understand the mechanism of the antiparasitic action of peroxides. |
Levitsky, Dmitri O; Gloriozova, Tatyana A; Poroikov, Vladimir V; Dembitsky, Valery M Mathews Journal of Pharmaceutical Science Naturally Occurring Isocyano / Isothiocyanato Compounds : Their Pharmacological and SAR Activities Article de journal MATHEWS, Open Access Journals, 1 (1), p. 1–15, 2016. @article{Levitsky2016, title = {Mathews Journal of Pharmaceutical Science Naturally Occurring Isocyano / Isothiocyanato Compounds : Their Pharmacological and SAR Activities}, author = {Dmitri O Levitsky and Tatyana A Gloriozova and Vladimir V Poroikov and Valery M Dembitsky}, year = {2016}, date = {2016-01-01}, journal = {MATHEWS, Open Access Journals}, volume = {1}, number = {1}, pages = {1--15}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Zdvizhkov, Alexander T; Terent'Ev, Alexander O; Radulov, Peter S; Novikov, Roman A; Tafeenko, Viktor A; Chernyshev, Vladimir V; Ilovaisky, Alexey I; Levitsky, Dmitri O; Fleury, Fabrice; Nikishin, Gennady I Transformation of 2-allyl-1,3-diketones to bicyclic compounds containing 1,2-dioxolane and tetrahydrofuran rings using the I2/H2O2 system Article de journal Tetrahedron Letters, 57 (8), p. 949–952, 2016, ISSN: 18733581. @article{Zdvizhkov2016, title = {Transformation of 2-allyl-1,3-diketones to bicyclic compounds containing 1,2-dioxolane and tetrahydrofuran rings using the I2/H2O2 system}, author = {Alexander T Zdvizhkov and Alexander O Terent'Ev and Peter S Radulov and Roman A Novikov and Viktor A Tafeenko and Vladimir V Chernyshev and Alexey I Ilovaisky and Dmitri O Levitsky and Fabrice Fleury and Gennady I Nikishin}, url = {http://dx.doi.org/10.1016/j.tetlet.2016.01.061}, doi = {10.1016/j.tetlet.2016.01.061}, issn = {18733581}, year = {2016}, date = {2016-01-01}, journal = {Tetrahedron Letters}, volume = {57}, number = {8}, pages = {949--952}, publisher = {Elsevier Ltd}, abstract = {A one-pot procedure was developed for the assembly of bicyclic compounds containing 1,2-dioxolane and tetrahydrofuran rings based on the reaction of 2-allyl-1,3-diketones with the I2/H2O2 system. A fivefold molar excess of H2O2 and a twofold excess of I2 are required for the selective formation of tetrahydrofurodioxoles. The synthesis of these structurally complex molecules is unusual in that it does not produce the expected bridged tetraoxanes, products of the addition of several H2O2 molecules to a carbonyl group, or the products of double bond iodoperoxidation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A one-pot procedure was developed for the assembly of bicyclic compounds containing 1,2-dioxolane and tetrahydrofuran rings based on the reaction of 2-allyl-1,3-diketones with the I2/H2O2 system. A fivefold molar excess of H2O2 and a twofold excess of I2 are required for the selective formation of tetrahydrofurodioxoles. The synthesis of these structurally complex molecules is unusual in that it does not produce the expected bridged tetraoxanes, products of the addition of several H2O2 molecules to a carbonyl group, or the products of double bond iodoperoxidation. |
Sakanyan, Vehary; Hulin, Philippe; Alves De Sousa, Rodolphe ; Silva, Viviane A O; Hambardzumyan, Artur; Nedellec, Steven; Tomasoni, Christophe; Logé, Cédric; Pineau, Charles; Roussakis, Christos; Fleury, Fabrice; Artaud, Isabelle Activation of EGFR by small compounds through coupling the generation of hydrogen peroxide to stable dimerization of Cu/Zn SOD1 Article de journal Scientific Reports, 6 (January), p. 1–14, 2016, ISSN: 20452322. @article{Sakanyan2016, title = {Activation of EGFR by small compounds through coupling the generation of hydrogen peroxide to stable dimerization of Cu/Zn SOD1}, author = {Vehary Sakanyan and Philippe Hulin and Rodolphe {Alves De Sousa} and Viviane A O Silva and Artur Hambardzumyan and Steven Nedellec and Christophe Tomasoni and Cédric Logé and Charles Pineau and Christos Roussakis and Fabrice Fleury and Isabelle Artaud}, url = {http://dx.doi.org/10.1038/srep21088}, doi = {10.1038/srep21088}, issn = {20452322}, year = {2016}, date = {2016-01-01}, journal = {Scientific Reports}, volume = {6}, number = {January}, pages = {1--14}, publisher = {Nature Publishing Group}, abstract = {Activation of cell signaling by reactive chemicals and pollutants is an important issue for human health. It has been shown that lipophilic nitro-benzoxadiazole (NBD) compounds rapidly move across the plasma membrane and enhance Epidermal Growth Factor Receptor (EGFR) tyrosine phosphorylation in cancer cells. Unlike ligand-dependent activation, the mechanism of this induction relies on the generation of hydrogen peroxide, which is involved in the activation of the catalytic site of the receptor and the inactivation of protein tyrosine phosphatase PTP-1B. Production of H 2 O 2 during redox transformation of NBD compounds is associated with the transition of a monomeric form of Cu/Zn superoxide dismutase 1 (SOD1) to stable dimers. The highly stable and functionally active SOD1 dimer, in the absence of adequate activities in downstream reactions, promotes the disproportionate production and accumulation of intracellular hydrogen peroxide shortly after exposure to NBD compounds. The intrinsic fluorescence of small compounds was used to demonstrate their binding to SOD1. Our data indicate that H 2 O 2 and concomitantly generated electrophilic intermediates behave as independent entities, but all contribute to the biological reactivity of NBD compounds. This study opens a promising path to identify new biomarkers of oxidative/electrophilic stress in the progression of cancer and other diseases.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Activation of cell signaling by reactive chemicals and pollutants is an important issue for human health. It has been shown that lipophilic nitro-benzoxadiazole (NBD) compounds rapidly move across the plasma membrane and enhance Epidermal Growth Factor Receptor (EGFR) tyrosine phosphorylation in cancer cells. Unlike ligand-dependent activation, the mechanism of this induction relies on the generation of hydrogen peroxide, which is involved in the activation of the catalytic site of the receptor and the inactivation of protein tyrosine phosphatase PTP-1B. Production of H 2 O 2 during redox transformation of NBD compounds is associated with the transition of a monomeric form of Cu/Zn superoxide dismutase 1 (SOD1) to stable dimers. The highly stable and functionally active SOD1 dimer, in the absence of adequate activities in downstream reactions, promotes the disproportionate production and accumulation of intracellular hydrogen peroxide shortly after exposure to NBD compounds. The intrinsic fluorescence of small compounds was used to demonstrate their binding to SOD1. Our data indicate that H 2 O 2 and concomitantly generated electrophilic intermediates behave as independent entities, but all contribute to the biological reactivity of NBD compounds. This study opens a promising path to identify new biomarkers of oxidative/electrophilic stress in the progression of cancer and other diseases. |
Faucon, Adrien; Benhelli-Mokrani, Houda; Fleury, Fabrice; Dubreil, Laurence; Hulin, Philippe; Nedellec, Steven; Doussineau, Tristan; Antoine, Rodolphe; Orlando, Tomas; Lascialfari, Alessandro; ô, Jér; ï, Léna; Ishow, Eléna Tuning the architectural integrity of high-performance magneto-fluorescent core-shell nanoassemblies in cancer cells Article de journal Journal of Colloid and Interface Science, 479 , p. 139–149, 2016, ISSN: 10957103. @article{Faucon2016, title = {Tuning the architectural integrity of high-performance magneto-fluorescent core-shell nanoassemblies in cancer cells}, author = {Adrien Faucon and Houda Benhelli-Mokrani and Fabrice Fleury and Laurence Dubreil and Philippe Hulin and Steven Nedellec and Tristan Doussineau and Rodolphe Antoine and Tomas Orlando and Alessandro Lascialfari and Jér{ô}me Fresnais and Léna{ï}c Lartigue and Eléna Ishow}, url = {http://dx.doi.org/10.1016/j.jcis.2016.06.064}, doi = {10.1016/j.jcis.2016.06.064}, issn = {10957103}, year = {2016}, date = {2016-01-01}, journal = {Journal of Colloid and Interface Science}, volume = {479}, pages = {139--149}, publisher = {Elsevier Inc.}, abstract = {High-density nanoarchitectures, endowed with simultaneous fluorescence and contrast properties for MRI and TEM imaging, have been obtained using a simple self-assembling strategy based on supramolecular interactions between non-doped fluorescent organic nanoparticles (FON) and superparamagnetic nanoparticles. In this way, a high-payload core-shell structure FON@mag has been obtained, protecting the hydrophobic fluorophores from the surroundings as well as from emission quenching by the shell of magnetic nanoparticles. Compared to isolated nanoparticles, maghemite nanoparticles self-assembled as an external shell create large inhomogeneous magnetic field, which causes enhanced transverse relaxivity and exacerbated MRI contrast. The magnetic load of the resulting nanoassemblies is evaluated using magnetic sedimentation and more originally electrospray mass spectrometry. The role of the stabilizing agents (citrate versus polyacrylate anions) revealed to be crucial regarding the cohesion of the resulting high-performance magneto-fluorescent nanoassemblies, which questions their use after cell internalization as nanocarriers or imaging agents for reliable correlative light and electron microcopy.}, keywords = {}, pubstate = {published}, tppubtype = {article} } High-density nanoarchitectures, endowed with simultaneous fluorescence and contrast properties for MRI and TEM imaging, have been obtained using a simple self-assembling strategy based on supramolecular interactions between non-doped fluorescent organic nanoparticles (FON) and superparamagnetic nanoparticles. In this way, a high-payload core-shell structure FON@mag has been obtained, protecting the hydrophobic fluorophores from the surroundings as well as from emission quenching by the shell of magnetic nanoparticles. Compared to isolated nanoparticles, maghemite nanoparticles self-assembled as an external shell create large inhomogeneous magnetic field, which causes enhanced transverse relaxivity and exacerbated MRI contrast. The magnetic load of the resulting nanoassemblies is evaluated using magnetic sedimentation and more originally electrospray mass spectrometry. The role of the stabilizing agents (citrate versus polyacrylate anions) revealed to be crucial regarding the cohesion of the resulting high-performance magneto-fluorescent nanoassemblies, which questions their use after cell internalization as nanocarriers or imaging agents for reliable correlative light and electron microcopy. |
5 publications
Alligand, Brendan Étude du rôle des phosphorylations de Rad51 en Y54 et en Y315 sur son fonctionnement Thèse Université de Nantes, 2015. @phdthesis{alligand2015etude, title = {Étude du rôle des phosphorylations de Rad51 en Y54 et en Y315 sur son fonctionnement}, author = {Brendan Alligand}, url = {https://www.theses.fr/2015NANT2033}, year = {2015}, date = {2015-11-26}, school = {Université de Nantes}, abstract = {La Recombinaison Homologue (RH) permet la réparation des dommages à l’ADN les plus délétères : les Cassures double brin. L’étape centrale de la RH est basée sur l’activité d’échange de brins de RAD51. Ainsi, l’activité de RAD51 est cruciale pour le maintien de l’intégrité génomique. Toutefois, cette protéine possède également un côté sombre. En effet, la surexpression de RAD51 permet aux cellules cancéreuses de résister aux traitements. Ce qui en fait une cible thérapeutique potentielle pour sensibiliser les cellules cancéreuses au traitement. Une meilleure compréhension du contrôle de l’activité de RAD51 aiderait sûrement à développer des stratégies thérapeutiques. L’activité de RAD51 est régulée par des phosphorylations et plusieurs kinases sont connues pour cibler RAD51. C’est le cas de la kinase c-Abl qui phosphoryle les tyrosines Y54 et Y315 en réponse aux dommages à l’ADN. Mais le rôle de ces phosphorylations est peu connu. C’est pourquoi nous nous sommes intéressés à l’effet de ces phosphorylations sur RAD51. Dans ce but, nous avons produit des mutants de RAD51 mimant la phosphorylation. Leur activité a été analysée et comparée in vitro. Nous avons démontré que le mutant équivalent à une double phosphorylation est incapable de réaliser l’échange de brins. Un défaut de polymérisation de RAD51 serait à l’origine de cette inhibition. Par la suite, la régulation a été étudiée dans le contexte cellulaire. Les résultats préliminaires montrent un effet de la double phosphorylation sur la localisation cellulaire de RAD51. L’inactivation de RAD51 par cette double phosphorylation pourrait participer à la régulation de la voie de la Recombinaison Homologue et serait une étape clef dans la compréhension de la réponse aux dommages à l’ADN.}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } La Recombinaison Homologue (RH) permet la réparation des dommages à l’ADN les plus délétères : les Cassures double brin. L’étape centrale de la RH est basée sur l’activité d’échange de brins de RAD51. Ainsi, l’activité de RAD51 est cruciale pour le maintien de l’intégrité génomique. Toutefois, cette protéine possède également un côté sombre. En effet, la surexpression de RAD51 permet aux cellules cancéreuses de résister aux traitements. Ce qui en fait une cible thérapeutique potentielle pour sensibiliser les cellules cancéreuses au traitement. Une meilleure compréhension du contrôle de l’activité de RAD51 aiderait sûrement à développer des stratégies thérapeutiques. L’activité de RAD51 est régulée par des phosphorylations et plusieurs kinases sont connues pour cibler RAD51. C’est le cas de la kinase c-Abl qui phosphoryle les tyrosines Y54 et Y315 en réponse aux dommages à l’ADN. Mais le rôle de ces phosphorylations est peu connu. C’est pourquoi nous nous sommes intéressés à l’effet de ces phosphorylations sur RAD51. Dans ce but, nous avons produit des mutants de RAD51 mimant la phosphorylation. Leur activité a été analysée et comparée in vitro. Nous avons démontré que le mutant équivalent à une double phosphorylation est incapable de réaliser l’échange de brins. Un défaut de polymérisation de RAD51 serait à l’origine de cette inhibition. Par la suite, la régulation a été étudiée dans le contexte cellulaire. Les résultats préliminaires montrent un effet de la double phosphorylation sur la localisation cellulaire de RAD51. L’inactivation de RAD51 par cette double phosphorylation pourrait participer à la régulation de la voie de la Recombinaison Homologue et serait une étape clef dans la compréhension de la réponse aux dommages à l’ADN. |
Faucon, Adrien; Benhelli-Mokrani, Houda; w Córdova, Luis A; Brulin, Bénédicte; Heymann, Dominique; Hulin, Philippe; Nedellec, Steven; Ishow, Eléna Are Fluorescent Organic Nanoparticles Relevant Tools for Tracking Cancer Cells or Macrophages? Article de journal Advanced Healthcare Materials, 4 (17), p. 2727–2734, 2015, ISSN: 21922659. @article{Faucon2015, title = {Are Fluorescent Organic Nanoparticles Relevant Tools for Tracking Cancer Cells or Macrophages?}, author = {Adrien Faucon and Houda Benhelli-Mokrani and Luis A w Córdova and Bénédicte Brulin and Dominique Heymann and Philippe Hulin and Steven Nedellec and Eléna Ishow}, doi = {10.1002/adhm.201500562}, issn = {21922659}, year = {2015}, date = {2015-01-01}, journal = {Advanced Healthcare Materials}, volume = {4}, number = {17}, pages = {2727--2734}, abstract = {Strongly solvatochromic fluorophores are devised, containing alkyl chains and enable to self-assemble as very bright fluorescent organic nanoparticles (FONs) in water (φf = 0.28). The alkyl chains impart each fluorophore with strongly hydrophobic surroundings, causing distinct emission colors between FONs where the fluorophores are associated, and their disassembled state. Such color change is harnessed to assess the long-term fate of FONs in both cancer cells and monocytes/macrophages. Disintegration of the orange-emitting FONs by monocytes/macrophages is evidenced through the formation of micrometer green-yellowish emitting vesicles. By contrast, cancer cells retain longer the integrity of organic nanoparticles. In both cases, no significant toxicity is detected, making FONs as valuable bioimaging agents for cell tracking with weak risks of deleterious accumulation and low degradation rate. Long-term fate of fluorescent organic nanoparticles (FONs), known as very bright imaging agents and made of self-assembled solvatochromic fluorophores, is explored in both cancer cells and monocytes/macrophages. Disintegration of the orange-emitting FONs by monocytes/macrophages is evidenced through the formation of micrometer green-yellowish emitting vesicles. By contrast, cancer cells retain longer the integrity of organic nanoparticles.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Strongly solvatochromic fluorophores are devised, containing alkyl chains and enable to self-assemble as very bright fluorescent organic nanoparticles (FONs) in water (φf = 0.28). The alkyl chains impart each fluorophore with strongly hydrophobic surroundings, causing distinct emission colors between FONs where the fluorophores are associated, and their disassembled state. Such color change is harnessed to assess the long-term fate of FONs in both cancer cells and monocytes/macrophages. Disintegration of the orange-emitting FONs by monocytes/macrophages is evidenced through the formation of micrometer green-yellowish emitting vesicles. By contrast, cancer cells retain longer the integrity of organic nanoparticles. In both cases, no significant toxicity is detected, making FONs as valuable bioimaging agents for cell tracking with weak risks of deleterious accumulation and low degradation rate. Long-term fate of fluorescent organic nanoparticles (FONs), known as very bright imaging agents and made of self-assembled solvatochromic fluorophores, is explored in both cancer cells and monocytes/macrophages. Disintegration of the orange-emitting FONs by monocytes/macrophages is evidenced through the formation of micrometer green-yellowish emitting vesicles. By contrast, cancer cells retain longer the integrity of organic nanoparticles. |
Qi, Haoling; Cantrelle, François Xavier; Benhelli-Mokrani, Houda; Smet-Nocca, Caroline; Buée, Luc; Lippens, Guy; Bonnefoy, Eliette; Galas, Marie Christine; Landrieu, Isabelle Nuclear magnetic resonance spectroscopy characterization of interaction of Tau with DNA and its regulation by phosphorylation Article de journal Biochemistry, 54 (7), p. 1525–1533, 2015, ISSN: 15204995. @article{Qi2015, title = {Nuclear magnetic resonance spectroscopy characterization of interaction of Tau with DNA and its regulation by phosphorylation}, author = {Haoling Qi and François Xavier Cantrelle and Houda Benhelli-Mokrani and Caroline Smet-Nocca and Luc Buée and Guy Lippens and Eliette Bonnefoy and Marie Christine Galas and Isabelle Landrieu}, doi = {10.1021/bi5014613}, issn = {15204995}, year = {2015}, date = {2015-01-01}, journal = {Biochemistry}, volume = {54}, number = {7}, pages = {1525--1533}, abstract = {The capacity of endogenous Tau to bind DNA has been recently identified in neurons under physiological or oxidative stress conditions. Characterization of the protein domains involved in Tau-DNA complex formation is an essential first step in clarifying the contribution of Tau-DNA interactions to neurological biological processes. To identify the amino acid residues involved in the interaction of Tau with oligonucleotides, we have characterized a Tau-DNA complex using nuclear magnetic resonance spectroscopy. Interaction of an AT-rich or GC-rich 22 bp oligonucleotide with Tau showed multiple points of anchoring along the intrinsically disordered Tau protein. The main sites of contact characterized here correspond to the second half of the proline-rich domain (PRD) of Tau and the R2 repeat in the microtubule binding domain. This latter interaction site includes the PHF6∗ sequence known to govern Tau aggregation. The characterization was pursued by studying the binding of phosphorylated forms of Tau, displaying multiple phosphorylation sites mainly in the PRD, to the same oligonucleotide. No interaction of phospho-Tau with the oligonucleotide was detected, suggesting that pathological Tau phosphorylation could affect the physiological function of Tau mediated by DNA binding.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The capacity of endogenous Tau to bind DNA has been recently identified in neurons under physiological or oxidative stress conditions. Characterization of the protein domains involved in Tau-DNA complex formation is an essential first step in clarifying the contribution of Tau-DNA interactions to neurological biological processes. To identify the amino acid residues involved in the interaction of Tau with oligonucleotides, we have characterized a Tau-DNA complex using nuclear magnetic resonance spectroscopy. Interaction of an AT-rich or GC-rich 22 bp oligonucleotide with Tau showed multiple points of anchoring along the intrinsically disordered Tau protein. The main sites of contact characterized here correspond to the second half of the proline-rich domain (PRD) of Tau and the R2 repeat in the microtubule binding domain. This latter interaction site includes the PHF6∗ sequence known to govern Tau aggregation. The characterization was pursued by studying the binding of phosphorylated forms of Tau, displaying multiple phosphorylation sites mainly in the PRD, to the same oligonucleotide. No interaction of phospho-Tau with the oligonucleotide was detected, suggesting that pathological Tau phosphorylation could affect the physiological function of Tau mediated by DNA binding. |
Velic, Denis; Couturier, Anthony M; Ferreira, Maria Tedim; Rodrigue, Amélie; Poirier, Guy G; Fleury, Fabrice; Masson, Jean-Yves DNA Damage Signalling and Repair Inhibitors: The Long-Sought-After Achilles’ Heel of Cancer Article de journal Biomolecules, 5 (4), p. 3204–3259, 2015, ISSN: 2218-273X. @article{biom5043204, title = {DNA Damage Signalling and Repair Inhibitors: The Long-Sought-After Achilles’ Heel of Cancer}, author = {Denis Velic and Anthony M Couturier and Maria Tedim Ferreira and Amélie Rodrigue and Guy G Poirier and Fabrice Fleury and Jean-Yves Masson}, url = {https://www.mdpi.com/2218-273X/5/4/3204}, doi = {10.3390/biom5043204}, issn = {2218-273X}, year = {2015}, date = {2015-01-01}, journal = {Biomolecules}, volume = {5}, number = {4}, pages = {3204--3259}, abstract = {For decades, radiotherapy and chemotherapy were the two only approaches exploiting DNA repair processes to fight against cancer. Nowadays, cancer therapeutics can be a major challenge when it comes to seeking personalized targeted medicine that is both effective and selective to the malignancy. Over the last decade, the discovery of new targeted therapies against DNA damage signalling and repair has offered the possibility of therapeutic improvements in oncology. In this review, we summarize the current knowledge of DNA damage signalling and repair inhibitors, their molecular and cellular effects, and future therapeutic use.}, keywords = {}, pubstate = {published}, tppubtype = {article} } For decades, radiotherapy and chemotherapy were the two only approaches exploiting DNA repair processes to fight against cancer. Nowadays, cancer therapeutics can be a major challenge when it comes to seeking personalized targeted medicine that is both effective and selective to the malignancy. Over the last decade, the discovery of new targeted therapies against DNA damage signalling and repair has offered the possibility of therapeutic improvements in oncology. In this review, we summarize the current knowledge of DNA damage signalling and repair inhibitors, their molecular and cellular effects, and future therapeutic use. |
Terent'ev, Alexander O; Zdvizhkov, Alexander T; Levitsky, Dmitri O; Fleury, Fabrice; Pototskiy, Roman A; Kulakova, Alena N; Nikishin, Gennady I Organocatalytic peroxidation of malonates, β-ketoesters, and cyanoacetic esters using n-Bu4NI/t-BuOOH-mediated intermolecular oxidative C(sp3)-O coupling Article de journal Tetrahedron, 71 (47), p. 8985–8990, 2015, ISSN: 14645416. @article{Terentev2015, title = {Organocatalytic peroxidation of malonates, β-ketoesters, and cyanoacetic esters using n-Bu4NI/t-BuOOH-mediated intermolecular oxidative C(sp3)-O coupling}, author = {Alexander O Terent'ev and Alexander T Zdvizhkov and Dmitri O Levitsky and Fabrice Fleury and Roman A Pototskiy and Alena N Kulakova and Gennady I Nikishin}, url = {http://dx.doi.org/10.1016/j.tet.2015.09.047}, doi = {10.1016/j.tet.2015.09.047}, issn = {14645416}, year = {2015}, date = {2015-01-01}, journal = {Tetrahedron}, volume = {71}, number = {47}, pages = {8985--8990}, publisher = {Elsevier Ltd}, abstract = {A new organocatalytic approach for the synthesis of peroxides based on CH activation of a sp3-hybridized carbon atom is reported. Peroxides were prepared in 31-89% yield by the reaction of malonates, β-ketoesters, and cyanoacetic esters with a Bu4NI/tert-butyl hydroperoxide system. The formation of the expected hydroxylation products was not observed. In the discovered reaction, tert-butyl hydroperoxide plays a dual role by acting as the oxidant and the O-reagent for the C-O coupling. The synthesis can be scaled up to generate gram quantities of the target products.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new organocatalytic approach for the synthesis of peroxides based on CH activation of a sp3-hybridized carbon atom is reported. Peroxides were prepared in 31-89% yield by the reaction of malonates, β-ketoesters, and cyanoacetic esters with a Bu4NI/tert-butyl hydroperoxide system. The formation of the expected hydroxylation products was not observed. In the discovered reaction, tert-butyl hydroperoxide plays a dual role by acting as the oxidant and the O-reagent for the C-O coupling. The synthesis can be scaled up to generate gram quantities of the target products. |