Thomas CHABOT
Doctorant Université
septembre 2017 - octobre 2020
| Équipe : |
Publications
2 publications
Chabot, Thomas; Cheraud, Yvonnick; Fleury, Fabrice
Relationships between DNA repair and RTK-mediated signaling pathways Article de journal
Dans: 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}
}
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.
1 publication
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
Dans: Cancers, vol. 11, no. 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.
1 publication
Silva, Viviane A O; Lafont, Florian; Benhelli-Mokrani, Houda; Breton, Magali Le; Hulin, Philippe; Chabot, Thomas; Paris, François; 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
Dans: International Journal of Molecular Sciences, vol. 17, no. 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.