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Accueil > Départements > Biologie des Génomes > Carl MANN : Sénescence et stabilité génomique

Publications de l’équipe


  • M. Bakail, A. Gaubert, J. Andreani, G. Moal, G. Pinna, E. Boyarchuk, M. - C. Gaillard, R. Courbeyrette, C. Mann, J. - Y. Thuret, B. Guichard, B. Murciano, N. Richet, A. Poitou, C. Frederic, M. - H. Le Du, M. Agez, C. Roelants, Z. A. Gurard-Levin, G. Almouzni, N. Cherradi, R. Guerois, et F. Ochsenbein, « Design on a Rational Basis of High-Affinity Peptides Inhibiting the Histone Chaperone ASF1 », Cell Chemical Biology, sept. 2019.
    Résumé : Anti-silencing function 1 (ASF1) is a conserved H3-H4 histone chaperone involved in histone dynamics during replication, transcription, and DNA repair. Overexpressed in proliferating tissues including many tumors, ASF1 has emerged as a promising therapeutic target. Here, we combine structural, computational, and biochemical approaches to design peptides that inhibit the ASF1-histone interaction. Starting from the structure of the human ASF1-histone complex, we developed a rational design strategy combining epitope tethering and optimization of interface contacts to identify a potent peptide inhibitor with a dissociation constant of 3 nM. When introduced into cultured cells, the inhibitors impair cell proliferation, perturb cell-cycle progression, and reduce cell migration and invasion in a manner commensurate with their affinity for ASF1. Finally, we find that direct injection of the most potent ASF1 peptide inhibitor in mouse allografts reduces tumor growth. Our results open new avenues to use ASF1 inhibitors as promising leads for cancer therapy.
    Mots-clés : AMIG, B3S, Cancer, Cell Penetrating Peptide, Chromatin, DBG, Drug Design, Epigenetics, INTGEN, PARI, Peptide Inhibitor, PF, Protein Binding, Protein-Protein Interaction, Rosetta Design, SEN, X-Ray Crystallography.

  • C. Carvalho, V. L'Hôte, R. Courbeyrette, G. Kratassiouk, G. Pinna, J. - C. Cintrat, C. Denby-Wilkes, C. Derbois, R. Olaso, J. - F. Deleuze, C. Mann, et J. - Y. Thuret, « Glucocorticoids delay RAF-induced senescence promoted by EGR1 », Journal of Cell Science, vol. 132, nᵒ 16, p. UNSP jcs230748, août 2019.
    Résumé : Expression of hyperactive RAF kinases, such as the oncogenic B-RAF-V600E mutant, in normal human cells triggers a proliferative arrest that blocks tumor formation. We discovered that glucocorticoids delayed the entry into senescence induced by B-RAF-V600E in human fibroblasts, and allowed senescence bypass when the cells were regularly passaged, but that they did not allow proliferation of cells that were already senescent. Transcriptome and siRNA analyses revealed that the EGR1 gene is one target of glucocorticoid action. Transcription of the EGR1 gene is activated by the RAF-MEK-ERK MAPK pathway and acts as a sensor of hyper-mitogenic pathway activity. The EGR1 transcription factor regulates the expression of p15 and p21 (encoded by CDKN2B and CDKN1A, respectively) that are redundantly required for the proliferative arrest of BJ fibroblasts upon expression of B-RAF-V600E. Our results highlight the need to evaluate the action of glucocorticoid on cancer progression in melanoma, thyroid and colon carcinoma in which B-RAF-V600E is a frequent oncogene, and cancers in which evasion from senescence has been shown.
    Mots-clés : B-RAF-V600E, CDKN1A, CDKN2B, DBG, EGR1, Glucocorticoid, GTR, Oncogene-induced senescence, PARI, PF, SEN.


  • K. Contrepois, C. Coudereau, B. A. Benayoun, N. Schuler, P. - F. Roux, O. Bischof, R. Courbeyrette, C. Carvalho, J. - Y. Thuret, Z. Ma, C. Derbois, M. - C. Nevers, H. Volland, C. E. Redon, W. M. Bonner, J. - F. Deleuze, C. Wiel, D. Bernard, M. P. Snyder, C. E. Rübe, R. Olaso, F. Fenaille, et C. Mann, « Histone variant H2A.J accumulates in senescent cells and promotes inflammatory gene expression », Nature Communications, vol. 8, p. 14995, mai 2017.
    Résumé : The senescence of mammalian cells is characterized by a proliferative arrest in response to stress and the expression of an inflammatory phenotype. Here we show that histone H2A.J, a poorly studied H2A variant found only in mammals, accumulates in human fibroblasts in senescence with persistent DNA damage. H2A.J also accumulates in mice with aging in a tissue-specific manner and in human skin. Knock-down of H2A.J inhibits the expression of inflammatory genes that contribute to the senescent-associated secretory phenotype (SASP), and over expression of H2A.J increases the expression of some of these genes in proliferating cells. H2A.J accumulation may thus promote the signalling of senescent cells to the immune system, and it may contribute to chronic inflammation and the development of aging-associated diseases.
    Mots-clés : DBG, SEN.


  • R. Culerrier, M. Carraz, C. Mann, et M. Djabali, « MSK1 triggers the expression of the INK4AB/ARF locus in oncogene-induced senescence », Molecular Biology of the Cell, vol. 27, nᵒ 17, p. 2726-2734, sept. 2016.
    Résumé : The tumor suppressor proteins p15(INK4B), p16(INK4A), and p14(ARF), encoded by the INK4AB/ARF locus, are crucial regulators of cellular senescence. The locus is epigenetically silenced by the repressive Polycomb complexes in growing cells but is activated in response to oncogenic stress. Here we show that the mitogen- and stress-activated kinase (MSK1) is up-regulated after RAF1 oncogenic stress and that the phosphorylated (activated) form of MSK1 is significantly increased in the nucleus and recruited to the INK4AB/ARF locus. We show that MSK1 mediates histone H3S28 phosphorylation at the INK4AB/ARF locus and contributes to the rapid transcriptional activation of p15(INK4B) and p16(INK4A) in human cells despite the presence of the repressive H3K27me3 mark. Furthermore, we show that upon MSK1 depletion in oncogenic RAF1-expressing cells, H3S28ph presence at the INK4 locus and p15(INK4B) and p16(INK4A) expression are reduced. Finally, we show that H3S28-MSK-dependent phosphorylation functions in response to RAF1 signaling and that ERK and p38α contribute to MSK1 activation in oncogene-induced senescence.
    Mots-clés : DBG, SEN.

  • D. H. Hamdi, F. Chevalier, J. - E. Groetz, F. Durantel, J. - Y. Thuret, C. Mann, et Y. Saintigny, « Comparable Senescence Induction in Three-dimensional Human Cartilage Model by Exposure to Therapeutic Doses of X-rays or C-ions », International Journal of Radiation Oncology, Biology, Physics, vol. 95, nᵒ 1, p. 139-146, mai 2016.
    Résumé : PURPOSE: Particle therapy using carbon ions (C-ions) has been successfully used in the treatment of tumors resistant to conventional radiation therapy. However, the potential side effects to healthy cartilage exposed to lower linear energy transfer (LET) ions in the beam track before the tumor have not been evaluated. The aim of the present study was to assess the extent of damage after C-ion irradiation in a 3-dimensional (3D) cartilage model close to human homeostasis. METHODS AND MATERIALS: Primary human articular chondrocytes from a healthy donor were cultured in a collagen scaffold to construct a physioxic 3D cartilage model. A 2-dimensional (2D) culture was used as a reference. The cells were irradiated with a single dose of a monoenergetic C-ion beam with a LET of approximatively 30 keV/μm. This LET corresponds to the entrance channel of C-ions in the shallow healthy tissues before the spread-out Bragg peak (∼100 keV/μm) during hadron therapy protocols. The same dose of X-rays was used as a reference. Survival, cell death, and senescence assays were performed. RESULTS: As expected, in the 2D culture, C-ions were more efficient than X-rays in reducing cell survival with a relative biological effectiveness of 2.6. This correlated with stronger radiation-induced senescence (two-fold) but not with higher cell death induction. This differential effect was not reflected in the 3D culture. Both ionizing radiation types induced a comparable rate of senescence induction in the 3D model. CONCLUSIONS: The greater biological effectiveness of C-ions compared with low LET radiation when evaluated in treatment planning systems might be misevaluated using 2D culture experiments. Radiation-induced senescence is an important factor of potential cartilage attrition. The present data should encourage the scientific community to use relevant models and beams to improve the use of charged particles with better safety for patients.
    Mots-clés : Bone Neoplasms, Carbon, Cartilage, Cell Aging, Cell Culture Techniques, Cell Death, Cell Survival, Cells, Cultured, Chondrocytes, Chondrosarcoma, DBG, Heavy Ion Radiotherapy, Humans, Linear Energy Transfer, Radiation Injuries, Relative Biological Effectiveness, SEN, X-Rays.


  • T. Chandra, P. A. Ewels, S. Schoenfelder, M. Furlan-Magaril, S. W. Wingett, K. Kirschner, J. - Y. Thuret, S. Andrews, P. Fraser, et W. Reik, « Global reorganization of the nuclear landscape in senescent cells », Cell Reports, vol. 10, nᵒ 4, p. 471-483, févr. 2015.
    Résumé : Cellular senescence has been implicated in tumor suppression, development, and aging and is accompanied by large-scale chromatin rearrangements, forming senescence-associated heterochromatic foci (SAHF). However, how the chromatin is reorganized during SAHF formation is poorly understood. Furthermore, heterochromatin formation in senescence appears to contrast with loss of heterochromatin in Hutchinson-Gilford progeria. We mapped architectural changes in genome organization in cellular senescence using Hi-C. Unexpectedly, we find a dramatic sequence- and lamin-dependent loss of local interactions in heterochromatin. This change in local connectivity resolves the paradox of opposing chromatin changes in senescence and progeria. In addition, we observe a senescence-specific spatial clustering of heterochromatic regions, suggesting a unique second step required for SAHF formation. Comparison of embryonic stem cells (ESCs), somatic cells, and senescent cells shows a unidirectional loss in local chromatin connectivity, suggesting that senescence is an endpoint of the continuous nuclear remodelling process during differentiation.
    Mots-clés : Cell Aging, Cell Line, Cell Proliferation, Chromatin, Chromatin Assembly and Disassembly, DBG, Heterochromatin, Humans, In Situ Hybridization, Fluorescence, SEN.

  • S. Lazorthes, C. Vallot, S. Briois, M. Aguirrebengoa, J. - Y. Thuret, G. St Laurent, C. Rougeulle, P. Kapranov, C. Mann, D. Trouche, et E. Nicolas, « A vlincRNA participates in senescence maintenance by relieving H2AZ-mediated repression at the INK4 locus », Nature Communications, vol. 6, p. 5971, janv. 2015.
    Résumé : Non-coding RNAs (ncRNAs) play major roles in proper chromatin organization and function. Senescence, a strong anti-proliferative process and a major anticancer barrier, is associated with dramatic chromatin reorganization in heterochromatin foci. Here we analyze strand-specific transcriptome changes during oncogene-induced human senescence. Strikingly, while differentially expressed RNAs are mostly repressed during senescence, ncRNAs belonging to the recently described vlincRNA (very long intergenic ncRNA) class are mainly activated. We show that VAD, a novel antisense vlincRNA strongly induced during senescence, is required for the maintenance of senescence features. VAD modulates chromatin structure in cis and activates gene expression in trans at the INK4 locus, which encodes cell cycle inhibitors important for senescence-associated cell proliferation arrest. Importantly, VAD inhibits the incorporation of the repressive histone variant H2A.Z at INK4 gene promoters in senescent cells. Our data underline the importance of vlincRNAs as sensors of cellular environment changes and as mediators of the correct transcriptional response.
    Mots-clés : Cell Aging, Cell Line, Chromatin, DBG, Heterochromatin, Humans, RNA, Untranslated, SEN.

  • S. Lazorthes, C. Vallot, S. Briois, M. Aguirrebengoa, J. - Y. Thuret, G. St Laurent, C. Rougeulle, P. Kapranov, C. Mann, D. Trouche, et E. Nicolas, « Erratum: A vlincRNA participates in senescence maintenance by relieving H2AZ-mediated repression at the INK4 locus », Nature Communications, vol. 6, p. 6918, avr. 2015.
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Publications Principales avant 2015

1. Jeanblanc M, Ragu S, Gey C, Contrepois K, Courbeyrette R, Thuret JY, Mann C. Parallel pathways in RAF-induced senescence and conditions for its reversion. 2012. Oncogene. 31, 3072-85.

2. Jiao Y, Seeger K, Lautrette A, Gaubert A, Mousson F, Guerois R, Mann C*, Ochsenbein F. Surprising complexity of the Asf1 histone chaperone-Rad53 kinase interaction. 2012. Proc Natl Acad Sci U S A. 109, 2866-2871. (*=co-corresponding authors).

3. Contrepois K, Thuret JY, Courbeyrette, R, Fenaille F, Mann C (2012). Deacetylation of H4-K16Ac and heterochromatin assembly in senescence. Epigenetics Chromatin. 5, 15.

4. Contrepois K, Ezan E, Mann C, Fenaille F. 2010. Ultra-high performance liquid chromatography-mass spectrometry for the fast profiling of histone post-translational modifications. J. Proteome Res. 9, 5501-5509.

5. A. Galvani, R. Courbeyrette, M. Agez, F. Ochsenbein, C. Mann*, J.Y. Thuret J*. 2008. In vivo study of the nucleosome assembly functions of ASF1 histone chaperones in human cells. Mol Cell Biol., 28, 3672-3685. (*=co-corresponding authors).

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