References of "Close, Pierre"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailITGBL1 is a new immunomodulator that favors development of melanoma tumors by inhibiting natural killer cells cytotoxicity
cheli, yann; tulic, meri; El Hachem, Najla ULiege et al

in Molecular Cancer (2021)

Resistances to immunotherapies remains a major hurdle towards a cure for melanoma in numerous patients. An increase in the mesenchymal phenotype and a loss of differentiation have been clearly associated ... [more ▼]

Resistances to immunotherapies remains a major hurdle towards a cure for melanoma in numerous patients. An increase in the mesenchymal phenotype and a loss of differentiation have been clearly associated with resistance to targeted therapies. Similar phenotypes have been more recently also linked to resistance to immune checkpoint therapies. We demonstrated here that the loss of MIcrophthalmia associated Transcription Factor (MITF), a pivotal player in melanocyte differentiation, favors the escape of melanoma cells from the immune system. We identified Integrin beta-like protein 1 (ITGBL1), a secreted protein, upregulated in anti-PD1 resistant patients and in MITFlow melanoma cells, as the key immunomodulator. ITGBL1 inhibited immune cell cytotoxicity against melanoma cells by inhibiting NK cells cytotoxicity and counteracting beneficial effects of anti-PD1 treatment, both in vitro and in vivo. Mechanistically, MITF inhibited RUNX2, an activator of ITGBL1 transcription. Interestingly, VitaminD3, an inhibitor of RUNX2, improved melanoma cells to death by immune cells. In conclusion, our data suggest that inhibition of ITGBL1 might improve melanoma response to immunotherapies. [less ▲]

Detailed reference viewed: 37 (5 ULiège)
Full Text
Peer Reviewed
See detailWobble tRNA modification and hydrophilic amino acid patterns dictate protein fate.
Rapino, Francesca ULiege; ZHOU, ZHAOLI; RONCERO SANCHEZ, Ana Maria et al

in Nature Communications (2021), 12(1), 2170

Regulation of mRNA translation elongation impacts nascent protein synthesis and integrity and plays a critical role in disease establishment. Here, we investigate features linking regulation of codon ... [more ▼]

Regulation of mRNA translation elongation impacts nascent protein synthesis and integrity and plays a critical role in disease establishment. Here, we investigate features linking regulation of codon-dependent translation elongation to protein expression and homeostasis. Using knockdown models of enzymes that catalyze the mcm(5)s(2) wobble uridine tRNA modification (U(34)-enzymes), we show that gene codon content is necessary but not sufficient to predict protein fate. While translation defects upon perturbation of U(34)-enzymes are strictly dependent on codon content, the consequences on protein output are determined by other features. Specific hydrophilic motifs cause protein aggregation and degradation upon codon-dependent translation elongation defects. Accordingly, the combination of codon content and the presence of hydrophilic motifs define the proteome whose maintenance relies on U(34)-tRNA modification. Together, these results uncover the mechanism linking wobble tRNA modification to mRNA translation and aggregation to maintain proteome homeostasis. [less ▲]

Detailed reference viewed: 39 (15 ULiège)
Full Text
Peer Reviewed
See detailLoss of tRNA-modifying enzyme Elp3 activates a p53-dependent antitumor checkpoint in hematopoiesis.
Rosu, Adeline ULiege; El Hachem, Najla ULiege; Rapino, Francesca ULiege et al

in The Journal of experimental medicine (2021), 218(3),

The hematopoietic system is highly sensitive to perturbations in the translational machinery, of which an emerging level of regulation lies in the epitranscriptomic modification of transfer RNAs (tRNAs ... [more ▼]

The hematopoietic system is highly sensitive to perturbations in the translational machinery, of which an emerging level of regulation lies in the epitranscriptomic modification of transfer RNAs (tRNAs). Here, we interrogate the role of tRNA anticodon modifications in hematopoiesis by using mouse models of conditional inactivation of Elp3, the catalytic subunit of Elongator that modifies wobble uridine in specific tRNAs. Loss of Elp3 causes bone marrow failure by inducing death in committing progenitors and compromises the grafting activity of hematopoietic stem cells. Mechanistically, Elp3 deficiency activates a p53-dependent checkpoint in what resembles a misguided amino acid deprivation response that is accompanied by Atf4 overactivation and increased protein synthesis. While deletion of p53 rescues hematopoiesis, loss of Elp3 prompts the development of p53-mutated leukemia/lymphoma, and inactivation of p53 and Elongator cooperatively promotes tumorigenesis. Specific tRNA-modifying enzymes thus condition differentiation and antitumor fate decisions in hematopoietic stem cells and progenitors. [less ▲]

Detailed reference viewed: 46 (18 ULiège)
Full Text
Peer Reviewed
See detailLoss of the Transfer RNA Wobble Uridine-Modifying Enzyme Elp3 Delays T Cell Cycle Entry and Impairs T Follicular Helper Cell Responses through Deregulation of Atf4.
Lemaitre, Pierre ULiege; Bai, Qiang ULiege; Legrand, Céline ULiege et al

in Journal of immunology (Baltimore, Md. : 1950) (2021)

The activation of T cells is accompanied by intensive posttranscriptional remodeling of their proteome. We observed that protein expression of enzymes that modify wobble uridine in specific tRNAs, namely ... [more ▼]

The activation of T cells is accompanied by intensive posttranscriptional remodeling of their proteome. We observed that protein expression of enzymes that modify wobble uridine in specific tRNAs, namely elongator subunit 3 (Elp3) and cytosolic thiouridylase (Ctu)2, increased in the course of T cell activation. To investigate the role of these tRNA epitranscriptomic modifiers in T cell biology, we generated mice deficient for Elp3 in T cells. We show that deletion of Elp3 has discrete effects on T cells. In vitro, Elp3-deficient naive CD4(+) T cells polarize normally but are delayed in entering the first cell cycle following activation. In vivo, different models of immunization revealed that Elp3-deficient T cells display reduced expansion, resulting in functional impairment of T follicular helper (TFH) responses, but not of other CD4(+) effector T cell responses. Transcriptomic analyses identified a progressive overactivation of the stress-responsive transcription factor Atf4 in Elp3-deficient T cells. Overexpression of Atf4 in wild-type T cells phenocopies the effect of Elp3 loss on T cell cycle entry and TFH cell responses. Reciprocally, partial silencing of Atf4 or deletion of its downstream effector transcription factor Chop rescues TFH responses of Elp3-deficient T cells. Together, our results reveal that specific epitranscriptomic tRNA modifications contribute to T cell cycle entry and promote optimal TFH responses. [less ▲]

Detailed reference viewed: 38 (7 ULiège)
Full Text
Peer Reviewed
See detailThe X-linked trichothiodystrophy-causing gene RNF113A links the spliceosome to cell survival upon DNA damage
Shostak, Kateryna ULiege; Jiang, Zheshen ULiege; CHARLOTEAUX, Benoit ULiege et al

in Nature Communications (2020), 11(1),

Prolonged cell survival occur through the expression of specific protein isoforms generated by alternate splicing of mRNA precursors in cancer cells. How alternate splicing regulates tumor development and ... [more ▼]

Prolonged cell survival occur through the expression of specific protein isoforms generated by alternate splicing of mRNA precursors in cancer cells. How alternate splicing regulates tumor development and resistance to targeted therapies in cancer remain poorly understood. Here we show that RNF113A, whose loss-of-function causes the X-linked trichothiodystrophy, is overexpressed in lung cancer and protects from Cisplatin-dependent cell death. RNF113A is a RNA-binding protein which regulates the splicing of multiple candidates involved in cell survival. RNF113A deficiency triggers cell death upon DNA damage through multiple mechanisms, including apoptosis via the destabilization of the prosurvival protein MCL-1, ferroptosis due to enhanced SAT1 expression and increased production of ROS due to altered Noxa1 expression. RNF113A deficiency circumvents the resistance to Cisplatin and to BCL-2 inhibitors through the destabilization of MCL-1, which thus defines spliceosome inhibitors as a therapeutic approach to treat tumors showing acquired resistance to specific drugs due to MCL-1 stabilization. [less ▲]

Detailed reference viewed: 62 (13 ULiège)
See detailProtein synthesis at the speed of codons
Joiret, Marc ULiege; Geris, Liesbet ULiege; Close, Pierre ULiege

Speech/Talk (2020)

Introduction to open boundaries transport model on a 1D lattice and presentation of the totally asymmetric simple exclusion process and its application to protein synthesis modeling.

Detailed reference viewed: 47 (3 ULiège)
Full Text
Peer Reviewed
See detailmRNA translation rate modeling with an extended TASEP incorporating tRNAs modifications
Joiret, Marc ULiege; Rapino, Francesca ULiege; Close, Pierre ULiege et al

Poster (2019, September 05)

Translational regulation through synonymous codon usage has been recently shown to play an important role in health and disease. Modified tRNAs are important actors involved in regulating protein ... [more ▼]

Translational regulation through synonymous codon usage has been recently shown to play an important role in health and disease. Modified tRNAs are important actors involved in regulating protein expression levels by optimizing the decoding of differentially used codons, nevertheless their contribution in protein synthesis dynamics remain unclear. Totally Asymmetric Simple Exclusion Process (TASEP) models have been used to quantify the transcripts translation rate by ribosomes. Our work aims at extending TASEP modeling to accommodate for tRNA modifications effects. We generated a computational stochastic model quantifying protein synthesis rates. The algorithm uses ribosome residence time per codon from transcripts codons sequences, relative transcripts abundance and tables of (modified or not) tRNA relative abundance. Important features in the model include the elongation rate variation caused by charged amino-acids in the ribosomal exit tunnel, proline ring opening delay at the peptide transfer center and optionally transcript secondary structure slow down effects. The model allows to compare relative protein expression levels as well as RiboSeq profiles in different scenarios with a controllable pool of ribosomes. We intend to use our model to help understand how codon usage and tRNA modifications dynamically interact and impact on protein synthesis. [less ▲]

Detailed reference viewed: 123 (19 ULiège)
Peer Reviewed
See detailmRNA specific translation in resistant melanoma
El Hachem, Najla ULiege; Close, Pierre ULiege

Poster (2019, September)

Detailed reference viewed: 42 (6 ULiège)
Full Text
Peer Reviewed
See detailTranslational offsetting as a mode of estrogen receptor α-dependent regulation of gene expression
Lorent, J.; Kusnadi, E. P.; van Hoef, V. et al

in EMBO Journal (2019)

Estrogen receptor alpha (ERα) activity is associated with increased cancer cell proliferation. Studies aiming to understand the impact of ERα on cancer-associated phenotypes have largely been limited to ... [more ▼]

Estrogen receptor alpha (ERα) activity is associated with increased cancer cell proliferation. Studies aiming to understand the impact of ERα on cancer-associated phenotypes have largely been limited to its transcriptional activity. Herein, we demonstrate that ERα coordinates its transcriptional output with selective modulation of mRNA translation. Importantly, translational perturbations caused by depletion of ERα largely manifest as “translational offsetting” of the transcriptome, whereby amounts of translated mRNAs and corresponding protein levels are maintained constant despite changes in mRNA abundance. Transcripts whose levels, but not polysome association, are reduced following ERα depletion lack features which limit translation efficiency including structured 5′UTRs and miRNA target sites. In contrast, mRNAs induced upon ERα depletion whose polysome association remains unaltered are enriched in codons requiring U34-modified tRNAs for efficient decoding. Consistently, ERα regulates levels of U34-modifying enzymes and thereby controls levels of U34-modified tRNAs. These findings unravel a hitherto unprecedented mechanism of ERα-dependent orchestration of transcriptional and translational programs that may be a pervasive mechanism of proteome maintenance in hormone-dependent cancers. © 2019 The Authors [less ▲]

Detailed reference viewed: 55 (3 ULiège)
Full Text
Peer Reviewed
See detailWobble uridine tRNA modification: a new vulnerability of refractory melanoma
Rapino, Francesca ULiege; Close, Pierre ULiege

in Molecular and Cellular Oncology (2018)

Detailed reference viewed: 61 (10 ULiège)
Full Text
Peer Reviewed
See detailCodon-specific translation reprogramming promotes resistance to targeted therapy
Rapino, Francesca ULiege; Delaunay, Sylvain ULiege; Rambow, Florian et al

in Nature (2018), 558

Reprogramming of mRNA translation has a key role in cancer development and drug resistance. However, the molecular mechanisms that are involved in this process remain poorly understood. Wobble tRNA ... [more ▼]

Reprogramming of mRNA translation has a key role in cancer development and drug resistance. However, the molecular mechanisms that are involved in this process remain poorly understood. Wobble tRNA modifications are required for specific codon decoding during translation. Here we show, in humans, that the enzymes that catalyse modifications of wobble uridine 34 (U34) tRNA (U34 enzymes) are key players of the protein synthesis rewiring that is induced by the transformation driven by the BRAFV600E oncogene and by resistance to targeted therapy in melanoma. We show that BRAFV600E-expressing melanoma cells are dependent on U34 enzymes for survival, and that concurrent inhibition of MAPK signalling and ELP3 or CTU1 and/or CTU2 synergizes to kill melanoma cells. Activation of the PI3K signalling pathway, one of the most common mechanisms of acquired resistance to MAPK therapeutic agents, markedly increases the expression of U34 enzymes. Mechanistically, U34 enzymes promote glycolysis in melanoma cells through the direct, codon-dependent, regulation of the translation of HIF1A mRNA and the maintenance of high levels of HIF1α protein. Therefore, the acquired resistance to anti-BRAF therapy is associated with high levels of U34 enzymes and HIF1α. Together, these results demonstrate that U34 enzymes promote the survival and resistance to therapy of melanoma cells by regulating specific mRNA translation. [less ▲]

Detailed reference viewed: 267 (82 ULiège)
Full Text
Peer Reviewed
See detailThe endosomal protein CEMIP links Wnt signaling to MEK1-ERK1/2 activation in Selumetinib-resistant intestinal organoids
Duong, Hong Quan ULiege; Nemazanyy, Ivan; Rambow, Florian et al

in Cancer Research (2018)

MAPK signaling pathways are constitutively active in colon cancer and also promote acquired resistance to MEK1 inhibition. Here we demonstrate that BRAFV600E-mutated colorectal cancers acquire resistance ... [more ▼]

MAPK signaling pathways are constitutively active in colon cancer and also promote acquired resistance to MEK1 inhibition. Here we demonstrate that BRAFV600E-mutated colorectal cancers acquire resistance to MEK1 inhibition by inducing expression of the scaffold protein CEMIP through a beta-catenin- and FRA-1-dependent pathway. CEMIP was found in endosomes and bound MEK1 to sustain ERK1/2 activation in MEK1 inhibitor-resistant BRAFV600E-mutated colorectal cancers. The CEMIP-dependent pathway maintained c-Myc protein levels through ERK1/2 and provided metabolic advantage in resistant cells, potentially by sustaining amino acids synthesis. CEMIP silencing circumvented resistance to MEK1 inhibition, partly, through a decrease of both ERK1/2 signaling and c-Myc. Together, our data identify a cross-talk between Wnt and MAPK signaling cascades, which involves CEMIP. Activation of this pathway promotes survival by potentially regulating levels of specific amino acids via a Myc-associated cascade. Targeting this node may provide a promising avenue for treatment of colon cancers that have acquired resistance to targeted therapies [less ▲]

Detailed reference viewed: 61 (11 ULiège)
Full Text
Peer Reviewed
See detailDynamic regulation of tRNA modifications in Cancer
Close, Pierre ULiege; Debojit, Bose; Chariot, Alain ULiege et al

in Translational Epigenetics (2018)

Transfer RNAs are decorated by chemical modifications of their nucleosides. These modifications affect all aspects of tRNA biology including translation and tRNA turnover. Interestingly, it was discovered ... [more ▼]

Transfer RNAs are decorated by chemical modifications of their nucleosides. These modifications affect all aspects of tRNA biology including translation and tRNA turnover. Interestingly, it was discovered decades ago that levels of modified tRNA nucleosides are changed in cancer patients and that the activity of modifying enzymes varies along with an altered turnover of tRNAs. The advent of new methods has sparked a new interest in this connection. Here, we give an overview on what is known about the link between tRNA modifications and cancer and how dynamic alterations in this fundamental cellular phenomenon may contribute to the malignancy of tumors. [less ▲]

Detailed reference viewed: 31 (3 ULiège)
Full Text
See detailLoss of transfer RNA U34 modifying enzymes impairs hematopoietic stem and progenitor cell differentiation and function
Rosu, Adeline ULiege; Bai, Qiang ULiege; Ramery, Eve ULiege et al

Poster (2017, February 03)

Hematopoietic stem and progenitor cells (HSPCs) require fine-tuned protein translation for their normal maintenance and function. Conserved modifications of the wobble uridine base (U34) in transfer RNAs ... [more ▼]

Hematopoietic stem and progenitor cells (HSPCs) require fine-tuned protein translation for their normal maintenance and function. Conserved modifications of the wobble uridine base (U34) in transfer RNAs catalyzed by the Elongator complex are required for optimal protein translation efficacy and fidelity, but their biological importance in mammalian stem and progenitor cells remains largely unexplored. Here, we studied the impact of loss of activity of the catalytic subunit Elp3 of Elongator on HSPC differentiation and function. Hematopoietic-cell-specific depletion of Elp3 in conditional knockout mice resulted in shortened lifespan associated with hematopoietic failure and lymphoma development. Elp3 deletion caused apoptosis of specific bone marrow multipotent progenitors and blocked differentiation of committed progenitors, resulting in blood and bone marrow pancytopenia. In contrast, Elp3-deficient hematopoietic stem cells (HSCs) expanded with age and did not exhaust throughout life, although they were defective in reconstituting hematopoiesis in competitive transplantation assays. Mechanistically, loss of Elp3 did not result in detectable alterations in global protein synthesis rates in any HSPC subset. Rather, Elp3-deficient HSPCs displayed enhanced activity of the stress integrator and apoptosis and cell cycle regulator p53. Thus, this study supports the notion that Elongator activity is required in distinct HSPC subsets to avoid aberrant p53 activation, which otherwise results in discrete loss of function phenotypes in HSCs and downstream progenitors. [less ▲]

Detailed reference viewed: 123 (20 ULiège)
Full Text
Peer Reviewed
See detailLoss of Elp3 Impairs the Acetylation and Distribution of Connexin-43 in the Developing Cerebral Cortex.
Laguesse, Sophie ULiege; Close, Pierre ULiege; Van Hees, Laura ULiege et al

in Frontiers in Cellular Neuroscience (2017), 11

The Elongator complex is required for proper development of the cerebral cortex. Interfering with its activity in vivo delays the migration of postmitotic projection neurons, at least through a defective ... [more ▼]

The Elongator complex is required for proper development of the cerebral cortex. Interfering with its activity in vivo delays the migration of postmitotic projection neurons, at least through a defective alpha-tubulin acetylation. However, this complex is already expressed by cortical progenitors where it may regulate the early steps of migration by targeting additional proteins. Here we report that connexin-43 (Cx43), which is strongly expressed by cortical progenitors and whose depletion impairs projection neuron migration, requires Elongator expression for its proper acetylation. Indeed, we show that Cx43 acetylation is reduced in the cortex of Elp3cKO embryos, as well as in a neuroblastoma cell line depleted of Elp1 expression, suggesting that Cx43 acetylation requires Elongator in different cellular contexts. Moreover, we show that histones deacetylase 6 (HDAC6) is a deacetylase of Cx43. Finally, we report that acetylation of Cx43 regulates its membrane distribution in apical progenitors of the cerebral cortex. [less ▲]

Detailed reference viewed: 76 (26 ULiège)
Full Text
Peer Reviewed
See detailtRNA modification: is cancer having a wobble?
Rapino, Francesca ULiege; Zhou, Zhaoli ULiege; Delaunay, Sylvain ULiege et al

in Trends in Cancer (2017), 3

Translational control of protein synthesis supports tumor development and progression to metastasis. Wobble tRNA modifications are required during translation elongation and sustain proteome homeostasis ... [more ▼]

Translational control of protein synthesis supports tumor development and progression to metastasis. Wobble tRNA modifications are required during translation elongation and sustain proteome homeostasis. Recent work has highlighted the surprising upregulation of the wobble uridine 34 (U34) tRNA cascade in cancer, which underlies the specific requirement for this pathway in tumor development. [less ▲]

Detailed reference viewed: 137 (33 ULiège)
Full Text
Peer Reviewed
See detailELP3 links tRNA modification to IRES-dependent translation of LEF-1 to promote metastasis in breast cancer
Delaunay, Sylvain ULiege; Rapino, Francesca ULiege; Tharun, Lars et al

in Journal of Experimental Medicine (2016), 213

Quantitative and qualitative changes in mRNA translation occur in tumor cells and support cancer progression and metastasis. Post-transcriptional nucleoside modifications of transfer RNAs (tRNAs) at the ... [more ▼]

Quantitative and qualitative changes in mRNA translation occur in tumor cells and support cancer progression and metastasis. Post-transcriptional nucleoside modifications of transfer RNAs (tRNAs) at the wobble U34 base are highly conserved and contribute to translation fidelity. Here, we show that ELP3 and CTU1/2, partner enzymes in U34 mcm5s2-tRNA modification, are upregulated in human breast cancers and sustain metastasis. Elp3 genetic ablation strongly impaired invasion and metastasis formation in the PyMT model of invasive breast cancer. Mechanistically, ELP3 and CTU1/2 support cellular invasion through the translation of the oncoprotein DEK. As a result, DEK promotes the IRES-dependent translation of the pro-invasive transcription factor LEF1. Consistently, a DEK mutant, whose codon composition is independent of U34 mcm5s2-tRNA modification, escapes the ELP3- and CTU1-dependent regulation and restores the IRES-dependent LEF1 expression. Our results demonstrate the key role of U34 tRNA modification to support specific translation during breast cancer progression and highlight a functional link between tRNA modification- and IRES-dependent translation during tumor cell invasion and metastasis. [less ▲]

Detailed reference viewed: 125 (31 ULiège)
See detailtRNA modification: Elogator sustains Breast cancer metastasis
Delaunay, Sylvain ULiege; Rapino, Francesca ULiege; Tharun, Lars et al

Conference (2016, May)

Detailed reference viewed: 76 (11 ULiège)
Peer Reviewed
See detailtRNA modification: Elogator promotes metastasis in breast cancer
Delaunay, Sylvain ULiege; Rapino, Francesca ULiege; Zhou, Zhaoli ULiege et al

Conference (2016, January 25)

Quantitative and qualitative changes in mRNA translation occur in tumor cells and support cancer progression and metastasis. Post-transcriptional nucleoside modifications of transfer RNAs (tRNAs) at the ... [more ▼]

Quantitative and qualitative changes in mRNA translation occur in tumor cells and support cancer progression and metastasis. Post-transcriptional nucleoside modifications of transfer RNAs (tRNAs) at the wobble U34 base are highly conserved and contribute to translation fidelity. Here, we show that ELP3 and CTU1/2, partner enzymes in U34 mcm5s2-tRNA modification, are upregulated in human breast cancers and sustain metastasis. Elp3 genetic ablation strongly impaired invasion and metastasis formation in the PyMT model of invasive breast cancer. Mechanistically, ELP3 and CTU1/2 support cellular invasion through the translation of the oncoprotein DEK. As a result, DEK promotes the IRES-dependent translation of the pro-invasive transcription factor LEF1. Consistently, a DEK mutant, whose codon composition is independent of U34 mcm5s2-tRNA modification, escapes the ELP3- and CTU1- dependent regulation and restores the IRES-dependent LEF1 expression. Our results demonstrate the key role of U34 tRNA modification to support specific translation during breast cancer progression and highlight a functional link between tRNA modification- and IRES-dependent translation during tumor cell invasion and metastasis. [less ▲]

Detailed reference viewed: 90 (16 ULiège)