Signalisation, développement et tumeurs cérébrales

Publications de l’équipe

Année de publication : 2020

Jamie Zagozewski, Ghazaleh M Shahriary, Ludivine Coudière Morrison, Olivier Saulnier, Margaret Stromecki, Agnes Fresnoza, Gareth Palidwor, Christopher J Porter, Antoine Forget, Olivier Ayrault, Cynthia Hawkins, Jennifer A Chan, Maria C Vladoiu, Lakshmikirupa Sundaresan, Janilyn Arsenio, Michael D Taylor, Vijay Ramaswamy, Tamra E Werbowetski-Ogilvie (2020 Jul 21)

An OTX2-PAX3 signaling axis regulates Group 3 medulloblastoma cell fate.

Nature communications : 3627 : DOI : 10.1038/s41467-020-17357-4 En savoir plus
Résumé

OTX2 is a potent oncogene that promotes tumor growth in Group 3 medulloblastoma. However, the mechanisms by which OTX2 represses neural differentiation are not well characterized. Here, we perform extensive multiomic analyses to identify an OTX2 regulatory network that controls Group 3 medulloblastoma cell fate. OTX2 silencing modulates the repressive chromatin landscape, decreases levels of PRC2 complex genes and increases the expression of neurodevelopmental transcription factors including PAX3 and PAX6. Expression of PAX3 and PAX6 is significantly lower in Group 3 medulloblastoma patients and is correlated with reduced survival, yet only PAX3 inhibits self-renewal in vitro and increases survival in vivo. Single cell RNA sequencing of Group 3 medulloblastoma tumorspheres demonstrates expression of an undifferentiated progenitor program observed in primary tumors and characterized by translation/elongation factor genes. Identification of mTORC1 signaling as a downstream effector of OTX2-PAX3 reveals roles for protein synthesis pathways in regulating Group 3 medulloblastoma pathogenesis.

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Sebastian M Waszak, Giles W Robinson, Brian L Gudenas, Kyle S Smith, Antoine Forget, Marija Kojic, Jesus Garcia-Lopez, Jennifer Hadley, Kayla V Hamilton, Emilie Indersie, Ivo Buchhalter, Jules Kerssemakers, Natalie Jäger, Tanvi Sharma, Tobias Rausch, Marcel Kool, Dominik Sturm, David T W Jones, Aksana Vasilyeva, Ruth G Tatevossian, Geoffrey Neale, Bérangère Lombard, Damarys Loew, Joy Nakitandwe, Michael Rusch, Daniel C Bowers, Anne Bendel, Sonia Partap, Murali Chintagumpala, John Crawford, Nicholas G Gottardo, Amy Smith, Christelle Dufour, Stefan Rutkowski, Tone Eggen, Finn Wesenberg, Kristina Kjaerheim, Maria Feychting, Birgitta Lannering, Joachim Schüz, Christoffer Johansen, Tina V Andersen, Martin Röösli, Claudia E Kuehni, Michael Grotzer, Marc Remke, Stéphanie Puget, Kristian W Pajtler, Till Milde, Olaf Witt, Marina Ryzhova, Andrey Korshunov, Brent A Orr, David W Ellison, Laurence Brugieres, Peter Lichter, Kim E Nichols, Amar Gajjar, Brandon J Wainwright, Olivier Ayrault, Jan O Korbel, Paul A Northcott, Stefan M Pfister (2020 Apr 17)

Germline Elongator mutations in Sonic Hedgehog medulloblastoma.

Nature : 396-401 : DOI : 10.1038/s41586-020-2164-5 En savoir plus
Résumé

Cancer genomics has revealed many genes and core molecular processes that contribute to human malignancies, but the genetic and molecular bases of many rare cancers remains unclear. Genetic predisposition accounts for 5 to 10% of cancer diagnoses in children, and genetic events that cooperate with known somatic driver events are poorly understood. Pathogenic germline variants in established cancer predisposition genes have been recently identified in 5% of patients with the malignant brain tumour medulloblastoma. Here, by analysing all protein-coding genes, we identify and replicate rare germline loss-of-function variants across ELP1 in 14% of paediatric patients with the medulloblastoma subgroup Sonic Hedgehog (MB) ELP1 was the most common medulloblastoma predisposition gene and increased the prevalence of genetic predisposition to 40% among paediatric patients with MB. Parent-offspring and pedigree analyses identified two families with a history of paediatric medulloblastoma. ELP1-associated medulloblastomas were restricted to the molecular SHHα subtype and characterized by universal biallelic inactivation of ELP1 owing to somatic loss of chromosome arm 9q. Most ELP1-associated medulloblastomas also exhibited somatic alterations in PTCH1, which suggests that germline ELP1 loss-of-function variants predispose individuals to tumour development in combination with constitutive activation of SHH signalling. ELP1 is the largest subunit of the evolutionarily conserved Elongator complex, which catalyses translational elongation through tRNA modifications at the wobble (U) position. Tumours from patients with ELP1-associated MB were characterized by a destabilized Elongator complex, loss of Elongator-dependent tRNA modifications, codon-dependent translational reprogramming, and induction of the unfolded protein response, consistent with loss of protein homeostasis due to Elongator deficiency in model systems. Thus, genetic predisposition to proteome instability may be a determinant in the pathogenesis of paediatric brain cancers. These results support investigation of the role of protein homeostasis in other cancer types and potential for therapeutic interference.

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Samuel Cheshier, Michael D Taylor, Olivier Ayrault, Sabine Mueller (2020 Jan 3)

Introduction. Pediatric brain tumor.

Neurosurgical focus : E1 : DOI : 10.3171/2019.10.FOCUS19799 En savoir plus
Résumé

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Année de publication : 2019

Volker Hovestadt, Olivier Ayrault, Fredrik J Swartling, Giles W Robinson, Stefan M Pfister, Paul A Northcott (2019 Dec 11)

Medulloblastomics revisited: biological and clinical insights from thousands of patients.

Nature reviews. Cancer : 42-56 : DOI : 10.1038/s41568-019-0223-8 En savoir plus
Résumé

Medulloblastoma, a malignant brain tumour primarily diagnosed during childhood, has recently been the focus of intensive molecular profiling efforts, profoundly advancing our understanding of biologically and clinically heterogeneous disease subgroups. Genomic, epigenomic, transcriptomic and proteomic landscapes have now been mapped for an unprecedented number of bulk samples from patients with medulloblastoma and, more recently, for single medulloblastoma cells. These efforts have provided pivotal new insights into the diverse molecular mechanisms presumed to drive tumour initiation, maintenance and recurrence across individual subgroups and subtypes. Translational opportunities stemming from this knowledge are continuing to evolve, providing a framework for improved diagnostic and therapeutic interventions. In this Review, we summarize recent advances derived from this continued molecular characterization of medulloblastoma and contextualize this progress towards the deployment of more effective, molecularly informed treatments for affected patients.

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Hiromichi Suzuki, Sachin A Kumar, Shimin Shuai, Ander Diaz-Navarro, Ana Gutierrez-Fernandez, Pasqualino De Antonellis, Florence M G Cavalli, Kyle Juraschka, Hamza Farooq, Ichiyo Shibahara, Maria C Vladoiu, Jiao Zhang, Namal Abeysundara, David Przelicki, Patryk Skowron, Nicole Gauer, Betty Luu, Craig Daniels, Xiaochong Wu, Antoine Forget, Ali Momin, Jun Wang, Weifan Dong, Seung-Ki Kim, Wieslawa A Grajkowska, Anne Jouvet, Michelle Fèvre-Montange, Maria Luisa Garrè, Amulya A Nageswara Rao, Caterina Giannini, Johan M Kros, Pim J French, Nada Jabado, Ho-Keung Ng, Wai Sang Poon, Charles G Eberhart, Ian F Pollack, James M Olson, William A Weiss, Toshihiro Kumabe, Enrique López-Aguilar, Boleslaw Lach, Maura Massimino, Erwin G Van Meir, Joshua B Rubin, Rajeev Vibhakar, Lola B Chambless, Noriyuki Kijima, Almos Klekner, László Bognár, Jennifer A Chan, Claudia C Faria, Jiannis Ragoussis, Stefan M Pfister, Anna Goldenberg, Robert J Wechsler-Reya, Swneke D Bailey, Livia Garzia, A Sorana Morrissy, Marco A Marra, Xi Huang, David Malkin, Olivier Ayrault, Vijay Ramaswamy, Xose S Puente, John A Calarco, Lincoln Stein, Michael D Taylor (2019 Oct 31)

Recurrent noncoding U1 snRNA mutations drive cryptic splicing in SHH medulloblastoma.

Nature : 707-711 : DOI : 10.1038/s41586-019-1650-0 En savoir plus
Résumé

In cancer, recurrent somatic single-nucleotide variants-which are rare in most paediatric cancers-are confined largely to protein-coding genes. Here we report highly recurrent hotspot mutations (r.3A>G) of U1 spliceosomal small nuclear RNAs (snRNAs) in about 50% of Sonic hedgehog (SHH) medulloblastomas. These mutations were not present across other subgroups of medulloblastoma, and we identified these hotspot mutations in U1 snRNA in only <0.1% of 2,442 cancers, across 36 other tumour types. The mutations occur in 97% of adults (subtype SHHδ) and 25% of adolescents (subtype SHHα) with SHH medulloblastoma, but are largely absent from SHH medulloblastoma in infants. The U1 snRNA mutations occur in the 5' splice-site binding region, and snRNA-mutant tumours have significantly disrupted RNA splicing and an excess of 5' cryptic splicing events. Alternative splicing mediated by mutant U1 snRNA inactivates tumour-suppressor genes (PTCH1) and activates oncogenes (GLI2 and CCND2), and represents a target for therapy. These U1 snRNA mutations provide an example of highly recurrent and tissue-specific mutations of a non-protein-coding gene in cancer.

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Francesca Bufalieri, Paola Infante, Flavia Bernardi, Miriam Caimano, Paolo Romania, Marta Moretti, Ludovica Lospinoso Severini, Julie Talbot, Ombretta Melaiu, Mirella Tanori, Laura Di Magno, Diana Bellavia, Carlo Capalbo, Stéphanie Puget, Enrico De Smaele, Gianluca Canettieri, Daniele Guardavaccaro, Luca Busino, Angelo Peschiaroli, Simonetta Pazzaglia, Giuseppe Giannini, Gerry Melino, Franco Locatelli, Alberto Gulino, Olivier Ayrault, Doriana Fruci, Lucia Di Marcotullio (2019 Jul 26)

ERAP1 promotes Hedgehog-dependent tumorigenesis by controlling USP47-mediated degradation of βTrCP.

Nature communications : 3304 : DOI : 10.1038/s41467-019-11093-0 En savoir plus
Résumé

The Hedgehog (Hh) pathway is essential for embryonic development and tissue homeostasis. Aberrant Hh signaling may occur in a wide range of human cancers, such as medulloblastoma, the most common brain malignancy in childhood. Here, we identify endoplasmic reticulum aminopeptidase 1 (ERAP1), a key regulator of innate and adaptive antitumor immune responses, as a previously unknown player in the Hh signaling pathway. We demonstrate that ERAP1 binds the deubiquitylase enzyme USP47, displaces the USP47-associated βTrCP, the substrate-receptor subunit of the SCF ubiquitin ligase, and promotes βTrCP degradation. These events result in the modulation of Gli transcription factors, the final effectors of the Hh pathway, and the enhancement of Hh activity. Remarkably, genetic or pharmacological inhibition of ERAP1 suppresses Hh-dependent tumor growth in vitro and in vivo. Our findings unveil an unexpected role for ERAP1 in cancer and indicate ERAP1 as a promising therapeutic target for Hh-driven tumors.

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Maud Blanluet, Julien Masliah-Planchon, Irina Giurgea, Franck Bielle, Elodie Girard, Mamy Andrianteranagna, Stéphane Clemenceau, Christine Bourneix, Lydie Burglen, Diane Doummar, Audrey Rapinat, Badreddine Mohand Oumoussa, Olivier Ayrault, Celio Pouponnot, David Gentien, Gaëlle Pierron, Olivier Delattre, François Doz, Franck Bourdeaut (2019 Mar 9)

SHH medulloblastoma in a young adult with a TCF4 germline pathogenic variation.

Acta neuropathologica : DOI : 10.1007/s00401-019-01983-4 En savoir plus
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Laura Duciel, Océane Anezo, Kalpana Mandal, Cécile Laurent, Nathalie Planque, Frédéric M Coquelle, David Gentien, Jean-Baptiste Manneville, Simon Saule (2019 Mar 1)

Protein tyrosine phosphatase 4A3 (PTP4A3/PRL-3) promotes the aggressiveness of human uveal melanoma through dephosphorylation of CRMP2.

Scientific reports : 2990 : DOI : 10.1038/s41598-019-39643-y En savoir plus
Résumé

Uveal melanoma (UM) is an aggressive tumor in which approximately 50% of patients develop metastasis. Expression of the PTP4A3 gene, encoding a phosphatase, is predictive of poor patient survival. PTP4A3 expression in UM cells increases their migration in vitro and invasiveness in vivo. Here, we show that CRMP2 is mostly dephosphorylated on T514 in PTP4A3 expressing cells. We also demonstrate that inhibition of CRMP2 expression in UM cells expressing PTP4A3 increases their migration in vitro and invasiveness in vivo. This phenotype is accompanied by modifications of the actin microfilament network, with shortened filaments, whereas cells with a inactive mutant of the phosphatase do not show the same behavior. In addition, we showed that the cell cytoplasm becomes stiffer when CRMP2 is downregulated or PTP4A3 is expressed. Our results suggest that PTP4A3 acts upstream of CRMP2 in UM cells to enhance their migration and invasiveness and that a low level of CRMP2 in tumors is predictive of poor patient survival.

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Chia-Hsiang Chang, Marco Zanini, Hamasseh Shirvani, Jia-Shing Cheng, Hua Yu, Chih-Hsin Feng, Audrey L Mercier, Shiue-Yu Hung, Antoine Forget, Chun-Hung Wang, Sara Maria Cigna, I-Ling Lu, Wei-Yi Chen, Sophie Leboucher, Won-Jing Wang, Martial Ruat, Nathalie Spassky, Jin-Wu Tsai, Olivier Ayrault (2019 Jan 30)

Atoh1 Controls Primary Cilia Formation to Allow for SHH-Triggered Granule Neuron Progenitor Proliferation.

Developmental cell : 184-199.e5 : DOI : S1534-5807(18)31085-2 En savoir plus
Résumé

During cerebellar development, granule neuron progenitors (GNPs) proliferate by transducing Sonic Hedgehog (SHH) signaling via the primary cilium. Precise regulation of ciliogenesis, thus, ensures proper GNP pool expansion. Here, we report that Atoh1, a transcription factor required for GNPs formation, controls the presence of primary cilia, maintaining GNPs responsiveness to SHH. Loss of primary cilia abolishes the ability of Atoh1 to keep GNPs in a proliferative state. Mechanistically, Atoh1 promotes ciliogenesis by transcriptionally regulating Cep131, which facilitates centriolar satellite (CS) clustering to the basal body. Importantly, ectopic expression of Cep131 counteracts the effects of Atoh1 loss in GNPs by restoring proper localization of CS and ciliogenesis. This Atoh1-CS-primary cilium-SHH pro-proliferative pathway is also conserved in SHH-type medulloblastoma, a pediatric brain tumor arising from the GNPs. Together, our data reveal how Atoh1 modulates the primary cilium to regulate GNPs development.

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Année de publication : 2018

Arthur T Molines, Jessica Marion, Salem Chabout, Laetitia Besse, Jim P Dompierre, Grégory Mouille, Frédéric M Coquelle (2018 Jun 28)

EB1 contributes to microtubule bundling and organization, along with root growth, in Arabidopsis thaliana.

Biology open : DOI : bio030510 En savoir plus
Résumé

Microtubules are involved in plant development and adaptation to their environment, but the sustaining molecular mechanisms remain elusive. Microtubule-end-binding 1 (EB1) proteins participate in directional root growth in However, a connection to the underlying microtubule array has not been established yet. We show here that EB1 proteins contribute to the organization of cortical microtubules in growing epidermal plant cells, without significant modulation of microtubule dynamics. Using super-resolution stimulated emission depletion (STED) microscopy and an original quantification approach, we also demonstrate a significant reduction of apparent microtubule bundling in cytoplasmic-EB1-deficient plants, suggesting a function for EB1 in the interaction between adjacent microtubules. Furthermore, we observed root growth defects in EB1-deficient plants, which are not related to cell division impairment. Altogether, our results support a role for EB1 proteins in root development, in part by maintaining the organization of cortical microtubules.This article has an associated First Person interview with the first author of the paper.

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Alexandra Garancher, Charles Y Lin, Morgane Morabito, Wilfrid Richer, Nathalie Rocques, Magalie Larcher, Laure Bihannic, Kyle Smith, Catherine Miquel, Sophie Leboucher, Nirmitha I Herath, Fanny Dupuy, Pascale Varlet, Christine Haberler, Christine Walczak, Nadine El Tayara, Andreas Volk, Stéphanie Puget, François Doz, Olivier Delattre, Sabine Druillennec, Olivier Ayrault, Robert J Wechsler-Reya, Alain Eychène, Franck Bourdeaut, Paul A Northcott, Celio Pouponnot (2018 Mar 14)

NRL and CRX Define Photoreceptor Identity and Reveal Subgroup-Specific Dependencies in Medulloblastoma.

Cancer cell : 435-449.e6 : DOI : 10.1016/j.ccell.2018.02.006 En savoir plus
Résumé

Cancer cells often express differentiation programs unrelated to their tissue of origin, although the contribution of these aberrant phenotypes to malignancy is poorly understood. An aggressive subgroup of medulloblastoma, a malignant pediatric brain tumor of the cerebellum, expresses a photoreceptor differentiation program normally expressed in the retina. We establish that two photoreceptor-specific transcription factors, NRL and CRX, are master regulators of this program and are required for tumor maintenance in this subgroup. Beyond photoreceptor lineage genes, we identify BCL-XL as a key transcriptional target of NRL and provide evidence substantiating anti-BCL therapy as a rational treatment opportunity for select MB patients. Our results highlight the utility of studying aberrant differentiation programs in cancer and their potential as selective therapeutic vulnerabilities.

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Selma Maacha, Simon Saule (2018 Mar 12)

Evaluation of Tumor Cell Invasiveness In Vivo: The Chick Chorioallantoic Membrane Assay.

Methods in molecular biology (Clifton, N.J.) : 71-77 : DOI : 10.1007/978-1-4939-7701-7_8 En savoir plus
Résumé

Metastases is largely responsible for the mortality among cancer patients. Metastasis formation is a complex multistep process, which results from the propagation of cancer cells from the primary tumor to distant sites of the body. Research on cancer metastasis aims to understand the mechanisms involved in the spread of cancer cells through the development of in vivo assays that assess cell invasion. Here we describe the use of the chick chorioallantoic membrane to evaluate cancer cell invasiveness in vivo. The chick chorioallantoic membrane assay is based on the detection and quantification of disseminated human tumor cells in the chick embryo femurs by real-time PCR amplification of human Alu sequences.

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Année de publication : 2017

Katie B Grausam, Samuel D R Dooyema, Laure Bihannic, Hasitha Premathilake, A Sorana Morrissy, Antoine Forget, Amanda M Schaefer, Justin H Gundelach, Slobodan Macura, Diane M Maher, Xin Wang, Alex H Heglin, Xijin Ge, Erliang Zeng, Stephanie Puget, Indra Chandrasekar, Kameswaran Surendran, Richard J Bram, Ulrich Schüller, Michael D Talyor, Olivier Ayrault, Haotian Zhao (2017 May 12)

ATOH1 Promotes Leptomeningeal Dissemination and Metastasis of Sonic Hedgehog Subgroup Medulloblastomas.

Cancer research : 3766-3777 : DOI : 10.1158/0008-5472.CAN-16-1836 En savoir plus
Résumé

Medulloblastoma arising from the cerebellum is the most common pediatric brain malignancy, with leptomeningeal metastases often present at diagnosis and recurrence associated with poor clinical outcome. In this study, we used mouse medulloblastoma models to explore the relationship of tumor pathophysiology and dysregulated expression of the NOTCH pathway transcription factor ATOH1, which is present in aggressive medulloblastoma subtypes driven by aberrant Sonic Hedgehog/Patched (SHH/PTCH) signaling. In experiments with conditional ATOH1 mouse mutants crossed tomice, which develop SHH-driven medulloblastoma, animals withtransgene expression developed highly penetrant medulloblastoma at a young age with extensive leptomeningeal disease and metastasis to the spinal cord and brain, resembling xenografts of human SHH medulloblastoma. Metastatic tumors retained abnormal SHH signaling like tumor xenografts. Conversely,expression was detected consistently in recurrent and metastatic SHH medulloblastoma. Chromatin immunoprecipitation sequencing and gene expression profiling identified candidate ATOH1 targets in tumor cells involved in development and tumorigenesis. Among these targets specific to metastatic tumors, there was an enrichment in those implicated in extracellular matrix remodeling activity, cytoskeletal network and interaction with microenvironment, indicating a shift in transcriptomic and epigenomic landscapes during metastasis. Treatment with bone morphogenetic protein or SHH pathway inhibitors decreased tumor cell proliferation and suppressed metastatic tumor growth, respectively. Our work reveals a dynamic ATOH1-driven molecular cascade underlying medulloblastoma metastasis that offers possible therapeutic opportunities..

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Neuerburg A, Friesen O, Zuckermann M, Rajendran V, Gronych J, Ayrault O, Korshunov A, Jones DT, Kool M,Northcott PA, Lichter P, Cortés-Ledesma F, Pfister SM, Liu HK (2017 Mar 20)

Chd7 is indispensable for mammalian brain development through activation of a neuronal differentiation programme.

Nature Communications : 8 : 14758 : DOI : 10.1038/ncomms14758 En savoir plus
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Malika Foy, Océane Anézo, Simon Saule, Nathalie Planque (2017 Mar 13)

PRL-3/PTP4A3 phosphatase regulates integrin β1 in adhesion structures during migration of human ocular melanoma cells.

Experimental cell research : DOI : S0014-4827(17)30117-9 En savoir plus
Résumé

In a previous transcriptomic analysis of 63 ocular melanomas of the uvea, we found that expression of the PRL-3/PTP4A3 gene, encoding a phosphatase that is anchored to the plasma membrane, was associated with the risk of metastasis, and a poor prognosis. We also showed that PRL-3 overexpression in OCM-1 ocular melanoma cells significantly increased cell migration in vitro and invasiveness in vivo, suggesting a direct role for PRL-3 in the metastatic spreading of uveal melanoma. Here, we aimed to identify PRL-3 substrates at the plasma membrane involved in adhesion to the extracellular matrix. We focused on integrin β1, which is the most highly expressed integrin in our cohort of uveal melanomas. We show that preventing PRL-3 anchorage to the plasma membrane i) abolishes PRL-3-induced migration in OCM-1 cells, ii) specifically enhances the spreading of OCM-1 cells overexpressing PRL-3, and iii) favors the maturation of large focal adhesions (FAs) containing integrin β1 on collagen I. Knockdown experiments confirmed integrin β1 involvement in PRL3-induced migration. We identified interactions between PRL-3 and integrin β1, as well as with FAK P-Y397, an auto-activated form of Focal Adhesion Kinase found in FAs. We also show that integrin β1 may be dephosphorylated by PRL-3 in its intracytoplasmic S/T region, an important motif for integrin-mediated cell adhesion. Finally, we observed that PRL-3 regulated the clustering of integrin β1 in FAs on collagen I but not on fibronectin. This work identifies PRL-3 as a new regulator of cell adhesion structures to the extracellular matrix, and further supports PRL-3 as a key actor of metastasis in uveal melanoma, of which molecular mechanisms are still poorly understood.

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