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Duployez N, Chebrek L, Helevaut N, Fournier E, Bemba M, Caillault A, Geffroy S, Preudhomme C. A novel type of NPM1 mutation characterized by multiple internal tandem repeats in a case of cytogenetically normal acute myeloid leukemia. Haematologica 2018; 103:e575-e577. [PMID: 29903763 DOI: 10.3324/haematol.2018.190959] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Nicolas Duployez
- CHU Lille, Laboratory of Hematology .,Univ. Lille, INSERM, UMR-S 1172
| | | | - Nathalie Helevaut
- CHU Lille, Laboratory of Hematology.,Univ. Lille, INSERM, UMR-S 1172
| | - Elise Fournier
- Univ. Lille, INSERM, UMR-S 1172.,CH Dunkerque, Laboratory of Hematology, F-59385
| | - Maxime Bemba
- CH Dunkerque, Hematology Department, F-59385, France
| | | | - Sandrine Geffroy
- CHU Lille, Laboratory of Hematology.,Univ. Lille, INSERM, UMR-S 1172
| | - Claude Preudhomme
- CHU Lille, Laboratory of Hematology.,Univ. Lille, INSERM, UMR-S 1172
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2
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Salson M, Giraud M, Caillault A, Grardel N, Duployez N, Ferret Y, Duez M, Herbert R, Rocher T, Sebda S, Quief S, Villenet C, Figeac M, Preudhomme C. High-throughput sequencing in acute lymphoblastic leukemia: Follow-up of minimal residual disease and emergence of new clones. Leuk Res 2016; 53:1-7. [PMID: 27930944 DOI: 10.1016/j.leukres.2016.11.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 10/28/2016] [Accepted: 11/11/2016] [Indexed: 01/22/2023]
Abstract
Minimal residual disease (MRD) is known to be an independent prognostic factor in patients with acute lymphoblastic leukemia (ALL). High-throughput sequencing (HTS) is currently used in routine practice for the diagnosis and follow-up of patients with hematological neoplasms. In this retrospective study, we examined the role of immunoglobulin/T-cell receptor-based MRD in patients with ALL by HTS analysis of immunoglobulin H and/or T-cell receptor gamma chain loci in bone marrow samples from 11 patients with ALL, at diagnosis and during follow-up. We assessed the clinical feasibility of using combined HTS and bioinformatics analysis with interactive visualization using Vidjil software. We discuss the advantages and drawbacks of HTS for monitoring MRD. HTS gives a more complete insight of the leukemic population than conventional real-time quantitative PCR (qPCR), and allows identification of new emerging clones at each time point of the monitoring. Thus, HTS monitoring of Ig/TR based MRD is expected to improve the management of patients with ALL.
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Affiliation(s)
- Mikaël Salson
- Univ. Lille, CNRS, Centrale Lille, Inria, UMR 9189 - CRIStAL - Centre de Recherche en Informatique Signal et Automatique de Lille, F-59000 Lille, France.
| | - Mathieu Giraud
- Univ. Lille, CNRS, Centrale Lille, Inria, UMR 9189 - CRIStAL - Centre de Recherche en Informatique Signal et Automatique de Lille, F-59000 Lille, France.
| | - Aurélie Caillault
- Univ. Lille, CHU Lille, Department of Hematology, F-59000 Lille, France.
| | - Nathalie Grardel
- Univ. Lille, CHU Lille, Department of Hematology, F-59000 Lille, France.
| | - Nicolas Duployez
- Univ. Lille, CHU Lille, Department of Hematology, F-59000 Lille, France
| | - Yann Ferret
- Univ. Lille, CHU Lille, Department of Hematology, F-59000 Lille, France
| | - Marc Duez
- School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - Ryan Herbert
- Univ. Lille, CNRS, Centrale Lille, Inria, UMR 9189 - CRIStAL - Centre de Recherche en Informatique Signal et Automatique de Lille, F-59000 Lille, France
| | - Tatiana Rocher
- Univ. Lille, CNRS, Centrale Lille, Inria, UMR 9189 - CRIStAL - Centre de Recherche en Informatique Signal et Automatique de Lille, F-59000 Lille, France
| | - Shéhérazade Sebda
- Univ. Lille, Plate-forme de génomique fonctionnelle et structurale, F-59000 Lille, France
| | - Sabine Quief
- Univ. Lille, Plate-forme de génomique fonctionnelle et structurale, F-59000 Lille, France
| | - Céline Villenet
- Univ. Lille, Plate-forme de génomique fonctionnelle et structurale, F-59000 Lille, France
| | - Martin Figeac
- Univ. Lille, Plate-forme de génomique fonctionnelle et structurale, F-59000 Lille, France; Univ. Lille, CHU Lille, Cellule bioinformatique, plateau commun de séquençage, F-59000 Lille, France
| | - Claude Preudhomme
- Univ. Lille, CHU Lille, Department of Hematology, F-59000 Lille, France.
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3
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Ferret Y, Caillault A, Sebda S, Duez M, Grardel N, Duployez N, Villenet C, Figeac M, Preudhomme C, Salson M, Giraud M. Multi-loci diagnosis of acute lymphoblastic leukaemia with high-throughput sequencing and bioinformatics analysis. Br J Haematol 2016; 173:413-20. [PMID: 26898266 DOI: 10.1111/bjh.13981] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 12/21/2015] [Indexed: 12/31/2022]
Abstract
High-throughput sequencing (HTS) is considered a technical revolution that has improved our knowledge of lymphoid and autoimmune diseases, changing our approach to leukaemia both at diagnosis and during follow-up. As part of an immunoglobulin/T cell receptor-based minimal residual disease (MRD) assessment of acute lymphoblastic leukaemia patients, we assessed the performance and feasibility of the replacement of the first steps of the approach based on DNA isolation and Sanger sequencing, using a HTS protocol combined with bioinformatics analysis and visualization using the Vidjil software. We prospectively analysed the diagnostic and relapse samples of 34 paediatric patients, thus identifying 125 leukaemic clones with recombinations on multiple loci (TRG, TRD, IGH and IGK), including Dd2/Dd3 and Intron/KDE rearrangements. Sequencing failures were halved (14% vs. 34%, P = 0.0007), enabling more patients to be monitored. Furthermore, more markers per patient could be monitored, reducing the probability of false negative MRD results. The whole analysis, from sample receipt to clinical validation, was shorter than our current diagnostic protocol, with equal resources. V(D)J recombination was successfully assigned by the software, even for unusual recombinations. This study emphasizes the progress that HTS with adapted bioinformatics tools can bring to the diagnosis of leukaemia patients.
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Affiliation(s)
- Yann Ferret
- Laboratoire d'Hématologie, Centre Hospitalier Régional Universitaire de Lille, Lille, France
| | - Aurélie Caillault
- Laboratoire d'Hématologie, Centre Hospitalier Régional Universitaire de Lille, Lille, France
| | - Shéhérazade Sebda
- Functional and Structural Genomic Platform, Université de Lille, Lille, France
| | - Marc Duez
- School of Social and Community Medicine, University of Bristol, Bristol, UK.,SIRIC ONCOLille, CRIStAL, UMR 9189, Université de Lille, Lille, France
| | - Nathalie Grardel
- Laboratoire d'Hématologie, Centre Hospitalier Régional Universitaire de Lille, Lille, France
| | - Nicolas Duployez
- Laboratoire d'Hématologie, Centre Hospitalier Régional Universitaire de Lille, Lille, France
| | - Céline Villenet
- Functional and Structural Genomic Platform, Université de Lille, Lille, France
| | - Martin Figeac
- Functional and Structural Genomic Platform, Université de Lille, Lille, France
| | - Claude Preudhomme
- Laboratoire d'Hématologie, Centre Hospitalier Régional Universitaire de Lille, Lille, France
| | - Mikaël Salson
- CRIStAL, UMR 9189, CNRS, Université de Lille, Lille, France.,Inria, Lille, France
| | - Mathieu Giraud
- CRIStAL, UMR 9189, CNRS, Université de Lille, Lille, France.,Inria, Lille, France
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Neuzillet Y, Rebouissou S, De Reynies A, Lepage M, Krucker C, Chapeaublanc E, Herault A, Kamoun A, Caillault A, Letouze E, Elarouci N, Decoux Y, Molinie V, Vordos D, Laplanche A, Maille P, Soyeux P, Ofualuka K, Reyal F, Biton A, Sibony M, Paoletti X, Southgate J, Benhamou S, Allory Y, Radvanyi F, Lebret T. L’Epidermal Growth Factor Receptor (EGFR) est une cible thérapeutique pour un sous-groupe de tumeurs de vessie agressives de phénotype de type basal. Prog Urol 2014; 24:806. [DOI: 10.1016/j.purol.2014.08.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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5
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Rebouissou S, Bernard-Pierrot I, de Reynies A, Lepage ML, Krucker C, Chapeaublanc E, Herault A, Kamoun A, Caillault A, Letouze E, Elarouci N, Neuzillet Y, Denoux Y, Molinie V, Vordos D, Laplanche A, Maille P, Soyeux P, Ofualuka K, Reyal F, Biton A, Sibony M, Paoletti X, Southgate J, Benhamou S, Lebret T, Allory Y, Radvanyi F. EGFR as a potential therapeutic target for a subset of muscle-invasive bladder cancers presenting a basal-like phenotype. Sci Transl Med 2014; 6:244ra91. [DOI: 10.1126/scitranslmed.3008970] [Citation(s) in RCA: 237] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Duployez N, Nibourel O, Marceau-Renaut A, Willekens C, Helevaut N, Caillault A, Villenet C, Celli-Lebras K, Boissel N, Jourdan E, Dombret H, Figeac M, Preudhomme C, Renneville A. Minimal residual disease monitoring in t(8;21) acute myeloid leukemia based on RUNX1-RUNX1T1 fusion quantification on genomic DNA. Am J Hematol 2014; 89:610-5. [PMID: 24616160 DOI: 10.1002/ajh.23696] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 02/17/2014] [Accepted: 02/24/2014] [Indexed: 11/10/2022]
Abstract
Although acute myeloid leukemia (AML) with t(8;21) belongs to the favorable risk AML subset, relapse incidence may reach 30% in those patients. RUNX1-RUNX1T1 fusion transcript is a well-established marker for minimal residual disease (MRD) monitoring. In this study, we investigated the feasibility and performances of RUNX1-RUNX1T1 DNA as MRD marker in AML with t(8;21). In 17/22 patients with t(8;21)-positive AML treated in the French CBF-2006 trial, breakpoints in RUNX1 and RUNX1T1 were identified using long-range PCR followed by next-generation sequencing. RUNX1-RUNX1T1 DNA quantification was performed by real-time quantitative PCR using patient-specific primers and probe. MRD levels were evaluated in 71 follow-up samples from 16 patients, with a median of four samples [range 2-7] per patient. RUNX1 breakpoints were located in intron 5 in all cases. RUNX1T1 breakpoints were located in intron 1b in 15 cases and in intron 1a in two cases. RUNX1-RUNX1T1 MRD levels measured on DNA and RNA were strongly correlated (r = 0.8, P < 0.0001). Discordant MRD results were observed in 10/71 (14%) of the samples: in three samples from two patients who relapsed, RUNX1-RUNX1T1 was detectable only on DNA, while RUNX1-RUNX1T1 was detectable only on RNA in seven samples. MRD monitoring on genomic DNA is feasible, but with sensitivity variations depending on the patient breakpoint sequence and the qPCR assay efficiency. Although interpretation of the results is easier because it is closely related to the number of leukemic cells, this method greatly increases time, cost and complexity, which limits its interest in routine practice.
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Affiliation(s)
- Nicolas Duployez
- Laboratory of Hematology; Biology and Pathology Center; Lille France
| | - Olivier Nibourel
- Laboratory of Hematology; Biology and Pathology Center; Lille France
- Inserm U-837, Team 3; Cancer Research Institute; Lille France
| | - Alice Marceau-Renaut
- Laboratory of Hematology; Biology and Pathology Center; Lille France
- Inserm U-837, Team 3; Cancer Research Institute; Lille France
| | | | - Nathalie Helevaut
- Laboratory of Hematology; Biology and Pathology Center; Lille France
| | - Aurélie Caillault
- Laboratory of Hematology; Biology and Pathology Center; Lille France
| | | | | | - Nicolas Boissel
- Department of Adult Hematology; St. Louis Hospital; Paris France
| | - Eric Jourdan
- Department of Hematology and Oncology; Nîmes University Hospital; Nîmes France
| | - Hervé Dombret
- Department of Adult Hematology; St. Louis Hospital; Paris France
| | | | - Claude Preudhomme
- Laboratory of Hematology; Biology and Pathology Center; Lille France
- Inserm U-837, Team 3; Cancer Research Institute; Lille France
| | - Aline Renneville
- Laboratory of Hematology; Biology and Pathology Center; Lille France
- Inserm U-837, Team 3; Cancer Research Institute; Lille France
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7
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Giraud M, Salson M, Duez M, Villenet C, Quief S, Caillault A, Grardel N, Roumier C, Preudhomme C, Figeac M. Fast multiclonal clusterization of V(D)J recombinations from high-throughput sequencing. BMC Genomics 2014; 15:409. [PMID: 24885090 PMCID: PMC4070559 DOI: 10.1186/1471-2164-15-409] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 05/08/2014] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND V(D)J recombinations in lymphocytes are essential for immunological diversity. They are also useful markers of pathologies. In leukemia, they are used to quantify the minimal residual disease during patient follow-up. However, the full breadth of lymphocyte diversity is not fully understood. RESULTS We propose new algorithms that process high-throughput sequencing (HTS) data to extract unnamed V(D)J junctions and gather them into clones for quantification. This analysis is based on a seed heuristic and is fast and scalable because in the first phase, no alignment is performed with germline database sequences. The algorithms were applied to TR γ HTS data from a patient with acute lymphoblastic leukemia, and also on data simulating hypermutations. Our methods identified the main clone, as well as additional clones that were not identified with standard protocols. CONCLUSIONS The proposed algorithms provide new insight into the analysis of high-throughput sequencing data for leukemia, and also to the quantitative assessment of any immunological profile. The methods described here are implemented in a C++ open-source program called Vidjil.
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Affiliation(s)
- Mathieu Giraud
- />Laboratoire d’Informatique Fondamentale de Lille (LIFL, UMR CNRS 8022, Université Lille 1) and Inria Lille – Cité scientifique – Bâtiment M3, 59655 Villeneuve d’Ascq, France
| | - Mikaël Salson
- />Laboratoire d’Informatique Fondamentale de Lille (LIFL, UMR CNRS 8022, Université Lille 1) and Inria Lille – Cité scientifique – Bâtiment M3, 59655 Villeneuve d’Ascq, France
| | - Marc Duez
- />Laboratoire d’Informatique Fondamentale de Lille (LIFL, UMR CNRS 8022, Université Lille 1) and Inria Lille – Cité scientifique – Bâtiment M3, 59655 Villeneuve d’Ascq, France
- />SIRIC OncoLille, Lille, France
| | - Céline Villenet
- />Functional and Structural Genomic Platform, Université Lille 2, IFR 114 Lille, France
| | - Sabine Quief
- />Functional and Structural Genomic Platform, Université Lille 2, IFR 114 Lille, France
- />Lille Institute for Cancer Research (IRCL), Lille, France
| | - Aurélie Caillault
- />Department of Hematology, Biology and Pathology Center, Lille, France
| | - Nathalie Grardel
- />Department of Hematology, Biology and Pathology Center, Lille, France
| | - Christophe Roumier
- />Department of Hematology, Biology and Pathology Center, Lille, France
- />Inserm U-837, Cancer Research Institute, Lille, France
| | - Claude Preudhomme
- />Department of Hematology, Biology and Pathology Center, Lille, France
- />Inserm U-837, Cancer Research Institute, Lille, France
| | - Martin Figeac
- />Functional and Structural Genomic Platform, Université Lille 2, IFR 114 Lille, France
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Dyrskjøt L, Zieger K, Real FX, Malats N, Carrato A, Hurst C, Kotwal S, Knowles M, Malmström PU, de la Torre M, Wester K, Allory Y, Vordos D, Caillault A, Radvanyi F, Hein AMK, Jensen JL, Jensen KME, Marcussen N, Orntoft TF. Gene expression signatures predict outcome in non-muscle-invasive bladder carcinoma: a multicenter validation study. Clin Cancer Res 2007; 13:3545-51. [PMID: 17575217 DOI: 10.1158/1078-0432.ccr-06-2940] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Clinically useful molecular markers predicting the clinical course of patients diagnosed with non-muscle-invasive bladder cancer are needed to improve treatment outcome. Here, we validated four previously reported gene expression signatures for molecular diagnosis of disease stage and carcinoma in situ (CIS) and for predicting disease recurrence and progression. EXPERIMENTAL DESIGN We analyzed tumors from 404 patients diagnosed with bladder cancer in hospitals in Denmark, Sweden, England, Spain, and France using custom microarrays. Molecular classifications were compared with pathologic diagnosis and clinical outcome. RESULTS Classification of disease stage using a 52-gene classifier was found to be highly significantly correlated with pathologic stage (P < 0.001). Furthermore, the classifier added information regarding disease progression of T(a) or T(1) tumors (P < 0.001). The molecular 88-gene progression classifier was highly significantly correlated with progression-free survival (P < 0.001) and cancer-specific survival (P = 0.001). Multivariate Cox regression analysis showed the progression classifier to be an independently significant variable associated with disease progression after adjustment for age, sex, stage, grade, and treatment (hazard ratio, 2.3; P = 0.007). The diagnosis of CIS using a 68-gene classifier showed a highly significant correlation with histopathologic CIS diagnosis (odds ratio, 5.8; P < 0.001) in multivariate logistic regression analysis. CONCLUSION This multicenter validation study confirms in an independent series the clinical utility of molecular classifiers to predict the outcome of patients initially diagnosed with non-muscle-invasive bladder cancer. This information may be useful to better guide patient treatment.
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Affiliation(s)
- Lars Dyrskjøt
- Molecular Diagnostic Laboratory, Department of Clinical Biochemistry, Aarhus University Hospital, Skejby, Denmark
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9
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Bernard-Pierrot I, Brams A, Dunois-Lardé C, Caillault A, Diez de Medina SG, Cappellen D, Graff G, Thiery JP, Chopin D, Ricol D, Radvanyi F. Oncogenic properties of the mutated forms of fibroblast growth factor receptor 3b. Carcinogenesis 2005; 27:740-7. [PMID: 16338952 DOI: 10.1093/carcin/bgi290] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Germinal activating mutations of FGFR3 are responsible for several forms of dwarfism due to the inhibitory effect of FGFR3 on bone growth. Surprisingly, identical somatic activating mutations have been found at the somatic level in tumours: at high frequency in benign epithelial tumours (seborrheic keratosis, urothelial papilloma) and in low-grade, low-stage urothelial carcinomas, and at a lower frequency in other types of urothelial carcinoma, in cervix carcinoma, and in haematological cancer, multiple myeloma. FGFR3 exists as two isoforms, FGFR3b and FGFR3c, differs in ligand specificity and tissue expression. FGFR3b is the main form in epithelial cells and derived tumours, whereas FGFR3c is the main form in mesenchyme-derived cells and multiple myeloma. Several lines of evidence suggest that mutated FGFR3c has transforming properties. Although mutated FGFR3b is mostly found in benign epithelial tumours or carcinomas of low malignant potential, we present evidence here that mutated FGFR3b is oncogenic. All bladder tumours presenting FGFR3 mutations expressed this receptor more strongly than normal urothelium or non-mutated tumours. NIH-3T3 cells transfected with a mutated form of FGFR3b--FGFR3b-S249C, the most common mutation in bladder tumours--presented a spindle-cell morphology, grew in soft agar and gave rise to tumours when xenografted into nude mice. We identified one line of 17 bladder cell lines tested (MGH-U3) that expressed a mutated form of FGFR3b, FGFR3b-Y375C. We showed using siRNA and SU5402, an FGFR inhibitor, that the tumour properties of MGH-U3 depended on mutated receptor activity. Thus, in two different models, mutated FGFR3b presents oncogenic properties.
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Affiliation(s)
- Isabelle Bernard-Pierrot
- UMR 144, CNRS-Institut Curie, 26 rue d'Ulm, 75248 Paris Cedex 05, and INSERM 0337 and Service d'Urologie, Centre Hospitalier Universitaire Henri Mondor, AP-HP, Université Paris XII, 94010 Créteil Cedex, France
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10
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Bernard-Pierrot I, Ricol D, Cassidy A, Graham A, Elvin P, Caillault A, Lair S, Broët P, Thiery JP, Radvanyi F. Inhibition of human bladder tumour cell growth by fibroblast growth factor receptor 2b is independent of its kinase activity. Involvement of the carboxy-terminal region of the receptor. Oncogene 2005; 23:9201-11. [PMID: 15516981 DOI: 10.1038/sj.onc.1208150] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The b isoform of fibroblast growth factor receptor 2, FGFR2b/FGFR2-IIIb/Ksam-IIC1/KGFR, a tyrosine kinase receptor, is expressed in a wide variety of epithelia and is downregulated in several human carcinomas including prostate, salivary and urothelial cell carcinomas. FGFR2b has been shown to inhibit growth in tumour cell lines derived from these carcinomas. Here, we investigated the molecular mechanisms underlying the inhibition of human urothelial carcinoma cell growth following FGFR2b expression. Using a nylon DNA array, we analysed the gene expression profile of the T24 bladder tumour cell line, transfected or not with a construct encoding FGFR2b. The expression of FGFR2b in T24 cells decreased insulin-like growth factor (IGF)-II mRNA levels. This decrease was correlated with a decrease in IGF-II secretion and may have been responsible for the observed inhibition of cell growth because the addition of exogenous IGF-II restored growth rates to normal levels. Using SU5402, an inhibitor of FGFR tyrosine kinase activity, and a kinase dead mutant of the receptor, FGFR2b Y659F/Y660F, we also demonstrated that the growth inhibition and decrease in IGF-II secretion induced by FGFR2b did not require tyrosine kinase activity. Finally, we demonstrated the involvement of the distal carboxy-terminal domain of the receptor in decreasing IGF-II expression and inhibiting T24 cell growth, as Ksam-IIC3, a variant of FGFR2b carrying a short carboxy-terminus, neither downregulated IGF-II nor inhibited cell proliferation. Our data suggest that FGFR2b inhibits the growth of bladder carcinoma cells by reducing IGF-II levels via its carboxy-terminal domain, independent of its tyrosine kinase activity.
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