Diversité et plasticité des tumeurs de l’enfant

Publications de l’équipe

Année de publication : 2013

Franck Bourdeaut, Camille Grison, Claude-Alain Maurage, Annie Laquerriere, Alexandre Vasiljevic, Marie-Bernadette Delisle, Sophie Michalak, Dominique Figarella-Branger, François Doz, Wilfrid Richer, Gaelle Pierron, Catherine Miquel, Olivier Delattre, Jérôme Couturier (2013 Apr 13)

MYC and MYCN amplification can be reliably assessed by aCGH in medulloblastoma.

Cancer genetics : 124-9 : DOI : 10.1016/j.cancergen.2013.02.003 En savoir plus
Résumé

As prognostic factors, MYC and MYCN amplifications are routinely assessed in medulloblastomas. Fluorescence in situ hybridization (FISH) is currently considered as the technique of reference. Recently, array comparative genomic hybridization (aCGH) has been developed as an alternative technique to evaluate genomic abnormalities in other tumor types; however, this technique has not been widely adopted as a replacement for FISH in medulloblastoma. In this study, 34 tumors were screened by both FISH and aCGH. In all cases showing amplification by FISH, aCGH also unambiguously revealed the abnormality. The aCGH technique was also performed on tumors showing no amplification by FISH, and the absence of amplification was confirmed in all cases. Interestingly, one tumor showed a subclonal MYC amplification by FISH. This subclonal amplification was observed in approximately 20% of tumor cells and was clearly evident on aCGH. In conclusion, our analysis confirms that aCGH is as safe as FISH for the detection of MYC/MYCN gene amplification. Given its cost efficiency in comparison to two FISH tests and the global genomic information additionally provided by an aCGH experiment, this reproducible technique can be safely retained as an alternative to FISH for routine investigation of medulloblastoma.

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Franck Bourdeaut, Catherine Miquel, Federico Di Rocco, Camille Grison, Wilfrid Richer, Laurence Brugieres, Gaelle Pierron, Syril James, Genevieve Baujat, Olivier Delattre, Corinne Collet (2013 Jan 18)

Germline mutations in FGF receptors and medulloblastomas.

American journal of medical genetics. Part A : 382-5 : DOI : 10.1002/ajmg.a.35719 En savoir plus
Résumé

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Alex Cazes, Caroline Louis-Brennetot, Pierre Mazot, Florent Dingli, Bérangère Lombard, Valentina Boeva, Romain Daveau, Julie Cappo, Valérie Combaret, Gudrun Schleiermacher, Stéphanie Jouannet, Sandrine Ferrand, Gaëlle Pierron, Emmanuel Barillot, Damarys Loew, Marc Vigny, Olivier Delattre, Isabelle Janoueix-Lerosey (2013 Jan 1)

Characterization of rearrangements involving the ALK gene reveals a novel truncated form associated with tumor aggressiveness in neuroblastoma.

Cancer research : 195-204 : DOI : 10.1158/0008-5472.CAN-12-1242 En savoir plus
Résumé

Activating mutations of the ALK gene have been identified in sporadic and familial cases of neuroblastoma (NB), a cancer of the peripheral nervous system, and are thought to be the primary mechanism of oncogenic activation of this receptor in this pediatric neoplasm. To address the possibility that ALK activation may occur through genomic rearrangements as detected in other cancers, we first took advantage of high-resolution array-comparative genomic hybridization to search for ALK rearrangements in NB samples. Using complementary experiments by capture/paired-end sequencing and FISH experiments, various types of rearrangements were fully characterized, including partial gains or amplifications, in several NB cell lines and primary tumors. In the CLB-Bar cell line, we described a genomic rearrangement associated with an amplification of the ALK locus, leading to the expression of a 170 kDa protein lacking part of the extracellular domain encoded by exons 4 to 11, named ALK(Δ4-11). Analysis of genomic DNA from the tumor at diagnosis and relapse revealed that the ALK gene was amplified at diagnosis but that the rearranged ALK allele was observed at the relapse stage only, suggesting that it may be implicated in tumor aggressiveness. Consistently, oncogenic and tumorigenic properties of the ALK(Δ4-11) variant were shown after stable expression in NIH3T3 cells. Moreover, we documented an increased constitutive kinase activity of this variant, as well as an impaired maturation and retention into intracellular compartments. These results indicate that genomic rearrangements constitute an alternative mechanism to ALK point mutations resulting in receptor activation.

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Année de publication : 2012

Didier Surdez, Magdalena Benetkiewicz, Virginie Perrin, Zhi-Yan Han, Gaëlle Pierron, Stelly Ballet, François Lamoureux, Françoise Rédini, Anne-Valérie Decouvelaere, Estelle Daudigeos-Dubus, Birgit Geoerger, Gonzague de Pinieux, Olivier Delattre, Franck Tirode (2012 Aug 30)

Targeting the EWSR1-FLI1 oncogene-induced protein kinase PKC-β abolishes ewing sarcoma growth.

Cancer research : 4494-503 En savoir plus
Résumé

Ewing sarcoma is a rare but aggressive disease most common in young adults. This cancer is driven by a unique chimeric fusion oncogene but targeted strategies have been elusive. Here we report the identification of the protein kinase PKC-ß (PRKCB) as a disease-specific druggable target for treatment of Ewing sarcoma. We found that transcriptional activation of PRKCB was directly regulated by the chimeric fusion oncogene EWSR1-FLI1 that drives this cancer. PRKCB phosphorylated histone H3T6 to permit global maintenance of H3K4 trimethylation at a variety of gene promoters. PRKCB loss induced apoptosis in vitro and prevented tumor growth in vivo. Gene expression profiling revealed a strong overlap between genes modulated by EWSR1-FLI1 and PRKCB in regulating crucial signaling pathways. Taken together, our findings offer a preclinical proof-of-concept for PRKCB as a promising therapeutic target in Ewing sarcoma.

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Pierre Mazot, Alex Cazes, Florent Dingli, Joffrey Degoutin, Théano Irinopoulou, Marie-Claude Boutterin, Bérangère Lombard, Damarys Loew, Bengt Hallberg, Ruth Helen Palmer, Olivier Delattre, Isabelle Janoueix-Lerosey, Marc Vigny (2012 Apr 6)

Internalization and down-regulation of the ALK receptor in neuroblastoma cell lines upon monoclonal antibodies treatment.

PloS one : e33581 : DOI : 10.1371/journal.pone.0033581 En savoir plus
Résumé

Recently, activating mutations of the full length ALK receptor, with two hot spots at positions F1174 and R1275, have been characterized in sporadic cases of neuroblastoma. Here, we report similar basal patterns of ALK phosphorylation between the neuroblastoma IMR-32 cell line, which expresses only the wild-type receptor (ALK(WT)), and the SH-SY5Y cell line, which exhibits a heterozygous ALK F1174L mutation and expresses both ALK(WT) and ALK(F1174L) receptors. We demonstrate that this lack of detectable increased phosphorylation in SH-SY5Y cells is a result of intracellular retention and proteasomal degradation of the mutated receptor. As a consequence, in SH-SY5Y cells, plasma membrane appears strongly enriched for ALK(WT) whereas both ALK(WT) and ALK(F1174L) were present in intracellular compartments. We further explored ALK receptor trafficking by investigating the effect of agonist and antagonist mAb (monoclonal antibodies) on ALK internalization and down-regulation, either in SH-SY5Y cells or in cells expressing only ALK(WT). We observe that treatment with agonist mAbs resulted in ALK internalization and lysosomal targeting for receptor degradation. In contrast, antagonist mAb induced ALK internalization and recycling to the plasma membrane. Importantly, we correlate this differential trafficking of ALK in response to mAb with the recruitment of the ubiquitin ligase Cbl and ALK ubiquitylation only after agonist stimulation. This study provides novel insights into the mechanisms regulating ALK trafficking and degradation, showing that various ALK receptor pools are regulated by proteasome or lysosome pathways according to their intracellular localization.

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Gaëlle Pierron, Franck Tirode, Carlo Lucchesi, Stéphanie Reynaud, Stelly Ballet, Sarah Cohen-Gogo, Virginie Perrin, Jean-Michel Coindre, Olivier Delattre (2012 Mar 4)

A new subtype of bone sarcoma defined by BCOR-CCNB3 gene fusion.

Nature genetics : 461-6 : DOI : 10.1038/ng.1107 En savoir plus
Résumé

The identification of subtype-specific translocations has revolutionized the diagnostics of sarcoma and has provided new insight into oncogenesis. We used RNA-seq to investigate samples from individuals diagnosed with small round cell tumors of bone, possibly Ewing sarcoma, but which lacked the canonical EWSR1-ETS translocation. A new fusion was observed between BCOR (encoding the BCL6 co-repressor) and CCNB3 (encoding the testis-specific cyclin B3) on the X chromosome. RNA-seq results were confirmed by RT-PCR and through cloning of the tumor-specific genomic translocation breakpoints. In total, 24 BCOR-CCNB3-positive tumors were identified among a series of 594 sarcoma cases. Gene profiling experiments indicated that BCOR-CCNB3-positive cases are biologically distinct from other sarcomas, particularly Ewing sarcoma. Finally, we show that CCNB3 immunohistochemistry is a powerful diagnostic marker for this subgroup of sarcoma and that overexpression of BCOR-CCNB3 or of truncated CCNB3 activates S phase in NIH3T3 cells. Thus, the intrachromosomal X-chromosome fusion described here represents a new subtype of bone sarcoma caused by a newly identified gene fusion mechanism.

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Sophie Postel-Vinay, Amélie S Véron, Franck Tirode, Gaelle Pierron, Stéphanie Reynaud, Heinrich Kovar, Odile Oberlin, Eve Lapouble, Stelly Ballet, Carlo Lucchesi, Udo Kontny, Anna González-Neira, Piero Picci, Javier Alonso, Ana Patino-Garcia, Brigitte Bressac de Paillerets, Karine Laud, Christian Dina, Philippe Froguel, Françoise Clavel-Chapelon, Francois Doz, Jean Michon, Stephen J Chanock, Gilles Thomas, David G Cox, Olivier Delattre (2012 Feb 12)

Common variants near TARDBP and EGR2 are associated with susceptibility to Ewing sarcoma.

Nature genetics : 323-7 : DOI : 10.1038/ng.1085 En savoir plus
Résumé

Ewing sarcoma, a pediatric tumor characterized by EWSR1-ETS fusions, is predominantly observed in populations of European ancestry. We performed a genome-wide association study (GWAS) of 401 French individuals with Ewing sarcoma, 684 unaffected French individuals and 3,668 unaffected individuals of European descent and living in the United States. We identified candidate risk loci at 1p36.22, 10q21 and 15q15. We replicated these loci in two independent sets of cases and controls. Joint analysis identified associations with rs9430161 (P = 1.4 × 10(-20); odds ratio (OR) = 2.2) located 25 kb upstream of TARDBP, rs224278 (P = 4.0 × 10(-17); OR = 1.7) located 5 kb upstream of EGR2 and, to a lesser extent, rs4924410 at 15q15 (P = 6.6 × 10(-9); OR = 1.5). The major risk haplotypes were less prevalent in Africans, suggesting that these loci could contribute to geographical differences in Ewing sarcoma incidence. TARDBP shares structural similarities with EWSR1 and FUS, which encode RNA binding proteins, and EGR2 is a target gene of EWSR1-ETS. Variants at these loci were associated with expression levels of TARDBP, ADO (encoding cysteamine dioxygenase) and EGR2.

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Fabien Reyal, Charlotte Guyader, Charles Decraene, Carlo Lucchesi, Nathalie Auger, Franck Assayag, Ludmilla De Plater, David Gentien, Marie-France Poupon, Paul Cottu, Patricia De Cremoux, Pierre Gestraud, Anne Vincent-Salomon, Jean-Jacques Fontaine, Sergio Roman-Roman, Olivier Delattre, Didier Decaudin, Elisabetta Marangoni (2012 Jan 18)

Molecular profiling of patient-derived breast cancer xenografts.

Breast cancer research : BCR : R11 En savoir plus
Résumé

Identification of new therapeutic agents for breast cancer (BC) requires preclinical models that reproduce the molecular characteristics of their respective clinical tumors. In this work, we analyzed the genomic and gene expression profiles of human BC xenografts and the corresponding patient tumors.

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Année de publication : 2011

Jerzy Klijanienko, Jérôme Couturier, Franck Bourdeaut, Paul Fréneaux, Stelly Ballet, Hervé Brisse, Réal Lagacé, Olivier Delattre, Gaëlle Pierron, Philippe Vielh, Xavier Sastre-Garau, Jean Michon (2011 Dec 20)

Fine-needle aspiration as a diagnostic technique in 50 cases of primary Ewing sarcoma/peripheral neuroectodermal tumor. Institut Curie’s experience.

Diagnostic cytopathology : 19-25 : DOI : 10.1002/dc.21491 En savoir plus
Résumé

Fine-needle aspiration (FNA) followed by a core-needle biopsy during general anesthesia is a method for diagnosing pediatric tumors in our Institute. To complete the diagnosis in the case of round cell sarcomas, cytology material is also used for genomic analyses, that is, karyotyping and molecular biology-derived techniques. Fifty primary Ewing sarcomas/peripheral neuroectodermal tumors (ES/PNET) in 50 patients were sampled. Cytological diagnoses were « malignant » in all cases and accurate (ES/PNET) in 46 (92%). Two (4%) cases were misdiagnosed as neuroblastoma, and two others (4%) as rhabdomyosarcoma and nephroblastoma. No suspicious or false-negative results were rendered. Karyotyping was performed in 20 (40%) cases and was interpretable in 17 cases but not in three cases. Molecular search for ES/PNET fusion transcripts were performed in all cases and were detected in 44 (88%) cases, but not in six (12%) cases. In conclusion, FNA assisted by genomic techniques is powerful methods to accurate diagnose ES/PNET.

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Franck Bourdeaut, Sandrine Ferrand, Laurence Brugières, Marjorie Hilbert, Agnès Ribeiro, Ludovic Lacroix, Jean Bénard, Valérie Combaret, Jean Michon, Dominique Valteau-Couanet, Bertrand Isidor, Xavier Rialland, Maryline Poirée, Anne-Sophie Defachelles, Michel Peuchmaur, Gudrun Schleiermacher, Gaëlle Pierron, Marion Gauthier-Villars, Isabelle Janoueix-Lerosey, Olivier Delattre, (2011 Nov 11)

ALK germline mutations in patients with neuroblastoma: a rare and weakly penetrant syndrome.

European journal of human genetics : EJHG : 291-7 : DOI : 10.1038/ejhg.2011.195 En savoir plus
Résumé

Neuroblastic tumours may occur in a predisposition context. Two main genes are involved: PHOX2B, observed in familial cases and frequently associated with other neurocristopathies (Ondine’s and Hirschsprung’s disease); and ALK, mostly in familial tumours. We have assessed the frequency of mutations of these two genes in patients with a presumable higher risk of predisposition. We sequenced both genes in 26 perinatal cases (prebirth and <1 month of age, among which 10 were multifocal), 16 multifocal postnatal (>1 month) cases, 3 pairs of affected relatives and 8 patients with multiple malignancies. The whole coding sequences of the two genes were analysed in tumour and/or constitutional DNAs. We found three ALK germline mutations, all in a context of multifocal tumours. Two mutations (T1151R and R1192P) were inherited and shared by several unaffected patients, thus illustrating an incomplete penetrance. Younger age at tumour onset did not seem to offer a relevant selection criterion for ALK analyses. Conversely, multifocal tumours might be the most to benefit from the genetic screening. Finally, no PHOX2B germline mutation was found in this series. In conclusion, ALK deleterious mutations are rare events in patients with a high probability of predisposition. Other predisposing genes remain to be discovered.

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Franck Bourdeaut, Bertrand Isidor, Sandrine Ferrand, Caroline Thomas, Anne Moreau, Marc-David Leclair, Albert David, Gaelle Pierron, Cedric Le Caignec, Olivier Delattre (2011 Jun 15)

Homozygous PTEN deletion in neuroblastoma arising in a child with Cowden syndrome.

American journal of medical genetics. Part A : 1763-6 : DOI : 10.1002/ajmg.a.34066 En savoir plus
Résumé

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Charline Normand, Jean Michon, Isabelle Janoueix-Lerosey, Olivier Delattre, Gudrun Schleiermacher (2011 May 26)

[Genetic alterations in neuroblastoma and their usefulness for clinical management].

Bulletin du cancer : 477-88 : DOI : 10.1684/bdc.2011.1364 En savoir plus
Résumé

Neuroblastoma, the most frequent solid extracranial tumor of childhood, is characterized by a wide variability of its clinical course. The most important clinical prognostic markers are stage and age at diagnosis, but these markers are insufficient to predict outcome reliably and to determine treatment intensity. Recent evidence indicates that neuroblastoma can be considered as a « genetic disease », firstly by the recent observation that certain alleles of specific genes significantly increase the relative risk to develop neuroblastoma, and the discovery of mutations in genes such as ALK or PHOX2B in rare familial cases. On the other hand, a large number of recurrent genetic somatic alterations have been described in neuroblastoma. Recent technological advances, such as array-CGH (comparative genomic hybridisation), now enable the analysis of these markers in a single step and allow the definition of genomic profiles associated with typical clinical features. Numerical chromosome alterations are observed more frequently in tumors of younger children with localised disease and a good prognosis, whereas segmental chromosome alterations are found more frequently in tumors of older children with advanced stages of disease and a poorer outcome. Future therapeutic stratification schemes can make use of the tumor genomic profile by proposing less intense treatment for infants with a neuroblastoma harboring a favorable tumor genomic profile, while intensifying treatment in case of a defavorable tumor genomic profile. Such approaches require standardisation of the molecular techniques and the interpretation of results for application in international trials.

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Année de publication : 2010

Pascale Mariani, Marick Lae, Armelle Degeorges, Wulfran Cacheux, Emmanuelle Lappartient, Audrey Margogne, Jean-Yves Pierga, Véronique Girre, Laurent Mignot, Marie Christine Falcou, Rémy-Jacques Salmon, Olivier Delattre, Patricia De Cremoux (2010 Nov 2)

Concordant analysis of KRAS status in primary colon carcinoma and matched metastasis.

Anticancer research : 4229-35 En savoir plus
Résumé

KRAS somatic mutations are the main predictive factor for non response to EGFR-targeted monoclonal antibodies in metastatic colorectal cancer (mCRC) patients. We compared KRAS mutational status in the primary tumour and the corresponding metastases (1 to 4 sites) in 38 mCRC patients. KRAS mutational status was analysed using direct sequencing, SNAPShot multiplex PCR and Scorpion Taqman PCR analysis. Results showed 54% of primary tumours had KRAS mutations. A concordance of 97% between primaries and metastatic sites was observed. A tumour heterogeneity was also demonstrated in 5% of mCRC. One case with three different primary tumours harboured three different KRAS mutations, and only one was represented in the unique metastasis of this patient. We concluded there was a high concordance in the KRAS status between the primary tumour and metastases. More than one informative block and more sensitive assay may increase the accuracy of KRAS status determination.

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Eléonore Gravier, Gaëlle Pierron, Anne Vincent-Salomon, Nadège Gruel, Virginie Raynal, Alexia Savignoni, Yann De Rycke, Jean-Yves Pierga, Carlo Lucchesi, Fabien Reyal, Alain Fourquet, Sergio Roman-Roman, François Radvanyi, Xavier Sastre-Garau, Bernard Asselain, Olivier Delattre (2010 Sep 16)

A prognostic DNA signature for T1T2 node-negative breast cancer patients.

Genes, chromosomes & cancer : 1125-34 : DOI : 10.1002/gcc.20820 En savoir plus
Résumé

Predicting evolution of small node-negative breast carcinoma is a real challenge in clinical practice. The aim of this study was to search whether qualitative or quantitative DNA changes may help to predict metastasis of small node-negative breast carcinoma. Small invasive ductal carcinomas without axillary lymph node involvement (T1T2N0) from 168 patients with either good (111 patients with no event at 5 years after diagnosis) or poor (57 patients with early metastasis) outcome were analyzed with comparative genomic hybridization (CGH) array. A CGH classifier, identifying low- and high-risk groups of metastatic recurrence, was established in a training set of 78 patients, then validated, and compared with clinicopathological parameters in a distinct set of 90 patients. The genomic status of regions located on 2p22.2, 3p23, and 8q21-24 and the number of segmental alterations were defined in the training set to classify tumors into low- or high-risk groups. In the validation set, in addition to estrogen receptors and grade, this CGH classifier provided significant prognostic information in multivariate analysis (odds ratio, 3.34; 95% confidence interval 1.01-11.02; P = 4.78 × 10(-2), Wald test). This study shows that tumor DNA contains important prognostic information that may help to predict metastasis in T1T2N0 tumors of the breast.

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Ahmed Idbaih, Cyril Dalmasso, Mathilde Kouwenhoven, Judith Jeuken, Catherine Carpentier, Thierry Gorlia, Johan M Kros, Pim French, Johannes Teepen, Philippe Broët, Olivier Delattre, Karima Mokhtari, Marc Sanson, Jean-Yves Delattre, Martin van den Bent, Khê Hoang-Xuan (2010 Sep 8)

Genomic aberrations associated with outcome in anaplastic oligodendroglial tumors treated within the EORTC phase III trial 26951.

Journal of neuro-oncology : 221-30 : DOI : 10.1007/s11060-010-0380-9 En savoir plus
Résumé

Despite similar morphological aspects, anaplastic oligodendroglial tumors (AOTs) form a heterogeneous clinical subgroup of gliomas. The chromosome arms 1p/19q codeletion has been shown to be a relevant biomarker in AOTs and to be perfectly exclusive from EGFR amplification in gliomas. To identify new genomic regions associated with prognosis, 60 AOTs from the EORTC trial 26951 were analyzed retrospectively using BAC-array-based comparative genomic hybridization. The data were processed using a binary tree method. Thirty-three BACs with prognostic value were identified distinguishing four genomic subgroups of AOTs with different prognosis (p < 0.0001). Type I tumors (25%) were characterized by: (1) an EGFR amplification, (2) a poor prognosis, (3) a higher rate of necrosis, and (4) an older age of patients. Type II tumors (21.7%) had: (1) loss of prognostic BACs located on 1p tightly associated with 19q deletion, (2) a longer survival, (3) an oligodendroglioma phenotype, and (4) a frontal location in brain. Type III AOTs (11.7%) exhibited: (1) a deletion of prognostic BACs located on 21q, and (2) a short survival. Finally, type IV tumors (41.7%) had different genomic patterns and prognosis than type I, II and III AOTs. Multivariate analysis showed that genomic type provides additional prognostic data to clinical, imaging and pathological features. Similar results were obtained in the cohort of 45 centrally reviewed-validated cases of AOTs. Whole genome analysis appears useful to screen the numerous genomic abnormalities observed in AOTs and to propose new biomarkers particularly in the non-1p/19q codeleted AOTs.

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