Stefan M Pfister

Publications (48)692.47 Total impact

• Article: Robust molecular subgrouping and copy-number profiling of medulloblastoma from small amounts of archival tumour material using high-density DNA methylation arrays.

  Volker Hovestadt, Marc Remke, Marcel Kool, Torsten Pietsch, Paul A Northcott, Roger Fischer, Florence M G Cavalli, Vijay Ramaswamy, Marc Zapatka, Guido Reifenberger, Stefan Rutkowski, Matthias Schick, Melanie Bewerunge-Hudler, Andrey Korshunov, Peter Lichter, Michael D Taylor, Stefan M Pfister, David T W Jones
  Acta Neuropathologica 05/2013; · 9.32 Impact Factor
• Article: Differential expression and methylation of brain developmental genes define location-specific subsets of pilocytic astrocytoma.

  Sally R Lambert, Hendrik Witt, Volker Hovestadt, Manuela Zucknick, Marcel Kool, Danita M Pearson, Andrey Korshunov, Marina Ryzhova, Koichi Ichimura, Nada Jabado, Adam M Fontebasso, Peter Lichter, Stefan M Pfister, V Peter Collins, David T W Jones
  [show abstract] [hide abstract]
  ABSTRACT: Pilocytic astrocytomas (PAs) are the most common brain tumors in pediatric patients and can cause significant morbidity, including chronic neurological deficiencies. They are characterized by activating alterations in the mitogen-activated protein kinase pathway, but little else is known about their development. To map the global DNA methylation profiles of these tumors, we analyzed 62 PAs and 7 normal cerebellum samples using Illumina 450K microarrays. These data revealed two subgroups of PA that separate according to tumor location (infratentorial versus supratentorial), and identified key neural developmental genes that are differentially methylated between the two groups, including NR2E1 and EN2. Integration with transcriptome microarray data highlighted significant expression differences, which were unexpectedly associated with a strong positive correlation between methylation and expression. Differentially methylated probes were often identified within the gene body and/or regions up- or downstream of the gene, rather than at the transcription start site. We also identified a large number of differentially methylated genes between cerebellar PAs and normal cerebellum, which were again enriched for developmental genes. In addition, we found a significant association between differentially methylated genes and SUZ12 binding sites, indicating potential disruption of the polycomb repressor complex 2 (PRC2). Taken together, these data suggest that PA from different locations in the brain may arise from region-specific cells of origin, and highlight the potential disruption of key developmental regulators during tumorigenesis. These findings have implications for future basic research and clinical trials, as therapeutic targets and drug sensitivity may differ according to tumor location.
  Acta Neuropathologica 05/2013; · 9.32 Impact Factor
• Article: Meningeal hemangiopericytoma and solitary fibrous tumors carry the NAB2-STAT6 fusion and can be diagnosed by nuclear expression of STAT6 protein.

  Leonille Schweizer, Christian Koelsche, Felix Sahm, Rosario M Piro, David Capper, David E Reuss, Stefan Pusch, Antje Habel, Jochen Meyer, Tanja Göck, [......], Albert Becker, Stephanie Heim, Matthias Simon, Christel Herold-Mende, Gunhild Mechtersheimer, Werner Paulus, Rainer König, Otmar D Wiestler, Stefan M Pfister, Andreas von Deimling
  [show abstract] [hide abstract]
  ABSTRACT: Non-central nervous system hemangiopericytoma (HPC) and solitary fibrous tumor (SFT) are considered by pathologists as two variants of a single tumor entity now subsumed under the entity SFT. Recent detection of frequent NAB2-STAT6 fusions in both, HPC and SFT, provided additional support for this view. On the other hand, current neuropathological practice still distinguishes between HPC and SFT. The present study set out to identify genes involved in the formation of meningeal HPC. We performed exome sequencing and detected the NAB2-STAT6 fusion in DNA of 8/10 meningeal HPC thereby providing evidence of close relationship of these tumors with peripheral SFT. Due to the considerable effort required for exome sequencing, we sought to explore surrogate markers for the NAB2-STAT6 fusion protein. We adopted the Duolink proximity ligation assay and demonstrated the presence of NAB2-STAT6 fusion protein in 17/17 HPC and the absence in 15/15 meningiomas. More practical, presence of the NAB2-STAT6 fusion protein resulted in a strong nuclear signal in STAT6 immunohistochemistry. The nuclear reallocation of STAT6 was detected in 35/37 meningeal HPC and 25/25 meningeal SFT but not in 87 meningiomas representing the most important differential diagnosis. Tissues not harboring the NAB2-STAT6 fusion protein presented with nuclear expression of NAB2 and cytoplasmic expression of STAT6 proteins. In conclusion, we provide strong evidence for meningeal HPC and SFT to constitute variants of a single entity which is defined by NAB2-STAT6 fusion. In addition, we demonstrate that this fusion can be rapidly detected by STAT6 immunohistochemistry which shows a consistent nuclear reallocation. This immunohistochemical assay may prove valuable for the differentiation of HPC and SFT from other mesenchymal neoplasms.
  Acta Neuropathologica 04/2013; · 9.32 Impact Factor
• Article: Emerging insights into the ependymoma epigenome.

  Stephen C Mack, Hendrik Witt, Xin Wang, Till Milde, Yuan Yao, Kelsey C Bertrand, Andrey Korshunov, Stefan M Pfister, Michael D Taylor
  [show abstract] [hide abstract]
  ABSTRACT: Ependymoma is the third most common pediatric brain tumor, yet because of the paucity of effective therapeutic interventions, 45% of patients remain incurable. Recent transcriptional and copy number profiling of the disease has identified few driver genes and in fact points to a balanced genomic profile. Candidate gene approaches looking at hypermethylated promoters and genome-wide epigenetic arrays suggest that DNA methylation may be critical to ependymoma pathogenesis. This review attempts to highlight existing and emerging evidence implicating the ependymoma epigenome as a key player and that epigenetic modifiers may offer new targeted therapeutic avenues for patients.
  Brain Pathology 03/2013; 23(2):206-9. · 3.99 Impact Factor
• Article: The role of chromatin remodeling in medulloblastoma.

  David T W Jones, Paul A Northcott, Marcel Kool, Stefan M Pfister
  [show abstract] [hide abstract]
  ABSTRACT: The unexpectedly high frequency and universality of alterations to the chromatin machinery is one of the most striking themes emerging from the current deluge of cancer genomics data. Medulloblastoma (MB), a malignant pediatric brain tumor, is no exception to this trend, with a wealth of recent studies indicating multiple alterations at all levels of chromatin processing. MB is typically now regarded as being composed of four major molecular entities (WNT, SHH, Group 3 and Group 4), which vary in their clinical and biological characteristics. Similarities and differences across these subgroups are also reflected in the specific chromatin modifiers that are found to be altered in each group, and each new cancer genome sequence or microarray profile is adding to this important knowledge base. These data are fundamentally changing our understanding of tumor developmental pathways, not just for MB but also for cancer as a whole. They also provide a new class of targets for the development of rational, personalized therapeutic approaches. The mechanisms by which these chromatin remodelers are dysregulated in MB, and the consequences both for future basic research and for translation to the clinic, will be examined here.
  Brain Pathology 03/2013; 23(2):193-9. · 3.99 Impact Factor
• Article: Secretory meningiomas are defined by combined KLF4 K409Q and TRAF7 mutations.

  David E Reuss, Rosario M Piro, David T W Jones, Matthias Simon, Ralf Ketter, Marcel Kool, Albert Becker, Felix Sahm, Stefan Pusch, Jochen Meyer, [......], Christel Herold-Mende, Christian Hartmann, Christian Mawrin, Nathalia Giese, Roland Eils, V Peter Collins, Rainer König, Otmar D Wiestler, Stefan M Pfister, Andreas von Deimling
  [show abstract] [hide abstract]
  ABSTRACT: Meningiomas are among the most frequent intracranial tumors. The secretory variant of meningioma is characterized by glandular differentiation, formation of intracellular lumina and pseudopsammoma bodies, expression of a distinct pattern of cytokeratins and clinically by pronounced perifocal brain edema. Here we describe whole-exome sequencing analysis of DNA from 16 secretory meningiomas and corresponding constitutional tissues. All secretory meningiomas invariably harbored a mutation in both KLF4 and TRAF7. Validation in an independent cohort of 14 secretory meningiomas by Sanger sequencing or derived cleaved amplified polymorphic sequence (dCAPS) assay detected the same pattern, with KLF4 mutations observed in a total of 30/30 and TRAF7 mutations in 29/30 of these tumors. All KLF4 mutations were identical, affected codon 409 and resulted in a lysine to glutamine exchange (K409Q). KLF4 mutations were not found in 89 non-secretory meningiomas, 267 other intracranial tumors including gliomas, glioneuronal tumors, pituitary adenomas and metastases, 59 peripheral nerve sheath tumors and 52 pancreatic tumors. TRAF7 mutations were restricted to the WD40 domains. While KLF4 mutations were exclusively seen in secretory meningiomas, TRAF7 mutations were also observed in 7/89 (8 %) of non-secretory meningiomas. KLF4 and TRAF7 mutations were mutually exclusive with NF2 mutations. In conclusion, our findings suggest an essential contribution of combined KLF4 K409Q and TRAF7 mutations in the genesis of secretory meningioma and demonstrate a role for TRAF7 alterations in other non-NF2 meningiomas.
  Acta Neuropathologica 03/2013; 125(3):351-8. · 9.32 Impact Factor
• Article: Mutations in SETD2 and genes affecting histone H3K36 methylation target hemispheric high-grade gliomas.

  Adam M Fontebasso, Jeremy Schwartzentruber, Dong-Anh Khuong-Quang, Xiao-Yang Liu, Dominik Sturm, Andrey Korshunov, David T W Jones, Hendrik Witt, Marcel Kool, Steffen Albrecht, [......], Pawel P Liberski, Peter Hauser, Miklos Garami, Almos Klekner, Laszlo Bognar, Gelareh Zadeh, Damien Faury, Stefan M Pfister, Nada Jabado, Jacek Majewski
  [show abstract] [hide abstract]
  ABSTRACT: Recurrent mutations affecting the histone H3.3 residues Lys27 or indirectly Lys36 are frequent drivers of pediatric high-grade gliomas (over 30 % of HGGs). To identify additional driver mutations in HGGs, we investigated a cohort of 60 pediatric HGGs using whole-exome sequencing (WES) and compared them to 543 exomes from non-cancer control samples. We identified mutations in SETD2, a H3K36 trimethyltransferase, in 15 % of pediatric HGGs, a result that was genome-wide significant (FDR = 0.029). Most SETD2 alterations were truncating mutations. Sequencing the gene in this cohort and another validation cohort (123 gliomas from all ages and grades) showed SETD2 mutations to be specific to high-grade tumors affecting 15 % of pediatric HGGs (11/73) and 8 % of adult HGGs (5/65) while no SETD2 mutations were identified in low-grade diffuse gliomas (0/45). Furthermore, SETD2 mutations were mutually exclusive with H3F3A mutations in HGGs (P = 0.0492) while they partly overlapped with IDH1 mutations (4/14), and SETD2-mutant tumors were found exclusively in the cerebral hemispheres (P = 0.0055). SETD2 is the only H3K36 trimethyltransferase in humans, and SETD2-mutant tumors showed a substantial decrease in H3K36me3 levels (P < 0.001), indicating that the mutations are loss-of-function. These data suggest that loss-of-function SETD2 mutations occur in older children and young adults and are specific to HGG of the cerebral cortex, similar to the H3.3 G34R/V and IDH mutations. Taken together, our results suggest that mutations disrupting the histone code at H3K36, including H3.3 G34R/V, IDH1 and/or SETD2 mutations, are central to the genesis of hemispheric HGGs in older children and young adults.
  Acta Neuropathologica 02/2013; · 9.32 Impact Factor
• Source

  Available from: Giuseppe Cinalli

  Article: Epigenetic Silencing of DKK3 in Medulloblastoma.

  Francesca Valdora, Barbara Banelli, Sara Stigliani, Stefan M Pfister, Stefano Moretti, Marcel Kool, Marc Remke, Alfa H C Bai, Claudio Brigati, Thomas Hielscher, Massimo Romani, Tiziana Servidei, Massimo Zollo, Giuseppe Cinalli, André Oberthuer, Gian Paolo Tonini, Simona Coco
  [show abstract] [hide abstract]
  ABSTRACT: Medulloblastoma (MB) is a malignant pediatric brain tumor arising in the cerebellum consisting of four distinct subgroups: WNT, SHH, Group 3 and Group 4, which exhibit different molecular phenotypes. We studied the expression of Dickkopf (DKK) 1-4 family genes, inhibitors of the Wnt signaling cascade, in MB by screening 355 expression profiles derived from four independent datasets. Upregulation of DKK1, DKK2 and DKK4 mRNA was observed in the WNT subgroup, whereas DKK3 was downregulated in 80% MBs across subgroups with respect to the normal cerebellum (p < 0.001). Since copy number aberrations targeting the DKK3 locus (11p15.3) are rare events, we hypothesized that epigenetic factors could play a role in DKK3 regulation. Accordingly, we studied 77 miRNAs predicting to repress DKK3; however, no significant inverse correlation between miRNA/mRNA expression was observed. Moreover, the low methylation levels in the DKK3 promoters (median: 3%, 5% and 5% for promoter 1, 2 and 3, respectively) excluded the downregulation of gene expression by methylation. On the other hand, the treatment of MB cells with Trichostatin A (TSA), a potent inhibitor of histone deacetylases (HDAC), was able to restore both DKK3 mRNA and protein. In conclusion, DKK3 downregulation across all MB subgroups may be due to epigenetic mechanisms, in particular, through chromatin condensation.
  International Journal of Molecular Sciences 01/2013; 14(4):7492-505. · 2.60 Impact Factor
• Article: Aberrant patterns of H3K4 and H3K27 histone lysine methylation occur across subgroups in medulloblastoma.

  Adrian M Dubuc, Marc Remke, Andrey Korshunov, Paul A Northcott, Shing H Zhan, Maria Mendez-Lago, Marcel Kool, David T W Jones, Alexander Unterberger, A Sorana Morrissy, [......], Cynthia Hawkins, Rajeev Vibhakar, Sidney Croul, James T Rutka, William A Weiss, Steven J M Jones, Charles G Eberhart, Marco A Marra, Stefan M Pfister, Michael D Taylor
  [show abstract] [hide abstract]
  ABSTRACT: Recent sequencing efforts have described the mutational landscape of the pediatric brain tumor medulloblastoma. Although MLL2 is among the most frequent somatic single nucleotide variants (SNV), the clinical and biological significance of these mutations remains uncharacterized. Through targeted re-sequencing, we identified mutations of MLL2 in 8 % (14/175) of MBs, the majority of which were loss of function. Notably, we also report mutations affecting the MLL2-binding partner KDM6A, in 4 % (7/175) of tumors. While MLL2 mutations were independent of age, gender, histological subtype, M-stage or molecular subgroup, KDM6A mutations were most commonly identified in Group 4 MBs, and were mutually exclusive with MLL2 mutations. Immunohistochemical staining for H3K4me3 and H3K27me3, the chromatin effectors of MLL2 and KDM6A activity, respectively, demonstrated alterations of the histone code in 24 % (53/220) of MBs across all subgroups. Correlating these MLL2- and KDM6A-driven histone marks with prognosis, we identified populations of MB with improved (K4+/K27-) and dismal (K4-/K27-) outcomes, observed primarily within Group 3 and 4 MBs. Group 3 and 4 MBs demonstrate somatic copy number aberrations, and transcriptional profiles that converge on modifiers of H3K27-methylation (EZH2, KDM6A, KDM6B), leading to silencing of PRC2-target genes. As PRC2-mediated aberrant methylation of H3K27 has recently been targeted for therapy in other diseases, it represents an actionable target for a substantial percentage of medulloblastoma patients with aggressive forms of the disease.
  Acta Neuropathologica 11/2012; · 9.32 Impact Factor
• Article: Medulloblastomics: the end of the beginning.

  Paul A Northcott, David T W Jones, Marcel Kool, Giles W Robinson, Richard J Gilbertson, Yoon-Jae Cho, Scott L Pomeroy, Andrey Korshunov, Peter Lichter, Michael D Taylor, Stefan M Pfister
  [show abstract] [hide abstract]
  ABSTRACT: The division of medulloblastoma into different subgroups by microarray expression profiling has dramatically changed our perspective of this malignant childhood brain tumour. Now, the availability of next-generation sequencing and complementary high-density genomic technologies has unmasked novel driver mutations in each medulloblastoma subgroup. The implications of these findings for the management of patients are readily apparent, pinpointing previously unappreciated diagnostic and therapeutic targets. In this Review, we summarize the 'explosion' of data emerging from the application of modern genomics to medulloblastoma, and in particular the recurrent targets of mutation in medulloblastoma subgroups. These data are currently making their way into clinical trials as we seek to integrate conventional and molecularly targeted therapies.
  Nature Reviews Cancer 11/2012; 12(12):818-34. · 29.54 Impact Factor
• Article: LIN28A immunoreactivity is a potent diagnostic marker of embryonal tumor with multilayered rosettes (ETMR).

  Andrey Korshunov, Marina Ryzhova, David T W Jones, Paul A Northcott, Peter van Sluis, Richard Volckmann, Jan Koster, Rogier Versteeg, Cynthia Cowdrey, Arie Perry, [......], Felice Giangaspero, Eleonora Aronica, Ulrich Schüller, Martin Hasselblatt, V Peter Collins, Andreas von Deimling, Peter Lichter, Annie Huang, Stefan M Pfister, Marcel Kool
  [show abstract] [hide abstract]
  ABSTRACT: Embryonal tumor with multilayered rosettes (ETMR, previously known as ETANTR) is a highly aggressive embryonal CNS tumor, which almost exclusively affects infants and is associated with a dismal prognosis. Accurate diagnosis is of critical clinical importance because of its poor response to current treatment protocols and its distinct biology. Amplification of the miRNA cluster at 19q13.42 has been identified previously as a genetic hallmark for ETMR, but an immunohistochemistry-based assay for clinical routine diagnostics [such as INI-1 for atypical teratoid rhabdoid tumor (AT/RT)] is still lacking. In this study, we screened for an ETMR-specific marker using a gene-expression profiling dataset of more than 1,400 brain tumors and identified LIN28A as a highly specific marker for ETMR. The encoded protein binds small RNA and has been implicated in stem cell pluripotency, metabolism and tumorigenesis. Using an LIN28A specific antibody, we carried out immunohistochemical analysis of LIN28A in more than 800 childhood brain-tumor samples and confirmed its high specificity for ETMR. Strong LIN28A immunoexpression was found in all 37 ETMR samples tested, whereas focal reactivity was only present in a small (6/50) proportion of AT/RT samples. All other pediatric brain tumors were completely LIN28A-negative. In summary, we established LIN28A immunohistochemistry as a highly sensitive and specific, rapid, inexpensive diagnostic tool for routine pathological verification of ETMR.
  Acta Neuropathologica 11/2012; · 9.32 Impact Factor
• Article: Hotspot Mutations in H3F3A and IDH1 Define Distinct Epigenetic and Biological Subgroups of Glioblastoma.

  Dominik Sturm, Hendrik Witt, Volker Hovestadt, Dong-Anh Khuong-Quang, David T W Jones, Carolin Konermann, Elke Pfaff, Martje Tönjes, Martin Sill, Sebastian Bender, [......], Tom Mikkelsen, Kenneth Aldape, Guido Reifenberger, V Peter Collins, Jacek Majewski, Andrey Korshunov, Peter Lichter, Christoph Plass, Nada Jabado, Stefan M Pfister
  [show abstract] [hide abstract]
  ABSTRACT: Glioblastoma (GBM) is a brain tumor that carries a dismal prognosis and displays considerable heterogeneity. We have recently identified recurrent H3F3A mutations affecting two critical amino acids (K27 and G34) of histone H3.3 in one-third of pediatric GBM. Here, we show that each H3F3A mutation defines an epigenetic subgroup of GBM with a distinct global methylation pattern, and that they are mutually exclusive with IDH1 mutations, which characterize a third mutation-defined subgroup. Three further epigenetic subgroups were enriched for hallmark genetic events of adult GBM and/or established transcriptomic signatures. We also demonstrate that the two H3F3A mutations give rise to GBMs in separate anatomic compartments, with differential regulation of transcription factors OLIG1, OLIG2, and FOXG1, possibly reflecting different cellular origins.
  Cancer cell 10/2012; 22(4):425-37. · 25.29 Impact Factor
• Article: HD-MB03 is a novel Group 3 medulloblastoma model demonstrating sensitivity to histone deacetylase inhibitor treatment.

  Till Milde, Marco Lodrini, Larissa Savelyeva, Andrey Korshunov, Marcel Kool, Lena M Brueckner, André S L M Antunes, Ina Oehme, Arnulf Pekrun, Stefan M Pfister, Andreas E Kulozik, Olaf Witt, Hedwig E Deubzer
  [show abstract] [hide abstract]
  ABSTRACT: Medulloblastomas are the most common malignant brain tumors in childhood. Emerging evidence suggests that medulloblastoma comprises at least four distinct diseases (WNT, SHH, Group 3 and 4) with different biology, clinical presentation, and outcome, with especially poor prognosis in Group 3. The tight connection of biology and clinical behavior in patients emphasizes the need for subgroup-specific preclinical models in order to develop treatments tailored to each subgroup. Herein we report on the novel cell line HD-MB03, isolated from tumor material of a patient with metastasized Group 3 medulloblastoma, and preclinical testing of different histone deacetylase inhibitors (HDACis) in this model. HD-MB03 cells grow long term in vitro and form metastatic tumors in vivo upon orthotopic transplantation. HD-MB03 cells reflect the original Group 3 medulloblastoma at the histological and molecular level, showing large cell morphology, similar expression patterns for markers Ki67, p53, and glial fibrillary acidic protein (GFAP), a gene expression profile most closely matching Group 3 medulloblastomas, and persistence of typical molecular alterations, i.e., isochromosome 17q [i(17q)] and MYC amplification. Protein expression analysis of HDACs 2, 5, 8, and 9 as well as the predictive marker HR23B showed intermediate to strong expression, suggesting sensitivity to HDACis. Indeed, treatment with HDACis Helminthosporium carbonum (HC)-toxin, vorinostat, and panobinostat revealed high sensitivity to this novel drug class, as well as a radiation-sensitizing effect with significantly increased cell death upon concomitant treatment. In summary, our data indicate that HD-MB03 is a suitable preclinical model for Group 3 medulloblastoma, and HDACis could represent a therapeutic option for this subgroup.
  Journal of Neuro-Oncology 10/2012; · 3.21 Impact Factor
• Article: Dissecting the genomic complexity underlying medulloblastoma.

  David T W Jones, Natalie Jäger, Marcel Kool, Thomas Zichner, Barbara Hutter, Marc Sultan, Yoon-Jae Cho, Trevor J Pugh, Volker Hovestadt, Adrian M Stütz, [......], Paul A Northcott, Michael D Taylor, Matthew Meyerson, Scott L Pomeroy, Marie-Laure Yaspo, Jan O Korbel, Andrey Korshunov, Roland Eils, Stefan M Pfister, Peter Lichter
  [show abstract] [hide abstract]
  ABSTRACT: Medulloblastoma is an aggressively growing tumour, arising in the cerebellum or medulla/brain stem. It is the most common malignant brain tumour in children, and shows tremendous biological and clinical heterogeneity. Despite recent treatment advances, approximately 40% of children experience tumour recurrence, and 30% will die from their disease. Those who survive often have a significantly reduced quality of life. Four tumour subgroups with distinct clinical, biological and genetic profiles are currently identified. WNT tumours, showing activated wingless pathway signalling, carry a favourable prognosis under current treatment regimens. SHH tumours show hedgehog pathway activation, and have an intermediate prognosis. Group 3 and 4 tumours are molecularly less well characterized, and also present the greatest clinical challenges. The full repertoire of genetic events driving this distinction, however, remains unclear. Here we describe an integrative deep-sequencing analysis of 125 tumour-normal pairs, conducted as part of the International Cancer Genome Consortium (ICGC) PedBrain Tumor Project. Tetraploidy was identified as a frequent early event in Group 3 and 4 tumours, and a positive correlation between patient age and mutation rate was observed. Several recurrent mutations were identified, both in known medulloblastoma-related genes (CTNNB1, PTCH1, MLL2, SMARCA4) and in genes not previously linked to this tumour (DDX3X, CTDNEP1, KDM6A, TBR1), often in subgroup-specific patterns. RNA sequencing confirmed these alterations, and revealed the expression of what are, to our knowledge, the first medulloblastoma fusion genes identified. Chromatin modifiers were frequently altered across all subgroups. These findings enhance our understanding of the genomic complexity and heterogeneity underlying medulloblastoma, and provide several potential targets for new therapeutics, especially for Group 3 and 4 patients.
  Nature 07/2012; 488(7409):100-5. · 36.28 Impact Factor
• Source

  Available from: Giuseppe Cinalli

  Article: Subgroup-specific structural variation across 1,000 medulloblastoma genomes.

  Paul A Northcott, David J H Shih, John Peacock, Livia Garzia, A Sorana Morrissy, Thomas Zichner, Adrian M Stütz, Andrey Korshunov, Jüri Reimand, Steven E Schumacher, [......], Eric Bouffet, Stephen W Scherer, James T Rutka, David Malkin, Steven C Clifford, Steven J M Jones, Jan O Korbel, Stefan M Pfister, Marco A Marra, Michael D Taylor
  [show abstract] [hide abstract]
  ABSTRACT: Medulloblastoma, the most common malignant paediatric brain tumour, is currently treated with nonspecific cytotoxic therapies including surgery, whole-brain radiation, and aggressive chemotherapy. As medulloblastoma exhibits marked intertumoural heterogeneity, with at least four distinct molecular variants, previous attempts to identify targets for therapy have been underpowered because of small samples sizes. Here we report somatic copy number aberrations (SCNAs) in 1,087 unique medulloblastomas. SCNAs are common in medulloblastoma, and are predominantly subgroup-enriched. The most common region of focal copy number gain is a tandem duplication of SNCAIP, a gene associated with Parkinson's disease, which is exquisitely restricted to Group 4α. Recurrent translocations of PVT1, including PVT1-MYC and PVT1-NDRG1, that arise through chromothripsis are restricted to Group 3. Numerous targetable SCNAs, including recurrent events targeting TGF-β signalling in Group 3, and NF-κB signalling in Group 4, suggest future avenues for rational, targeted therapy.
  Nature 07/2012; 488(7409):49-56. · 36.28 Impact Factor
• Article: Medulloblastoma exome sequencing uncovers subtype-specific somatic mutations.

  Trevor J Pugh, Shyamal Dilhan Weeraratne, Tenley C Archer, Daniel A Pomeranz Krummel, Daniel Auclair, James Bochicchio, Mauricio O Carneiro, Scott L Carter, Kristian Cibulskis, Rachel L Erlich, [......], Stacey B Gabriel, Gad Getz, Natalie Jäger, David T W Jones, Peter Lichter, Stefan M Pfister, Thomas M Roberts, Matthew Meyerson, Scott L Pomeroy, Yoon-Jae Cho
  [show abstract] [hide abstract]
  ABSTRACT: Medulloblastomas are the most common malignant brain tumours in children. Identifying and understanding the genetic events that drive these tumours is critical for the development of more effective diagnostic, prognostic and therapeutic strategies. Recently, our group and others described distinct molecular subtypes of medulloblastoma on the basis of transcriptional and copy number profiles. Here we use whole-exome hybrid capture and deep sequencing to identify somatic mutations across the coding regions of 92 primary medulloblastoma/normal pairs. Overall, medulloblastomas have low mutation rates consistent with other paediatric tumours, with a median of 0.35 non-silent mutations per megabase. We identified twelve genes mutated at statistically significant frequencies, including previously known mutated genes in medulloblastoma such as CTNNB1, PTCH1, MLL2, SMARCA4 and TP53. Recurrent somatic mutations were newly identified in an RNA helicase gene, DDX3X, often concurrent with CTNNB1 mutations, and in the nuclear co-repressor (N-CoR) complex genes GPS2, BCOR and LDB1. We show that mutant DDX3X potentiates transactivation of a TCF promoter and enhances cell viability in combination with mutant, but not wild-type, β-catenin. Together, our study reveals the alteration of WNT, hedgehog, histone methyltransferase and now N-CoR pathways across medulloblastomas and within specific subtypes of this disease, and nominates the RNA helicase DDX3X as a component of pathogenic β-catenin signalling in medulloblastoma.
  Nature 07/2012; 488(7409):106-10. · 36.28 Impact Factor
• Article: DNA copy number alterations in central primitive neuroectodermal tumors and tumors of the pineal region: an international individual patient data meta-analysis.

  André O von Bueren, Joachim Gerss, Christian Hagel, Haoyang Cai, Marc Remke, Martin Hasselblatt, Burt G Feuerstein, Sarah Pernet, Olivier Delattre, Andrey Korshunov, Stefan Rutkowski, Stefan M Pfister, Michael Baudis
  [show abstract] [hide abstract]
  ABSTRACT: Little is known about frequency, association with clinical characteristics, and prognostic impact of DNA copy number alterations (CNA) on survival in central primitive neuroectodermal tumors (CNS-PNET) and tumors of the pineal region. Searches of MEDLINE, Pubmed, and EMBASE--after the original description of comparative genomic hybridization in 1992 and July 2010--identified 15 case series of patients with CNS-PNET and tumors of the pineal region whose tumors were investigated for genome-wide CNA. One additional case study was identified from contact with experts. Individual patient data were extracted from publications or obtained from investigators, and CNAs were converted to a digitized format suitable for data mining and subgroup identification. Summary profiles for genomic imbalances were generated from case-specific data. Overall survival (OS) was estimated using the Kaplan-Meier method, and by univariable and multivariable Cox regression models. In their overall CNA profiles, low grade tumors of the pineal region clearly diverged from CNS-PNET and pineoblastoma. At a median follow-up of 89 months, 7-year OS rates of CNS-PNET, pineoblastoma, and low grade tumors of the pineal region were 22.9 ± 6, 0 ± 0, and 87.5 ± 12 %, respectively. Multivariable analysis revealed that histology (CNS-PNET), age (≤2.5 years), and possibly recurrent CNAs were associated with unfavorable OS. DNA copy number profiling suggests a close relationship between CNS-PNET and pineoblastoma. Low grade tumors of the pineal region differed from CNS-PNET and pineoblastoma. Due to their high biological and clinical variability, a coordinated prospective validation in future studies is necessary to establish robust risk factors.
  Journal of Neuro-Oncology 07/2012; 109(2):415-23. · 3.21 Impact Factor
• Article: Markers of survival and metastatic potential in childhood CNS primitive neuro-ectodermal brain tumours: an integrative genomic analysis.

  Daniel Picard, Suzanne Miller, Cynthia E Hawkins, Eric Bouffet, Hazel A Rogers, Tiffany S Y Chan, Seung-Ki Kim, Young-Shin Ra, Jason Fangusaro, Andrey Korshunov, [......], Ching C Lau, Ho-Keung Ng, Chris Jones, Timothy Van Meter, Steven C Clifford, Charles Eberhart, Amar Gajjar, Stefan M Pfister, Richard G Grundy, Annie Huang
  [show abstract] [hide abstract]
  ABSTRACT: Childhood CNS primitive neuro-ectodermal brain tumours (PNETs) are very aggressive brain tumours for which the molecular features and best treatment approaches are unknown. We assessed a large cohort of these rare tumours to identify molecular markers to enhance clinical management of this disease. We obtained 142 primary hemispheric CNS PNET samples from 20 institutions in nine countries and examined transcriptional profiles for a subset of 51 samples and copy number profiles for a subset of 77 samples. We used clustering, gene, and pathway enrichment analyses to identify tumour subgroups and group-specific molecular markers, and applied immunohistochemical and gene-expression analyses to validate and assess the clinical significance of the subgroup markers. We identified three molecular subgroups of CNS PNETs that were distinguished by primitive neural (group 1), oligoneural (group 2), and mesenchymal lineage (group 3) gene-expression signatures with differential expression of cell-lineage markers LIN28 and OLIG2. Patients with group 1 tumours were most often female (male:female ratio 0·61 for group 1 vs 1·25 for group 2 and 1·63 for group 3; p=0·043 [group 1 vs groups 2 and 3]), youngest (median age at diagnosis 2·9 years [95% CI 2·4-5·2] for group 1 vs 7·9 years [6·0-9·7] for group 2 and 5·9 years [4·9-7·8] for group 3; p=0·005), and had poorest survival (median survival 0·8 years [95% CI 0·5-1·2] in group 1, 1·8 years [1·4-2·3] in group 2 and 4·3 years [0·8-7·8] in group 3; p=0·019). Patients with group 3 tumours had the highest incidence of metastases at diagnosis (no distant metastasis:metastasis ratio 0·90 for group 3 vs 2·80 for group 1 and 5·67 for group 2; p=0·037). LIN28 and OLIG2 are promising diagnostic and prognostic molecular markers for CNS PNET that warrant further assessment in prospective clinical trials. Canadian Institute of Health Research, Brainchild/SickKids Foundation, and the Samantha Dickson Brain Tumour Trust.
  The lancet oncology 06/2012; 13(8):838-48. · 14.47 Impact Factor
• Source

  Available from: Pawel Buczkowicz

  Article: K27M mutation in histone H3.3 defines clinically and biologically distinct subgroups of pediatric diffuse intrinsic pontine gliomas.

  Dong-Anh Khuong-Quang, Pawel Buczkowicz, Patricia Rakopoulos, Xiao-Yang Liu, Adam M Fontebasso, Eric Bouffet, Ute Bartels, Steffen Albrecht, Jeremy Schwartzentruber, Louis Letourneau, [......], Marcel Kool, Andreas von Deimling, Dominik Sturm, Andrey Korshunov, Damien Faury, David T Jones, Jacek Majewski, Stefan M Pfister, Nada Jabado, Cynthia Hawkins
  [show abstract] [hide abstract]
  ABSTRACT: Pediatric glioblastomas (GBM) including diffuse intrinsic pontine gliomas (DIPG) are devastating brain tumors with no effective therapy. Here, we investigated clinical and biological impacts of histone H3.3 mutations. Forty-two DIPGs were tested for H3.3 mutations. Wild-type versus mutated (K27M-H3.3) subgroups were compared for HIST1H3B, IDH, ATRX and TP53 mutations, copy number alterations and clinical outcome. K27M-H3.3 occurred in 71 %, TP53 mutations in 77 % and ATRX mutations in 9 % of DIPGs. ATRX mutations were more frequent in older children (p < 0.0001). No G34V/R-H3.3, IDH1/2 or H3.1 mutations were identified. K27M-H3.3 DIPGs showed specific copy number changes, including all gains/amplifications of PDGFRA and MYC/PVT1 loci. Notably, all long-term survivors were H3.3 wild type and this group of patients had better overall survival. K27M-H3.3 mutation defines clinically and biologically distinct subgroups and is prevalent in DIPG, which will impact future therapeutic trial design. K27M- and G34V-H3.3 have location-based incidence (brainstem/cortex) and potentially play distinct roles in pediatric GBM pathogenesis. K27M-H3.3 is universally associated with short survival in DIPG, while patients wild-type for H3.3 show improved survival. Based on prognostic and therapeutic implications, our findings argue for H3.3-mutation testing at diagnosis, which should be rapidly integrated into the clinical decision-making algorithm, particularly in atypical DIPG.
  Acta Neuropathologica 06/2012; 124(3):439-47. · 9.32 Impact Factor
• Article: Nestin Expression Identifies Ependymoma Patients with Poor Outcome.

  Till Milde, Thomas Hielscher, Hendrik Witt, Marcel Kool, Stephen C Mack, Hedwig E Deubzer, Ina Oehme, Marco Lodrini, Axel Benner, Michael D Taylor, Andreas von Deimling, Andreas E Kulozik, Stefan M Pfister, Olaf Witt, Andrey Korshunov
  [show abstract] [hide abstract]
  ABSTRACT: Ependymomas are primary brain tumors found throughout the central nervous system (CNS) in children and adults. Currently, many treatment protocols stratify grade I and II ependymomas as low-risk tumors, whereas grade III anaplastic ependymomas are considered high-risk tumors. The prognostic significance of World Health Organization (WHO) grade II or III, however, remains debated, and it is furthermore increasingly recognized that the pathologic differentiation between grades II and III is arbitrary in daily practice, thus resulting in imprecise risk stratification. Therefore, prognostic markers enabling more precise stratification to guide treatment decisions are urgently needed. An analysis of n = 379 tumor samples revealed that protein expression of nestin, a marker for neural stem and progenitor cells established as a routine staining in most neuropathology centers, is associated with poor outcome in intracranial ependymomas. Most importantly, nestin-positive grade II ependymomas have the same prognosis as grade III ependymomas. Multivariable analysis demonstrates that nestin positivity is an independent marker for poor progression-free survival (PFS) and overall survival (OS). Gene expression analysis for transcriptionally co-regulated genes revealed a strong association of developmental and epigenetic processes with nestin. In summary, our data implicate nestin as a useful novel marker for intracranial ependymoma risk stratification easily implementable in routine diagnostics.
  Brain Pathology 05/2012; 22(6):848-860. · 3.99 Impact Factor