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Kumar R, Liu APY, Northcott PA. Medulloblastoma genomics in the modern molecular era. Brain Pathol 2019; 30:679-690. [PMID: 31799776 DOI: 10.1111/bpa.12804] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 11/17/2019] [Indexed: 12/13/2022] Open
Abstract
Medulloblastoma (MB) represents a spectrum of biologically and clinically distinct entities. Initially described histopathologically as a small, round blue cell tumor arising in the cerebellum, MB has emerged as a paradigm for molecular classification in cancer. Recent advances in genomic, transcriptomic and epigenomic profiling of MB have further refined molecular classification and complemented conventional histopathological diagnosis. Herein, we review the main clinical and molecular features of the four consensus subgroups of MB (WNT, SHH, Group 3 and Group 4). We also highlight hereditary predisposition syndromes associated with increased risk of MB. Finally, we explore advances in the classification of the consensus molecular groups while also presenting cutting-edge frontiers in identifying intratumoral heterogeneity and cellular origins of MB.
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Affiliation(s)
- Rahul Kumar
- Department of Developmental Neurobiology, Division of Brain Tumor Research, St. Jude Children's Research Hospital, Memphis, TN.,St. Jude Graduate School of Biomedical Sciences, Memphis, TN
| | - Anthony P Y Liu
- Department of Developmental Neurobiology, Division of Brain Tumor Research, St. Jude Children's Research Hospital, Memphis, TN.,Department of Oncology, Division of Neurooncology, St. Jude Children's Research Hospital, Memphis, TN
| | - Paul A Northcott
- Department of Developmental Neurobiology, Division of Brain Tumor Research, St. Jude Children's Research Hospital, Memphis, TN
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Abstract
Medulloblastoma is the most common malignant brain tumor of childhood. Although there is now long-term survival or cure for the majority of children, the survivors bear a significant burden of complications due, at least in part, to the intense therapies given to ensure eradication of the tumor. Significant efforts have been made over the years to be able to distinguish between patients who do and do not need intensive therapies. This review summarizes the history and current state of clinical risk stratification, pathologic diagnosis and genetics. Recent developments in correlation between genetics and pathology, genome-wide association studies and the biology of medulloblastoma metastasis are discussed in detail. The current state of clinical treatment trials are reviewed and placed into the perspective of potential novel therapies in the near term.
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Affiliation(s)
- Donya Aref
- University Health Network Pathology, Arthur & Sonia Labatt Brain Tumour Research Centre, Department of Laboratory Medicine & Pathobiology, Toronto, ON, Canada
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Abstract
Background:The purpose of this study was to determine incidence, survival rate, and prognostic factors as well as the frequency of Collins’ Law Violators (CLVs) in an unselected population of medulloblastoma patients. Collins’ Law dictates that ’cure’ of a child with a tumor occurs after a period that includes the child’s age at diagnosis plus 9 months.Methods:Using the Alberta Cancer Registry a population-based review identified 49 patients with medulloblastoma (19 adults, 30 children) diagnosed from 1975-96. Pathology was reviewed in all cases. All patients had surgical resection, followed by radiotherapy in 47 patients and chemotherapy in 17.Results:The overall 5-year survival was 50%. There was a trend for the extent of resection to be associated with a longer survival (Long rank test, p< 0.06) but this was not significant. Tumor recurrence occurred a median of 22.4 months (range, 6.4-192.3) after diagnosis and median survival after recurrence was 9.3 months (range, 0.4-64.9). The survival curve did not appear to plateau but was affected by tumor-related deaths in 3 (21.4%) of the 21 long-term survivors diagnosed in childhood. These three patients had recurrences a mean of 11.7 years after diagnosis and are designated as CLVs.Conclusions:The survival rate in an unselected population of patients with medulloblastoma is poor. Aggressive resection of the tumors prolongs survival. The Collins’ Law Violators were relatively common and we suggest this concept be abandoned in medulloblastoma.
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Jay V, MacNeill S, Zielenska M. MYCN Amplification in Pediatric Brain Tumors: Detection by Differential Polymerase Chain Reaction. J Histotechnol 2013. [DOI: 10.1179/his.1997.20.2.115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Northcott PA, Dubuc AM, Pfister S, Taylor MD. Molecular subgroups of medulloblastoma. Expert Rev Neurother 2012; 12:871-84. [PMID: 22853794 DOI: 10.1586/ern.12.66] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Recent efforts at stratifying medulloblastomas based on their molecular features have revolutionized our understanding of this morbidity. Collective efforts by multiple independent groups have subdivided medulloblastoma from a single disease into four distinct molecular subgroups characterized by disparate transcriptional signatures, mutational spectra, copy number profiles and, most importantly, clinical features. We present a summary of recent studies that have contributed to our understanding of the core medulloblastoma subgroups, focusing largely on clinically relevant discoveries that have already, and will continue to, shape research.
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Affiliation(s)
- Paul A Northcott
- The Arthur & Sonia Labatt Brain Tumour Research Center, Hospital for Sick Children, Toronto, ON, Canada
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Wright KD, von der Embse K, Coleman J, Patay Z, Ellison DW, Gajjar A. Isochromosome 17q, MYC amplification and large cell/anaplastic phenotype in a case of medullomyoblastoma with extracranial metastases. Pediatr Blood Cancer 2012; 59:561-4. [PMID: 22147345 PMCID: PMC3392450 DOI: 10.1002/pbc.24002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 10/17/2011] [Indexed: 01/16/2023]
Abstract
Medullomyoblastoma (MMB) is a rare variant of medulloblastoma, a member of the family of central nervous system (CNS) embryonal tumors. The outcome of standard therapy for CNS embryonal tumors is often unpredictable in the setting of MMB. Here, we present the clinical course and treatment of an almost 4-year-old girl with MMB that was characterized by MYC amplification, isochromosome 17q and large cell/anaplastic histopathology.
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Affiliation(s)
- Karen D. Wright
- Department of Oncology, Division of Neuro-Oncology, St. Jude Children’s Research Hospital, Memphis, TN,Address for correspondence and reprints: Karen D. Wright, MD, Department of Oncology, Division of Neuro-Oncology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place – Mailstop 260, Memphis, TN 38105-3678, Tel. 901-595-5898, Fax 901-595-4386,
| | | | - Jamie Coleman
- Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN
| | - Zoltan Patay
- Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN
| | - David W. Ellison
- Department of Pathology, St. Jude Children’s Research Hospital, Memphis, TN
| | - Amar Gajjar
- Department of Oncology, Division of Neuro-Oncology, St. Jude Children’s Research Hospital, Memphis, TN
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Abstract
PURPOSE OF REVIEW Most children diagnosed with cancer today are expected to be cured. Medulloblastoma, the most common pediatric malignant brain tumor, is an example of a disease that has benefitted from advances in diagnostic imaging, surgical techniques, radiation therapy and combination chemotherapy over the past decades. It was an incurable disease 50 years ago, but approximately 70% of children with medulloblastoma are now cured of their disease. However, the pace of increasing the cure rate has slowed over the past 2 decades, and we have likely reached the maximal benefit that can be achieved with cytotoxic therapy and clinical risk stratification. Long-term toxicity of therapy also remains significant. To increase cure rates and decrease long-term toxicity, there is great interest in incorporating biologic 'targeted' therapy into treatment of medulloblastoma, but this will require a paradigm shift in how we classify and study disease. RECENT FINDINGS Using genome-based high-throughput analytic techniques, several groups have independently reported methods of molecular classification of medulloblastoma within the past year. This has resulted in a working consensus to view medulloblastoma as four molecular subtypes, including wingless-type murine mammary tumor virus integration site (WNT) pathway subtype, Sonic Hedgehog pathway subtype and two less well defined subtypes (groups C and D). SUMMARY Novel classification and risk stratification based on biologic subtypes of disease will form the basis of further study in medulloblastoma and identify specific subtypes that warrant greater research focus.
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Abstract
Embryonal brain tumors are a heterogeneous group of neoplasms united by the presence of poorly differentiated stem-like cells. Molecular details are increasingly being used to separate them into biologically and clinically meaningful groups. For medulloblastoma, integrated mRNA expression profiling and DNA analysis by a number of research groups defines 4-6 distinctive molecular variants. A subset with prominent Wnt activity is associated with good clinical outcomes and classic histology. Medulloblastomas showing a Hedgehog gene expression signature are frequently of the desmoplastic/nodular subtype. Interestingly, Hedgehog activity is found in tumors arising either in infants or older teenagers and adults. The association of clinically aggressive medulloblastoma with MYC expression, large cell/anaplastic change and high levels of photoreceptor differentiation transcripts has also been noted in several studies. Immunohistochemical analysis of just one or two genes per molecular medulloblastoma variant may be sufficient for accurate classification, and this would be of great practical utility if validated. Advances have also been made in the classification of central nervous system (CNS) Primitive Neuroectodermal Tumors (PNET), as several groups have identified an amplicon at chromosome 19q13.41-42, which appears to define a unique PNET subtype associated with prominent true rosettes, young age and very poor outcomes.
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Affiliation(s)
- Charles G Eberhart
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Md 21205, USA.
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Wang X, Cui M, Wang L, Chen X, Xin P. Inhibition of neurotrophin receptor p75 intramembran proteolysis by gamma-secretase inhibitor reduces medulloblastoma spinal metastasis. Biochem Biophys Res Commun 2010; 403:264-9. [DOI: 10.1016/j.bbrc.2010.11.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Accepted: 11/04/2010] [Indexed: 12/01/2022]
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Zhou L, Picard D, Ra YS, Li M, Northcott PA, Hu Y, Stearns D, Hawkins C, Taylor MD, Rutka J, Der SD, Huang A. Silencing of thrombospondin-1 is critical for myc-induced metastatic phenotypes in medulloblastoma. Cancer Res 2010; 70:8199-210. [PMID: 20876797 DOI: 10.1158/0008-5472.can-09-4562] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mechanisms by which c-Myc (Myc) amplification confers aggressive medulloblastoma phenotypes are poorly defined. Here, we show using orthotopic models that high Myc expression promotes cell migration/invasion and induces metastatic tumors, which recapitulate aggressive histologic features of Myc-amplified primary human medulloblastoma. Using ChIP-chip analysis, we identified cell migration and adhesion genes, including Tsp-1/THBS1, ING4, PVRL3, and PPAP2B, as Myc-bound loci in medulloblastoma cells. Expression of Tsp-1 was most consistently and robustly diminished in medulloblastoma cell lines and primary human tumors with high Myc expression (n = 101, P = 0.032). Strikingly, stable Tsp-1 expression significantly attenuated in vitro transformation and invasive/migratory properties of high Myc-expressing medulloblastoma cells without altering cell proliferation, whereas RNA interference-mediated Myc knockdown was consistently accompanied by increased Tsp-1 levels and reduced cell migration and invasion in medulloblastoma cells. Chromatin immunoprecipitation (ChIP) assays revealed colocalization of Myc and obligate partner Max and correlated diminished RNA polymerase II occupancy (∼3-fold decrease, P < 0.01) with increased Myc binding at a core Tsp-1 promoter. Reporter gene and/or gel shift assays confirmed direct repression of Tsp-1 transcription by Myc and also identified JPO2, a Myc interactor associated with metastatic medulloblastoma, as a cofactor in Myc-mediated Tsp-1 repression. These findings indicate the Myc-regulatory network targets Tsp-1 via multiple mechanisms in medulloblastoma transformation, and highlight a novel critical role for Tsp-1 in Myc-mediated aggressive medulloblastoma phenotypes.
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Affiliation(s)
- Limei Zhou
- Sonia and Arthur Labatt Brain Tumor Research Centre, Hospital for Sick Children, University Avenue, Toronto, Ontario, Canada M5G 1X8
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Childhood medulloblastoma: novel approaches to the classification of a heterogeneous disease. Acta Neuropathol 2010; 120:305-16. [PMID: 20652577 DOI: 10.1007/s00401-010-0726-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 07/12/2010] [Accepted: 07/12/2010] [Indexed: 10/19/2022]
Abstract
Increasing recognition of pediatric medulloblastoma as a heterogeneous disease, with histopathological and molecular variants that have distinct biological behaviors, will impact how the disease is classified and treated. A combination of clinicopathological evaluation and assays based on molecular subgroups of disease will allow stratification of patients into risk groups and a more tailored approach to therapy. Patients with low-risk disease could be treated with de-escalated adjuvant therapy to maximize cure while reducing long-term adverse effects, and novel therapies could be sought for patients with high-risk disease. My review encompasses a brief overview of the clinical landscape, the current World Health Organization (WHO) classification of medulloblastoma, the status of molecular subgroups, and how potential stratification schemes might impact pathologists and their practice.
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Zitterbart K, Filkova H, Tomasikova L, Necesalova E, Zambo I, Kantorova D, Slamova I, Vranova V, Zezulkova D, Pesakova M, Pavelka Z, Veselska R, Kuglik P, Sterba J. Low-level copy number changes of MYC genes have a prognostic impact in medulloblastoma. J Neurooncol 2010; 102:25-33. [PMID: 20607354 DOI: 10.1007/s11060-010-0289-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Accepted: 06/21/2010] [Indexed: 01/22/2023]
Abstract
High-level amplifications of MYC genes are associated with poor outcomes in childhood medulloblastoma (MB). However, the occurrence of MYCN and MYCC copy number increases below the intense amplification pattern is rarely reported, and its clinical impact has not yet been determined. Here, we describe this phenomenon and its prognostic significance in a cohort of 29 MB patients. Using interphase fluorescence in situ hybridization (I-FISH), low-level copy number alterations, i.e. gain of MYCN, were shown in 5/27 (19%) samples, whereas amplification was revealed in only 1/27 (4%) samples. MYCC gain was revealed in 6/29 (21%) MB, while amplification was disclosed in only 2/29 (7%). Hyperploidy and co-incidence of gains in both MYC loci were frequently observed in samples with copy number aberrations. Survival analysis has clearly shown that MYC copy number increases are associated with lowered event-free survival and overall survival in MB. In the case of MYCN, this negative correlation was statistically significant. We conclude that limited numerical alterations in loci 2p24 (MYCN) and 8q24 (MYCC), as assessed by I-FISH, are present in MB with a higher frequency than high-level amplifications. Poor prognoses were observed in patients with copy number increases in MYC genes. Our data illustrate the importance of further investigations in multicenter trials to better refine the emerging genomic-based prognostic stratification in MB.
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Affiliation(s)
- Karel Zitterbart
- Department of Pediatric Oncology, University Hospital Brno, Masaryk University, Cernopolni 9, 613 00 Brno, Czech Republic.
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Shalaby T, von Bueren AO, Hürlimann ML, Fiaschetti G, Castelletti D, Masayuki T, Nagasawa K, Arcaro A, Jelesarov I, Shin-ya K, Grotzer M. Disabling c-Myc in childhood medulloblastoma and atypical teratoid/rhabdoid tumor cells by the potent G-quadruplex interactive agent S2T1-6OTD. Mol Cancer Ther 2010; 9:167-79. [PMID: 20053783 DOI: 10.1158/1535-7163.mct-09-0586] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We investigated here the effects of S2T1-6OTD, a novel telomestatin derivative that is synthesized to target G-quadruplex-forming DNA sequences, on a representative panel of human medulloblastoma (MB) and atypical teratoid/rhabdoid (AT/RT) childhood brain cancer cell lines. S2T1-6OTD proved to be a potent c-Myc inhibitor through its high-affinity physical interaction with the G-quadruplex structure in the c-Myc promoter. Treatment with S2T1-6OTD reduced the mRNA and protein expressions of c-Myc and hTERT, which is transcriptionally regulated by c-Myc, and decreased the activities of both genes. In remarkable contrast to control cells, short-term (72-hour) treatment with S2T1-6OTD resulted in a dose- and time-dependent antiproliferative effect in all MB and AT/RT brain tumor cell lines tested (IC(50), 0.25-0.39 micromol/L). Under conditions where inhibition of both proliferation and c-Myc activity was observed, S2T1-6OTD treatment decreased the protein expression of the cell cycle activator cyclin-dependent kinase 2 and induced cell cycle arrest. Long-term treatment (5 weeks) with nontoxic concentrations of S2T1-6OTD resulted in a time-dependent (mainly c-Myc-dependent) telomere shortening. This was accompanied by cell growth arrest starting on day 28 followed by cell senescence and induction of apoptosis on day 35 in all of the five cell lines investigated. On in vivo animal testing, S2T1-6OTD may well represent a novel therapeutic strategy for childhood brain tumors.
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Affiliation(s)
- Tarek Shalaby
- Department of Oncology, University Children's Hospital Zurich, Zurich, Switzerland
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Northcott PA, Rutka JT, Taylor MD. Genomics of medulloblastoma: from Giemsa-banding to next-generation sequencing in 20 years. Neurosurg Focus 2010; 28:E6. [DOI: 10.3171/2009.10.focus09218] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Advances in the field of genomics have recently enabled the unprecedented characterization of the cancer genome, providing novel insight into the molecular mechanisms underlying malignancies in humans. The application of high-resolution microarray platforms to the study of medulloblastoma has revealed new oncogenes and tumor suppressors and has implicated changes in DNA copy number, gene expression, and methylation state in its etiology. Additionally, the integration of medulloblastoma genomics with patient clinical data has confirmed molecular markers of prognostic significance and highlighted the potential utility of molecular disease stratification. The advent of next-generation sequencing technologies promises to greatly transform our understanding of medulloblastoma pathogenesis in the next few years, permitting comprehensive analyses of all aspects of the genome and increasing the likelihood that genomic medicine will become part of the routine diagnosis and treatment of medulloblastoma.
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Affiliation(s)
- Paul A. Northcott
- 1Division of Neurosurgery, Arthur and Sonia Labatt Brain Tumour Research Centre
- 2Program in Developmental and Stem Cell Biology, The Hospital for Sick Children; and
- 3Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada
| | - James T. Rutka
- 1Division of Neurosurgery, Arthur and Sonia Labatt Brain Tumour Research Centre
- 3Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada
| | - Michael D. Taylor
- 1Division of Neurosurgery, Arthur and Sonia Labatt Brain Tumour Research Centre
- 2Program in Developmental and Stem Cell Biology, The Hospital for Sick Children; and
- 3Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada
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Alam G, Cui H, Shi H, Yang L, Ding J, Mao L, Maltese WA, Ding HF. MYCN promotes the expansion of Phox2B-positive neuronal progenitors to drive neuroblastoma development. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 175:856-66. [PMID: 19608868 DOI: 10.2353/ajpath.2009.090019] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Amplification of the oncogene MYCN is a tumorigenic event in the development of a subset of neuroblastomas that commonly consist of undifferentiated or poorly differentiated neuroblasts with unfavorable clinical outcome. The cellular origin of these neuroblasts is unknown. Additionally, the cellular functions and target cells of MYCN in neuroblastoma development remain undefined. Here we examine the cell types that drive neuroblastoma development in TH-MYCN transgenic mice, an animal model of the human disease. Neuroblastoma development in these mice begins with hyperplastic lesions in early postnatal sympathetic ganglia. We show that both hyperplasia and primary tumors are composed predominantly of highly proliferative Phox2B(+) neuronal progenitors. MYCN induces the expansion of these progenitors by both promoting their proliferation and preventing their differentiation. We further identify a minor population of undifferentiated nestin(+) cells in both hyperplastic lesions and primary tumors that may serve as precursors of Phox2B(+) neuronal progenitors. These findings establish the identity of neuroblasts that characterize the tumor phenotype and suggest a cellular pathway by which MYCN can promote neuroblastoma development.
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Affiliation(s)
- Goleeta Alam
- Department of Pathology and Cancer Center, Medical College of Georgia, 1120 15 Street, CN-4132, Augusta, GA 30912, USA
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Behdad A, Perry A. Central nervous system primitive neuroectodermal tumors: a clinicopathologic and genetic study of 33 cases. Brain Pathol 2009; 20:441-50. [PMID: 19725831 DOI: 10.1111/j.1750-3639.2009.00314.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Central nervous system (CNS) primitive neuroectodermal tumors (PNETs) include supratentorial, brain stem, and spinal cord tumors with medulloblastoma-like histopathology. The prognostic impact of various pathologic and genetic features has not been thoroughly investigated. After re-diagnosis of three infantile cases as atypical teratoid/rhabdoid tumor (AT/RT), 33 remaining CNS PNETs were retrieved for clinicopathologic and fluorescence in situ hybridization studies. Anaplastic and/or large cell features were seen in 18 of 33 (55%) examples and survival was decreased in these patients (P = 0.036). MYCN or MYCC gene amplifications were noted in about half, with a trend towards decreased survival (P = 0.112). Polysomies of chromosomes 2 and 8 were each individually associated with decreased survival in children, with an even stronger association when combined (P = 0.013). Neither EWS gene rearrangements, nor AT/RT-like 22q deletions were encountered. We conclude that in CNS PNET: (i) routine application of INI1 immunohistochemistry helps rule out AT/RT, particularly in infants; (ii) MYC gene amplifications (especially MYCN) are common; (iii) involvement of CNS parenchyma by Ewing sarcoma/peripheral PNET is rare enough that EWS gene testing is not necessary unless significant dural involvement is present; and (iv) both anaplastic/large cell features and polysomies of 2 and 8 are associated with more aggressive clinical behavior.
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Affiliation(s)
- Amir Behdad
- Department of Pathology, Cedar Sinai Medical Center, Los Angeles, Calif, USA
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McCabe MG, Ichimura K, Pearson DM, Liu L, Clifford SC, Ellison DW, Collins VP. Novel mechanisms of gene disruption at the medulloblastoma isodicentric 17p11 breakpoint. Genes Chromosomes Cancer 2009; 48:121-31. [DOI: 10.1002/gcc.20625] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kool M, Koster J, Bunt J, Hasselt NE, Lakeman A, van Sluis P, Troost D, Meeteren NSV, Caron HN, Cloos J, Mrsić A, Ylstra B, Grajkowska W, Hartmann W, Pietsch T, Ellison D, Clifford SC, Versteeg R. Integrated genomics identifies five medulloblastoma subtypes with distinct genetic profiles, pathway signatures and clinicopathological features. PLoS One 2008; 3:e3088. [PMID: 18769486 PMCID: PMC2518524 DOI: 10.1371/journal.pone.0003088] [Citation(s) in RCA: 524] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Accepted: 07/29/2008] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Medulloblastoma is the most common malignant brain tumor in children. Despite recent improvements in cure rates, prediction of disease outcome remains a major challenge and survivors suffer from serious therapy-related side-effects. Recent data showed that patients with WNT-activated tumors have a favorable prognosis, suggesting that these patients could be treated less intensively, thereby reducing the side-effects. This illustrates the potential benefits of a robust classification of medulloblastoma patients and a detailed knowledge of associated biological mechanisms. METHODS AND FINDINGS To get a better insight into the molecular biology of medulloblastoma we established mRNA expression profiles of 62 medulloblastomas and analyzed 52 of them also by comparative genomic hybridization (CGH) arrays. Five molecular subtypes were identified, characterized by WNT signaling (A; 9 cases), SHH signaling (B; 15 cases), expression of neuronal differentiation genes (C and D; 16 and 11 cases, respectively) or photoreceptor genes (D and E; both 11 cases). Mutations in beta-catenin were identified in all 9 type A tumors, but not in any other tumor. PTCH1 mutations were exclusively identified in type B tumors. CGH analysis identified several fully or partly subtype-specific chromosomal aberrations. Monosomy of chromosome 6 occurred only in type A tumors, loss of 9q mostly occurred in type B tumors, whereas chromosome 17 aberrations, most common in medulloblastoma, were strongly associated with type C or D tumors. Loss of the inactivated X-chromosome was highly specific for female cases of type C, D and E tumors. Gene expression levels faithfully reflected the chromosomal copy number changes. Clinicopathological features significantly different between the 5 subtypes included metastatic disease and age at diagnosis and histology. Metastatic disease at diagnosis was significantly associated with subtypes C and D and most strongly with subtype E. Patients below 3 yrs of age had type B, D, or E tumors. Type B included most desmoplastic cases. We validated and confirmed the molecular subtypes and their associated clinicopathological features with expression data from a second independent series of 46 medulloblastomas. CONCLUSIONS The new medulloblastoma classification presented in this study will greatly enhance the understanding of this heterogeneous disease. It will enable a better selection and evaluation of patients in clinical trials, and it will support the development of new molecular targeted therapies. Ultimately, our results may lead to more individualized therapies with improved cure rates and a better quality of life.
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Affiliation(s)
- Marcel Kool
- Department of Human Genetics, Academic Medical Center, Amsterdam, the Netherlands.
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Entz-Werle N, Carli ED, Ducassou S, Legrain M, Grill J, Dufour C. Medulloblastoma: what is the role of molecular genetics? Expert Rev Anticancer Ther 2008; 8:1169-81. [PMID: 18588461 DOI: 10.1586/14737140.8.7.1169] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Among pediatric malignancies, medulloblastoma (MB) is one of the most common malignant tumors of the CNS. In the past few years, thanks to a multidisciplinary approach including surgery, chemo- and radiation therapy, survival has significantly improved. Despite that, a third of patients still have a low chance of being cured and long-term survivors experience severe treatment-related sequelae. MBs are usually classified according to a clinical risk stratification, based on histological features, age at diagnosis, extent of tumor resection and presence or absence of metastases. However, these clinical variables have recently been reported to be poor for defining risk-related disease. Retrospective studies have identified histological or biological factors that have distinct roles in prognosis. As several pathways have been discovered to be involved in MB pathogenesis, they should be taken into account to more accurately stratify patients and their treatment and to develop innovative therapies.
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Affiliation(s)
- Natacha Entz-Werle
- Service de Pédiatrie, U 682 Inserm CHRU Hautepierre, Avenue Molière - 67098 Strasbourg Cedex France.
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Behesti H, Marino S. Cerebellar granule cells: insights into proliferation, differentiation, and role in medulloblastoma pathogenesis. Int J Biochem Cell Biol 2008; 41:435-45. [PMID: 18755286 DOI: 10.1016/j.biocel.2008.06.017] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Revised: 05/30/2008] [Accepted: 06/09/2008] [Indexed: 12/28/2022]
Abstract
Cerebellar granule cells originate from precursors located in the dorsal region of rhombomere one within the hindbrain of developing embryos. They undergo proliferation for an extensive period well into postnatal stages of development to form the major cell type of the cerebellum, the most populous structure within the mammalian brain. Granule cell development is highly dependent upon the cerebellar environment and contact with neighbouring cells. In recent years, the molecular basis of these interactions has started to be unravelled. Granule cell precursors and the molecular mechanisms involved in controlling their proliferation have been shown to be involved in the pathogenesis of medulloblastoma, the most common malignant pediatric brain tumour. Here, we review the control of granule cell generation with emphasis on the molecular regulators of cell proliferation and differentiation during normal and malignant development.
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Affiliation(s)
- Hourinaz Behesti
- Institute of Cell and Molecular Science, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, E1 2AT London, United Kingdom.
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de Haas T, Hasselt N, Troost D, Caron H, Popovic M, Zadravec-Zaletel L, Grajkowska W, Perek M, Osterheld MC, Ellison D, Baas F, Versteeg R, Kool M. Molecular risk stratification of medulloblastoma patients based on immunohistochemical analysis of MYC, LDHB, and CCNB1 expression. Clin Cancer Res 2008; 14:4154-60. [PMID: 18593994 DOI: 10.1158/1078-0432.ccr-07-4159] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Medulloblastoma is the most common malignant embryonal brain tumor in children. The current clinical risk stratification to select treatment modalities is not optimal because it does not identify the standard-risk patients with resistant disease or the unknown number of high-risk patients who might be overtreated with current protocols. The aim of this study is to improve the risk stratification of medulloblastoma patients by using the expression of multiple prognostic markers in combination with current clinical parameters. EXPERIMENTAL DESIGN Candidate prognostic markers were selected from literature or from medulloblastoma expression data. Selected genes were immunohistochemically analyzed for their prognostic value using medulloblastoma tissue arrays containing 124 well-characterized patient samples. RESULTS Protein expression analyses showed that the combined expression of three genes was able to predict survival in medulloblastoma patients. Low MYC expression identified medulloblastoma patients with a very good outcome. In contrast, concomitant expression of LDHB and CCNB1 characterized patients with a very poor outcome. Multivariate analyses showed that both expression of MYC and the LDHB/CCNB1 gene signature were strong prognostic markers independent of the clinical parameters metastasis and residual disease. Combined analysis of clinical and molecular markers enabled greater resolution of disease risk than clinical factors alone. CONCLUSIONS A molecular risk stratification model for medulloblastoma patients is proposed based on the signature of MYC, LDHB, and CCNB1 expression. Combined with clinical variables, the model may provide a more accurate basis for targeting therapy in children with this disease.
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Affiliation(s)
- Talitha de Haas
- Department of Human Genetics, Neuropathology, and Neurogenetics, Academic Medical Center, Amsterdam, the Netherlands
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Abstract
The past decades have seen an increase in the survival rates of patients with standard-risk medulloblastoma. Efforts have, therefore, been focused on obtaining better results in the treatment of patients with high-risk tumors. In addition to consolidated therapies, novel approaches such as small molecules, monoclonal antibodies, and antiangiogenic therapies that aim to improve outcomes and quality of life are now available through new breakthroughs in the molecular biology of medulloblastoma. The advent of innovative anticancer drugs tested in brain tumors has important consequences for personalized therapy. Gene expression profiling of medulloblastoma can be used to identify the genes and signaling transduction pathways that are crucial for the tumorigenesis process, thereby revealing both new targets for therapy and sensitive/resistance phenotypes. The interpretation of microarray data for new treatments of patients with high-risk medulloblastoma, as well as other poor prognosis tumors, should be developed through a consensus multidisciplinary approach involving oncologists, neurosurgeons, radiotherapists, biotechnologists, bioinformaticists, and other professionals.
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Affiliation(s)
- Iacopo Sardi
- Department of Pediatrics, Onco-hematology and Neuro-surgery Units, University of Florence Medical School, A. Meyer Children's Hospital, Florence, Italy.
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Shimato S, Natsume A, Takeuchi H, Wakabayashi T, Fujii M, Ito M, Ito S, Park IH, Bang JH, Kim SU, Yoshida J. Human neural stem cells target and deliver therapeutic gene to experimental leptomeningeal medulloblastoma. Gene Ther 2007; 14:1132-42. [PMID: 17508009 DOI: 10.1038/sj.gt.3302932] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Medulloblastomas are highly malignant neuroectodermal cerebellar tumors of children. One of the reasons for the difficulty for the treatment of medulloblastomas is their inherent tendency to metastasize through the cerebrospinal fluid (CSF) pathway leading to leptomeningeal dissemination. Recently, genetically modified neural stem cells (NSCs) were shown to have the capability of selectively migrating into glioma mass and delivering therapeutic agents with significant therapeutic benefits. In the present study, we applied the NSC strategy to target medulloblastomas, particularly their leptomeningeal dissemination. We used NSCs that were retrovirally transduced with the cytosine deaminase gene (CD-NSCs). In vitro studies demonstrated that CD-NSCs had sufficient migratory activity toward medulloblastoma cells and exerted a remarkable bystander effect on these cells following the application of 5-fluorocytosine (5-FC). It is noteworthy that neutralization of the hepatocyte growth factor blocked their migration In animal studies using our leptomeningeal dissemination model, CD-NSCs implanted directly into CSF space were shown to distribute diffusely within the disseminated tumor cells and could provide remarkable antitumor effect after intraperitoneal administration of 5-FC. Furthermore, CD-NSC treatment followed by 5-FC administration prolonged survival periods significantly in experimental animals. Our data suggest that the CD-NSC strategy can also be applied to target leptomeningeal dissemination of medulloblastomas.
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Affiliation(s)
- S Shimato
- Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
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24
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Anti-proliferative activity of the quassinoid NBT-272 in childhood medulloblastoma cells. BMC Cancer 2007; 7:19. [PMID: 17254356 PMCID: PMC1794252 DOI: 10.1186/1471-2407-7-19] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Accepted: 01/25/2007] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND With current treatment strategies, nearly half of all medulloblastoma (MB) patients die from progressive tumors. Accordingly, the identification of novel therapeutic strategies remains a major goal. Deregulation of c-MYC is evident in numerous human cancers. In MB, over-expression of c-MYC has been shown to correlate with anaplasia and unfavorable prognosis. In neuroblastoma--an embryonal tumor with biological similarities to MB--the quassinoid NBT-272 has been demonstrated to inhibit cellular proliferation and to down-regulate c-MYC protein expression. METHODS To study MB cell responses to NBT-272 and their dependence on the level of c-MYC expression, DAOY (wild-type, empty vector transfected or c-MYC transfected), D341 (c-MYC amplification) and D425 (c-MYC amplification) human MB cells were used. The cells were treated with different concentrations of NBT-272 and the impact on cell proliferation, apoptosis and c-MYC expression was analyzed. RESULTS NBT-272 treatment resulted in a dose-dependent inhibition of cellular proliferation (IC50 in the range of 1.7-9.6 ng/ml) and in a dose-dependent increase in apoptotic cell death in all human MB cell lines tested. Treatment with NBT-272 resulted in up to 90% down-regulation of c-MYC protein, as demonstrated by Western blot analysis, and in a significant inhibition of c-MYC binding activity. Anti-proliferative effects were slightly more prominent in D341 and D425 human MB cells with c-MYC amplification and slightly more pronounced in c-MYC over-expressing DAOY cells compared to DAOY wild-type cells. Moreover, treatment of synchronized cells by NBT-272 induced a marked cell arrest at the G1/S boundary. CONCLUSION In human MB cells, NBT-272 treatment inhibits cellular proliferation at nanomolar concentrations, blocks cell cycle progression, induces apoptosis, and down-regulates the expression of the oncogene c-MYC. Thus, NBT-272 may represent a novel drug candidate to inhibit proliferation of human MB cells in vivo.
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Kuttler F, Mai S. Formation of non-random extrachromosomal elements during development, differentiation and oncogenesis. Semin Cancer Biol 2006; 17:56-64. [PMID: 17116402 DOI: 10.1016/j.semcancer.2006.10.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Accepted: 10/17/2006] [Indexed: 11/25/2022]
Abstract
Extrachromosomal elements (EEs) were first discovered as minute chromatin bodies [Cox et al. Minute chromatin bodies in malignant tumors of childhood. Lancet 1965;62:55-8], and subsequently characterized as small circular DNA molecules physically separated from chromosomes. They include episomes, minichromosomes, small polydispersed DNAs or double minutes. This review focuses on eukaryotic EEs generated by genome rearrangements under physiological or pathological conditions. Some of those rearrangements occur randomly, but others are strictly non-random, highly regulated, and involve specific chromosomal locations (V(D)J-recombination, telomere maintenance mechanisms, c-myc deregulation). The multiple mechanisms of EEs formation are strongly interconnected and frequently linked to gene amplification. Identification of genes located on EEs will undoubtedly allow a better understanding of genome dynamics and oncogenic pathways.
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Affiliation(s)
- Fabien Kuttler
- Manitoba Institute of Cell Biology, CancerCare Manitoba, University of Manitoba, 675 McDermot Avenue, Winnipeg, Man. R3E 0V9, Canada.
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Trojanek J, Ho T, Croul S, Wang JY, Chintapalli J, Koptyra M, Giordano A, Khalili K, Reiss K. IRS-1-Rad51 nuclear interaction sensitizes JCV T-antigen positive medulloblastoma cells to genotoxic treatment. Int J Cancer 2006; 119:539-48. [PMID: 16572421 DOI: 10.1002/ijc.21828] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The large T-antigen from human polyomavirus JC (JCV T-antigen) is suspected to play a role in malignant transformation. Previously, we reported that JCV T-antigen requires the presence of a functional insulin-like growth factor I receptor (IGF-IR) for transformation of fibroblasts and for survival of medulloblastoma cell lines; that IGF-IR is phosphorylated in medulloblastoma biopsies and that JCV T-antigen inhibits homologous recombination-directed DNA repair, causing accumulation of mutations. Here we are evaluating whether JCV T-antigen positive and negative mouse medulloblastoma cell lines, which significantly differ in their tumorigenic properties, are also different in their abilities to repair double strand breaks of DNA (DSBs). Our results show that despite much stronger tumorigenic potential, JCV T-antigen positive medulloblastoma cells are more sensitive to genotoxic agents (cisplatin and gamma-irradiation). Subsequent analysis of DNA repair of DSBs indicated that homologous recombination-directed DNA repair (HRR) was selectively attenuated in JCV T-antigen positive medulloblastoma cells. JCV T-antigen did not affect HRR directly. In the presence of JCV T-antigen, insulin receptor substrate 1 (IRS-1) translocated to the nucleus where it co-localized with Rad51, possibly attenuating HRR.
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Affiliation(s)
- Joanna Trojanek
- Center for Neurovirology, Department of Neuroscience, Temple University, Philadelphia, PA 19122, USA
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Inda MM, Muñoz J, Coullin P, Fauvet D, Danglot G, Tuñón T, Bernheim A, Castresana JS. High promoter hypermethylation frequency of p14/ARF in supratentorial PNET but not in medulloblastoma. Histopathology 2006; 48:579-87. [PMID: 16623784 DOI: 10.1111/j.1365-2559.2006.02374.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
AIMS Medulloblastoma (MB) is the most common primitive neuroectodermal tumour (PNET) of the central nervous system. Although supratentorial PNET (sPNET) and MB are histologically similar, their clinical behaviour differs, sPNET being more aggressive than MB. The aim of this study was to determine whether sPNET and MB are genetically different entities. METHODS AND RESULTS We investigated 32 PNET primary tumour samples (23 MB and nine sPNET) and four PNET cell lines, for the presence of CDKN2A homozygous deletions at exon 1-alpha of p16/INK4 and exon 1-beta of p14/ARF, and promoter hypermethylation of both genes. No homozygous deletion of either p16/INK4 or p14/ARF was demonstrated in any of the PNET primary tumour samples. Methylation of p16/INK4 was found in one of six sPNET and in one of 23 MB, while p14/ARF methylation was observed in three of six sPNET and in three of 21 MB. No methylation of p16/INK4 or p14/ARF was found in any of the PNET cell lines analysed. The three MB cell lines did not show p16/INK4 expression, and only the MB Daoy cell line (homozygously deleted at CDKN2A) presented loss of p14/ARF expression. CONCLUSIONS Our results in this limited series of central PNET show that p14/ARF is frequently involved in PNET carcinogenesis, with a higher frequency, but not statistically significant, for sPNET than for MB.
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Affiliation(s)
- M M Inda
- Laboratorio de Neuro-Oncología Molecular, Universidad de Navarra, Pamplona, Spain
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Gilbertson RJ, Gajjar A. Molecular biology of medulloblastoma: will it ever make a difference to clinical management? J Neurooncol 2006; 75:273-8. [PMID: 16195803 DOI: 10.1007/s11060-005-6750-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Over the last 10 years approximately 750 children with medulloblastoma have been treated on consortia based clinical trials at an estimated cost of over 150 million US dollars. Despite this enormous effort, no meaningful molecular data has been generated that will inform the next generation of clinical studies. It is imperative that the neuro-oncology community give greater priority to studies of medulloblastoma molecular biology: unless we do this our patients will face a bleak future in which there is no accurate disease-risk stratification tool and no effective new treatments. We review some of the reasons we have failed to translate knowledge of medulloblastoma disease biology to the clinic and look forward to the next generation of clinical and molecular studies that are seeking to correct this.
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Affiliation(s)
- Richard J Gilbertson
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 332 North Lauderdale St., Memphis, TN 38105, USA
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Stearns D, Chaudhry A, Abel TW, Burger PC, Dang CV, Eberhart CG. c-myc overexpression causes anaplasia in medulloblastoma. Cancer Res 2006; 66:673-81. [PMID: 16423996 DOI: 10.1158/0008-5472.can-05-1580] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Both anaplasia and increased c-myc gene expression have been shown to be negative prognostic indicators for survival in medulloblastoma patients. myc gene amplification has been identified in many large cell/anaplastic medulloblastoma, but no causative link between c-myc and anaplastic changes has been established. To address this, we stably overexpressed c-myc in two medulloblastoma cell lines, DAOY and UW228, and examined the changes in growth characteristics. When analyzed in vitro, cell lines with increased levels of c-myc had higher rates of growth and apoptosis as well as significantly improved ability to form colonies in soft agar compared with control. When injected s.c. into nu/nu mice, flank xenograft tumors with high levels of c-myc in DAOY cell line background were 75% larger than those derived from control. Overexpression of c-myc was required for tumor formation by UW228 cells. Most remarkably, the histopathology of the Myc tumors was severely anaplastic, with large areas of necrosis/apoptosis, increased nuclear size, and macronucleoli. Indices of proliferation and apoptosis were also significantly higher in Myc xenografts. Thus, c-myc seems to play a causal role in inducing anaplasia in medulloblastoma. Because anaplastic changes are often observed in recurrent medulloblastoma, we propose that c-myc dysregulation is involved in the progression of these malignant embryonal neoplasms.
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Affiliation(s)
- Duncan Stearns
- Department of Neuropathology, Johns Hopkins University School of Medicine, 558 Ross Building, 720 Rutland Avenue, Baltimore, MD 21205, USA.
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Hui ABY, Takano H, Lo KW, Kuo WL, Lam CNY, Tong CYK, Chang Q, Gray JW, Ng HK. Identification of a novel homozygous deletion region at 6q23.1 in medulloblastomas using high-resolution array comparative genomic hybridization analysis. Clin Cancer Res 2005; 11:4707-16. [PMID: 16000565 DOI: 10.1158/1078-0432.ccr-05-0128] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE The aim of this study is to comprehensively characterize genome copy number aberrations in medulloblastomas using high-resolution array comparative genomic hybridization. EXPERIMENTAL DESIGN High-density genomic arrays containing 1,803 BAC clones were used to define recurrent chromosomal regions of gains or losses throughout the whole genome of medulloblastoma. A series of 3 medulloblastoma cell lines and 16 primary tumors were investigated. RESULTS The detected consistent chromosomal aberrations included gains of 1q21.3-q23.1 (36.8%), 1q32.1 (47.4%), 2p23.1-p25.3 (52.6%), 7 (57.9%), 9q34.13-q34.3 (47.4%), 17p11.2-q25.3 (89.5%), and 20q13.31-q13.33 (42.1%), as well as losses of 3q26.1 (57.9%), 4q31.23-q32.3 (42.1%), 6q23.1-25.3 (57.9%), 8p22-23.3 (79%), 10q24.32-26.2 (57.9%), and 16q23.2-q24.3 (63.2%). One of the most notable aberrations was a homozygous deletion on chromosome 6q23 in the cell line DAOY, and single copy loss on 30.3% primary tumors. Further analyses defined a 0.887 Mbp minimal region of homozygous deletion at 6q23.1 flanked by markers SHGC-14149 (6q22.33) and SHGC-110551 (6q23.1). Quantitative reverse transcription-PCR analysis showed complete loss of expression of two genes located at 6q23.1, AK091351 (hypothetical protein FLJ34032) and KIAA1913, in the cell line DAOY. mRNA levels of these genes was reduced in cell lines D283 and D384, and in 50% and 70% of primary tumors, respectively. CONCLUSION Current array comparative genomic hybridization analysis generates a comprehensive pattern of chromosomal aberrations in medulloblastomas. This information will lead to a better understanding of medulloblastoma tumorigenesis. The delineated regions of gains or losses will indicate locations of medulloblastoma-associated genes. A 0.887 Mbp homozygous deletion region was newly identified at 6q23.1. Frequent detection of reduced expression of AK091351 and KIAA1913 genes implicates them as suppressors of medulloblastoma tumorigenesis.
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Affiliation(s)
- Angela B Y Hui
- Department of Anatomical and Cellular Pathology, Chinese University of Hong Kong, Hong Kong SAR, PR China
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Bayani J, Pandita A, Squire JA. Molecular cytogenetic analysis in the study of brain tumors: findings and applications. Neurosurg Focus 2005; 19:E1. [PMID: 16398459 DOI: 10.3171/foc.2005.19.5.2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Classic cytogenetics has evolved from black and white to technicolor images of chromosomes as a result of advances in fluorescence in situ hybridization (FISH) techniques, and is now called molecular cytogenetics. Improvements in the quality and diversity of probes suitable for FISH, coupled with advances in computerized image analysis, now permit the genome or tissue of interest to be analyzed in detail on a glass slide. It is evident that the growing list of options for cytogenetic analysis has improved the understanding of chromosomal changes in disease initiation, progression, and response to treatment. The contributions of classic and molecular cytogenetics to the study of brain tumors have provided scientists and clinicians alike with new avenues for investigation. In this review the authors summarize the contributions of molecular cytogenetics to the study of brain tumors, encompassing the findings of classic cytogenetics, interphase- and metaphase-based FISH studies, spectral karyotyping, and metaphase- and array-based comparative genomic hybridization. In addition, this review also details the role of molecular cytogenetic techniques in other aspects of understanding the pathogenesis of brain tumors, including xenograft, cancer stem cell, and telomere length studies.
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Affiliation(s)
- Jane Bayani
- Department of Applied Molecular Oncology, Ontario Cancer Institute, Princess Margaret Hospital, University Health Network, Ontario, Canada.
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Misaki K, Marukawa K, Hayashi Y, Fukusato T, Minamoto T, Hasegawa M, Yamashita J, Fujisawa H. Correlation of gamma-catenin expression with good prognosis in medulloblastomas. J Neurosurg 2005; 102:197-206. [PMID: 16156230 DOI: 10.3171/jns.2005.102.2.0197] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Medulloblastoma is a malignant cerebellar tumor of childhood and is difficult to cure due to frequent cerebrospinal fluid dissemination. Amplification of the c-myc gene (4%) and messenger (mRNA) overexpression (50%) are known to be adverse prognostic indicators. Because mRNA overexpression cannot be explained by gene amplification alone, mechanisms other than gene amplification are postulated. Molecules on the Wnt signal pathway in primary tumors were examined. METHODS Immunohistochemical and cytogenetic examinations of beta- and gamma-catenin, c-myc, N-myc, and cyclin D1 in 24 primary medulloblastomas were conducted, and their clinical relevance was evaluated. Cytoplasmic/membranous staining of beta- and gamma-catenin was detected in 19 (79%) and nine (37%) cases, respectively, and nuclear expression of cyclin D1 and c-myc was detected in six (25%) and 21 (83%) cases, respectively. The expression levels of gamma-catenin in Western blot analysis and immunohistochemistry were similar. By differential polymerase chain reaction, c-myc and N-myc were amplified separately in two large cell/anaplastic medulloblastomas. No cyclin D1 amplification, or beta- or gamma-catenin mutations were found. Kaplan-Meier analysis revealed no dissemination at diagnosis (Chang Grade M0) and gamma-catenin expression was correlated with good prognosis (p = 0.0002 and 0.003, respectively). Expression of gamma-catenin was also significant in the M0 group (p = 0.022). Expression of cyclin D1 showed a trend toward adverse outcome (p = 0.057) and all patients in whom cyclin D1 expression was found died of disease. CONCLUSIONS Expression of gamma-catenin is of great prognostic value and its immunohistochemistry may be useful for further stratification of treatment. Cyclin D expression may have the potential to be an adverse prognostic indicator.
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Affiliation(s)
- Koichi Misaki
- Department of Neurosurgery, Graduate School of Medical Science, Division of Diagnostic Molecular Oncology, Cancer Research Institute, Kanazawa University, Kanazawa, Japan
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Huang A, Ho CSW, Ponzielli R, Barsyte-Lovejoy D, Bouffet E, Picard D, Hawkins CE, Penn LZ. Identification of a novel c-Myc protein interactor, JPO2, with transforming activity in medulloblastoma cells. Cancer Res 2005; 65:5607-19. [PMID: 15994933 DOI: 10.1158/0008-5472.can-05-0500] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
c-myc oncogene activation is critical in the pathogenesis of a spectrum of human malignancies. The c-Myc NH2-terminal domain (MycNTD) is essential for cellular transformation, and mediates critical protein interactions that modulate c-Myc oncogenic properties. In medulloblastoma, the most common malignant pediatric brain tumor, deregulated c-myc expression is linked with poorer disease phenotypes and outcomes. The biological basis for these associations is, however, not well understood. To better understand mechanisms underlying Myc-mediated transformation of medulloblastoma, we sought to identify novel MycNTD protein interactors from a medulloblastoma cell line library using a unique two-hybrid system. We identified a novel MycNTD binding protein, JPO2, which shows nuclear colocalization with c-Myc, and interacts with c-Myc both in vitro and in mammalian cells. In Rat1a transformation assays, JPO2 potentiates c-Myc transforming activity, and can complement a transformation-defective Myc mutant. Immunohistochemical studies indicate tumor-specific JPO2 expression in human medulloblastoma, and an association of JPO2 expression with metastatic tumors. Significantly, JPO2 expression induces colony formation in UW228, a medulloblastoma cell line, whereas RNAi-mediated JPO2 knockdown impairs colony formation in UW228, and in Myc-transformed UW228 cells. These data provide evidence for biochemical and functional interaction between c-Myc and JPO2 in medulloblastoma transformation. JPO2 is closely related to JPO1, a Myc transcriptional target with transforming activity. As tumor-specific JPO1 expression in human and murine medulloblastoma has also been reported; these collective observations suggest important functional links between the novel JPO protein family and c-Myc in medulloblastoma transformation.
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Abstract
Central nervous system (CNS) neoplasms can be diagnostically challenging, due to remarkably wide ranges in histologic appearance, biologic behavior, and therapeutic approach. Nevertheless, accurate diagnosis is the critical first step in providing optimal patient care. As with other oncology-based specialties, there is a rapidly expanding interest and enthusiasm for identifying and utilizing new biomarkers to enhance the day-to-day practice of surgical neuropathology. In this regard, the field is primed by recent advances in basic research, elucidating the molecular mechanisms of tumorigenesis and progression in the most common adult and pediatric brain tumors. Thus far, few have made the transition into routine clinical practice, the most notable example being 1p and 19q testing in oligodendroglial tumors. However, the field is rapidly evolving and many other biomarkers are likely to emerge as useful ancillary diagnostic, prognostic, or therapeutic aids. The goal of this article is to highlight the most common genetic alterations currently implicated in CNS tumors, focusing most on those that are either already in common use in ancillary molecular diagnostics testing or are likely to become so in the near future.
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Affiliation(s)
- Christine E Fuller
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN 38105, and Division of Neuropathology, Washington University School of Medicine, St. Louis, MO, USA.
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Sarkar C, Deb P, Sharma MC. Recent advances in embryonal tumours of the central nervous system. Childs Nerv Syst 2005; 21:272-93. [PMID: 15682321 DOI: 10.1007/s00381-004-1066-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2004] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Embryonal tumours of the central nervous system (CNS) are the commonest malignant paediatric brain tumours. This group includes medulloblastomas, supratentorial primitive neuroectodermal tumours, atypical teratoid/rhabdoid tumours, ependymoblastomas, and medulloepitheliomas. Earlier, all these tumours were grouped under a broad category of primitive neuroectodermal tumours (PNETs). However, the current WHO classification (2000) separates them into individual types based on significant progress in the understanding of their distinctive clinical, pathological, molecular genetic, histogenetic, and behavioural characteristics. Furthermore, advances in histopathology and molecular genetics have shown great promise for refining risk assessment in these tumours, especially medulloblastomas, thus providing a more accurate basis for tailoring therapies to individual patients. Correlation of histological changes with genetic events has also led to a new model of medulloblastoma tumorigenesis. REVIEW This review presents an updated comparative profile of these tumours, highlighting the clinical and biological relevance of the recent advances.
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Affiliation(s)
- Chitra Sarkar
- Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi.
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Lamont JM, McManamy CS, Pearson AD, Clifford SC, Ellison DW. Combined histopathological and molecular cytogenetic stratification of medulloblastoma patients. Clin Cancer Res 2005; 10:5482-93. [PMID: 15328187 DOI: 10.1158/1078-0432.ccr-03-0721] [Citation(s) in RCA: 173] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study examined the utility of stratifying children with medulloblastomas by a combination of refined histopathological classification and molecular cytogenetic evaluation. Detailed histopathological classification of tumors from a cohort of patients (n = 87) composed mainly of children entered into the International Society of Pediatric Oncology (SIOP)/United Kingdom Children's Cancer Study Group PNET3 trial (n = 65), included identification of the large cell/anaplastic phenotype. Fluorescence in situ hybridization was used to detect chromosome 17 abnormalities, losses of 9q22 and 10q24, and amplification of the MYCC and MYCN oncogenes. The large cell/anaplastic phenotype, which was present in 20% of medulloblastomas, emerged as an independent prognostic indicator. Loss of 17p13.3 (38% of medulloblastomas) was found across all of the histopathological variants, whereas MYCC/MYCN amplification (6%/8% of medulloblastomas) was significantly associated with the large cell/anaplastic phenotype. Both of these genetic abnormalities emerged as prognostic indicators. Loss of 9q22 was associated with the nodular/desmoplastic medulloblastoma variant, whereas loss of 10q24 was found in all of the variants. Together with metastatic tumor at presentation, the large cell/anaplastic phenotype, 17p13.3 loss, or high-frequency MYC amplification defined a high-risk group of children whose outcome was significantly (P = 0.0002) poorer than a low-risk group without these tumor characteristics. Combined evaluation of novel histopathological features and molecular cytogenetic abnormalities promises to allow stratification of patients with medulloblastoma, such that those likely to be cured will be spared the side effects of maximal therapy, which can be targeted at those with aggressive disease.
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Affiliation(s)
- Jayne M Lamont
- Northern Institute for Cancer Research, University of Newcastle, Newcastle-upon-Tyne, United Kingdom
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Ray A, Ho M, Ma J, Parkes RK, Mainprize TG, Ueda S, McLaughlin J, Bouffet E, Rutka JT, Hawkins CE. A Clinicobiological Model Predicting Survival in Medulloblastoma. Clin Cancer Res 2004; 10:7613-20. [PMID: 15569993 DOI: 10.1158/1078-0432.ccr-04-0499] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE The purpose of this study was to determine the relative contributions of biological and clinical predictors of survival in patients with medulloblastoma (MB). EXPERIMENTAL DESIGN Clinical presentation and survival information were obtained for 119 patients who had undergone surgery for MB at the Hospital for Sick Children (Toronto, Ontario, Canada) between 1985 and 2001. A tissue microarray was constructed from the tumor samples. The arrays were assayed for immunohistochemical expression of MYC, p53, platelet-derived growth factor receptor-alpha, ErbB2, MIB-1, and TrkC and for apoptosis (terminal deoxynucleotidyl transferase-mediated nick end labeling). Both univariable and multivariable analyses were conducted to characterize the association between survival and both clinical and biological markers. For the strongest predictors of survival, a weighted predictive score was calculated based on their hazard ratios (HRs). The sum of these scores was then used to give an overall prediction of survival using a nomogram. RESULTS The four strongest predictors of survival in the final multivariable model were the presence of metastatic disease at presentation (HR, 2.02; P=0.01) and p53 (HR, 2.29; P=0.02), TrkC (HR, 0.65; P=0.14), and ErbB2 (HR, 1.51; P=0.21) immunopositivity. A linear prognostic index was derived, with coefficients equal to the logarithm of these HRs. The 5-year survival rate for patients at the 10th, 50th, and 90th percentiles of the score distribution was 80.0%, 71.0%, and 35.7%, respectively, with radiation therapy and 70.5%, 58.5%, and 20.0%, respectively, without radiation therapy. CONCLUSIONS In this study, we demonstrate an approach to combining both clinical and biological markers to quantify risk in MB patients. This provides further prognostic information than can be obtained when either clinical factors or biological markers are studied separately and establishes a framework for comparing prognostic markers in future clinical studies.
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Affiliation(s)
- Amit Ray
- Division of Neurosurgery, The Hospital for Sick Children, Toronto, Ontario, Canada
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Abstract
In the last decade, the molecular biology revolution has advanced considerably. These advances have enhanced our understanding of the genetic underpinnings of human brain tumors in general, and pediatric brain tumors in particular. We now know that many pediatric brain tumors arise from disturbances in developmentally regulated signaling pathways. The medulloblastoma, a tumor in which the developmental Hedgehog and WNT pathways have gone awry, is a prime example of this. New techniques in genetic engineering have allowed for the creation of sophisticated mouse models of brain tumors that recapitulate the human disease. Many laboratories are now using cDNA microarrays to study the expression level of thousands of genes that may be aberrantly expressed in brain tumors when compared to normal control cells. In the next decade, the use of several new molecular techniques to establish brain tumor diagnoses will likely become standard tools in the diagnostics and treatment stratification of children with central nervous system tumors.
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Affiliation(s)
- Torsten Pietsch
- Department of Neuropathology, University of Bonn Medical Center, Bonn, Germany
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Ramachandran C, Khatib Z, Escalon E, Fonseca HB, Jhabvala P, Medina LS, D'Souza B, Ragheb J, Morrison G, Melnick SJ. Molecular studies in pediatric medulloblastomas. Brain Tumor Pathol 2002; 19:15-22. [PMID: 12455884 DOI: 10.1007/bf02482451] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Ten pediatric medulloblastoma patients were analyzed for DNA content, cell cycle, expression of drug resistance, apoptosis, cell proliferation, and N-myc genes to determine their prognostic significance. Medulloblastoma patients with progressive disease had fourth ventricle foraminal extension and larger tumors in the imaging studies. Patients with aneuploid tumors responded well to treatment regimens as compared with those with diploid tumors. Cell cycle analysis showed that the patients with progressive disease had a high S-phase fraction in the tumor cell population as compared with patients with favorable response to treatment. The correlation coefficients between Bcl-2 and MRP, Bcl-2 and Bax, p53 and p21, as well as Ki67 and PCNA were positive and significant, indicating their possible coregulated expression. The relationship between these markers indicates their relative and cumulative effect on cellular drug resistance, apoptosis, and/or cell proliferation in pediatric medulloblastomas.
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Affiliation(s)
- Cheppail Ramachandran
- Miami Children's Hospital, Research Institute, 3100 SW 62nd Avenue, Miami, FL 33155, USA.
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Knoepfler PS, Cheng PF, Eisenman RN. N-myc is essential during neurogenesis for the rapid expansion of progenitor cell populations and the inhibition of neuronal differentiation. Genes Dev 2002; 16:2699-712. [PMID: 12381668 PMCID: PMC187459 DOI: 10.1101/gad.1021202] [Citation(s) in RCA: 407] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
To address the role of N-myc in neurogenesis and in nervous system tumors, it was conditionally disrupted in neuronal progenitor cells (NPCs) with a nestin-Cre transgene. Null mice display ataxia, behavioral abnormalities, and tremors that correlate with a twofold decrease in brain mass that disproportionately affects the cerebellum (sixfold reduced in mass) and the cerebral cortex, both of which show signs of disorganization. In control mice at E12.5, we observe a domain of high N-Myc protein expression in the rapidly proliferating cerebellar primordium. Targeted deletion of N-myc results in severely compromised proliferation as shown by a striking decrease in S phase and mitotic cells as well as in cells expressing the Myc target gene cyclin D2, whereas apoptosis is unaffected. Null progenitor cells also have comparatively high levels of the cdk inhibitors p27(Kip1) and p18(Ink4c), whereas p15(Ink4b), p21(Cip1), and p19(Ink4d) levels are unaffected. Many null progenitors also exhibit altered nuclear morphology and size. In addition, loss of N-myc disrupts neuronal differentiation as evidenced by ectopic staining of the neuron specific marker betaTUBIII in the cerebrum. Furthermore, in progenitor cell cultures derived from null embryonic brain, we observe a dramatic increase in neuronal differentiation compared with controls. Thus, N-myc is essential for normal neurogenesis, regulating NPC proliferation, differentiation, and nuclear size. Its effects on proliferation and differentiation appear due, at least in part, to down-regulation of a specific subset of cyclin-dependent kinase inhibitors.
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Affiliation(s)
- Paul S Knoepfler
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
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Ellison D. Classifying the medulloblastoma: insights from morphology and molecular genetics. Neuropathol Appl Neurobiol 2002; 28:257-82. [PMID: 12175339 DOI: 10.1046/j.1365-2990.2002.00419.x] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Significant advances in the treatment of the medulloblastoma (MB) have been made in the last 30 years, reducing mortality by 2-fold. Further improvements in the cure rate require an increased understanding of the biology of MBs, and this will translate into refinements in their classification. Scrutiny of the cytological variation found among MBs has recently led to the concept of the anaplastic MB, which overlaps the large-cell variant and appears to share its poor prognosis. In contrast, the MB with extensive nodularity, a distinctive nodular/desmoplastic variant occurring in infants, has a better outcome than most MBs in these young patients. Building on cytogenetic studies that have drawn attention to abnormalities on chromosome 17 in over a third of MBs, research shows non-random losses on chromosomes 8, 9, 10, 11 and 16, and gains on chromosomes 1, 7 and 9. Overexpression of ErbB2 receptors and losses on chromosome 17p have been proposed as independent indicators of aggressive behaviour, while high TrkC receptor expression indicates a favourable outcome. There is a strong association between anaplastic/large-cell tumours and MYC amplification, which has previously been linked with aggressive disease, but associations between abnormalities on chromosome 17 and anaplastic/large-cell MBs and between abnormalities in the shh/PTCH pathway and the desmoplastic variant are more controversial. Classification of the MB histopathologically and according to profiles of molecular abnormalities will help both to rationalize approaches to therapy, increasing the cure rate and reducing long-term side-effects, and to suggest novel treatments.
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Affiliation(s)
- D Ellison
- Northern Institute for Cancer Research, University of Newcastle-upon-Tyne, Newcastle-upon-Tyne, UK.
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Aldosari N, Bigner SH, Burger PC, Becker L, Kepner JL, Friedman HS, McLendon RE. MYCC and MYCN oncogene amplification in medulloblastoma. A fluorescence in situ hybridization study on paraffin sections from the Children's Oncology Group. Arch Pathol Lab Med 2002; 126:540-4. [PMID: 11958658 DOI: 10.5858/2002-126-0540-mamoai] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
CONTEXT Brain tumors are the most common solid tumor in childhood, and medulloblastoma is the most common malignant brain tumor in this age group. Cytogenetic abnormalities that have been described in childhood medulloblastoma include loss of 17p, amplification of MYCC (c-myc), amplification of MYCN (N-myc), and isochromosome 17q. Data on these tumors indicate that the frequency of MYCC amplification is 5% to 10%. Fluorescence in situ hybridization is a powerful tool for investigating these features on archival material. OBJECTIVES To determine if intratumoral heterogeneity exists for MYCC and MYCN in medulloblastomas and if tumors with amplified MYCC or MYCN exhibit consistent histologic patterns. DESIGN In this fluorescence in situ hybridization study, we investigated the frequency and prognostic significance of MYCC and MYCN amplification in 77 medulloblastomas derived from the Children's Oncology Group. RESULTS MYCC amplification occurred in only 4 (5.2%) of 77 tumors. The 4 patients died of clinically aggressive neoplasms within 7 months of diagnosis. Similarly, 4 of 77 patients' tumors were found to exhibit MYCN amplification, but survival data are incomplete at present, therefore prognostic significance cannot be characterized. CONCLUSIONS These data establish the frequency of MYCC amplification in a large cohort of children with medulloblastoma and further suggest that MYCC amplification may be a marker of poor prognosis. Intratumoral heterogeneity was identified for these oncogenes in that 1 patient's tumor exhibited evidence of both MYCN and MYCC amplification, and this patient experienced a shortened survival time.
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Affiliation(s)
- Naji Aldosari
- Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA
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Gilbertson R. Paediatric embryonic brain tumours. biological and clinical relevance of molecular genetic abnormalities. Eur J Cancer 2002; 38:675-85. [PMID: 11916550 DOI: 10.1016/s0959-8049(01)00315-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Embryonal tumours constitute the largest group of malignant paediatric brain tumours. Their origin and histological classification remain somewhat controversial. However, in recent years real progress has been made in our understanding of the molecular genetic abnormalities that govern the initiation and/or progression of these tumours. A number of these abnormalities appear to involve alterations in signalling systems that control normal cerebellar development. Increasing our understanding of both the biology and clinical relevance of these molecular defects is a major challenge to the field of paediatric neuro-oncology. However, it likely represents the only means by which we will advance the management of these tumours, significantly reducing disease-related morbidity and mortality. This review focuses on the principal molecular genetic abnormalities so far identified in embryonal brain tumours and discusses their biological and clinical relevance.
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Affiliation(s)
- R Gilbertson
- Department of Developmental Neurobiology, Room D2006G, St Jude Children's Research Hospital, 332 N. Lauderdale St, Memphis, TN 38105-2794, USA.
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Roberts P, Chumas PD, Picton S, Bridges L, Livingstone JH, Sheridan E. A review of the cytogenetics of 58 pediatric brain tumors. CANCER GENETICS AND CYTOGENETICS 2001; 131:1-12. [PMID: 11734311 DOI: 10.1016/s0165-4608(01)00483-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe the cytogenetic results of 58 pediatric central nervous system (CNS) tumors of variable histology, investigated between 1992 and 2000. Successful cytogenetics were obtained for 53 patients, with clonal chromosome abnormalities demonstrated in 25. Notable findings included (1) 2p abnormality in four primitive neuroectodermal tumors (PNET); (2) 1p loss in four low-grade gliomas and two PNET; (3) telomeric associations in one pilocytic astrocytoma; (4) chromosome 7 gain in four astrocytomas and two PNET; (5) 17p loss in four PNET; (6) double minutes in one PNET and three glioblastomas; and (7) chromosome 10 loss in four PNET. Higher grade tumors demonstrated greater karyotype complexity. Low-grade tumors showed either minimal simple chromosome changes or a normal karyotype. Chromosome abnormalities were more frequent in supratentorial tumors than their infratentorial counterparts. Our results add weight to the limited existing body of cytogenetic documentation for pediatric CNS tumors and provide further evidence that 2p loss is a consistent region of chromosome involvement in PNET. We advocate further studies of CNS tumors, in particular, to evaluate the importance of 2p changes and to compare cytogenetic results for supratentorial tumors and their infratentorial counterparts.
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Affiliation(s)
- P Roberts
- Regional Cytogenetics Unit, St. James's, Hospital, Beckett Street, Leeds, UK.
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Gilbertson R, Wickramasinghe C, Hernan R, Balaji V, Hunt D, Jones-Wallace D, Crolla J, Perry R, Lunec J, Pearson A, Ellison D. Clinical and molecular stratification of disease risk in medulloblastoma. Br J Cancer 2001; 85:705-12. [PMID: 11531256 PMCID: PMC2364121 DOI: 10.1054/bjoc.2001.1987] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The accurate assessment of disease risk among children with medulloblastoma remains a major challenge to the field of paediatric neuro-oncology. In the current study we investigated the capacity of molecular abnormalities to increase the accuracy of disease risk stratification above that afforded by clinical staging alone. 41 primary medulloblastoma tumour samples were analysed for ErbB2 receptor expression using immunohistochemistry, and for aberrations of chromosome 17 and amplification of the MYC oncogene using fluorescence in situ hybridisation. The ErbB2 receptor and deletion of 17p were detected in 80% and 49% of tumours, respectively. 17p loss occurred either in isolation (20%), or in association with gain of 17q (29%), compatible with an isochromosome of 17q. Amplification of MYC was detected in only 2 tumours. Significant prognostic factors included, 'metastatic disease' (P = 0.0006), 'sub-total tumour resection' (P = 0.007), 'high ErbB2 receptor expression' (P = 0.003) and 'isolated 17p loss' (P = 0.003). Combined analysis of clinical and molecular factors enabled greater resolution of disease risk than clinical factors alone, identifying a sub-population of patients with particularly favourable disease outcome. These data support the hypothesis that a combination of clinical and molecular factors may afford a more reliable means of assigning disease risk in patients with medulloblastoma, thereby providing a more accurate basis for targeting therapy in children with this disease.
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Affiliation(s)
- R Gilbertson
- Dept. Developmental Neurobiology, St Jude Children's Research Hospital, Room 2006G, 332 North Lauderdale St, Memphis, TN 38105, USA
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Gilhuis HJ, Anderl KL, Boerman RH, Jeuken JM, James CD, Raffel C, Scheithauer BW, Jenkins RB. Comparative genomic hybridization of medulloblastomas and clinical relevance: eleven new cases and a review of the literature. Clin Neurol Neurosurg 2000; 102:203-209. [PMID: 11154805 DOI: 10.1016/s0303-8467(00)00112-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Medulloblastomas are highly malignant primitive neuroectodermal tumors of the cerebellum that display a wide variety of histopathological patterns. However, these patterns do not provide an accurate prediction of clinical-biological behavior and no satisfactory morphological grading system has ever been presented. Genetic alterations may provide additional diagnostic information and allow clinically relevant subgrouping of primitive neuroectodermal tumors. We examined 10 medulloblastomas and one medulloblastoma cell line. One amplification site on chromosome 8q24 was detected in the cell line corresponding to the known amplification of the c-myc gene in this cell line. The gain of 2p21-24 in two tumors was shown to represent amplification of the N-myc gene by Southern blot hybridization and fluorescence in situ hybridization. The data show that the isochromosome 17 can be recognized using comparative genomic hybridization (CGH) by the typical combination of loss of 17p combined with gain of 17q. No specific pattern of genetic alterations could be linked to the clinical behavior of the tumors. We have compared our results with previous CGH studies on medulloblastomas.
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Affiliation(s)
- H J Gilhuis
- Department of Neurology, University Medical Center St Radboud, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
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47
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Taylor MD, Mainprize TG, Rutka JT. Molecular insight into medulloblastoma and central nervous system primitive neuroectodermal tumor biology from hereditary syndromes: a review. Neurosurgery 2000; 47:888-901. [PMID: 11014429 DOI: 10.1097/00006123-200010000-00020] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Through the study of uncommon familial syndromes, physicians and scientists have been able to illuminate the underlying mechanisms of some of the more common sporadic diseases; this is illustrated best by studies of familial retinoblastoma. A number of rare familial syndromes have been described in which affected individuals are at increased risk of developing medulloblastoma and/or supratentorial primitive neuroectodermal tumors. The descriptions of many of these syndromes are based on patients observed by clinicians in their clinical practice. Determination of the underlying genetic defects in these patients with uncommon syndromes has led to identification of a number of genes subsequently found to be mutated in sporadic medulloblastomas (tumor suppressor genes). Associated genes in the same signaling pathways have also been found to be abnormal in sporadic medulloblastoma. Identification of patients with these rare syndromes is important, as they are often at increased risk for additional neoplasms, as are family members and future children. We review the published literature describing hereditary syndromes that have been associated with an increased incidence of medulloblastoma and/or central nervous system primitive neuroectodermal tumor. Review of the underlying molecular abnormalities in comparison to changes found in sporadic neoplasms suggests pathways important for tumorigenesis.
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Affiliation(s)
- M D Taylor
- Division of Neurosurgery, University of Toronto, and the Arthur and Sonia Labatt Brain Tumor Research Centre, The Hospital for Sick Children, Canada
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Marino S, Vooijs M, van der Gulden H, Jonkers J, Berns A. Induction of medulloblastomas in p53-null mutant mice by somatic inactivation of Rb in the external granular layer cells of the cerebellum. Genes Dev 2000. [DOI: 10.1101/gad.14.8.994] [Citation(s) in RCA: 408] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Medulloblastomas are among the most common malignancies in childhood, and they are associated with substantial mortality and morbidity. The molecular pathogenesis as well as the ontogeny of these neoplasms is still poorly understood. We have generated a mouse model for medulloblastoma by Cre–LoxP-mediated inactivation ofRb and p53 tumor suppressor genes in the cerebellar external granular layer (EGL) cells. GFAP–Cre-mediated recombination was found both in astrocytes and in immature precursor cells of the EGL in the developing cerebellum.GFAP–Cre;RbLoxP/LoxP;p53−/−or LoxP/LoxP mice developed highly aggressive embryonal tumors of the cerebellum with typical features of medulloblastoma. These tumors were identified as early as 7 weeks of age on the outer surface of the molecular layer, corresponding to the location of the EGL cells during development. Our results demonstrate that loss of function of RB is essential for medulloblastoma development in the mouse and strongly support the hypothesis that medulloblastomas arise from multipotent precursor cells located in the EGL.
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Herms J, Neidt I, Lüscher B, Sommer A, Schürmann P, Schröder T, Bergmann M, Wilken B, Probst-Cousin S, Hernáiz-Driever P, Behnke J, Hanefeld F, Pietsch T, Kretzschmar HA. C-MYC expression in medulloblastoma and its prognostic value. Int J Cancer 2000. [DOI: 10.1002/1097-0215(20000920)89:5<395::aid-ijc1>3.0.co;2-v] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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50
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Jay V, Squire J, Bayani J, Alkhani AM, Rutka JT, Zielenska M. Oncogene amplification in medulloblastoma: analysis of a case by comparative genomic hybridization and fluorescence in situ hybridization. Pathology 1999; 31:337-44. [PMID: 10643003 DOI: 10.1080/003130299104693] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We describe amplification of the MYCC oncogene in a medulloblastoma with aggressive clinical behavior. The patient was a six year old boy who underwent gross total surgical excision of a cerebellar tumor. Despite chemotherapy and total neuraxis radiation, the clinical course was one of relentless progression, with extensive subarachnoid spread and death within eight months of presentation. The pathological features were consistent with the recently described, "large cell variant" of medulloblastoma. Tumor cells exhibited large vesicular nuclei, prominent nucleoli and strong immunoreactivity for synaptophysin. Polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) assay revealed no evidence of MYCN amplification or 1p deletion in the tumor. FISH analysis revealed evidence of MYCC amplification in the 20- to 30-fold range. Comparative genomic hybridization (CGH) revealed regions of gains and amplification in three locations, with gains of chromosome 7, amplification of 8q24 (corresponding to the MYCC locus) and gains of the long arm of chromosome 17 (suggestive of isochromosome 17q). While conventional karyotypic analysis was not successful in the present case, CGH provided invaluable information about gene amplification and losses/gains of chromosomes and chromosomal regions. Thus, CGH is a powerful technique applicable to frozen or paraffin-embedded material which helps to ascertain the presence of gene amplification even without prior knowledge of the gene to be tested.
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Affiliation(s)
- V Jay
- Division of Pathology, Hospital for Sick Children-University of Toronto, Ontario, Canada.
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