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Samkari A, Hwang E, Packer RJ. Medulloblastoma/Primitive neuroectodermal tumor and germ cell tumors: the uncommon but potentially curable primary brain tumors. Hematol Oncol Clin North Am 2012; 26:881-95. [PMID: 22794288 DOI: 10.1016/j.hoc.2012.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This article presents an overview of medulloblastomas, central nervous system primitive neuroectodermal tumors, and germ cell tumors for the practicing oncologist. Discussion includes the definition of these tumors, histopathologic findings, molecular and genetic characteristics, prognoses, and evolution of treatment.
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Affiliation(s)
- Ayman Samkari
- The Brain Tumor Institute, Division of Neurology, Children's National Medical Center, Washington, DC 20010, USA
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2
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Almairac F, Frenay M, Paquis P. Maladies génétiques et glioblastomes. Neurochirurgie 2010; 56:455-8. [DOI: 10.1016/j.neuchi.2010.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 07/09/2010] [Indexed: 11/30/2022]
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Abstract
The presence of multiple adenomatous polyps in the large bowel confers a high lifetime risk of colorectal cancer. Although many cases of classical familial adenomatous polyposis (> 100 polyps) can be accounted for by mutations in the adenomatous polyposis coli (APC) gene, a large group of patients remains with multiple (5-100) adenomas and in whom there is no detectable APC mutation. Recently two new genetic variants have been found to be associated with multiple colorectal adenomas and cancer, MYH/MUTYH on chromosome 1p and the HMPS/CRAC1 locus on chromosome 15q13-q14. New information also continues to emerge regarding the less common hamartomatous polyposis conditions, Peutz-Jeghers syndrome and Juvenile Polyposis syndrome. In approximately half to two thirds of these families, germline genetic variants can now be uncovered. In this review we draw together some of the most recent information pertinent to the molecular pathogenesis of colorectal polyposis.
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Affiliation(s)
- Lara Lipton
- Molecular and Population Genetics Laboratory, Cancer Research UK, London, WC2A 3PX, UK
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Jeannin S, Lebrun C, Van Den Bos F, Olschwang S, Bourg V, Frenay M. Syndrome de Turcot confirmé par biologie moléculaire. Rev Neurol (Paris) 2006; 162:741-6. [PMID: 16840983 DOI: 10.1016/s0035-3787(06)75072-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Turcot's syndrome is characterized clinically by the concurrence of a primary brain tumor and a familial adenomatous polyposis or a hereditary nonpolyposis colorectal cancer. OBSERVATION We report a case of a 45-year-old woman who underwent in 1995 neuro-oncological treatment for an anaplastic astrocytoma (grade III according to the World Health Organization classification). Treatment included complete surgery, radiotherapy, a first-line nitrosourea-based chemotherapy regimen and a second-line platinium salt-based regimen. It was then noted that the patient's brother had colorectal cancer. A genetic study detected a germ-line mutation on the hMSH2 gene specific of HNPCC syndrome (Human Non Polyposis Colorectal Cancer). Colonoscopy was normal. Eight years after the diagnosis, the patient developed a gliomatosis cerebri and died. CONCLUSION Relevant personal and familial history can provide the clue to the diagnosis of Turcot's syndrome. Molecular diagnosis may contribute to appropriate care of affected patients.
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Affiliation(s)
- S Jeannin
- Service de Neurologie, Hôpital Pasteur, Nice
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Abstract
Medulloblastoma is a primary brain tumor found in the cerebellum of children. The tumor occurs in association with two inherited cancer syndromes: Turcot syndrome and Gorlin syndrome. Insights into the molecular biology of the tumor have come from looking at alterations in the genes altered in these syndromes, PTC and APC, respectively. Murine models of medulloblastoma have been constructed based on these alterations. Additional murine models that, while mimicking the appearance of the human tumor, seem unrelated to the human tumor's molecular alterations have been made. In this review, the clinical picture, origin, molecular biology, and murine models of medulloblastoma are discussed. Although a great deal has been discovered about this tumor, the genetic alterations responsible for tumor development in a majority of patients have yet to be described.
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Affiliation(s)
- Corey Raffel
- Department of Neurologic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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Taylor MD, Zhang X, Liu L, Hui CC, Mainprize TG, Scherer SW, Wainwright B, Hogg D, Rutka JT. Failure of a medulloblastoma-derived mutant of SUFU to suppress WNT signaling. Oncogene 2004; 23:4577-83. [PMID: 15077159 DOI: 10.1038/sj.onc.1207605] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Germline mutations of APC in patients with Turcot syndrome (colon cancer and medulloblastoma), was well as somatic mutations of APC, beta-catenin, and Axin in sporadic medulloblastomas (MBs) have shown the importance of WNT signaling in the pathogenesis of MB. A subset of children with MB have germline mutations of SUFU, a known inhibitor of Hedgehog signal transduction. A recent report suggested that murine Sufu can bind beta-catenin, export it from the nucleus, and thereby repress beta-catenin/T-cell factor (Tcf)-mediated transcription. We show that an MB-derived mutant of SUFU has lost the ability to decrease nuclear levels of beta-catenin, and cannot inhibit beta-catenin/Tcf-mediated transcription as compared to wild type SUFU. Our results suggest that loss of function of SUFU results in overactivity of both the Sonic Hedgehog, and the WNT signaling pathways, leading to excessive proliferation and failure to differentiate resulting in MB.
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Affiliation(s)
- Michael D Taylor
- The Division of Neurosurgery, The Arthur and Sonia Labatt Brain Tumour Research Centre, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
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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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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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Abstract
Tumors of the central nervous system (CNS) can be devastating because they often affect children, are difficult to treat, and frequently cause mental impairment or death. New insights into the causes and potential treatment of CNS tumors have come from discovering connections with genes that control cell growth, differentiation, and death during normal development. Links between tumorigenesis and normal development are illustrated by three common CNS tumors: retinoblastoma, glioblastoma, and medulloblastoma. For example, the retinoblastoma (Rb) tumor suppressor protein is crucial for control of normal neuronal differentiation and apoptosis. Excessive activity of the epidermal growth factor receptor and loss of the phosphatase PTEN are associated with glioblastoma, and both genes are required for normal growth and development. The membrane protein Patched1 (Ptc1), which controls cell fate in many tissues, regulates cell growth in the cerebellum, and reduced Ptc1 function contributes to medulloblastoma. Just as elucidating the mechanisms that control normal development can lead to the identification of new cancer-related genes and signaling pathways, studies of tumor biology can increase our understanding of normal development. Learning that Ptc1 is a medulloblastoma tumor suppressor led directly to the identification of the Ptc1 ligand, Sonic hedgehog, as a powerful mitogen for cerebellar granule cell precursors. Much remains to be learned about the genetic events that lead to brain tumors and how each event regulates cell cycle progression, apoptosis, and differentiation. The prospects for beneficial work at the boundary between oncology and developmental biology are great.
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Affiliation(s)
- R Wechsler-Reya
- Department of Developmental Biology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305-5329, USA.
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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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Huang H, Mahler-Araujo BM, Sankila A, Chimelli L, Yonekawa Y, Kleihues P, Ohgaki H. APC mutations in sporadic medulloblastomas. THE AMERICAN JOURNAL OF PATHOLOGY 2000; 156:433-7. [PMID: 10666372 PMCID: PMC1850060 DOI: 10.1016/s0002-9440(10)64747-5] [Citation(s) in RCA: 195] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The cerebellar medulloblastoma (WHO Grade IV) is a highly malignant, invasive embryonal tumor with preferential manifestation in children. Several molecular alterations appear to be involved, including isochromosome 17q and the p53, PTCH, and beta-catenin gene mutations. In this study, 46 sporadic medulloblastomas were screened for the presence of mutations in genes of the Wnt signaling pathway (APC and beta-catenin). Single-strand conformational polymorphism (SSCP) analysis followed by direct DNA sequencing revealed 3 miscoding APC mutations in 2 (4.3%) medulloblastomas. One case contained a GCA-->GTA mutation at codon 1296 (Ala-->Val), and another case had double point mutations at codons 1472 (GTA-->ATA, Val-->Ile) and 1495 (AGT-->GGT, Ser-->Gly). Miscoding beta-catenin mutations were detected in 4 tumors (8.7%). Three of these were located at codon 33 (TCT -->TTT, Ser-->Phe) and another at codon 37 (TCT-->GCT, Ser-->Ala). Adenomatous polyposis coli (APC) gene and beta-catenin mutations were mutually exclusive and occurred in a total of 6 of 46 cases (13%). Although germline APC mutations are a well established cause of familial colon and brain tumors (Turcot syndrome), this study provides the first evidence that APC mutations are also operative in a subset of sporadic medulloblastomas.
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Affiliation(s)
- H Huang
- International Agency for Research on Cancer, Lyon, France
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Barel D, Cohen IJ, Mor C, Stern S, Shapiro R, Shomrat R, Galanti Y, Legum C, Zaizov R, Avigad S. Mutations of the adenomatous polyposis coli and p53 genes in a child with Turcot's syndrome. Cancer Lett 1998; 132:119-25. [PMID: 10397462 DOI: 10.1016/s0304-3835(98)00167-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Turcot's syndrome is a rare heritable complex that is characterized by an association between a primary neuroepithelial tumor of the central nervous system and multiple colonic polyps. The aim of this study was to analyze genetic alterations in a case of Turcot's syndrome in a 10.5-year-old boy in whom a colorectal tumor developed 3.5 years following astrocytoma. An APC germline non-sense mutation at codon 1284 leading to a truncated protein was identified, as was a somatic p53 mutation in the colorectal carcinoma in exon 7, codon 244. The latter was not identified in the primary astrocytoma. However, immunohistochemistry revealed high p53 protein expression in both tumors, suggesting an additional p53 mutation in the primary astrocytic tumor. The diverse p53 mutations observed in this unique syndrome in two different sites and stages of the disease may shed light on the multistep progression of the malignant events.
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Affiliation(s)
- D Barel
- Cancer Molecular Genetics, Felsenstein Medical Research Center, Petah Tiqva, Israel
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