Similar Datasets
Project description:Genomic DNA copy number alterations of neutron-induced medulloblastoma in Ptch heterozygous mice
| PRJNA726518 | ENA
Project description:We used high-resolution SNP genotyping to identify regions of genomic gain and loss in the genome of 212 medulloblastomas, a malignant pediatric brain tumor. Focal amplifications of fifteen known oncogenes and focal deletions of twenty known tumor suppressor genes (TSG) were revealed, most not previously implicated in medulloblastoma. Importantly, we identified novel amplifications and homozygous deletions, including recurrent, mutually exclusive, highly focal genetic events in genes targeting histone lysine methylation, particularly histone 3, lysine 9 (H3K9). Post-translational modification of histone proteins is critical for regulation of gene expression, can participate in determining stem cell fates, and has been implicated in carcinogenesis. Consistent with our genetic data, restoration of expression of genes controlling H3K9 methylation greatly diminishes proliferation of medulloblastoma in vitro. Copy number aberrations of genes with critical roles in writing, reading, removing, and blocking the state of histone lysine methylation, particularly H3K9, suggest that defective control of the histone code contributes to the pathogenesis of medulloblastoma. Keywords: Affymetrix SNP array Genomic DNA isolated from fresh frozen primary human medulloblastomas and medulloblastoma cell lines were subjected to SNP genotyping using either Affymetrix 100K or 500K GeneChip Mapping array sets for the purpose of obtaining genome-wide copy number and LOH profiles.
2010-04-06 | E-GEOD-14437 | biostudies-arrayexpress
Project description:Medulloblastomas are heterogeneous tumors that collectively represent the most common malignant brain tumor in children. To understand the molecular characteristics underlying their heterogeneity and to identify whether such characteristics represent risk factors for patients with this disease, we performed an integrated genomic analysis of a large series of primary tumors. Identified are six molecular subgroups of medulloblastoma, each with a unique combination of numerical and structural chromosomal aberrations that globally influence mRNA and miRNA expression. We reveal the relative contribution of each subgroup to clinical outcome as a whole and show that a previously unidentified molecular subgroup, characterized genetically by c-MYC copy number gains and transcriptionally by enrichment of photoreceptor pathways and increased miR-183-96-182 expression, is associated with significantly lower rates of event-free and overall survivals. Our results detail the complex genomic heterogeneity of medulloblastomas and identify a previously unrecognized molecular subgroup with poor clinical outcome for which more effective therapeutic strategies should be developed.
2022-07-10 | GSE207762 | GEO
Project description:We used high-resolution SNP genotyping to identify regions of genomic gain and loss in the genome of 212 medulloblastomas, a malignant pediatric brain tumor. Focal amplifications of fifteen known oncogenes and focal deletions of twenty known tumor suppressor genes (TSG) were revealed, most not previously implicated in medulloblastoma. Importantly, we identified novel amplifications and homozygous deletions, including recurrent, mutually exclusive, highly focal genetic events in genes targeting histone lysine methylation, particularly histone 3, lysine 9 (H3K9). Post-translational modification of histone proteins is critical for regulation of gene expression, can participate in determining stem cell fates, and has been implicated in carcinogenesis. Consistent with our genetic data, restoration of expression of genes controlling H3K9 methylation greatly diminishes proliferation of medulloblastoma in vitro. Copy number aberrations of genes with critical roles in writing, reading, removing, and blocking the state of histone lysine methylation, particularly H3K9, suggest that defective control of the histone code contributes to the pathogenesis of medulloblastoma. Keywords: Affymetrix SNP array
2009-04-15 | GSE14437 | GEO
Project description:Medulloblastoma, the most common malignant pediatric brain tumour is currently treated with non-specific cytotoxic therapies including surgery, whole brain radiation, and aggressive chemotherapy. As medulloblastoma exhibits marked intertumoural heterogeneity, with at least four distinct molecular variants, prior attempts to identify targets for therapy have been underpowered due to small samples sizes. Here we report somatic copy number aberrations (SCNAs) in 1087 unique medulloblastomas. SCNAs are more common than SNVs in medulloblastoma, and are predominantly subgroup enriched. The most common region of focal copy number gain is a tandem duplication of the Parkinson's disease gene SNCAIP, which is exquisitely restricted to Subgroup 4alpha. Recurrent translocations of PVT1, including PVT1-MYC and PVT1-NDRG1 that arise through localized chromosomal shattering (topochromothripsis) are restricted to Group 3 tumours. Numerous actionable SCNAs, including recurrent events targeting TGFbeta signaling in Group 3, and NF-kappaB signaling in Group 4 suggest future avenues for rational, targeted therapy This SuperSeries is composed of the SubSeries listed below.
2012-07-27 | GSE37385 | GEO
Project description:To investigate DNA copy number changes in rat mammary carcinomas induced by neutron or gamma-ray irradiation.
2020-10-29 | GSE160418 | GEO
Project description:Medulloblastoma, the most common malignant pediatric brain tumor, is highly heterogeneous with distinct molecular subtypes and cellular origins. Although current treatments improve survival rates, patients suffer severe treatment-related side effects and often relapse of tumors carrying resistance mutations, underscoring an urgent need for alternative targeted therapies. Currently, the genetic alterations underlying this disease are not fully understood. Here we identify GNAS, encoding the G-protein Gs-alpha, as a potent tumor suppressor gene in medulloblastoma. GNAS specifically defines a subset of aggressive Sonic Hedgehog (Shh)-group medulloblastomas. Gnas loss-of-function in distinct lineage progenitors of the developing hindbrain suffices to initiate medulloblastoma. We find that Gs-alpha is highly enriched at primary cilia of granule neuron precursors and suppresses Shh signaling not only by regulating classic cAMP-dependent pathway but also controlling ciliary trafficking of Smoothened. Concurrent cAMP elevation and Smoothened inhibition robustly arrests tumor cell growth in Gnas mutants. We further reveal oligodendrocyte progenitors as a novel cellular origin for anatomically-distinct Shh-associated medulloblastomas. Together, we identify a previously unrecognized tumor suppressor function of Gs-alpha in medulloblastoma partially mediated through inhibiting Shh signaling, and uncover Gs-alpha as a molecular link across disparate cells of origin among Shh-group medulloblastomas, pointing to G- protein modulation as a potential therapeutic avenue.
2014-08-24 | GSE60416 | GEO
Project description:Medulloblastoma, the most common malignant pediatric brain tumor, is highly heterogeneous with distinct molecular subtypes and cellular origins. Although current treatments improve survival rates, patients suffer severe treatment-related side effects and often relapse of tumors carrying resistance mutations, underscoring an urgent need for alternative targeted therapies. Currently, the genetic alterations underlying this disease are not fully understood. Here we identify GNAS, encoding the G-protein Gs-alpha, as a potent tumor suppressor gene in medulloblastoma. GNAS specifically defines a subset of aggressive Sonic Hedgehog (Shh)-group medulloblastomas. Gnas loss-of-function in distinct lineage progenitors of the developing hindbrain suffices to initiate medulloblastoma. We find that Gs-alpha is highly enriched at primary cilia of granule neuron precursors and suppresses Shh signaling not only by regulating classic cAMP-dependent pathway but also controlling ciliary trafficking of Smoothened. Concurrent cAMP elevation and Smoothened inhibition robustly arrests tumor cell growth in Gnas mutants. We further reveal oligodendrocyte progenitors as a novel cellular origin for anatomically-distinct Shh-associated medulloblastomas. Together, we identify a previously unrecognized tumor suppressor function of Gs-alpha in medulloblastoma partially mediated through inhibiting Shh signaling, and uncover Gs-alpha as a molecular link across disparate cells of origin among Shh-group medulloblastomas, pointing to G- protein modulation as a potential therapeutic avenue. We isolated genomic DNAs from the cerebellum of adult wildtype mice and tumor tissue from individual GFAP-Gnas or Olig1-Gnas mutants and performed the Copy number variation analysis.
2014-08-24 | E-GEOD-60416 | biostudies-arrayexpress
Project description: Not available
| S-EPMC2527508 | biostudies-literature
Project description: Not available
| S-EPMC2896163 | biostudies-literature