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GSE22875
Homo sapiens
23 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The transcription factor OTX2 has been implicated as an oncogene in medulloblastoma, which is the most common malignant brain tumor in children. It is highly expressed in most medulloblastomas and amplified in a subset of them. The role of OTX2 in medulloblastoma and its downstream targets are unclear. Therefore, we generated D425 medulloblastoma cells in which we can silence endogenous OTX2 by inducible shRNA. Silencing of OTX2 strongly inhibited cell proliferation and resulted in a neuronal-like differentiation. Expression profiling of time courses after silencing showed a progressive change in gene expression for many cellular processes. Down regulated genes were highly enriched for cell cycle and visual perception genes, while up regulated genes were enriched for genes involved in development and differentiation. This shift in expression profiles is reminiscent to changes described to occur during normal cerebellum development. OTX2 is expressed in proliferating granular progenitor cells, but the expression diminishes when these cells exit the cell cycle and start differentiating. ChIP-on-chip analyses of OTX2 in D425 cells showed that cell cycle and perception genes were direct OTX2 targets, while regulation of most differentiation genes appears to be indirect. These analyses provide the first insight in the molecular network of OTX2, demonstrating that OTX2 is essential in medulloblastoma and directly drives proliferation by regulating the expression of cell cycle genes. Since many of these genes also correlate in expression with OTX2 in primary tumors, they might be potential targets for therapy in medulloblastoma patients.
Publication Title
OTX2 directly activates cell cycle genes and inhibits differentiation in medulloblastoma cells.
Sample Metadata Fields
Cell line, Time
View Samples- Homo sapiens
- 62 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Smoothened (SMO)-inhibitors recently entered clinical trials for sonic-hedgehog driven medulloblastoma (SHH-MB). Clinical response appears highly variable. To understand the mechanism(s) of primary resistance and to identify pathways co-operating with aberrant SHH-signaling, we sequenced a large cohort of SHH-MBs across all age groups by sequencing, DNA methylation and expression profiling. Our data show that most adults but only half of the pediatric patients with SHH-MB will respond to SMO inhibition as predicted by molecular analysis of the primary tumor and tested in the SHH-xenografts, demonstrating that the next generation of SMO-inhibitor trials should be based on these predictive biomarkers.
Publication Title
Genomic and transcriptomic analyses match medulloblastoma mouse models to their human counterparts.
Sample Metadata Fields
Sex, Age
View Samples- Homo sapiens
- 15 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
Gene expression profiles generated from human tumor cells laser-microdissected from surgical samples of seven choroid plexus papillomas (Grade I WHO) as eight samples of epithelial cells lasermicrodissected from normal choroid plexus obtained at autopsy.
Publication Title
TWIST-1 is overexpressed in neoplastic choroid plexus epithelial cells and promotes proliferation and invasion.
Sample Metadata Fields
Sex, Age
View Samples- Homo sapiens
- 13 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Rhabdomyosarcoma (RMS) is the most common paediatric soft-tissue
Publication Title
Genomic imbalances in rhabdomyosarcoma cell lines affect expression of genes frequently altered in primary tumors: an approach to identify candidate genes involved in tumor development.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 58 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Pilocytic astrocytomas (PA) are the most common brain tumor in pediatric patients and can cause significant morbidity, including chronic neurological deficiencies. They are characterized by activating alterations in the mitogen-activated protein kinase (MAPK) pathway, but little else is known about their development. To further define their molecular development, we analysed the global DNA methylation profiles of 61 PAs and 6 normal cerebellum samples and integrated this data with transcriptome profiling. These data revealed two subgroups of PA that separate according to tumor location (infratentorial versus supratentorial), and identified key neural developmental genes that are differentially methylated between the two groups. Significant expression differences were identified for the majority of differentially methylated genes, and these were unexpectedly associated with a strong positive correlation between methylation and expression. We also identified a large number of differentially methylated/expressed genes between cerebellar PAs and normal cerebellum, which included additional developmental genes.
Publication Title
Differential expression and methylation of brain developmental genes define location-specific subsets of pilocytic astrocytoma.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 31 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Primary glioblastoma, representing over 90% of adult glioblastoma, develop rapidly without preexisting lower-grade glioma. We have generated a mouse model of primary glioblastoma driven by a single p53 mutation. These p53-mutant gliomas lose the syntenic region of human chromosome 10q, which is mapped to mouse chr19 and chr7. Loss of mouse chr19, containing Pten, activates PI3K/Akt signaling.
Publication Title
Opposing Tumor-Promoting and -Suppressive Functions of Rictor/mTORC2 Signaling in Adult Glioma and Pediatric SHH Medulloblastoma.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 58 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
To identify molecular subtypes of medulloblastoma we have profiled a series of 62 medulloblastoma tumors. Unsupervised hierarchical cluster analysis of these data identified 5 distinct molecular subtypes.
Publication Title
Integrated genomics identifies five medulloblastoma subtypes with distinct genetic profiles, pathway signatures and clinicopathological features.
Sample Metadata Fields
Sex
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Gene expression profiling of FACS sorted GFP+ve cells from sexed gonads of transgenic pSF1-eGFP mice
Publication Title
Expression profiling of purified mouse gonadal somatic cells during the critical time window of sex determination reveals novel candidate genes for human sexual dysgenesis syndromes.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 18 Downloadable Samples
(imblegenmousecgh3x720kwholegenometilingarray(buildmm9)[080603mm9wgcghhx3), Affymetrix Mouse Gene 1.1 ST Array (mogene11st)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
The G protein α subunit Gαs is a tumor suppressor in Sonic hedgehog-driven medulloblastoma.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 18 Downloadable Samples
- (imblegenmousecgh3x720kwholegenometilingarray(buildmm9)[080603mm9wgcghhx3), Affymetrix Mouse Gene 1.1 ST Array (mogene11st)
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.
Publication Title
The G protein α subunit Gαs is a tumor suppressor in Sonic hedgehog-driven medulloblastoma.
Sample Metadata Fields
Specimen part
View Samples