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GSE12430
Mus musculus
21 Downloadable Samples
Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
We are examining the genes that control initiation and progression of murine medulloblastomas that result from loss of patched. Approximately 25% of human medulloblastomas have mutations in patched or in other elements of the sonic hedgehog pathway. However, the cells from which these tumors originate (neural progenitors or stem cells), the cells that are responsible for tumor propagation (cancer stem cells), and the genes that are required for tumor progression are poorly understood. To address these questions, we have developed conditional patched knockout mice in which the gene is deleted in neural stem cells or progenitors. In addition, we have isolated a population of tumor-propagating cells from these tumors. By studying these models we will gain insight into the mechanisms of tumorigenesis and identify new targets for therapy.
Publication Title
Identification of CD15 as a marker for tumor-propagating cells in a mouse model of medulloblastoma.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 14 Downloadable Samples
- Affymetrix Murine Genome U74A Version 2 Array (mgu74av2)
Description
SUMMARY
Publication Title
Loss of patched and disruption of granule cell development in a pre-neoplastic stage of medulloblastoma.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 19 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
It is generally believed that cerebellar granule neurons originate exclusively from granule neuron precursors (GNPs) in the external germinal layer (EGL). Here we identify a rare population of neuronal progenitors in the developing cerebellum that expresses Nestin. Although Nestin is widely considered a marker for multipotent stem cells, these Nestin-expressing progenitors (NEPs) are committed to the granule neuron lineage. Unlike conventional GNPs, which reside in the outer EGL and proliferate extensively, NEPs reside in the deep part of the EGL and are quiescent. Expression profiling reveals that NEPs are distinct from GNPs, and in particular, express markedly reduced levels of genes associated with DNA repair. Consistent with this, upon aberrant activation of Sonic hedgehog (Shh) signaling, NEPs exhibit more severe genomic instability and give rise to tumors more efficiently than GNPs. These studies identify a novel progenitor for cerebellar granule neurons and a novel cell of origin for medulloblastoma.
Publication Title
A population of Nestin-expressing progenitors in the cerebellum exhibits increased tumorigenicity.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 19 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Medulloblastoma (MB) is the most common malignant brain tumor in children. Patients whose tumors exhibit overexpression or amplification of the MYC oncogene (c-MYC) usually have an extremely poor prognosis, but there are no animal models of this subtype of the disease. Here we show that cerebellar stem cells expressing Myc and mutant Trp53 (p53) generate aggressive tumors following orthotopic transplantation. These tumors consist of large, pleiomorphic cells and resemble human MYC-driven MB at a molecular level. Notably, antagonists of PI3K/mTOR signaling, but not Hedgehog signaling, inhibit growth of tumor cells. These findings suggest that cerebellar stem cells can give rise to MYC-driven MB, and identify a novel model that can be used to test therapies for this devastating disease.
Publication Title
An animal model of MYC-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
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- Mus musculus
- 19 Downloadable Samples
Illumina HiSeq 2000
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. Purpose: To known the gene expression profile of Medulloblastoma which drived by Gnas mutation Methods: mRNAs isolated from the cerebellum of control and Gnas mutants Results:Upregulation of Shh Signaling components in tumors Conclusions: The deletion of Gnas in hGFAP and Olig1 possitive cells result in substantial upregulation of shh signaling and formation of Medulloblastoma Overall design: cerebellum mRNA profiles of 3 60-day old wild type (Ctrl) and 8 Olig1Cre driven Gsa conditional knockout or 8 hGFAPCre driven conditional knockout mice were generated by deep sequencing using Illumina Hiseq2000
Publication Title
The G protein α subunit Gαs is a tumor suppressor in Sonic hedgehog-driven medulloblastoma.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 10 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
MYC-amplified medulloblastomas are highly lethal tumors. BET bromodomain inhibition was recently described to downregulate MYC-associated transcriptional activity in various cancer subtypes. To investigate whether JQ1, a BET bromodomain inhibitor is downregulation MYC and MYC-associated transcriptional activity, we performed global gene expression profiling of five medulloblastomas MYC-amplified patient-derived cell lines treated by JQ1 and the inactive form of JQ1.
Publication Title
BET bromodomain inhibition of MYC-amplified medulloblastoma.
Sample Metadata Fields
Specimen part, Cell line, Treatment
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Reduced chromatin binding of MYC is a key effect of HDAC inhibition in MYC amplified medulloblastoma.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
MYC is a driver oncogene in many cancers. Inhibition of MYC promises high therapeutic potential, but specific MYC inhibitors remain unavailable for clinical use. Previous studies suggest that MYC amplified Medulloblastoma cells are vulnerable to HDAC inhibition. Using co-immunoprecipitation, mass spectrometry and ChIP-sequencing we show that HDAC2 is a cofactor of MYC in MYC amplified primary medulloblastoma and cell lines. The MYC-HDAC2 complex is bound to genes defining the MYC-dependent transcriptional profile. Class I HDAC inhibition leads to stabilization and reduced DNA binding of MYC protein inducing a down-regulation of MYC activated genes (MAGs) and up-regulation of MYC repressed genes (MRGs). MAGs and MRGs are characterized by opposing biological functions and distinct E-box distribution. We conclude that MYC and HDAC2 (class I) are localized in a complex in MYC amplified medulloblastoma and drive a MYC-specific transcriptional program, which is reversed by the class I HDAC inhibitor entinostat. Thus, the development of HDAC inhibitors for treatment of MYC amplified medulloblastoma should include HDAC2 in its profile in order to directly target MYC´s trans-activating and trans-repressing function.
Publication Title
Reduced chromatin binding of MYC is a key effect of HDAC inhibition in MYC amplified medulloblastoma.
Sample Metadata Fields
Specimen part, Treatment
View Samples