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GSE42762
Homo sapiens
9 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Neuroblastoma is a pediatric tumor of the peripheral sympathetic nervous system with a highly variable prognosis. Activation of the PI3K/AKT pathway in neuroblastoma is correlated with poor patient prognosis, but the precise downstream effectors mediating this effect have not been determined. Here, we identify the forkhead transcription factor FOXO3a as a key target of the PI3K/AKT pathway in neuroblastoma. FOXO3a expression was elevated in low stage neuroblastoma tumors and normal embryonal neuroblasts, but reduced in late stage neuroblastoma. Inactivation of FOXO3a by AKT was essential for neuroblastoma cell survival. Treatment of neuroblastoma cells with the dual PI3K/mTOR inhibitor PI-103 activated FOXO3a and triggered apoptosis. This effect was rescued by FOXO3a silencing. Conversely, apoptosis induced by PI-103 or the AKT inhibitor MK-2206 was potentiated by FOXO3a overexpression. Further, levels of total or phosphorylated FOXO3a correlated closely with apoptotic sensitivity to MK-2206. In clinical specimens, there was an inverse relationship between gene expression signatures regulated by PI3K signaling and FOXO3a transcriptional activity. Moreover, high PI3K activity and low FOXO3a activity were each associated with an extremely poor prognosis. Our work indicates that expression of FOXO3a and its targets offer useful prognostic markers as well as biomarkers for PI3K/AKT inhibitor efficacy in neuroblastoma.
Publication Title
FOXO3a is a major target of inactivation by PI3K/AKT signaling in aggressive neuroblastoma.
Sample Metadata Fields
Specimen part, Cell line, Treatment
View Samples- Homo sapiens
- 161 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
A NOTCH3 transcriptional module induces cell motility in neuroblastoma.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 17 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Migratory embryonal neuroblasts give rise to several tissues, including the sympathetic nervous system (SNS). Neuroblastomas are paediatric tumours of the peripheral SNS with a highly variable prognosis. We observed that high NOTCH3 expression in neuroblastomas correlated with a poor prognosis. Expression of a NOTCH3 transgene in neuroblastoma cells induced many motility genes and conferred a highly motile phenotype. Expression of these motility genes strongly correlated with NOTCH3 expression in neuroblastomas and many other tumours, suggesting a general role for NOTCH3 in regulation of these genes. Silencing of NOTCH3 or genes of the Notch-processing -secretase complex induced apoptosis in all neuroblastoma cell lines tested. These data suggest that NOTCH3 is a key-regulator of motility, and indispensable for survival of neuroblastoma cells.
Publication Title
A NOTCH3 transcriptional module induces cell motility in neuroblastoma.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 11 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Genomic aberrations of Cyclin D1 (CCND1) and CDK4 in neuroblastoma indicate that dysregulation of the G1 entry checkpoint is an important cell cycle aberration in this pediatric tumor. Here we report that analysis of Affymetrix expression data of primary neuroblastic tumors shows an extensive over-expression of Cyclin D1 and CDK4 which correlates with histological subgroups and prognosis respectively. Immunohistochemical analysis demonstrated an over-expression of Cyclin D1 in neuroblasts and a low Cyclin D1 expression in all cell types in ganglioneuroma. This suggests an involvement of G1 regulating genes in neuronal differentiation processes which we further evaluated using RNA interference against Cyclin D1 and its kinase partner CDK4 in several neuroblastoma cell lines. This resulted in pRb pathway inhibition as shown by an almost complete disappearance of CDK4 specific pRb phosphorylation; reduction of E2F transcriptional activity and a decrease of Cyclin A protein levels. The Cyclin D1 and CDK4 knock-down resulted in a significant reduction in cell proliferation, a G1 specific cell cycle arrest and moreover an extensive neuronal differentiation. Affymetrix microarray profiling of siRNA treated cells revealed a shift in expression profile towards a neuronal phenotype. Several new potential downstream players are identified. We conclude that neuroblastoma functionally depend on over-expression of G1 regulating genes to maintain their undifferentiated phenotype.
Publication Title
Cyclin D1 and CDK4 activity contribute to the undifferentiated phenotype in neuroblastoma.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Neuroblastoma is an embryonal tumour of the peripheral sympathetic nervous system (SNS). One of the master regulator genes for peripheral SNS differentiation, the homeobox transcription factor PHOX2B, is mutated in familiar and sporadic neuroblastomas. Here we report that inducible expression of PHOX2B in the neuroblastoma cell line SJNB-8 down-regulates MSX1, a homeobox gene important for embryonic neural crest development. Inducible expression of MSX1 in SJNB-8 caused inhibition of both cell proliferation and colony formation in soft agar. Affymetrix micro- array and Northern blot analysis demonstrated that MSX1 strongly up-regulated the Delta-Notch pathway. These experiments describe for the first time regulation of the Delta-Notch pathway by MSX1, and connect these genes to the PHOX2B oncogene, indicative of a role in neuroblastoma biology.
Publication Title
The MSX1 homeobox transcription factor is a downstream target of PHOX2B and activates the Delta-Notch pathway in neuroblastoma.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 10 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Neuroblastoma is a pediatric tumor of the sympathetic nervous system. MYCN (V-myc myelocytomatosis viral-related oncogene, neuroblastoma derived [avian]) is amplified in 20% of neuroblastomas, and these tumors carry a poor prognosis. However, tumors without MYCN amplification also may have a poor outcome. Here, we identified downstream targets of MYCN by shRNA-mediated silencing MYCN in neuroblastoma cells. From these targets, 157 genes showed an expression profile correlating with MYCN mRNA levels in NB88, a series of 88 neuroblastoma tumors, and therefore represent in vivo relevant MYCN pathway genes. This 157-gene signature identified very poor prognosis tumors in NB88 and independent neuroblastoma cohorts and was more powerful than MYCN amplification or MYCN expression alone. Remarkably, this signature also identified poor outcome of a group of tumors without MYCN amplification. Most of these tumors have low MYCN mRNA levels but high nuclear MYCN protein levels, suggesting stabilization of MYCN at the protein level. One tumor has an MYC amplification and high MYC expression. Chip-on-chip analyses showed that most genes in this signature are directly regulated by MYCN. MYCN induces genes functioning in cell cycle and DNA repair while repressing neuronal differentiation genes. The functional MYCN-157 signature recognizes classical neuroblastoma with MYCN amplification, as well as a newly identified group marked by MYCN protein stabilization.
Publication Title
Functional MYCN signature predicts outcome of neuroblastoma irrespective of MYCN amplification.
Sample Metadata Fields
Specimen part, Cell line, Time
View Samples- Homo sapiens
- 17 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Mutations affecting the RAS-MAPK pathway frequently occur in relapse neuroblastoma tumors, which suggests that activation of this pathway is associated with a more aggressive phenotype. To explore this hypothesis we generated several model systems to define a neuroblastoma RAS-MAPK pathway signature. We could show that activation of this pathway in primary tumors indeed correlates with poor survival and is associated with known activating mutations in ALK and other RAS-MAPK pathway genes. From integrative analysis we could show that mutations in PHOX2B, CIC and DMD are also associated with an activated RAS-MAPK pathway. Mutation of PHOX2B and deletion of CIC in neuroblastoma cell lines induces activation of the RAS-MAPK pathway. This activation was independent of phosphorylated ERK in the CIC knock out systems. Furthermore, deletion of CIC causes a significant increase in tumor growth in vivo. These results show that the RAS-MAPK pathway is involved in tumor progression, and establish CIC as a powerful tumor suppressor that functions downstream of this pathway in neuroblastoma.
Publication Title
RAS-MAPK Pathway-Driven Tumor Progression Is Associated with Loss of CIC and Other Genomic Aberrations in Neuroblastoma.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 30 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Whole genome sequencing detected structural rearrangements of TERT in 17/75 high stage neuroblastoma with 5 cases resulting from chromothripsis. Rearrangements were associated with increased TERT expression and targeted immediate up- and down-stream regions of TERT, placing in 7 cases a super-enhancer close to the breakpoints. TERT rearrangements (23%), ATRX deletions (11%) and MYCN amplifications (37%) identify three almost non-overlapping groups of high stage neuroblastoma, each associated with very poor prognosis
Publication Title
TERT rearrangements are frequent in neuroblastoma and identify aggressive tumors.
Sample Metadata Fields
Specimen part
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- Homo sapiens
- 38 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
A NOTCH feed-forward loop drives reprogramming from adrenergic to mesenchymal state in neuroblastoma.
Sample Metadata Fields
Specimen part, Cell line, Time
View Samples