Oculopharyngeal muscular dystrophy (OPMD) is a late-onset progressive muscle disorder caused by a poly-alanine expansion mutation in PABPN1. The hallmark of OPMD is the accumulation of the mutant protein in insoluble nuclear inclusions. The molecular mechanisms associated with disease onset and progression are unknown. We performed a high-throughput cross-species transcriptome study of affected muscles from two OPMD animal models and from patients at pre-symptomatic and symptomatic stages. The most consistently and significantly OPMD-deregulated pathway across species is the ubiquitin-proteasome system (UPS). By analyzing expression profiles, we found that the majority of OPMD-deregulated genes are age-associated. Based on expression trends, disease onset can be separated from progression; the expression profiles of the proteasome-encoding genes are associated with onset but not with progression. In a muscle cell model, proteasome inhibition and the stimulation of immunoproteasome specifically affect the accumulation and aggregation of mutant PABPN1. We suggest that proteasome down-regulation during muscle aging triggers the accumulation of expPABPN1 that in turn enhances proteasome deregulation and leads to intranuclear inclusions (INI) formation.
Deregulation of the ubiquitin-proteasome system is the predominant molecular pathology in OPMD animal models and patients.
Sex, Age, Disease, Disease stage
View SamplesmRNA profiles of thousands of human tumors are available, but methods to deduce oncogenic signaling networks from these data lag behind. It is especially challenging to identify main-regulatory routes, and to generalize conclusions obtained from experimental models. We designed the bioinformatic platform R2 in parallel with a wet-lab approach of neuroblastoma. Here we demonstrate how R2 facilitates an integrated analysis of our neuroblastoma data. Analysis of the MYCN pathway suggested important regulatory connections to the polyamine synthesis route, the Notch pathway and the BMP/TGF pathway. A network of genes emerged connecting major oncogenes in neuroblastoma. Genes in the network carried strong prognostic values and were essential for tumor cell survival.
Sequencing of neuroblastoma identifies chromothripsis and defects in neuritogenesis genes.
Specimen part
View SamplesSparse populations of neurons in the dentate gyrus (DG) of the hippocampus are causally implicated in the encoding of contextual fear memories. However, engram-specific molecular mechanisms underlying memory consolidation remain largely unknown. Here we perform unbiased RNA sequencing of DG engram neurons 24h after contextual fear conditioning to identify transcriptome changes specific to memory consolidation. DG engram neurons exhibit a highly distinct pattern of gene expression, in which CREB-dependent transcription features prominently (P=6.2x10-13), including Atf3 (P=2.4x10-41), Penk (P=1.3x10-15), and Kcnq3 (P=3.1x10-12). Moreover, we validate the functional relevance of the RNAseq findings by establishing the causal requirement of intact CREB function specifically within the DG engram during memory consolidation, and identify a novel group of CREB target genes involved in the encoding of long-term memory. Overall design: Biological replicates: Fear conditioned: n=14, No shock controls: n=4, Home cage controls:n=3. The contents 10 dVenus+ and 10 dVenus- cells were aspirated from each animal (biological replicate)
Engram-specific transcriptome profiling of contextual memory consolidation.
Specimen part, Cell line, Treatment, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
A NOTCH3 transcriptional module induces cell motility in neuroblastoma.
Specimen part, Cell line
View SamplesMigratory 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.
A NOTCH3 transcriptional module induces cell motility in neuroblastoma.
Cell line
View SamplesGenomic 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.
Cyclin D1 and CDK4 activity contribute to the undifferentiated phenotype in neuroblastoma.
No sample metadata fields
View SamplesNeuroblastoma 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.
Functional MYCN signature predicts outcome of neuroblastoma irrespective of MYCN amplification.
Specimen part, Cell line, Time
View SamplesWhole 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
TERT rearrangements are frequent in neuroblastoma and identify aggressive tumors.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
A NOTCH feed-forward loop drives reprogramming from adrenergic to mesenchymal state in neuroblastoma.
Specimen part, Cell line, Time
View SamplesNeuroblastoma 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.
The MSX1 homeobox transcription factor is a downstream target of PHOX2B and activates the Delta-Notch pathway in neuroblastoma.
No sample metadata fields
View Samples