Cell-cycle-resolved analysis of RNA expression in neuroblastoma cells upon MYCN knockdown
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE97774 | GEO | 2017/09/12
SECONDARY ACCESSION(S): PRJNA383104
REPOSITORIES: GEO
Similar Datasets
Project 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.
2012-11-05 | GSE39218 | GEO
Project description:Wilms tumor (WT) is the most common renal tumor in childhood. Among others, MYCN copy number gain and MYCN P44L and MAX R60Q mutations have been identified in WT. The proto-oncogene MYCN encodes a transcription factor that requires dimerization with MAX to activate transcription of numerous target genes. MYCN gain has been associated with adverse prognosis. The MYCN P44L and MAX R60Q mutations, located in either the transactivating or basic helix-loop-helix domain, respectively, are predicted to be damaging by different pathogenicity prediction tools. We screened a large cohort of unselected WTs and revealed frequencies of 3 % for MYCN P44L and 0.8 % for MAX R60Q, associated with a higher risk of relapse in the case of MYCN. Biochemical characterization identified a reduced transcriptional activation potential for MAX R60Q, while the MYCN P44L mutation did not change activation potential or protein stability. The protein interactome of N-MYC-P44L was likewise not altered as shown by mass spectrometric analyses of purified N-MYC complexes. Nevertheless, we could identify a number of novel N-MYC partner proteins, and several of these are known for their oncogenic potential. Correlated expression in WT samples suggests a role in WT oncogenesis and they expand the range of potential biomarkers for WT stratification and targeting, especially for high-risk WT.
2022-02-17 | PXD025996 | Pride
Project description:Overexpression of MYC family members is linked to poor clinical outcome in many human cancers. These oncoproteins drive proliferation, alter metabolism, and mediate an antioxidant response to maintain tumor cell redox balance. However, to date, there are no effective inhibitors that specifically target MYC-amplified tumors. We demonstrate that MYCN-amplified, aggressive childhood neuroblastoma cells undergo ferroptotic cell death in vivo in the absence of intracellular cysteine, thus implicating MYCN as a predictive biomarker for ferroptosis sensitivity in neuroblastoma. Although cysteine is provided by both uptake from the microenvironment and MYCN-induced transsulfuration of methionine, glutathione levels remain low in these highly proliferative cancer cells due to concomitant cysteine utilization for protein and nucleotide synthesis. Consequently, MYCN-amplified neuroblastoma cells are highly susceptible to lipid peroxidation and ferroptosis, which must be counteracted by GPX4 activity. Pharmacological inhibition of both cystine uptake and transsulfuration combined with GPX4 inactivation resulted in tumor remission in an orthotopic MYCN-amplified neuroblastoma model. Our data show that MYCN-amplified neuroblastoma is sensitized to ferroptosis, which can be exploited therapeutically, by depleting the intracellular cysteine pool with concomitant GPX4 inactivation. These findings may help to develop novel clinical strategies to target MYCN-amplified tumors by inducing ferroptotic cell death.
2022-01-18 | GSE189174 | GEO
Project description:BACKGROUND Focal high-level amplifications of MYC define a subset of high-risk medulloblastoma patients. However, the prognostic role of MYCN oncogene amplification remains less clear. We aimed to evaluate the prognostic value of this alteration alone and in combination with biological modifiers in a large cohort of 67 pediatric medulloblastomas with MYCN amplification (MYCN-MB). METHODS Twenty-one MYCN-MB with MYCN amplication and 56 MYCN-MB were respectively examined using either gene expression profiling and array-CGH, or immunohistochemical analysis and FISH. All 67 tumors were further subject to mutational analyses. Semi non-negative matrix factorization–based and unsupervised hierarchical clustering methods were used to identify biological groups. We compared molecular, clinical, and prognostic characteristics both within biological MYCN-MB groups and with non-amplified tumors. RESULTS Transcriptomic analysis of this large cohort of MYCN-MBs demonstrated a significant enrichment of MYCN-MB in the SHH and group D variants. Further substantiating this biological dichotomy of MYCN-MB, respective group affiliations were also accompanied by variant-specific cytogenetic aberrations including deletion of 9q in the SHH variant, and gain of 7q and isochromosome 17q/17q gain in MYCN-MBs clustering with group D tumors. Among clinically relevant variables, SHH subtype and 10q loss for Non-SHH tumors comprised the most powerful markers of favorable prognosis in MYCN-MB. CONCLUSION We demonstrate considerable heterogeneity within MYCN-MB in terms of genetics, tumor biology, and clinical outcome. Thus, assessment of disease group and 10q copy-number status may improve risk stratification of this group and may delineate MYCN-MB with the same dismal prognosis as MYC amplified tumors. Furthermore, based on the enrichment of MYCN and GLI2 amplifications in SHH-driven medulloblastoma, amplification of these downstream signaling intermediates should be excluded before a patient is enrolled into a clinical trial using a Smoothened inhibitor.
2011-09-01 | GSE30530 | GEO
Project description:The net transcriptome of a cancer cell is defined by relative levels of transcription factors, activators, suppressors and co-factors. These in turn are controlled by epigenetic, genetic and metabolic restraints. Here we used RNA-Seq, ChIP-qPCR, and ChIP-Seq to determine the impact of MYCN protein levels on p53 and MYCN mediated transcription in neuroblastoma, a p53 wild-type neural crest derived pediatric malignancy. Of note, about 25% of neuroblastoma is MYCN amplified and expresses 10-100 fold higher levels of MYCN protein than non-amplified tumors. We hypothesized that p53 functions would be globally altered by extreme MYCN levels and this could help to explain aggressive biology and poor long term survival which distinguishes MYCN-amplified neuroblastoma. In fact, we found that in the context of high MYCN levels, activation of p53 results in marked changes in transcription of specific p53 and MYCN target loci regulating apoptosis, DNA repair and cell cycle progression. Co-immunoprecipitation of endogenous and GST-fused proteins, as well as ChIP-qPCR confirms formation of p53/MYCN complexes and enrichment of both transcription factors at active loci. This p53/MYC interaction is independent of MYC/MAX complexes. Together, these data demonstrate MYCN to be a direct co-factor modulating p53 transcriptional output in MYCN amplified cancer.
2018-05-17 | GSE83327 | GEO
Project description:The net transcriptome of a cancer cell is defined by relative levels of transcription factors, activators, suppressors and co-factors. These in turn are controlled by epigenetic, genetic and metabolic restraints. Here we used RNA-Seq, ChIP-qPCR, and ChIP-Seq to determine the impact of MYCN protein levels on p53 and MYCN mediated transcription in neuroblastoma, a p53 wild-type neural crest derived pediatric malignancy. Of note, about 25% of neuroblastoma is MYCN amplified and expresses 10-100 fold higher levels of MYCN protein than non-amplified tumors. We hypothesized that p53 functions would be globally altered by extreme MYCN levels and this could help to explain aggressive biology and poor long term survival which distinguishes MYCN-amplified neuroblastoma. In fact, we found that in the context of high MYCN levels, activation of p53 results in marked changes in transcription of specific p53 and MYCN target loci regulating apoptosis, DNA repair and cell cycle progression. Co-immunoprecipitation of endogenous and GST-fused proteins, as well as ChIP-qPCR confirms formation of p53/MYCN complexes and enrichment of both transcription factors at active loci. This p53/MYC interaction is independent of MYC/MAX complexes. Together, these data demonstrate MYCN to be a direct co-factor modulating p53 transcriptional output in MYCN amplified cancer.
2018-05-17 | GSE83317 | GEO
Project description:In neuroblastoma, amplification of the oncogenic basic helix-loop-helix (bHLH) transcription factor (TF) MYCN is the defining prognosticator of high-risk disease, occurs in one-third of neuroblastoma, and drastically reduces overall survival rates. As a proto-oncogene, targeted MYCN overexpression in peripheral neural crest is sufficient to initiate disease in mouse models. In MYCN amplified neuroblastoma, elevated expression of the factor is crucial to maintain tumor stemness and is associated with increased proliferation and aberrant cell cycle progression, as these tumors lack the ability to arrest in G1 in response to irradiation. MYCN down-regulation broadly reverses these oncogenic phenotypes in a variety of neuroblastoma models and recent thereapeutic strategies to indirectly target MYCN production or protein stability have reduced tumor growth in vivo. These observations motivate an investigation of MYCN binding in MYCN amplified tumors as it remains fundamentally unclear how elevated levels of the factor occupy the genome and alter transcriptional programs in neuroblastoma. Here we present the first dynamic chromatin and transcriptional landscape of direct MYCN perturbation in neuroblastoma. We find that at oncogenic levels, MYCN associates with E-box (CANNTG) binding motifs in an affinity dependent manner across most active cis-regulatory promoters and enhancers. MYCN shutdown globally reduces histone acetylation and transcription, consistent with prior descriptions of MYC proteins as non-linear amplifiers of gene expression. We establish that MYCN load at the promoter and proximal enhancers predicts transcriptional responsiveness to MYCN shutdown and that MYCN enhancer binding occurs prominently at the most strongly occupied and down-regulated genes, suggesting a role for these tissue specific elements in predicating MYCN responsive âtargetâ genes. At these invaded enhancers, we identify the lineage specific bHLH TWIST1 as a key collaborator and dependency of oncogenic MYCN. These data suggest that MYCN enhancer invasion helps shape transcriptional amplification of the neuroblastoma gene expression program to promote tumorigenesis. ChIP-Seq in SHEP21, BE2C, KELLY, and NGP neuroblastoma cell lines for H3K27ac, H3K4me3, RNA PolII, MYCN, BRD4, or TWIST1
2016-09-01 | E-GEOD-80151 | biostudies-arrayexpress
Project description:In neuroblastoma, amplification of the oncogenic basic helix-loop-helix (bHLH) transcription factor (TF) MYCN is the defining prognosticator of high-risk disease, occurs in one-third of neuroblastoma, and drastically reduces overall survival rates1,2. As a proto-oncogene, targeted MYCN overexpression in peripheral neural crest is sufficient to initiate disease in mouse models3. In MYCN amplified neuroblastoma, elevated expression of the factor is crucial to maintain tumor stemness4,5 and is associated with increased proliferation and aberrant cell cycle progression, as these tumors lack the ability to arrest in G1 in response to irradiation6-9. MYCN down-regulation broadly reverses these oncogenic phenotypes in a variety of neuroblastoma models10-12 and recent thereapeutic strategies to indirectly target MYCN production or protein stability have reduced tumor growth in vivo13-15. These observations motivate an investigation of MYCN binding in MYCN amplified tumors as it remains fundamentally unclear how elevated levels of the factor occupy the genome and alter transcriptional programs in neuroblastoma. Here we present the first dynamic chromatin and transcriptional landscape of direct MYCN perturbation in neuroblastoma. We find that at oncogenic levels, MYCN associates with E-box (CANNTG) binding motifs in an affinity dependent manner across most active cis-regulatory promoters and enhancers. MYCN shutdown globally reduces histone acetylation and transcription, consistent with prior descriptions of MYC proteins as non-linear amplifiers of gene expression. We establish that MYCN load at the promoter and proximal enhancers predicts transcriptional responsiveness to MYCN shutdown and that MYCN enhancer binding occurs prominently at the most strongly occupied and down-regulated genes, suggesting a role for these tissue specific elements in predicating MYCN responsive â??targetâ?? genes. At these invaded enhancers, we identify the lineage specific bHLH TWIST1 as a key collaborator and dependency of oncogenic MYCN. These data suggest that MYCN enhancer invasion helps shape transcriptional amplification of the neuroblastoma gene expression program to promote tumorigenesis. ATAC-Seq in SHEP21, BE2C, KELLY, NGP, and MM1S cell lines
2016-09-01 | E-GEOD-80152 | biostudies-arrayexpress
Project description:In neuroblastoma, amplification of the oncogenic basic helix-loop-helix (bHLH) transcription factor (TF) MYCN is the defining prognosticator of high-risk disease, occurs in one-third of neuroblastoma, and drastically reduces overall survival rates. As a proto-oncogene, targeted MYCN overexpression in peripheral neural crest is sufficient to initiate disease in mouse models. In MYCN amplified neuroblastoma, elevated expression of the factor is crucial to maintain tumor stemness and is associated with increased proliferation and aberrant cell cycle progression, as these tumors lack the ability to arrest in G1 in response to irradiation. MYCN down-regulation broadly reverses these oncogenic phenotypes in a variety of neuroblastoma models and recent thereapeutic strategies to indirectly target MYCN production or protein stability have reduced tumor growth in vivo. These observations motivate an investigation of MYCN binding in MYCN amplified tumors as it remains fundamentally unclear how elevated levels of the factor occupy the genome and alter transcriptional programs in neuroblastoma. Here we present the first dynamic chromatin and transcriptional landscape of direct MYCN perturbation in neuroblastoma. We find that at oncogenic levels, MYCN associates with E-box (CANNTG) binding motifs in an affinity dependent manner across most active cis-regulatory promoters and enhancers. MYCN shutdown globally reduces histone acetylation and transcription, consistent with prior descriptions of MYC proteins as non-linear amplifiers of gene expression. We establish that MYCN load at the promoter and proximal enhancers predicts transcriptional responsiveness to MYCN shutdown and that MYCN enhancer binding occurs prominently at the most strongly occupied and down-regulated genes, suggesting a role for these tissue specific elements in predicating MYCN responsive “target” genes. At these invaded enhancers, we identify the lineage specific bHLH TWIST1 as a key collaborator and dependency of oncogenic MYCN. These data suggest that MYCN enhancer invasion helps shape transcriptional amplification of the neuroblastoma gene expression program to promote tumorigenesis.
2018-01-30 | GSE100538 | GEO
Project description:MYCN and MYC profiling in neuroblastoma cell lines
2019-11-03 | GSE138295 | GEO