Primary brain tumors are classified and treated based on their histological features, however the factors which specify these tumor types remain largely unknown. We demonstrate that the over-expression of HRAS (V12) and MYC alone or in combination directs the development of glioma, CNS PNET, and atypical teratoid/rhabdoid (AT/RT)-like tumors from postnatal murine p53-deficient neural stem/progenitor cells.
Definition of genetic events directing the development of distinct types of brain tumors from postnatal neural stem/progenitor cells.
No sample metadata fields
View SamplesSMARCB1 (SNF5/INI1/BAF47), a core subunit of the SWI/SNF (BAF) chromatin remodeling complex, is inactivated in nearly all pediatric rhabdoid tumors. These aggressive cancers are among the most genomically stable, suggesting an epigenetic mechanism by which SMARCB1 loss drives transformation. Here, we show that despite indistinguishable mutational landscapes, human RTs show distinct enhancer H3K27ac signatures, which reveal remnants of differentiation programs. We show that SMARCB1 is required for the integrity of SWI/SNF complexes and that its loss alters enhancer targeting markedly impairing SWI/SNF binding to typical enhancers, particularly those required for differentiation, while maintaining SWI/SNF binding at super-enhancers. We show that these retained super-enhancers are essential for rhabdoid tumor survival, including some that are shared across all subtypes, such as SPRY1, and other lineage-specific super-enhancers like SOX2 in brain-derived RTs. Taken together, our findings reveal a novel chromatin-based epigenetic mechanism underlying the tumor suppressive activity of SMARCB1. Overall design: RNA-seq in six Smarcb1 deficient rhabdoid tumor cell lines, before and after Smarcb1 re-expression.
SMARCB1-mediated SWI/SNF complex function is essential for enhancer regulation.
No sample metadata fields
View SamplesSMARCB1 (SNF5/INI1/BAF47), a core subunit of the SWI/SNF (BAF) chromatin remodeling complex, is inactivated in nearly all pediatric rhabdoid tumors. These aggressive cancers are among the most genomically stable, suggesting an epigenetic mechanism by which SMARCB1 loss drives transformation. Here, we show that despite indistinguishable mutational landscapes, human RTs show distinct enhancer H3K27ac signatures, which reveal remnants of differentiation programs. We show that SMARCB1 is required for the integrity of SWI/SNF complexes and that its loss alters enhancer targeting markedly impairing SWI/SNF binding to typical enhancers, particularly those required for differentiation, while maintaining SWI/SNF binding at super-enhancers. We show that these retained super-enhancers are essential for rhabdoid tumor survival, including some that are shared across all subtypes, such as SPRY1, and other lineage-specific super-enhancers like SOX2 in brain-derived RTs. Taken together, our findings reveal a novel chromatin-based epigenetic mechanism underlying the tumor suppressive activity of SMARCB1. Overall design: RNA-seq for three primary Rhabdoid tumor samples
SMARCB1-mediated SWI/SNF complex function is essential for enhancer regulation.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genome-wide localization of SREBP-2 in hepatic chromatin predicts a role in autophagy.
Sex, Specimen part
View SamplesWe are using genome-wide ChIP-seq with isoform-specific antibodies and chromatin from select tissues of mice challenged with different dietary conditions that enrich for specific SREBPs.
Genome-wide localization of SREBP-2 in hepatic chromatin predicts a role in autophagy.
Sex, Specimen part
View SamplesThis study demonstrates quantitative and qualitative differences between type I IFN signatures in autoimmunity and viral infection using purified CD4pos T cells and CD16pos- and CD16neg-monocyte subsets. We were able to discriminate between cell-specific viral response signatures and the pathogenically amplified IFN signatures observed in autoimmunity. The differences were of both a qualitative and quantitative nature, as the signatures in the patients with SLE were characterized by much more complexly compiled gene patterns with increased absolute gene expression levels.
Cell-specific type I IFN signatures in autoimmunity and viral infection: what makes the difference?
Specimen part
View SamplesHuman engeneered skin carrying GFP positive melanoma cells was transplanted in immunocompromised rats.
low neurotrophin receptor CD271 regulates phenotype switching in melanoma.
Specimen part, Time
View SamplesMany cytokines are involved in the pathogenesis of autoimmune diseases and are recognized as relevant therapeutic targets to attenuate inflammation, such as TNF in RA and IFN/ in SLE. To relate the transcriptional imprinting of cytokines in a cell type-specific and disease-specific manner, we generated gene-expression profiles from peripheral monocytes of SLE and RA patients and compared them to in vitro-generated signatures induced by TNF, IFN2a and IFN. Monocytes from SLE and RA patients revealed disease-specific gene-expression profiles. In vitro-generated signatures induced by IFN2a and IFN showed similar profiles that only partially overlapped with those induced by TNF. Comparisons between disease-specific and in vitro-generated signatures identified cytokine-regulated genes in SLE and RA with qualitative and quantitative differences. The IFN-responses in SLE and RA were found to be regulated in a STAT1-dependent and STAT1-independent manner, respectively. Similarly, genes recognized as TNF-regulated were clearly distinguishable between RA and SLE patients. While the activity of SLE monocytes was mainly driven by IFN, the activity from RA monocytes showed a dominance of TNF that was characterized by STAT1 down-regulation. The responses to specific cytokines were revealed to be disease-dependent and reflected the interplay of cytokines within various inflammatory milieus. This study has demonstrated that monocytes from RA and SLE patients exhibit disease-specific gene-expression profiles, which can be molecularly dissected when compared to in vitro-generated cytokine signatures. The results suggest that an assessment of cytokine-response status in monocytes may be helpful for improvement of diagnosis and selection of the best cytokine target for therapeutic intervention.
The multifaceted balance of TNF-α and type I/II interferon responses in SLE and RA: how monocytes manage the impact of cytokines.
Specimen part, Disease, Disease stage, Treatment, Subject
View SamplesWilms tumor (nephroblastoma) is a pediatric kidney tumor that arises from renal progenitor cells. Since the blastemal type is associated with adverse prognosis, we characterized such Wilms tumors by exome and transcriptome analysis. We detected novel, recurrent somatic mutations affecting the SIX1/2 SALL1 pathway implicated in kidney development, the DROSHA/DGCR8 microprocessor genes as well as alterations in MYCN and TP53, the latter being strongly associated with dismal outcome. The DROSHA mutations impair the RNase III domains, while DGCR8 exhibits stereotypic E518K mutations in the RNA binding domain - both may skew miRNA representation. SIX1 and SIX2 mutations affect a single hotspot (Q177R) in the homeodomain indicative of a dominant effect. In larger cohorts, these mutations cluster in blastemal and chemotherapy-induced regressive tumors that likely derive from blastemal cells and these are characterized by generally higher SIX1/2 expression. These findings broaden the spectrum of human cancer genes and may open new avenues for stratification and therapeutic leads for Wilms tumors.
Mutations in the SIX1/2 pathway and the DROSHA/DGCR8 miRNA microprocessor complex underlie high-risk blastemal type Wilms tumors.
Sex
View SamplesDnmt3b is a DNA methytransferase which is an enzyme that methylated genomic DNA which contributes to genomic stability and transcriptional regulation.
Loss of Dnmt3b function upregulates the tumor modifier Ment and accelerates mouse lymphomagenesis.
Specimen part
View Samples