Recent genomic approaches have suggested the existence of multiple distinct subtypes of medulloblastoma. We studied a large cohort of medulloblastomas to determine how many subgroups of the disease exist, how they differ, and the extent of overlap between subgroups. We determined gene expression profiles and DNA copy number aberrations for 103 primary medulloblastomas. Bioinformatic tools were used for class discovery of medulloblastoma subgroups based on the most informative genes in the dataset. Immunohistochemistry for subgroup-specific signature genes was used to determine subgroup affiliation for 294 non-overlapping medulloblastomas on two independent tissue microarrays (TMAs). Multiple unsupervised analyses of transcriptional profiles identified four distinct, non-overlapping molecular variants: WNT, SHH, Group C, and Group D. Supervised analysis of these four subgroups revealed significant subgroup-specific demographics, histology, metastatic status, and DNA copy number aberrations. Immunohistochemistry for DKK1 (WNT), SFRP1 (SHH), NPR3 (Group C), and KCNA1 (Group D) could reliably and uniquely classify formalin fixed medulloblastomas in ~98% of cases. Group C patients (NPR3 +ve tumors) exhibited a significantly diminished progression free and overall survival irrespective of their metastatic status. Our integrative genomics approach to a large cohort of medulloblastomas has identified four disparate subgroups with distinct demographics, clinical presentation, transcriptional profiles, genetic abnormalities, and clinical outcome. Medulloblastomas can be reliably assigned to subgroups through immunohistochemistry, thereby making medulloblastoma sub-classification widely available. Future research on medulloblastoma and the development of clinical trials should take into consideration these four distinct types of medulloblastoma.
Medulloblastoma comprises four distinct molecular variants.
Sex, Age, Specimen part
View SamplesPrimitive neuro-ectodermal tumours (PNET) of the supratentorial region are rare, highly malignant embryonal brain tumours affecting young children. We recently highlighted the importance of a microRNA cluster housing miR-520g. We utilized the Illumina HumanWG-6 v3 R2 and HumanHT-12 v3 R2 Expression BeadChip platforms to profile the effects of miR-520g on gene expression.
Frequent amplification of a chr19q13.41 microRNA polycistron in aggressive primitive neuroectodermal brain tumors.
Specimen part, Cell line
View SamplesTranscriptome analysis of LDBM cells stimulated with IL-5
IL-5 triggers a cooperative cytokine network that promotes eosinophil precursor maturation.
Specimen part
View SamplesTo identify regulators of homeostatic eosinophilopoiesis in mice, we took a global approach to identify genome-wide transcriptome and epigenome changes that occur during homeostasis at critical developmental stages, including eosinophil-lineage commitment (eosinophil progenitor [EoP] compared to granulocyte-monocyte progenitor [GMP]) and lineage maturation (eosinophil compared to EoP). Our analyses revealed markedly greater transcriptome alterations associated with eosinophil maturation (1199 genes) compared to eosinophil-lineage commitment (490 genes), highlighting the greater transcriptional investment necessary for differentiation. Our analyses also delineated a 976 gene eosinophil-lineage transcriptome that included a repertoire of 56 transcription factors, many of which have never previously been associated with eosinophils. Epigenomic studies revealed that genes that were specifically induced with eosinophil-lineage commitment in EoPs were “poised” with active chromatin marks in GMPs, despite not being expressed in GMPs. In contrast, a majority of the genes that were highly and specifically induced with maturation in eosinophils was not associated with poised chromatin, suggesting distinct epigenetic regulation between genes induced with lineage commitment compared to genes induced with cell maturation during eosinophil development. Overall design: RNA Seq and H3K4me3 distribution of GMPs, EoPs and eosinophils sorted from Balb/c bone marrow. RNA Seq libraries were prepared from 2 independent sorts of each cell type (GMP, EoPs, Eosinophils [Eos]). ChIP Seq was performed with chromatin from one sort of each cell type.
Transcription Factor Repertoire of Homeostatic Eosinophilopoiesis.
No sample metadata fields
View SamplesEosinophils are major effector cells in type 2 inflammatory responses and become activated in response to IL-4 and IL-33, yet the molecular mechanism remains unclear. We examined the direct effect of these cytokines on eosinophils and demonstrated that murine eosinophils respond to IL-4 and IL-33 by phosphorylation of STAT-6 and NFkB, respectively. RNA sequencing analysis of murine eosinophils indicated that IL-33 regulates 519 genes, whereas IL-4 regulates only 28 genes, including 19 IL-33-regulated genes. Interestingly, IL-33 induced eosinophil activation via two distinct mechanisms, IL-4 independent and IL-4 secretion/auto-stimulation dependent. Anti-IL-4 or anti-IL-4Ra antibody-treated eosinophils, as well as Il4- or Stat6-deficient eosinophils, had attenuated protein secretion of a subset of IL-33-induced genes, including Retnla and Ccl17. However, the induction of most IL-33-regulated transcripts (e.g. Il6 and Il13) was IL-4 independent and blocked by NFkB inhibition. Indeed, IL-33 induced the rapid release of pre-formed IL-4 protein from eosinophils by an NFkB-dependent mechanism. Thus, we have identified a novel activation pathway in murine eosinophils that is induced by IL-33 and differentially dependent upon IL-4. These data suggest that IL-4 plays a critical role in auto-amplification of IL-33-induced eosinophil activation and could be a potential target for therapeutic approaches in IL-33-related eosinophil-associated diseases. Overall design: Low density bone marrow derived murine eosinophils were generated in culture over the period of 14 days. Eosinophils were activated by either IL-33 or IL-4 at 10 ng/ml for 1hr and 4hr. RNA was collected and subjected to next generation sequencing.
IL-33 markedly activates murine eosinophils by an NF-κB-dependent mechanism differentially dependent upon an IL-4-driven autoinflammatory loop.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Molecular characterization of choroid plexus tumors reveals novel clinically relevant subgroups.
Specimen part
View SamplesGene expression was assessed in a cohort of 40 choroid plexus tumors isolated from fresh-frozen tissue. We investigated unique expression patterns among tumor subgroups and refined the classification of choroid plexus tumors according to gene expression intensities.
Molecular characterization of choroid plexus tumors reveals novel clinically relevant subgroups.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Medulloblastoma subgroups remain stable across primary and metastatic compartments.
Sex, Age, Specimen part, Subject
View SamplesAffymetrix Human Gene 2.0 ST Array profiling of 9 pairs of matched primary-metastases medulloblastoma samples.
Medulloblastoma subgroups remain stable across primary and metastatic compartments.
Sex, Age, Specimen part, Subject
View SamplesAnalysis of a SigX knockout mutant of Pseudomonas aeruginosa H103 strain in minimal medium with glucose as carbon source (M9G).
The extra-cytoplasmic function sigma factor sigX modulates biofilm and virulence-related properties in Pseudomonas aeruginosa.
No sample metadata fields
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