Project description:Genomewide DNA methylation array profiling of nine posterior fossa ependymomas harboring activating mutations in ACVR1. Two samples clustered with the PFA subtype and demonstrated H3K27me3 loss by immunohistochemistry, while the remaining 7 showed retained H3K27me3 and formed a methylation cluster distinct from other ependymal tumors. For these previsouly unpublished cases, the Illumina Infinium EPIC 850k Human DNA Methylation Beadchip was used to obtain DNA methylation profiles across approximately 850,000 CpG sites of genomic DNA extracted from formalin-fixed, paraffin-embedded tumor tissue.
Project description:Two distinct groups of posterior fossa ependymoma, PF-EPN-A and PF-EPN-B have been identified in children and are often associated with widely distinct outcomes. We have identified an ultra-high-risk PF-EPN-A ependymoma with 6q loss. We performed RNA sequencing of posterior fossa ependymoma A (PF-EPN-A) tumor samples with chromosome 6q loss and balanced to understand the differences in 6q loss at the transcriptomic level
Project description:Posterior fossa subgroup A (PFA) ependymoma is a brain tumor of childhood with a high rate of recurrence. Here we have performed RNAseq on a longitudinal cohort of patient samples obtained at presentation and at recurrence(s), in order to identify the biological correlates of treatment failure and tumor evolution.
Project description:Despite histological similarity of ependymomas from throughout the neuraxis, the disease likely comprises multiple independent entities, each with a distinct molecular pathogenesis. Transcriptional profiling of two large independent cohorts of ependymomas reveals the existence of two demographically, transcriptionally, genetically and clinically distinct groups of posterior fossa (PF) ependymoma. Group A patients are younger, have laterally located tumors with a balanced genome, and are much more likely to exhibit recurrence, metastasis, and death as compared to Group B patients. Identification and optimization of immunohistochemical markers for PF ependymoma subgroups allowed validation of our findings on a third group of independent ependymomas using a human ependymoma tissue microarray, and provides a tool for prospective prognostication and stratification of PF ependymoma patients. This SuperSeries is composed of the following subset Series: GSE27283: Human ependymoma samples [expression] GSE27286: Human ependymoma samples, Subgrouping [aCGH - German Cancer Research Center human 33K BAC array] Refer to individual Series
Project description:Gene expression (mRNA) profiling of human ependymomas Despite the histological similarity of ependymomas from throughout the neuraxis, the disease likely comprises multiple independent entities, each with a distinct molecular pathogenesis. Transcriptional profiling of two large independent cohorts of ependymoma reveals the existence of two demographically, transcriptionally, genetically, and clinically distinct groups of posterior fossa (PF) ependymoma. Group-A patients are younger, have laterally located tumors with a balanced genome, and are much more likely to exhibit recurrence, secondary metastasis, and death as compared to Group-B patients. Identification and optimization of immunohistochemical markers for PF ependymoma subgroups allowed validation of our findings on a third independent group of tumors using a human ependymoma tissue microarray, and provides a tool for prospective prognostication and stratification of PF ependymoma patients. We analyzed 102 primary ependymomas on the Affymetrix Exon 1.0ST platform (Gene Level).
Project description:we used whole-genome microRNA microarray expression profiling as a discovery platform to identify a subset of miRNAs that were differently expressed in CD44-positive pediatric posterior fossa ependymoma compared with CD44-negative ones.
Project description:Pediatric ependymoma is a devastating brain cancer marked by its relapsing pattern and lack of effective chemotherapies. This shortage of treatments is due to limited knowledge about ependymoma tumorigenic mechanisms. By means of single-nucleus chromatin accessibility and gene expression profiling of posterior fossa primary tumors and distal metastases, we reveal key transcription factors and enhancers associated with the differentiation of ependymoma tumor cells into tumor-derived cell lineages and their transition into a mesenchymal-like state. We identify NFkB, AP-1, and MYC as mediators of this transition, and show that the gene expression profiles of tumor cells and infiltrating microglia are consistent with abundant pro-inflammatory signaling between these populations. In line with these results, both TGF-b1 and TNF-a induce the expression of mesenchymal genes on a patient-derived cell model, and TGF-b1 leads to an invasive phenotype. Altogether, these data suggest that tumor gliosis induced by inflammatory cytokines and oxidative stress underlies the mesenchymal phenotype of posterior fossa ependymoma. This SuperSeries is composed of the SubSeries listed below.
Project description:Gene expression (mRNA) profiling of human ependymomas Despite the histological similarity of ependymomas from throughout the neuraxis, the disease likely comprises multiple independent entities, each with a distinct molecular pathogenesis. Transcriptional profiling of two large independent cohorts of ependymoma reveals the existence of two demographically, transcriptionally, genetically, and clinically distinct groups of posterior fossa (PF) ependymoma. Group-A patients are younger, have laterally located tumors with a balanced genome, and are much more likely to exhibit recurrence, secondary metastasis, and death as compared to Group-B patients. Identification and optimization of immunohistochemical markers for PF ependymoma subgroups allowed validation of our findings on a third independent group of tumors using a human ependymoma tissue microarray, and provides a tool for prospective prognostication and stratification of PF ependymoma patients.