High and low cell density areas in posterior fossa ependymoma type A have a distinct transcriptome
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE249189 | GEO | 2024/01/31
REPOSITORIES: GEO
Similar Datasets
Project description:Posterior fossa type A (PF-EPN-A, PFA) ependymoma are aggressive tumors that mainly affect children and have a poor prognosis. Histopathology shows significant intratumoral heterogeneity, ranging from loose tissue to often sharply demarcated, extremely cell dense tumor areas. To determine molecular differences in morphologically different areas and to understand their clinical significance, we analyzed 113 PF-EPN-A samples, including 40 corresponding relapse samples. Relapsing tumors displayed a higher proportion of cell dense areas (p=0.036), a change in PF-EPN-A methylation subtypes (13/32 patients), and novel chromosome 1q gains and 6q losses (12/32 cases) compared to corresponding primary tumors.
2024-01-31 | GSE248617 | GEO
Project description:Posterior fossa type A (PF-EPN-A, PFA) ependymoma are aggressive tumors that mainly affect children and have a poor prognosis. Histopathology shows significant intratumoral heterogeneity, ranging from loose tissue to often sharply demarcated, extremely cell dense tumor areas. To determine molecular differences between these morphologically different areas and to understand their clinical significance, we analyzed 113 PF-EPN-A samples, including 40 corresponding relapse samples. Inter alia, DNA methylation profiles were analysed for high and low cell density regions seperately in 21 cases. Tumor areas with low and high cell density showed diverging DNA methylation profiles regarding their similarity to distinct previously discovered PF-EPN-A subtypes in 9/21 cases. Prognostically relevant chromosomal changes at 1q and 6q showed spatial heterogeneity within single tumors.
2024-01-31 | GSE248618 | GEO
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
2021-02-15 | GSE164292 | GEO
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.
2023-06-01 | GSE226957 | GEO
Project description:Posterior fossa A (PFA) ependymomas comprise one out of nine molecular groups of ependymoma. PFA tumors are mainly diagnosed in infants and young children, show a poor prognosis and are characterized by a lack of the repressive histone H3 lysine 27 trimethylation (H3K27me3) mark. Recently, we reported CXorf67 overexpression as hallmark of PFA ependymoma and showed that CXorf67 can interact with EZH2 thereby inhibiting polycomb repressive complex 2 (PRC2). Here, we report that the inhibitory mechanism of this interaction is similar as in diffuse midline gliomas harboring H3K27M mutations. A small, highly conserved peptide sequence located in the C-terminal region of CXorf67 mimics the H3K27M peptide and binds to the SET domain of EZH2. This interaction blocks EZH2 methyltransferase activity and causes H3K27 hypomethylation, an oncogenic mechanism that may be exploited for targeted therapy in PFA ependymoma. Based on its function, we have renamed CXorf67 into EZH2 Inhibitory Protein (EZHIP).
2019-07-08 | PXD012318 | Pride
Project description:Ependymoma (EPN) posterior fossa group A (PFA) has the highest rate of recurrence and the worst prognosis of all EPN types. At relapse, it is typically incurable even with re-resection and re-irradiation. The biology of recurrent PFA EPN remains largely unknown, which hinders clinical advances. In this large longitudinal multicenter study, we examined matched samples of primary and recurrent disease from PFA EPN patients (n=95) to investigate the biology of recurrence. DNA methylomic data was used to measure copy number variants (CNVs), revealing progressive large scale chromosome gains and losses in successive recurrences. These CNV changes were dominated by chromosome 1q gain and/or 6q loss (1q+/6q-), both previously identified as high-risk factors in PFA EPN, which were present in ~20% at presentation but increased to ~60% at 1st recurrence. These CNV changes were correlated with hypomethylation of heterochromatin associated DNA at presentation. Evolution of chromosomal aberrations was further explored using CNV analysis of single-nuclei RNAseq on approximately 46,000 PFA EPN cells from 6 matched pairs of primary and 1st relapse tumors that harbored CNV changes at recurrence. No evidence of rare subclones in primary tumors was observed, suggesting that chromosomal rearrangement events occur after initial presentation. Cellular and molecular characteristics associated with CNVs were examined by single-nuclei RNAseq, bulk transcriptomic analysis and immunohistochemistry, revealing that 1q+/6q- PFA have a significantly higher mitotic index, increased proportions of proliferative epithelial progenitors and decreased differentiated neoplastic subpopulations. Multivariate survival analyses showed that cases with 1q gain or 6q loss at 1st recurrence were significantly more likely to recur than cases with no 1q or 6q change. The high prevalence of 1q+/6q- at recurrence and the associated shortened survival, suggest that both these abnormalities should be routinely tested for, and used for trial stratification.
2023-06-01 | GSE227644 | GEO
Project description:Introduction: single-cell RNA sequencing identified multiple subpopulations in childhood posterior fossa ependymoma. The contribution of individual neoplastic subpopulations to bulk tumor transcriptome-based molecular classification and patient outcome was estimated by deconvolution in a cohort of clinically-annotated primary and recurrent EPN samples. The abundance of EPN subpopulations was estimated in primary EPN samples and showed that the ratio of subpopulation fractions dictated assignment to the two main transcriptomic classification subgroups in childhood posterior fossa ependymoma. Longitudinal analysis revealed that subpopulation fractions changed between presentation and recurrence. Outcome analyses demonstrated that a different proportions of subpopulations were associated with differential survival.
2020-07-31 | GSE125861 | GEO
Project description:Ependymoma (EPN) is a brain tumor commonly presenting in childhood that remains fatal in the majority of children. Intra-tumoral cellular heterogeneity in bulk tumor samples significantly confounds our understanding of EPN biology, impeding development of effective therapy. We used single-cell RNA sequencing to identify four neoplastic cell subpopulations in posterior fossa EPN patient samples that underlie traditional subgroup classification and harbor divergent lineage trajectories and clinical outcomes. Neoplastic subpopulations expressed gene signatures associated with normal ependyma, ependymoma, and mesenchymal phenotypes, consequently named ciliated (CEC), transportive (TEC), undifferentiated (UEC), and mesenchymal ependymoma cells (MEC). The abundance of EPN subpopulations as estimated by deconvolution of EPN bulk tumor transcriptomes showed that the ratio of MEC and CEC cell fractions dictated assignment to the two main classification subgroups in PFA. Longitudinal analysis revealed evolution of subpopulation fractions, notably MEC and CEC, which changed between presentation and recurrence. Outcome analyses demonstrated that a higher proportion of UEC or MEC subpopulations was associated with shorter survival, whereas CEC was associated with longer survival. Unsupervised pseudotime analysis revealed divergent subpopulation lineages. The first lineage conformed to a classic cancer stem cell trajectory where UEC progenitors differentiate sequentially to TECs and then CECs. In the second trajectory MECs arise from UECs via TECs, potentially in response to hypoxia-mediated cellular stress, a process that we recreated in vitro in a hypoxia treated EPN cell line. Our study reveals the existence of significant, unappreciated cellular heterogeneity in EPN and provides important resolution of EPN tumor biology.
2020-07-31 | GSE125969 | GEO
Project description:ACVR1-mutant posterior fossa ependymoma
| PRJNA802906 | ENA
Project description:Ependymomas are neuroepithelial tumors of the central nervous system (CNS), presenting in both adults and children but accounting for almost 10% of all pediatric CNS tumors and up to 30% of CNS tumors in children under 3 years (Bouffet et al., 2009; McGuire et al., 2009; Rodriguez et al., 2009). In children, most ependymomas arise in the posterior fossa, while most adult ependymomas present around the lower spinal cord and spinal nerve roots. Ependymomas display a wide range of morphological features, and several variants are listed in the World Health Organization (WHO) classification (Ellison et al., 2016). These variants are assigned to three WHO grades (I-III), but the clinical utility of this classification is acknowledged to be limited (Ellison et al., 2011). An increasing understanding of the genomic landscape of ependymoma and the discovery of distinct molecular groups by DNA methylation or gene expression profiling have begun to refine approaches to disease classification and prognostication, but have yet to be translated into clinical routine (Hoffman et al., 2014; Mack et al., 2014; Pajtler et al., 2017; Pajtler et al., 2015; Parker et al., 2014; Wani et al., 2012; Witt et al., 2011). Our comprehensive study of DNA methylation profiling across the entire disease demonstrated three molecular groups for each major anatomic compartment: supratentorial (ST), posterior fossa (PF), and spinal (SP) (Pajtler et al., 2015). In the ST compartment, two molecular groups (ST-EPN-RELA and ST-EPN-YAP1) align with tumors harboring specific genetic alterations, RELA and YAP1 fusion genes, which were initially discovered in a whole genome sequencing study (Parker et al., 2014). Among PF ependymomas, two of three molecular groups, PFA (PF-EPN-A) and PFB (PF-EPN-B), account for nearly all tumors; PF-SE tumors are rare, generally showing the morphology of a subependymoma (Pajtler et al., 2015). PFA tumors are found mainly in infants and young children (median age ≈ 3yrs) and have a relatively poor outcome, while PFB tumors are generally found in young adults (median age ≈ 30yrs) and are associated with a better prognosis (Pajtler et al., 2015; Witt et al., 2011). PFA tumors show few copy number alterations (CNAs), while PFB tumors harbor multiple CNAs that tend to affect entire chromosomes. While recurrent structural variants (SVs) are found in ST ependymomas, recurrent SVs or other mutations, such as single nucleotide variants (SNVs) and insertions or deletions (indels), have not been identified in PF ependymomas to date (Mack et al., 2014; Parker et al., 2014).
2018-06-26 | GSE104210 | GEO