Genotyping by array of 123 IDH WT glioblastomas
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Boisselier Blandine
PROVIDER: E-MTAB-6371 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Aims and methods: astroblastoma is a rare glial brain tumor with singular morphology. Recurrent MN1-BEND2 fusions have been recently identified in most of pediatric cases. Adolescent and adult cases, however, remain molecularly poorly defined. Here, we performed clinical and molecular characterization of a retrospective cohort of 14 adult and one adolescent gliomas with astroblastic features. Results: strikingly, we found MN1 fusions a rare event in this age group (1/15). Using methylation profiling and targeted sequencing, most cases were reclassified as either pleomorphic xanthoastrocytomas (PXA) or high-grade glioma (HGG). PXA-like ABM show BRAF mutation (6/7 with V600E mutation and 1/7 with G466E mutation) and CD34 expression. Conversely, HGG-like ABM harbored specific mutations of diffuse midline glioma (2/5) or glioblastoma (3/5). These latter patients showed an unfavorable clinical course with significantly shorter overall survival (p = 0.027). MAPK pathway alterations (including FGFR fusion, BRAF and NF1 mutations) were present in 10 of 15 patients and overrepresented in the HGG group (3/5) compared to previously reported prevalence of these alterations in GBM and diffuse midline glioma. Conclusion: We suggest that astroblastoma comprises a variety of molecularly sharply defined entities. Adults’ astroblastomas harboring molecular features of PXA and HGG should be reclassified. CNS high-grade neuroepithelial tumors with MN1 alterations appears to be a truly pediatric entity and is uncommon in adult cases with a histology of astroblastoma. Astroblastic morphology in adults should thus prompt thorough molecular investigation aiming at a clear histomolecular diagnosis and identifying actionable drug targets, especially in MAPK pathway.
2019-03-22 | E-MTAB-7490 | biostudies-arrayexpress
Project description:Purpose: To define copy number alterations and gene expression signatures underlying pediatric high-grade glioma (HGG). Patients and Methods: We conducted a high-resolution analysis of genomic imbalances in 78 de novo pediatric HGG, including 7 diffuse intrinsic pontine gliomas, and 10 HGG cases arising in children who received cranial irradiation for a previous cancer, using Affymetrix 500K GeneChips. Gene expression signatures for 53 tumors were analyzed with Affymetrix U133v2 arrays. Results were compared with publicly available data from adult tumors. Results: Pediatric and adult glioblastoma were clearly distinguished by frequent gain of chromosome 1q (30% vs 9%) and lower frequency of chromosome 7 gain (13% vs 74%), respectively. The most common focal amplifications also differed, with PDGFRA and EGFR predominant in childhood and adult populations respectively. These common alterations in pediatric HGG were detected at higher frequency in irradiation-induced tumors, suggesting that these are initiating events in childhood gliomagenesis. CDKN2A was the most common tumor suppressor gene targeted by homozygous deletion in pediatric HGG. No IDH1 hotspot mutations were found in pediatric tumors, highlighting molecular differences in pathogenesis between childhood HGG and adult secondary glioblastoma. Integrated copy number and gene expression data indicated that deregulated PDGFRA signaling plays a major role in pediatric HGG. Conclusions: Integrated molecular profiling showed substantial differences in the molecular features underlying pediatric and adult HGG, indicating that findings in adult tumors cannot be simply extrapolated to younger patients. PDGFRA may be a useful target for pediatric HGG including diffuse pontine gliomas. Keywords: disease state analysis 78 samples for SNP analysis, including 10 samples arising in children who received cranial irradiation for a previous cancer and 7 diffuse pontine gliomas; 53 of them with gene expression analysis; 2 tumor grades To have access to SNP CEL files, please contact Dr. Suzanne Baker (suzzane.baker@stjude.org).
2010-06-15 | E-GEOD-19578 | biostudies-arrayexpress
Project description:Diffuse gliomas represent the most prevalent class of primary brain tumor. Despite significant recent advances in the understanding of glioblastoma (WHO IV), its most malignant subtype, lower-grade (WHO II and III) glioma variants remain comparatively understudied, especially in light of their notably variable clinical behavior. To examine the foundations of this heterogeneity, we performed multidimensional molecular profiling, including global transcriptional analysis, on 101 lower-grade diffuse astrocytic gliomas collected at our own institution, and validated our findings using publically available gene expression and copy number data from large independent patient cohorts. We found that IDH mutational status delineated molecularly and clinically distinct glioma subsets, with IDH mutant (IDH mt) tumors exhibiting TP53 mutations, PDGFRA overexpression, and prolonged survival, and IDH wild-type (IDH wt) tumors exhibiting EGFR amplification, PTEN loss, and unfavorable disease outcome. Furthermore, global expression profiling revealed three robust molecular subclasses within lower-grade diffuse astrocytic gliomas, two of which were predominantly IDH mt and one almost entirely IDH wt. IDH mt subclasses were distinguished from each other on the basis of TP53 mutations, DNA copy number abnormalities, and links to distinct stages of neurogenesis in the subventricular zone (SVZ). This latter finding implicates discrete pools of neuroglial progenitors as cells of origin for the different subclasses of IDH mt tumors. In summary, we have elucidated molecularly distinct subclasses of lower-grade diffuse astrocytic glioma that dictate clinical behavior and demonstrate fundamental associations with both IDH mutational status and neuroglial developmental stage. 80 tumor samples, one normal tissue sample (brain)
2012-02-24 | E-GEOD-35158 | biostudies-arrayexpress
Project description:Recurrent glioblastoma (GBM) has a grim prognosis, though MGMT promoter methylation and IDH mutation provide a significant survival advantage. The product of IDH mutation, 2-hydroxyglutarate, increases global DNA methylation by inhibiting demethylases. While lower-grade IDH-mutant gliomas demonstrate increased methylation as a result of this process, DNA becomes relatively hypomethylated during progression from low-grade glioma to secondary (IDH-mutant) GBM. Here we show that global DNA hypomethylation also occurs during primary (IDH-wild type) GBM recurrence. Moreover, in a phase I trial of 14 patients with recurrent (IDH-wild type) GBM, we targeted DNA hypomethylation using a methyl donor treatment. In autopsied tumors from patients treated, we observed a global increase in DNA methylation compared to initial tumor. These results suggest that hypomethylation is a marker for recurrence, and its reprogramming represents a potential therapeutic vulnerability.
2021-12-31 | GSE111627 | GEO
Project description:Intratumoral microglia and MΦ constitute up to 70% of the tumor mass of high-grade gliomas (HGG) with profound impact on hallmarks of malignancy such as angiogenesis and immunosuppression. The dynamics and functional states of intratumoral myeloid cells during tumor progression and the molecular mechanisms controlling them are poorly understood. Here we define homeostatic and antigen-presenting myeloid cellular states in experimental and human HGG by longitudinal single-cell RNA-sequencing and combined transcriptome and proteome profiling, respectively. During glioma progression, myeloid cells gradually shift from a homeostatic to a tumor-associated effector state. We show that these dynamics are under strict control by early changes in resident microglia and the tumor genotype: In gliomas with mutations in isocitrate dehydrogenase (IDH), a disease-defining driver mutation, differentiation of invaded myeloid cells was blocked resulting in an immature, immunosuppressive phenotype. In late-stage IDH-mutant gliomas, monocyte-derived MΦ drive a tolerogenic remodeling of the glioma microenvironment thus preventing T-cell response. We define the molecular mechanism responsible for blocking functional differentiation in IDH-mutant gliomas to be causally related to enhanced metabolization of tryptophan to kynurenine, an endogenous ligand of the aryl hydrocarbon receptor (AHR), leading to a time-dependent uptake of extracellular tryptophan via LAT1-CD98 by intratumoral myeloid cells. Consequently, the immunosuppressive phenotype in IDH-mutant glioma models was reversed by pharmacologic inhibition of LAT1-CD98 or AHR. Thus, we provide evidence for a tumor genotype-dependent dynamic network of resident and recruited intratumoral myeloid cells shaping the immune microenvironment of IDH-mutant HGG and identify tryptophan metabolism as a viable therapeutic target for the immunotherapy of IDH-mutant tumors.
2021-03-04 | GSE166418 | GEO
Project description:Purpose: To define copy number alterations and gene expression signatures underlying pediatric high-grade glioma (HGG). Patients and Methods: We conducted a high-resolution analysis of genomic imbalances in 78 de novo pediatric HGG, including 7 diffuse intrinsic pontine gliomas, and 10 HGG cases arising in children who received cranial irradiation for a previous cancer, using Affymetrix 500K GeneChips. Gene expression signatures for 53 tumors were analyzed with Affymetrix U133v2 arrays. Results were compared with publicly available data from adult tumors. Results: Pediatric and adult glioblastoma were clearly distinguished by frequent gain of chromosome 1q (30% vs 9%) and lower frequency of chromosome 7 gain (13% vs 74%), respectively. The most common focal amplifications also differed, with PDGFRA and EGFR predominant in childhood and adult populations respectively. These common alterations in pediatric HGG were detected at higher frequency in irradiation-induced tumors, suggesting that these are initiating events in childhood gliomagenesis. CDKN2A was the most common tumor suppressor gene targeted by homozygous deletion in pediatric HGG. No IDH1 hotspot mutations were found in pediatric tumors, highlighting molecular differences in pathogenesis between childhood HGG and adult secondary glioblastoma. Integrated copy number and gene expression data indicated that deregulated PDGFRA signaling plays a major role in pediatric HGG. Conclusions: Integrated molecular profiling showed substantial differences in the molecular features underlying pediatric and adult HGG, indicating that findings in adult tumors cannot be simply extrapolated to younger patients. PDGFRA may be a useful target for pediatric HGG including diffuse pontine gliomas. Keywords: disease state analysis
2010-06-16 | GSE19578 | GEO
Project description:Diffuse gliomas represent the most prevalent class of primary brain tumor. Despite significant recent advances in the understanding of glioblastoma (WHO IV), its most malignant subtype, lower-grade (WHO II and III) glioma variants remain comparatively understudied, especially in light of their notably variable clinical behavior. To examine the foundations of this heterogeneity, we performed multidimensional molecular profiling, including global transcriptional analysis, on 101 lower-grade diffuse astrocytic gliomas collected at our own institution, and validated our findings using publically available gene expression and copy number data from large independent patient cohorts. We found that IDH mutational status delineated molecularly and clinically distinct glioma subsets, with IDH mutant (IDH mt) tumors exhibiting TP53 mutations, PDGFRA overexpression, and prolonged survival, and IDH wild-type (IDH wt) tumors exhibiting EGFR amplification, PTEN loss, and unfavorable disease outcome. Furthermore, global expression profiling revealed three robust molecular subclasses within lower-grade diffuse astrocytic gliomas, two of which were predominantly IDH mt and one almost entirely IDH wt. IDH mt subclasses were distinguished from each other on the basis of TP53 mutations, DNA copy number abnormalities, and links to distinct stages of neurogenesis in the subventricular zone (SVZ). This latter finding implicates discrete pools of neuroglial progenitors as cells of origin for the different subclasses of IDH mt tumors. In summary, we have elucidated molecularly distinct subclasses of lower-grade diffuse astrocytic glioma that dictate clinical behavior and demonstrate fundamental associations with both IDH mutational status and neuroglial developmental stage.
2012-02-24 | GSE35158 | GEO
Project description:Chromosomal instability (CIN), defined as an increased occurrence of chromosome segregation errors during cell division, is a prominent form of genomic instability (Bakhoum and Avi Landau, 2017). It is the major cause of aneuploidy, an imbalanced complement of whole chromosomes or chromosome arms, which is the most prevalent genetic alteration in human cancers (Vasudevan et al., 2021; Santaguida and Amon, 2015). Importantly, aneuploidy is commonly associated with ongoing CIN through consecutive cell divisions (Shelzer et al. 2011; Passerini et al., 2016), resulting in intratumor genetic heterogeneity, a central driver of cancer evolution and therapeutic resistance (Sansregret et al., 2018; Ben-David and Amon, 2019). Indeed, aneuploidy has been shown to act both as a tumor suppressor and as a tumor initiator (Weaver et al., 2007; Silk et al., 2013; Vasudevan et al., 2020), most likely depending on the specific chromosomes that are gained or lost (Ben-David et al., 2011; Sack et al., 2018; Adell et al., 2023). Despite the ubiquitous presence of CIN in several aneuploid cancer types and its clinical relevance, its presence in B-cell acute lymphoblastic leukemia (B-ALL) remains largely unexplored owing to the impaired proliferation of leukemic cells in vitro and the lack of reliable experimental models to comprehensively assess chromosome segregation in vivo. B-ALL is the most frequent childhood cancer, with 75% of cases occurring in children under 6 years of age, and it is characterized by the accumulation of highly proliferative immature B-cell precursors in the bone marrow (BM) (Hunger and Mullighan, 2015). The presence of CIN and its contribution to aneuploid cB-ALL progression is largely unknown due to the lack of preclinical models to study actively dividing cells. Accordingly, studies of CIN in cB-ALL are limited to the characterization of chromosomal copy-number heterogeneity (chr-CNH) in primary cB-ALL samples, but there is controversy over its presence due to the different techniques used to assess karyotype variability (Raimondi et al., 1996; Talamo et al., 2010; Alpar et al., 2014; Heerema et al.; 2007; Ramos-Muntada et al., 2022). Here, we explored the presence and the levels of CIN in different clinically-relevant aneuploid subtypes of cB-ALL using single-cell whole-genome sequencing (WGS) of primary samples to reliably assess chr-CNH, and by generating a large cohort of PDX models from primary cB-ALL samples (cB-ALL-PDX). Our results in cB-ALL-PDX models revealed variable levels of CIN in aneuploid cB-ALL subtypes, which significantly correlate with intraclonal karyotype heterogeneity and with disease progression. Additionally, mass-spectrometry analyses of cB-ALL-PDX samples revealed a CIN “signature” enriched in mitosis and chromosome segregation regulatory pathways. We speculate that this signature identifies adaptive mechanisms to ongoing CIN in aneuploid cB-ALL cells, which displayed a transcriptional signature characterized by an impaired mitotic spindle as observed by RNA-sequencing (RNA-Seq) analyses of a large cohort of primary cB-ALL patient samples. Our work might help to improve stratification of patients with cB-ALL with different levels of CIN who could benefit in the future from new therapeutic approaches aiming to target ongoing CIN.
2023-09-15 | PXD042785 | Pride
Project description:RNA-sequencing for myeloid inflammation-related genes was conducted on primary tumor samples from patients with IDH-wildtype glioblastoma (GBM) and grade 4 IDH-mutant astrocytoma (G4IMA). In addition, the IDH-wildtype murine glioma cell line GL261 and a strain of IDH-mutant GL261 were also sequenced using the murine counterpart of the RNA-sequencing myeloid innate immunity panel.
2024-05-29 | GSE268118 | GEO
Project description:Background: A feature of glioblastoma (GBM) is the cellular and molecular heterogeneity, both within and between tumors. This variability results in a risk for sampling bias and potential tumor escape from future targeted therapy. Heterogeneous gene expression within GBM is well documented, but little is known regarding the epigenetic heterogeneity. We therefore aimed to profile the intra-tumor DNA methylation heterogeneity in GBM. Methods: 3-4 biopsies per tumor from spatially separated regions were collected from 12 GBM patients. We performed genome-wide DNA methylation analysis (~850,000 CpG sites) and compared inter- and intra-tumor variation. Results: All samples were classified as GBM IDH wt or IDH mutated by DNA methylation profiling, but the GBM subtype differed within five tumors. Some GBM samples exhibited higher DNA methylation differences within tumors than between, and many CpG sites (mean: 17,000) had different methylation levels within the tumors. Conclusions: We demonstrated that intra-tumor DNA methylation heterogeneity is a feature of GBM. Although all biopsies were classified as GBM IDH wt/mutated by DNA methylation analysis, the assigned subtype differed in samples from the same patient. The observed DNA methylation heterogeneity within tumors is important to consider for methylation-based biomarkers and future improvements in stratification of GBM patients.
2019-02-27 | GSE116298 | GEO