Project description:This SuperSeries is composed of the following subset Series: GSE16581: Genomic landscape of meningiomas: gene expression GSE16583: Genomic landscape of meningiomas: genotyping Refer to individual Series
Project description:Meningiomas are one of the most common adult brain tumors. For most patients, surgical excision is curative. However, up to 20% recur. Currently, the molecular determinants predicting recurrence and malignant transformation are lacking. We performed global genetic and genomic analysis of 85 meningioma samples of various grades. Copy number alterations were assessed by 100K SNP arrays and correlated with gene expression, proliferation indices, and clinical outcome. In addition to chromosome 22q loss, which was detected in the majority of clinical samples, chromosome 18q and 6q loss significantly predicted recurrence and was associated with anaplastic histology. Five "classes" of meningiomas were detected by gene expression analysis that correlated with copy number alterations, recurrence risk, and malignant histology. These classes more accurately predicted tumor recurrence than Ki-67 index, the gold standard for determining risk of recurrence, and highlight substantial expression heterogeneity between meningiomas. These data offer the most complete description of the genomic landscape of meningiomas and provide a set of tools that could be used to more accurately stratify meningioma patients into prognostic risk groups.
Project description:Meningiomas are one of the most common adult brain tumors. For most patients, surgical excision is curative. However, up to 20% recur. Currently, the molecular determinants predicting recurrence and malignant transformation are lacking. We performed global genetic and genomic analysis of 85 meningioma samples of various grades. Copy number alterations were assessed by 100K SNP arrays and correlated with gene expression, proliferation indices, and clinical outcome. In addition to chromosome 22q loss, which was detected in the majority of clinical samples, chromosome 18q and 6q loss significantly predicted recurrence and was associated with anaplastic histology. Five classes of meningiomas were detected by gene expression analysis that correlated with copy number alterations, recurrence risk, and malignant histology. These classes more accurately predicted tumor recurrence than Ki-67 index, the gold standard for determining risk of recurrence, and highlight substantial expression heterogeneity between meningiomas. These data offer the most complete description of the genomic landscape of meningiomas and provide a set of tools that could be used to more accurately stratify meningioma patients into prognostic risk groups.
Project description:Meningiomas are mostly benign brain tumors, with a potential for becoming atypical or malignant. Based on comprehensive genomic, transcriptomic and epigenomic analyses of meningiomas, we compared benign tumors to atypical ones. We show that the vast majority of primary (de novo atypical meningiomas display loss of NF2, which co-occurs either with genomic instability or recurrent mutations in SMARCB1. These tumors harbor increased H3K27me3 repressive signal and a hypermethylated phenotype, mainly occupying the polycomb repressive complex 2 (PRC2 binding sites in human embryonic stem cells (hESCs, thereby phenocopying a more primitive cellular state. Consistent with this observation, and based on differential gene expression analysis as well as correlation of mRNA:miRNA regulatory networks, atypical meningiomas exhibit up-regulation of EZH2, the catalytic subunit of the PRC2 complex, well as the E2F2 and FOXM1 transcriptional networks that promote proliferation through activation of the cell cycle pathways. In addition, based on H3K27ac ChIP-seq analysis, we show atypical tumors to display an activated super-enhancer near the meningeal identity transcription factor ZIC1, leading to its transcriptional upregulation. Importantly, these primary atypical meningiomas do not harbor activating TERT promoter mutations, which have been reported in atypical tumors that progressed from benign ones. Our results establish the genomic landscape of primary atypical meningiomas, differentiating their profile from benign and progressed tumors and establishing novel therapeutic targets.
Project description:Meningiomas are one of the most common adult brain tumors. For most patients, surgical excision is curative. However, up to 20% recur. Currently, the molecular determinants predicting recurrence and malignant transformation are lacking. We performed global genetic and genomic analysis of 85 meningioma samples of various grades. Copy number alterations were assessed by 100K SNP arrays and correlated with gene expression, proliferation indices, and clinical outcome. In addition to chromosome 22q loss, which was detected in the majority of clinical samples, chromosome 18q and 6q loss significantly predicted recurrence and was associated with anaplastic histology. Five "classes" of meningiomas were detected by gene expression analysis that correlated with copy number alterations, recurrence risk, and malignant histology. These classes more accurately predicted tumor recurrence than Ki-67 index, the gold standard for determining risk of recurrence, and highlight substantial expression heterogeneity between meningiomas. These data offer the most complete description of the genomic landscape of meningiomas and provide a set of tools that could be used to more accurately stratify meningioma patients into prognostic risk groups. Tumor biopsies from 53 female and 32 male subjects with sporadic meningioma were identified from the UCLA Neuro-oncology Program Tissue Bank through institutional review board approved protocols. 57 tumors were designated "benign" WHO I, 20 tumors were "atypical" WHO II, and 8 were "anaplastic" WHO III. Affymetrix SNP arrays were performed according to the manufacturer's instructions on DNA extracted from flash frozen meningioma tumors.
Project description:Meningiomas are mostly benign brain tumors, with a potential for becoming atypical or malignant. Based on comprehensive genomic, transcriptomic and epigenomic analyses of meningiomas, we compared benign tumors to atypical ones. We show that the vast majority of primary (de novo) atypical meningiomas display loss of NF2, which co-occurs either with genomic instability or recurrent mutations in SMARCB1. These tumors harbor increased H3K27me3 repressive signal and a hypermethylated phenotype, mainly occupying the polycomb repressive complex 2 (PRC2) binding sites in human embryonic stem cells (hESCs), thereby phenocopying a more primitive cellular state. Consistent with this observation, and based on differential gene expression analysis as well as correlation of mRNA:miRNA regulatory networks, atypical meningiomas exhibit up-regulation of EZH2, the catalytic subunit of the PRC2 complex, well as the E2F2 and FOXM1 transcriptional networks that promote proliferation through activation of the cell cycle pathways. In addition, based on H3K27ac ChIP-seq analysis, we show atypical tumors to display an activated super-enhancer near the meningeal identity transcription factor ZIC1, leading to its transcriptional upregulation. Importantly, these primary atypical meningiomas do not harbor activating TERT promoter mutations, which have been reported in atypical tumors that progressed from benign ones. Our results establish the genomic landscape of primary atypical meningiomas, differentiating their profile from benign and progressed tumors and establishing novel therapeutic targets.
Project description:Meningiomas are one of the most common adult brain tumors. For most patients, surgical excision is curative. However, up to 20% recur. Currently, the molecular determinants predicting recurrence and malignant transformation are lacking. We performed global genetic and genomic analysis of 85 meningioma samples of various grades. Copy number alterations were assessed by 100K SNP arrays and correlated with gene expression, proliferation indices, and clinical outcome. In addition to chromosome 22q loss, which was detected in the majority of clinical samples, chromosome 18q and 6q loss significantly predicted recurrence and was associated with anaplastic histology. Five classes of meningiomas were detected by gene expression analysis that correlated with copy number alterations, recurrence risk, and malignant histology. These classes more accurately predicted tumor recurrence than Ki-67 index, the gold standard for determining risk of recurrence, and highlight substantial expression heterogeneity between meningiomas. These data offer the most complete description of the genomic landscape of meningiomas and provide a set of tools that could be used to more accurately stratify meningioma patients into prognostic risk groups. Tumor biopsies from 43 female and 25 male subjects with sporadic meningioma were identified from the UCLA Neuro-oncology Program Tissue Bank through institutional review board approved protocols. 43 tumors were designated "benign" WHO I, 19 tumors were "atypical" WHO II, and 6 were "anaplastic" WHO III. Gene expression analysis was performed on the 68 tumor biopsies.
Project description:Meningiomas are mostly benign brain tumors, with a potential for becoming atypical or malignant. Based on comprehensive genomic, transcriptomic and epigenomic analyses of meningiomas, we compared benign tumors to atypical ones. We show that the vast majority of primary (de novo) atypical meningiomas display loss of NF2, which co-occurs either with genomic instability or recurrent mutations in SMARCB1. These tumors harbor increased H3K27me3 repressive signal and a hypermethylated phenotype, mainly occupying the polycomb repressive complex 2 (PRC2) binding sites in human embryonic stem cells (hESCs), thereby phenocopying a more primitive cellular state. Consistent with this observation, and based on differential gene expression analysis as well as correlation of mRNA:miRNA regulatory networks, atypical meningiomas exhibit up-regulation of EZH2, the catalytic subunit of the PRC2 complex, well as the E2F2 and FOXM1 transcriptional networks that promote proliferation through activation of the cell cycle pathways. In addition, based on H3K27ac ChIP-seq analysis, we show atypical tumors to display an activated super-enhancer near the meningeal identity transcription factor ZIC1, leading to its transcriptional upregulation. Importantly, these primary atypical meningiomas do not harbor activating TERT promoter mutations, which have been reported in atypical tumors that progressed from benign ones. Our results establish the genomic landscape of primary atypical meningiomas, differentiating their profile from benign and progressed tumors and establishing novel therapeutic targets.
Project description:<p>Meningiomas are the most common primary brain tumor in the US. Although the tumor suppressor gene NF2 is disrupted in approximately half of meningiomas, the complete spectrum of genetic changes in meningiomas remains poorly understood, particularly in the large subset of tumors without NF2 alterations. Therefore we performed whole-genome sequencing from 11 Grade I meningioma tumor-normal pairs and whole-exome sequencing from an additional 6 tumor-normal pairs to identify somatic mutations, insertions-deletions, copy-number alterations and rearrangements. We validated our results by performing focused sequencing across 48 additional meningiomas.</p>
Project description:We report genomic analysis of 300 meningiomas, the most common primary brain tumors, leading to the discovery of mutations in TRAF7, a proapoptotic E3 ubiquitin ligase, in nearly one-fourth of all meningiomas. Mutations in TRAF7 commonly occurred with a recurrent mutation (K409Q) in KLF4, a transcription factor known for its role in inducing pluripotency, or with AKT1(E17K), a mutation known to activate the PI3K pathway. SMO mutations, which activate Hedgehog signaling, were identified in ~5% of non-NF2 mutant meningiomas. These non-NF2 meningiomas were clinically distinctive-nearly always benign, with chromosomal stability, and originating from the medial skull base. In contrast, meningiomas with mutant NF2 and/or chromosome 22 loss were more likely to be atypical, showing genomic instability, and localizing to the cerebral and cerebellar hemispheres. Collectively, these findings identify distinct meningioma subtypes, suggesting avenues for targeted therapeutics.