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 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 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 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. The H3k27ac ChIP-seq data for 15 benign meningiomas and 2 dura samples listed below were created by Dr. Justin Cotney in Dr. James Noonan’s lab at Yale and previously published in a paper by our group with Drs. Cotney and Noonan as co-authors (Clark et al. Science, 2013). Sample IDs: MN-297, MN-288, MN-292, MN-163, MN-1037, MN-105, MN-201, MN-249, MN-191, MN-1066, MN-169, MN-291, MN-24, MN-79, MN-1044, CONTROL1, CONTROL2. In this study, we used these benign meningioma H3k27ac ChIP-seq data as controls and compared them to the newly created ChIP-seq data. Sample IDs: MN-54, MN-97 and MN-171. This GEO entry contains ChIP-seq results for both data sets.
Project description:Meningiomas are common brain tumors that are classified into three World Health Organization grades (Grade I: benign, Grade II: atypical and Grade III: malignant) and are molecularly ill-defined tumors. The purpose of this study was identify microRNA (miRNA) molecular signatures unique to the different grades of meningiomas correlating them to prognosis. We have used a miRNA expression microarray to show that meningiomas of all three grades fall into two main molecular groups designated “benign” and “malignant” meningiomas. While all typical meningiomas fall into the benign group and all anaplastic meningiomas fall into the malignant group, atypical meningiomas distribute into either one of these groups. We have identified a miRNA signature that distinguishes benign meningiomas from malignant meningiomas. We studied the gene expression profiles of 340 mammalian miRNAs in 37 primary meningioma tumors by means of DNA microarrays.
Project description:Meningiomas are common brain tumors that are classified into three World Health Organization grades (Grade I: benign, Grade II: atypical and Grade III: malignant) and are molecularly ill-defined tumors. The purpose of this study was identify microRNA (miRNA) molecular signatures unique to the different grades of meningiomas correlating them to prognosis. We have used a miRNA expression microarray to show that meningiomas of all three grades fall into two main molecular groups designated “benign” and “malignant” meningiomas. While all typical meningiomas fall into the benign group and all anaplastic meningiomas fall into the malignant group, atypical meningiomas distribute into either one of these groups. We have identified a miRNA signature that distinguishes benign meningiomas from malignant meningiomas.