Project description:Meningiomas are the most common primary brain tumors in adults. Although generally benign, a subset is of higher grade, recurs even after multiple surgeries, and frequently fatal. Around half of meningiomas harbor inactivating mutations in NF2. While low-grade NF2 mutant meningiomas harbor few additional mutations in addition to NF2 inactivation, high-grade NF2 mutant tumors frequently harbor a highly aberrant genome. We and others have previously shown that NF2 inactivation leads to YAP1 activation and that YAP1 acts as an oncogene in NF2 mutant meningiomas. Here, we show that high-grade NF2 mutant meningiomas downregulate YAP1 signaling, in part through upregulating the expression of the YAP1 competitor VGLL4 and the YAP1 upstream regulators FAT3/4. Overexpression of VGLL4 resulted in the downregulation of YAP activity and the growth inhibition of low-grade NF2 mutant meningioma cells. Our results have important implications for the efficacy of therapies targeting oncogenic YAP1 in high-grade NF2 mutant meningiomas.
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. Analysis of meningioma gene expression data for each mutation subtype. Includes gene expression data from 75 unique meningiomas and 39 replicates.
Project description:Aims: Whereas recent molecular analysis has revealed that sporadic meningioma has various genetic, epigenetic, and transcriptomic profiles, those of meningioma in NF2 patients are not fully elucidated. This study probed meningiomas' clinical, histological, and molecular characteristics in NF2 patients. Methods: A long-term retrospective follow-up (13.5 ± 5.5 years) study involving 159 meningiomas in NF2 patients was performed. We assessed their characteristics by performing immunohistochemistry (IHC), bulk-RNA sequencing, and copy number analysis. All variables of meningiomas in NF2 patients were compared with those of 189 sporadic NF2-altered meningiomas. Results: Most meningiomas in NF2 patients were stable, and the mean annual growth rate was 1.0 ± 1.8 cm3/yr. Twenty-eight meningiomas (17.6%) in 25 patients (43.1%) were resected during the follow-up period. WHO grade 1 meningiomas in NF2 patients` were more frequent than in sporadic NF2-altered meningiomas (92.9% vs 80.9%). Transcriptomic analysis for NF2 patients`/sporadic NF2-altered WHO grade 1 meningiomas (n = 14 versus 15, respectively) showed that tumours in NF2 patients had still higher immune response and immune cell infiltration than sporadic NF2-altered meningiomas. Furthermore, RNA-seq/IHC-derived immunophenotyping corroborated this higher immune response by identifying myeloid cell infiltration, especially macrophages. Conclusions: Clinical, histological, and transcriptomic analyses for meningiomas in NF2 patients demonstrated that meningiomas in NF2 patients showed less aggressive behaviour than sporadic NF2-altered meningiomas and elicited marked immune response by identifying myeloid cell infiltration, especially macrophages.
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.
Project description:The transcriptional coactivator YAP is the key downstream effector of the Hippo pathway. YAP overexpression in the developing mouse brain results in excessive expansion of the neural progenitor pool and severe perturbation of brain development. Nf2/Merlin is a tumor suppressor whose mutations are found in many human cancers. Loss of Merlin during brain development causes overexpansion of the neural progenitor pool. We used microarrays to identify the gene expression changes caused by YAP overexpression and Nf2 deletion. We used a double-transgenic system to overexpress YAP in the developing mouse brain by crossing mice carrying a doxycycline-dependent allele of YAP1-S127A (TetO-YAP1) with those expressing the reverse tetracycline-dependent transactivator rtTA under the control of the neural progenitor-specific Nestin promoter (Nes-rtTA) and feeding the dam with doxycycline-containing food (200 mg/kg) from E7.5. We conditionally deleted Nf2 using the telencephalon-specific Emx1-Cre.
Project description:Experiment: Establishment of expression profiles in grade I and grade II meningiomas and in normal control brain samples. We extracted DNA from specimens and performed mutational analysis in meningiomas and extracted RNA that was processed and hybridized to Affymetrix microarrays.
Project description:We analyzed the expression profiles of human and mouse meningiomas (driven by NF2 loss, YAP1-MAML2, TRAF7/KLF4/SMO1/AKT1, or constitutively active non-fusion YAP1). We found that YAP1-MAML2 meningiomas resemble NF2mutant tumors and constitutively exert de-regulated YAP1 activity that is dependent on the interaction with TEADs.
Project description:We analyzed the expression profiles of human and mouse meningiomas (driven by NF2 loss, YAP1-MAML2, TRAF7/KLF4/SMO1/AKT1, or constitutively active non-fusion YAP1). We found that YAP1-MAML2 meningiomas resemble NF2mutant tumors and constitutively exert de-regulated YAP1 activity that is dependent on the interaction with TEADs.
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:Meningiomas are frequent central nervous system tumors. Although most meningiomas are benign (WHO grade I) and curable by surgery, WHO grade II and III tumors remain therapeutically challenging due to frequent recurrence. Interestingly, relapse also occurs in some WHO grade I meningiomas. Hence, we investigated the transcriptional features defining aggressive (recurrent, malignantly progressing or WHO grade III) meningiomas in 144 cases. Meningiomas were categorized into non-recurrent (NR), recurrent (R), and tumors undergoing malignant progression (M) in addition to their WHO grade. Unsupervised transcriptomic analysis in 62 meningiomas revealed transcriptional profiles lining up according to WHO grade and clinical subgroup. Notably aggressive subgroups (R+M tumors and WHO grade III) shared a large set of differentially expressed genes (n=332; p<0.01, FC>1.25). In an independent multicenter validation set (n=82), differential expression of 10 genes between WHO grades was confirmed. Additionally, among WHO grade I tumors differential expression between NR and aggressive R+M tumors was af rmed for PTTG1, AURKB, ECT2, UBE2C and PRC1, while MN1 and LEPR discriminated between NR and R+M WHO grade II tumors. Univariate survival analysis revealed a significant association with progression-free survival for PTTG1, LEPR, MN1, ECT2, PRC1, COX10, UBE2C expression, while multivariate analysis identified a prediction for PTTG1 and LEPR mRNA expression independent of gender, WHO grade and extent of resection. Finally, stainings of PTTG1 and LEPR confirmed malignancy-associated protein expression changes. In conclusion, based on the so far largest study sample of WHO grade III and recurrent meningiomas we report a comprehensive transcriptional landscape and two prognostic markers. Comparative transcriptomic analysis of 62 low- and high-grade meningiomas