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: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: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: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
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.
Project description:Meningiomas represent one of the most common and clinically heterogeneous brain tumor types that only modestly correlate with histopathologic features. While emerging molecular profiling efforts have linked specific genomic drivers to distinct clinical patterns, the proteomic landscape of meningiomas remains largely unexplored. We utilize mass spectrometry to profile a clinically well-annotated cohort (n=69) of meningiomas stratified to span all three World Health Organization (WHO) grades and various degrees of clinical aggressiveness. In total, we quantify 3042 unique proteins and compare the patterns across different clinical parameters. Unsupervised clustering analysis highlighted distinct proteomic (n=106 proteins, Welch’s t-test, P<0.01) and pathway-level (e.g. Notch and PI3K/AKT/mTOR) differences between convexity and skull base meningiomas. Supervised comparative analyses of different pathological grades revealed distinct patterns between benign (WHO Grade I) and atypical/malignant (WHO Grade II and III) meningiomas with classic oncogenes often enriched in higher grade lesions. Independent of WHO grade, clinically aggressive meningiomas, that rapidly recurred, also had distinctive protein patterns that converged on mRNA processing and impaired activation of the extracellular matrix naba matrisome complex. Larger sized meningiomas, and those with previous radiation exposure, also had distinct protein profiles. Collectively, we highlight distinct clinically-dependent proteomic patterns of meningiomas that may help better predict outcome and guide the development of more personalized and directed therapies.
Project description:Meningiomas are the most common primary brain tumor. Though typically benign with a low mutational burden, histopathologic analysis has poor predictive value for malignant behavior and there are no proven chemotherapies. Although DNA methylation patterns distinguish subgroups of meningiomas and have higher predictive value for tumor behavior than histologic classification, little is known about differences in DNA methylation between meningiomas and surrounding normal dura tissue. Using multimodal studies of meningioma/dura pairs, we identified 4 distinct DNA methylation patterns. Diffuse DNA hypomethylation of malignant meningiomas readily facilitated their identification from lower grade tumors by unsupervised clustering. All clusters and 12/12 meningioma-dura pairs exhibited hypomethylation of the gene promoters of a module associated with the craniofacial patterning transcription factor FOXC1 and its upstream lncRNA FOXCUT. Furthermore, we identified an epigenetic continuum of increasing hypermethylation of polycomb repressive complex target promoters with increased histopathologic grade suggesting progressive epigenetic dysregulation is associated with increasing tumor aggressiveness. These findings are a starting point for future investigations of the role of epigenetic dysregulation of FOXC1 and cranial patterning genes in early stages of meningioma formation as well as studies of the utility of polycomb inhibitors for treatment of aggressive meningiomas.
Project description:Meningiomas are the most common primary brain tumor. Though typically benign with a low mutational burden, histopathologic analysis has poor predictive value for malignant behavior and there are no proven chemotherapies. Although DNA methylation patterns distinguish subgroups of meningiomas and have higher predictive value for tumor behavior than histologic classification, little is known about differences in DNA methylation between meningiomas and surrounding normal dura tissue. Using multimodal studies of meningioma/dura pairs, we identified 4 distinct DNA methylation patterns. Diffuse DNA hypomethylation of malignant meningiomas readily facilitated their identification from lower grade tumors by unsupervised clustering. All clusters and 12/12 meningioma-dura pairs exhibited hypomethylation of the gene promoters of a module associated with the craniofacial patterning transcription factor FOXC1 and its upstream lncRNA FOXCUT. Furthermore, we identified an epigenetic continuum of increasing hypermethylation of polycomb repressive complex target promoters with increased histopathologic grade suggesting progressive epigenetic dysregulation is associated with increasing tumor aggressiveness. These findings are a starting point for future investigations of the role of epigenetic dysregulation of FOXC1 and cranial patterning genes in early stages of meningioma formation as well as studies of the utility of polycomb inhibitors for treatment of aggressive meningiomas.