Genomic markers of recurrence risk in atypical meningioma following gross total resection

Clinical implications of DNA methylation-based integrated classification of histologically defined grade 2 meningiomas

The combination of DNA methylation analysis with histopathological and genetic features allows for a more accurate risk stratification and classification of meningiomas. Nevertheless, the implications of this classification for patients with grade 2 meningiomas, a particularly heterogeneous tumor entity, are only partially understood. We correlate the outcomes of histopathologically confirmed grade 2 meningioma with an integrated molecular-morphologic risk stratification and determine its clinical implications. Grade 2 meningioma patients treated at our institution were re-classified using an integrated risk stratification involving DNA methylation array-based data, copy number assessment and TERT promoter mutation analyses. Grade 2 meningioma cases according to the WHO 2021 criteria treated between 2007 and 2021 (n = 100) were retrospectively analyzed. The median clinical and radiographic follow-up periods were 59.8 and 54.4 months. A total of 38 recurrences and 17 deaths were observed. The local control rates of the entire cohort after 2-, 4-, and 6-years were 84.3%, 68.5%, and 50.8%, with a median local control time of 77.2 months. The distribution of the integrated risk groups were as follows: 31 low, 54 intermediate, and 15 high risk cases. In the multivariable Cox regression analysis, integrated risk groups were significantly associated with the risk of local recurrence (hazard ratio (HR) intermediate: 9.91, HR high-risk: 7.29, p < 0.01). Gross total resections decreased the risk of local tumor progression (HR gross total resection: 0.19, p < 0.01). The comparison of 1p status and integrated risk groups (low vs. intermediate/high) revealed nearly identical local control rates within their respective subgroups. In summary, only around 50% of WHO 2021 grade 2 meningiomas have an intermediate risk profile. Integrated molecular risk stratification is crucial to guide the management of patients with grade 2 tumors and should be routinely applied to avoid over- and undertreatment, especially concerning the use of adjuvant radiotherapy.

Inhibition of BMP signaling pathway induced senescence and calcification in anaplastic meningioma

PURPOSE

Meningiomas are the most common type of brain tumors and are generally benign, but malignant atypical meningiomas and anaplastic meningiomas frequently recur with poor prognosis. The metabolism of meningiomas is little known, so few effective treatment options other than surgery and radiation are available, and the targets for treatment of recurrence are not well defined. The Aim of this paper is to find the therapeutic target.

METHODS

The effects of bone morphogenetic protein (BMP) signal inhibitor (K02288) and upstream regulator Gremlin2 (GREM2) on meningioma's growth and senescence were examined. In brief, we examined as follows: 1) Proliferation assay by inhibiting BMP signaling. 2) Comprehensive analysis of forced expression GREM2.3) Correlation between GREM2 mRNA expression and proliferation marker in 87 of our clinical samples. 4) Enrichment analysis between GREM2 high/low expressed groups using RNA-seq data (42 cases) from the public database GREIN. 5) Changes in metabolites and senescence markers associated with BMP signal suppression.

RESULTS

Inhibitors of BMP receptor (BMPR1A) and forced expression of GREM2 shifted tryptophan metabolism from kynurenine/quinolinic acid production to serotonin production in malignant meningiomas, reduced NAD + /NADH production, decreased gene cluster expression involved in oxidative phosphorylation, and caused decrease in ATP. Finally, malignant meningiomas underwent cellular senescence, decreased proliferation, and eventually formed psammoma bodies. Reanalyzed RNA-seq data of clinical samples obtained from GREIN showed that increased expression of GREM2 decreased the expression of genes involved in oxidative phosphorylation, similar to our experimental results.

CONCLUSIONS

The GREM2-BMPR1A-tryptophan metabolic pathway in meningiomas is a potential new therapeutic target.

Atypical meningioma: Histopathological, genetic, and epigenetic features to predict recurrence risk

Grading assessed according to World Health Organization (WHO) criteria is a major prognostic factor for determining the risk of recurrence in patients with meningiomas and establishing the most appropriate therapeutic strategy after surgery. However, the main issue is to predict the recurrence risk of WHO grade 2 meningioma and, more specifically, of the atypical subtype. Indeed, owing to a reported recurrence rate of 50%, either radiotherapy or observation is currently considered an option after gross total surgical resection of atypical meningiomas. These heterogeneous clinical outcomes are likely related to the broad histopathological diagnostic criteria for this subtype, and whether meningiomas only present as brain invasion should be classified as atypical remains controversial. Over the last few years, several studies have shown that DNA methylation profiling, next-generation sequencing, and transcriptomics can better stratify meningiomas for their recurrence risk than histology. The main limitations to the widespread use of these approaches to classify meningiomas are their high cost and the need for sophisticated technologies. However, all studies concurred that atypical meningiomas without chromosome 1p deletion display a low recurrence risk, suggesting that the assessment of this cytogenetic alteration could represent an easy and quick method to determine which patients could benefit from adjuvant treatment after surgery. In addition, prognostically unfavorable molecular groups can be distinguished using specific immunostainings, although further validation is required.

H3 K27M mutation in rosette-forming glioneuronal tumors: a potential diagnostic pitfall

According to the fifth edition of the World Health Organization (WHO) classification of tumors of the central nervous system (CNS), diffuse midline glioma H3 K27-altered is a grade 4 infiltrative glioma that arises from midline anatomical structures and is characterized by the loss of H3 K27me3 and co-occurring H3 K27M mutation or EZHIP overexpression. However, the H3 K27M mutation has also been observed in circumscribed gliomas and glioneuronal tumors arising in midline anatomical structures, which may result in diagnostic pitfalls.Rosette-forming glioneuronal tumor (RGNT) is a CNS WHO grade 1 neoplasm that histologically features neurocytic and glial components and originates in midline anatomical structures.This study aimed to assess whether RGNTs, similar to other midline tumors, may exhibit immunohistochemical loss of H3 K27me3 and harbor the H3 K27M mutation.All seven analyzed RGNTs displayed immunohistochemical loss of H3 K27me3 in all tumor cells or H3 K27me3 mosaic immunostaining. In one case, H3 K27me3 loss was associated with the H3 K27M mutation, whereas the other six cases did not exhibit any H3 mutations or EZHIP overexpression. During a follow-up period of 23 months, the H3 K27M-mutant case remained unchanged in size despite partial resection, indicating that the H3 mutation may not confer higher biological aggressiveness to RGNT.The immunohistochemical loss of H3 K27me3 co-occurring with the H3 K27M mutation may result in the potential misdiagnosis of RGNT, especially in cases of small biopsy specimens consisting of only the glial component.