ABSTRACT: Glioblastoma (GBM) is the most frequent and most aggressive form of diffuse glioma. The prognosis is very poor, with a median overall survival of 15 months after maximum safe resection and radiochemotherapy.GBM is one of the most genetically unstable cancers. It is characterized by numerous chromosome (chr) copy number alterations (CNA), such as chr 7 gain, chr 9p loss, and chr 10 loss, along with CDKN2A homozygous deletion (chr 9p21) and EGFR amplification (chr 7p11).Chromosome instability (CIN) may be the cause or the consequence of GBM development. In high-grade diffuse gliomas (HGG), CIN may initiate tumorigenesis. To identify recurrent genomic abnormalities in IDH WT glioblastomas, SNP arrays (Illumina 850K CytoSNP) were analyzed for 123 IDH WT GBM cases.
Project description:Glioblastoma (GBM) is the most frequent and most aggressive form of diffuse glioma. The prognosis is very poor, with a median overall survival of 15 months after maximum safe resection and radiochemotherapy.GBM is one of the most genetically unstable cancers. It is characterized by numerous chromosome (chr) copy number alterations (CNA), such as chr 7 gain, chr 9p loss, and chr 10 loss, along with CDKN2A homozygous deletion (chr 9p21) and EGFR amplification (chr 7p11).Chromosome instability (CIN) may be the cause or the consequence of GBM development. In high-grade diffuse gliomas (HGG), CIN may initiate tumorigenesis. To identify recurrent genomic abnormalities in IDH WT glioblastomas, SNP arrays (Illumina 850K CytoSNP) were analyzed for 123 IDH WT GBM cases.
Project description:Glioma is the most common of all primary brain tumors with poor prognosis and high mortality. The 2016 World Health Organization classification of the tumors of central nervous system uses molecular parameters in addition to histology to redefine many tumor entities. The new classification scheme divides diffuse gliomas into low-grade glioma (LGG) and glioblastoma (GBM) as per histology. LGGs are further divided into isocitrate dehydrogenase (IDH) wild type or mutant, which is further classified into either oligodendroglioma that harbors 1p/19q codeletion or diffuse astrocytoma that has an intact 1p/19q loci but enriched for ATRX loss and TP53 mutation. GBMs are divided into IDH wild type that corresponds to primary or de novo GBMs and IDH mutant that corresponds to secondary or progressive GBMs. To make the 2016 WHO subtypes of diffuse gliomas more robust, we carried out Prediction Analysis of Microarrays (PAM) to develop DNA methylation signatures for these subtypes.In this study, we applied PAM on a training set of diffuse gliomas derived from The Cancer Genome Atlas (TCGA) and identified DNA methylation signatures to classify LGG IDH wild type from LGG IDH mutant, LGG IDH mutant with 1p/19q codeletion from LGG IDH mutant with intact 1p/19q loci and GBM IDH wild type from GBM IDH mutant with an accuracy of 99-100%. The signatures were validated using the test set of diffuse glioma samples derived from TCGA with an accuracy of 96 to 99%. In addition, we also carried out additional validation of all three signatures using independent LGG and GBM cohorts. Further, the methylation signatures identified a fraction of samples as discordant, which were found to have molecular and clinical features typical of the subtype as identified by methylation signatures.Thus, we identified methylation signatures that classified different subtypes of diffuse glioma accurately and propose that these signatures could complement 2016 WHO classification scheme of diffuse glioma.
Project description:High-grade gliomas (HGG) are extremely aggressive lesions and represent the most common primary malignant brain tumors without an effective therapy. Standard treatment for HGG usually includes surgery followed by radiotherapy and chemotherapy. However, the prognosis of patients with HGG remains dismal. We review the humanized epidermal growth factor receptor (EGFR) and the major EGFR target drugs in HGG treatments, focusing on the EGFR antibody nimotuzumab as a new therapeutic strategy in HGG. We found that nimotuzumab with or without radiotherapy, chemotherapy in newly diagnosed or recurrent HGG, such as glioblastoma multiforme (GBM), anaplastic astrocytomas (AA), and diffuse intrinsic pontine glioma (DIPG), might improve the response rate or the survival time. In conclusion, nimotuzumab is a very well-tolerated drug with acceptable toxicity, and it may have promising value in the combination treatment. As a result, multiple center randomized controlled Phase III clinical trials need to be conducted to confirm the efficacy and toxicity for nimotuzumab in HGG.
Project description:<h4>Background</h4>Increasing evidence has shown that long non-coding RNAs (lncRNAs) are important prognostic biomarkers and epigenetic regulators with critical roles in cancer initiation and progression. However, the expression and clinical prognostic value of antisense lncRNAs in diffuse glioma patients remain unknown.<h4>Methods</h4>Here, we profiled differentially expressed antisense lncRNAs in glioma using RNA sequencing data from Chinese Glioma Genome Atlas database. Cox regression was performed to evaluate the prognostic value. Gene oncology (GO) and gene set enrichment analysis (GSEA) were used for functional analysis of antisense LncRNAs.<h4>Results</h4>Expression profiling identified 169 aberrantly expressed antisense lncRNAs between lower grade glioma (LGG) (grade II and III) and glioblastoma multiforme (GBM), 113 antisense lncRNAs between LGG IDH-wt and IDH-mut samples, and 70 antisense lncRNAs between GBM IDH-wt and IDH-mut samples, respectively. Among them, three antisense lncRNAs (WDFY3-AS2, MCM3AP-AS1 and LBX2-AS1) were significantly associated with prognosis and malignant progression of patients. WDFY3-AS2, the top one of downregulated antisense lncRNAs in GBM with fold change of 0.441 (<i>P?</i><?0.001), showed specific decreased expression in classical, mesenchymal, LGG IDH-wt, GBM IDH-wt or MGMT promoter unmethylated stratified patients. Chi square test found that WDFY3-AS2 was significantly associated with the clinical and molecular features of glioma. Univariate and multivariate Cox regression analysis indicated that WDFY3-AS2 was independently correlated with overall survival (OS) of patients. Kaplan-Meier analysis found that patients with high WDFY3-AS2 expression had longer OS than the low expression ones in the stratified cohorts. Additionally, GO and GSEA showed that gene sets correlated with WDFY3-AS2 expression were involved in regulation of synaptic transmission, glutamate receptor and TNF signaling pathway.<h4>Conclusion</h4>Our findings provided convincing evidence that WDFY3-AS2 is a novel valuable prognostic biomarker for diffuse glioma.
Project description:Background:Tumor infiltrating lymphocytes (TILs) and programmed death ligand 1 (PD-L1) are targets of immune checkpoint inhibitors. Methods:Forty-three World Health Organization (WHO) grade II/III gliomas (39 IDH-mutant [mut], 4 IDH-wildtype [wt]) and 14 IDH-mut glioblastomas (GBM) were analyzed for TIL (CD3+; PD1+) infiltration and PD-L1 expression. Results were compared with the data of a previously published series of 117 IDH-wt glioblastomas. PD-L1 gene expression levels were evaluated in 677 diffuse gliomas grades II-IV from The Cancer Genome Atlas (TCGA) database. Results:TIL and PD-L1 expression were observed in approximately half of WHO grade II/III gliomas. IDH-wt status was associated with significantly higher TIL infiltration and PD-L1 expression among all (grades II-IV) cases (n = 174, P < 0.001) and within the cohort of glioblastomas (n = 131, P < 0.001). In low-grade glioma (LGG) and glioblastoma cohorts of TCGA, significantly higher PD-L1 gene expression levels were evident in IDH-wt compared with IDH-mut samples (LGG: N = 516; P = 1.933e-11, GBM: N = 161; P < 0.009). Lower PD-L1 gene expression was associated with increased promoter methylation (Spearman correlation coefficient -0.36; P < 0.01) in the LGG cohort of TCGA. IDH-mut gliomas had higher PD-L1 gene promoter methylation levels than IDH-wt gliomas (P < 0.01). Conclusions:The immunological tumor microenvironment of diffuse gliomas differs in association with IDH mutation status. IDH-wt gliomas display a more prominent TIL infiltration and higher PD-L1 expression than IDH-mut cases. Mechanistically this may be at least in part due to differential PD-L1 gene promoter methylation levels. Our findings may be relevant for immune modulatory treatment strategies in glioma patients.
Project description:High-grade gliomas (HGG) are a devastating group of cancers, and represent the leading cause of brain tumour-related death in both children and adults. Therapies aimed at mechanisms intrinsic to glioma cells have translated to only limited success; effective therapeutic strategies will need also to target elements of the tumour microenvironment that promote glioma progression. Neuronal activity promotes the growth of a range of molecularly and clinically distinct HGG types, including adult and paediatric glioblastoma (GBM), anaplastic oligodendroglioma, and diffuse intrinsic pontine glioma (DIPG). An important mechanism that mediates this neural regulation of brain cancer is activity-dependent cleavage and secretion of the synaptic adhesion molecule neuroligin-3 (NLGN3), which promotes glioma proliferation through the PI3K-mTOR pathway. However, the necessity of NLGN3 for glioma growth, the proteolytic mechanism of NLGN3 secretion, and the further molecular consequences of NLGN3 secretion in glioma cells remain unknown. Here we show that HGG growth depends on microenvironmental NLGN3, identify signalling cascades downstream of NLGN3 binding in glioma, and determine a therapeutically targetable mechanism of secretion. Patient-derived orthotopic xenografts of paediatric GBM, DIPG and adult GBM fail to grow in Nlgn3 knockout mice. NLGN3 stimulates several oncogenic pathways, such as early focal adhesion kinase activation upstream of PI3K-mTOR, and induces transcriptional changes that include upregulation of several synapse-related genes in glioma cells. NLGN3 is cleaved from both neurons and oligodendrocyte precursor cells via the ADAM10 sheddase. ADAM10 inhibitors prevent the release of NLGN3 into the tumour microenvironment and robustly block HGG xenograft growth. This work defines a promising strategy for targeting NLGN3 secretion, which could prove transformative for HGG therapy.
Project description:Aims and methods: astroblastoma is a rare glial brain tumor with singular morphology. Recurrent MN1-BEND2 fusions have been recently identified in most of pediatric cases. Adolescent and adult cases, however, remain molecularly poorly defined. Here, we performed clinical and molecular characterization of a retrospective cohort of 14 adult and one adolescent gliomas with astroblastic features. Results: strikingly, we found MN1 fusions a rare event in this age group (1/15). Using methylation profiling and targeted sequencing, most cases were reclassified as either pleomorphic xanthoastrocytomas (PXA) or high-grade glioma (HGG). PXA-like ABM show BRAF mutation (6/7 with V600E mutation and 1/7 with G466E mutation) and CD34 expression. Conversely, HGG-like ABM harbored specific mutations of diffuse midline glioma (2/5) or glioblastoma (3/5). These latter patients showed an unfavorable clinical course with significantly shorter overall survival (p = 0.027). MAPK pathway alterations (including FGFR fusion, BRAF and NF1 mutations) were present in 10 of 15 patients and overrepresented in the HGG group (3/5) compared to previously reported prevalence of these alterations in GBM and diffuse midline glioma. Conclusion: We suggest that astroblastoma comprises a variety of molecularly sharply defined entities. Adults’ astroblastomas harboring molecular features of PXA and HGG should be reclassified. CNS high-grade neuroepithelial tumors with MN1 alterations appears to be a truly pediatric entity and is uncommon in adult cases with a histology of astroblastoma. Astroblastic morphology in adults should thus prompt thorough molecular investigation aiming at a clear histomolecular diagnosis and identifying actionable drug targets, especially in MAPK pathway.
Project description:OBJECTIVE:To study the expression of IL13RA2 in gliomas and to analyze its correlation with clinicopathological/molecular features, immune cell infiltration and prognostic significance. METHODS:mRNA expression data for IL13RA2 were downloaded and analyzed from two open access datasets (TCGA & CGGA). IL13RA2 protein expression was examined by immunohistochemistry. The association between IL13RA2 and important clinicopathological/molecular markers was examined using ?2 and Spearman correlation tests. The TIMER tool was used to evaluate the correlation of IL13RA2 with multiple intra-tumoral immune cell types in glioma. Kaplan-Meier test and multivariate Cox analyses were applied to evaluate the prognosis. RESULTS:Out of the 297 glioma tissues and 20 normal brain tissues in our cohort, IL13RA2 protein was highly expressed in 115 glioma tissues (115/297, 38.7%), but no expression was detected in normal brain tissues (0/20, 0%). The expression of IL13RA2 was significantly higher in GBMs (P<0.001). More than half of GBMs (68/132, 51.5%) were high expression of IL13RA2 protein, especially GBM patients with IDH wild-type and TERT promoter mutated (60/78, 76.9%). Moreover, 11/13 (84.6%) diffuse midline gliomas and 31/51 (64.7%) IDH wild-type LGGs also highly expressed IL13RA2 in our cohorts. Chi-square test showed that the expression of IL13RA2 was correlated with patient age, WHO grade, Ki67 index, IDH status, TERT promoter status and immune cell infiltration. Additionally, IL13RA2 was strongly associated with patients' OS and served as a negative prognostic marker in infiltrating gliomas. CONCLUSION:IL13RA2 was high expression in some glioma subtypes, and significantly correlated with poor prognosis. Based on its role in CAR-T therapy, it might act as an extremely important and specific therapeutic target for human malignant gliomas, especially in IDH wild-type LGG, "IDH wild-type and TERT promoter mutated" GBM and H3K27M-mutated diffuse midline glioma, and improve the clinical outcomes of these patients.
Project description:Isocitrate dehydrogenase (IDH) mutant glioblastoma (GBM), accounts for ~10% GBMs, arises from lower grade diffuse glioma and preferentially appears in younger patients. Here, we aim to establish a robust gene expression-based molecular classification of IDH-mutant GBM. A total of 33 samples from the Chinese Glioma Genome Atlas RNA-sequencing data were selected as training set, and 21 cases from Chinese Glioma Genome Atlas microarray data were used as validation set. Consensus clustering identified three groups with distinguished prognostic and molecular features. G1 group, with a poorer clinical outcome, mainly contained TERT promoter wild-type and male cases. G2 and G3 groups had better prognosis differed in gender. Gene ontology analysis showed that genes enriched in G1 group were involved in DNA replication, cell division and cycle. On the basis of the differential genes between G1 and G2/G3 groups, a six-gene signature was developed with a Cox proportional hazards model. Kaplan-Meier analysis found that the acquired signature could differentiate the outcome of low- and high-risk cases. Moreover, the signature could also serve as an independent prognostic factor for IDH-mutant GBM in the multivariate Cox regression analysis. Gene ontology and gene set enrichment analyses revealed that gene sets correlated with high-risk group were involved in cell cycle, cell proliferation, DNA replication and repair. These finding highlights heterogeneity within IDH-mutant GBMs and will advance our molecular understanding of this lethal cancer.
Project description:Molecular characterization of diffuse gliomas has thus far largely focused on genomic and transcriptomic interrogations. Here, we utilized mass spectrometry and overlay protein-level information onto genomically defined cohorts of diffuse gliomas to improve our downstream molecular understanding of these lethal malignancies. Bulk and macrodissected tissues were utilized to quantitate 5,496 unique proteins over three glioma cohorts subclassified largely based on their IDH and 1p19q codeletion status (IDH wild type (IDHwt), n = 7; IDH mutated (IDHmt), 1p19q non-codeleted, n = 7; IDH mutated, 1p19q-codeleted, n = 10). Clustering analysis highlighted proteome and systems-level pathway differences in gliomas according to IDH and 1p19q-codeletion status, including 287 differentially abundant proteins in macrodissection-enriched tumor specimens. IDHwt tumors were enriched for proteins involved in invasiveness and epithelial to mesenchymal transition (EMT), while IDHmt gliomas had increased abundances of proteins involved in mRNA splicing. Finally, these abundance changes were compared with IDH-matched GBM stem-like cells (GSCs) to better pinpoint protein patterns enriched in putative cellular drivers of gliomas. Using this integrative approach, we outline specific proteins involved in chloride transport (e.g. chloride intracellular channel 1, CLIC1) and EMT (e.g. procollagen-lysine, 2-oxoglutarate 5-dioxygenase 3, PLOD3, and serpin peptidase inhibitor clade H member 1, SERPINH1) that showed concordant IDH-status-dependent abundance differences in both primary tissue and purified GSC cultures. Given the downstream position proteins occupy in driving biology and phenotype, understanding the proteomic patterns operational in distinct glioma subtypes could help propose more specific, personalized, and effective targets for the management of patients with these aggressive malignancies.