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IDH1 mutations frequently occur early in human glioma. While IDH1 mutation has been shown to promote gliomagenesis via DNA and histone methylation, little is known regarding its regulation in antiviral immunity. Here, we discover that IDH1 mutation inhibits virus-induced interferon (IFN) antiviral responses in glioma cells. Mechanistically, D2HG produced by mutant IDH1 enhances the binding of DNMT1 to IRF3/7 promoters such that IRF3/7 are downregulated, leading to impaired type I IFN response in glioma cells, which enhances the susceptibility of gliomas to viral infection. Furthermore, we identify DNMT1 as a potential biomarker predicting which IDH1mut gliomas are most likely to respond to oncolytic virus. Finally, both D2HG and ectopic mutant IDH1 can potentiate the replication and oncolytic efficacy of VSVΔ51 in female mouse models. These findings reveal a pivotal role for IDH1 mutation in regulating antiviral response and demonstrate that IDH1 mutation confers sensitivity to oncolytic virotherapy., (© 2023. Springer Nature Limited.)

Glioblastoma (GBM) is the deadliest form of brain cancer. It is a highly angiogenic and immunosuppressive malignancy. Although immune checkpoint blockade therapies have revolutionized treatment for many types of cancer, their therapeutic efficacy in GBM has been far less than expected or even ineffective. In this study, we found that the genomic signature of glioma-derived endothelial cells (GdEC) correlates with an immunosuppressive state and poor prognosis of patients with glioma. We established an in vitro model of GdEC differentiation for drug screening and used this to determine that cyclic adenosine monophosphate (cAMP) activators could effectively block GdEC formation by inducing oxidative stress. Furthermore, cAMP activators impaired GdEC differentiation in vivo, normalized the tumor vessels, and altered the tumor immune profile, especially increasing the influx and function of CD8+ effector T cells. Dual blockade of GdECs and PD-1 induced tumor regression and established antitumor immune memory. Thus, our study reveals that endothelial transdifferentiation of GBM shapes an endothelial immune cell barrier and supports the clinical development of combining GdEC blockade and immunotherapy for GBM. See related Spotlight by Lee et al., p. 1300., (©2023 American Association for Cancer Research.)

Objective: Glutathione peroxidase 1 (GPX1) is a major selenoprotein in most animal tissues, primarily expressed in the cytoplasm and mitochondria of cells and peroxidase structures of certain cells. GPX1 expression is highly correlated with carcinogenesis and disease progression. The goal of the study was to determine the association between GPX1 expression and tumor therapy, and to identify GPX1 prognostic value in various malignancies., Methods: The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), and Human Protein Atlas (HPA) databases were used to detect the levels of GPX1 expression in human tumor tissues and normal tissues. Indeed, correlations between GPX1 and tumor purity, tumor mutation burden (TMB), microsatellite instability (MSI), and DNA mismatch repair genes (MMRs) were explored using the TCGA cohort. Functional and enrichment analyses were performed by the GeneMANIA database and Gene Set Enrichment Analysis (GSEA), respectively. Cox regression models and Kaplan - Meier curves were used to screen for independent risk factors and estimate brain lower-grade glioma (LGG) survival probability. The Chinese Glioma Genome Atlas (CGGA) database was used to determine whether GPX1 had a race-specific effect on overall survival (OS) in LGG. The cross-interaction between GPX1 and chemoradiotherapy on LGG OS was determined by Kaplan - Meier curves. Logistic regression models of multiplicative interactions were constructed. Furthermore, the relationship between GPX1 and LGG treatment regimens was also explored through the Genomics of Drug Sensitivity in Cancer (GDSC) database., Results: GPX1 was highly expressed in various tumors, GPX1 overexpression was significantly correlated with the poor prognosis of LGG. GPX1 was found to be an independent predictive factor for LGG in both univariate and multivariate Cox models. The nomogram showed a high predictive accuracy (C-index: 0.804, 95% CI: 0.74-0.86). In addition, GPX1 was significantly associated with TMB, MSI, and MMRs in diverse cancers. GPX1 was involved in IL6/JAK/STAT3, inflammatory response, and apoptosis signaling pathways. Besides, non-radiotherapy, chemotherapy, and low GPX1 expression were important factors affecting the better prognosis of LGG. GPX1 acted as a tumor promoter, which has taken the worst effect on LGG survival, but a multiplicative interaction of GPX1*chemoradiotherapy may improve the poor clinical outcome. GPX1 was negatively correlated with the half inhibition concentration (IC50) of temozolomide (TMZ) (Spearman = -0.44, P = 4.52 ×10 -26 )., Conclusion: In LGG patients, high GPX1 expression was linked to a shorter OS. The interaction between GPX1 and chemoradiotherapy exhibits a beneficial clinical effect and chemotherapy was recommended for LGG patients, especially for those with high GPX1 expression. Besides, high GPX1 expression can predict TMZ sensitivity in LGG, providing potential evidence for chemotherapy. On the whole, this study presents a wealth of biological as well as clinical significance for the roles of GPX1 in human tumors, particularly in LGG., Competing Interests: Conflict of interests The authors declare that they have no competing interests., (Copyright © 2022 Elsevier GmbH. All rights reserved.)

Diffuse midline glioma, H3 K27M-mutant (H3 K27M-mt DMG), is a rare and highly aggressive tumor that is more common in children than in adults. Few studies have compared the differences between pediatric and adult patients with this rare tumor. We here report our retrospective study of 94 adult and 70 pediatric cases of diffuse midline glioma. Surgical tumor samples were analyzed by routine histopathology and immunohistochemistry for H3 K27M, IDH1 R132H, ATRX, p53, OLIG2, glial fibrillary acidic protein, and Ki-67; Sanger sequencing for hot mutation spots in genes including H3F3A, HIST1H3B, IDH1, IDH2, TERT, and BRAF; and methylation-specific polymerase chain reaction for O6-methylguanine DNA methyltransferase promoter methylation. The most frequent anatomic locations in adult and pediatric patients were the thalamus and brainstem, respectively. Molecular profiling revealed higher frequencies of ATRX loss and H3.3 mutation in adult than in pediatric H3 K27M-mt DMGs. TERT promoter mutations and O6-methylguanine DNA methyltransferase promoter methylation were not detected in pediatric patients but were present in a few adult patients. During the follow-up period, 93/122 patients (70.1%) died from the disease, with a median survival time of 10.5 months (range: 1 to 104 mo). Kaplan-Meier analyses demonstrated that the prognosis was better for adult patients than the pediatric cohort (P=0.0003). Multivariate analyses indicated that patient age, primary tumor size, status of ATRX expression, and Ki-67 index were independent prognosticators. The present study showed that there were differences between adult and pediatric H3 K27M-mt DMGs in terms of the anatomic location of tumor, molecular changes, and prognosis., Competing Interests: Conflicts of Interest and Source of Funding: Supported by grants from the National Natural Science Foundation of China (NSFC 81872107, 81872108) and Sichuan STA Key Programs (2021YFS0114). The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: For lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) sensitive mutation and synchronous brain metastasis (syn-BM), when and how to apply radiotherapy (RT) during first-line tyrosine kinase inhibitor (TKI) treatment remains debatable., Methods: From a real-world multicenter database, EGFR-mutant patients with syn-BM diagnosed between 2010-2020 and treated with first-line TKIs were enrolled and divided into upfront TKI + RT and upfront TKI groups. Median intracranial progression-free survival (mIC-PFS), median overall survival (mOS), and their risk factors were estimated., Results: There were 60 and 186 patients in the upfront TKI + RT group and upfront TKI group, respectively. Their mIC-PFS were 28.9 months (m) and 17.5 m (p = 0.023), and mOS were 42.7 m and 40.1 m (p = 0.51). Upfront brain RT improved mIC-PFS in patients ≤60-year-old (p = 0.035), with symptomatic BM (p = 0.002), and treated with first-generation TKIs (p = 0.012). There was no significant difference in mOS in any subgroup. Upfront brain stereotactic radiosurgery (SRS) showed a trend of better mIC-PFS and mOS. mIC-PFS was independently correlated with symptomatic BM (HR = 1.54, p = 0.030), EGFR L858R mutation (HR = 1.57, p = 0.019), and upfront brain RT (HR = 0.47, p = 0.001). mOS was independently correlated with being female (HR = 0.54, p = 0.007), ECOG 3-4 (HR = 10.47, p < 0.001), BM number>3 (HR = 2.19, p = 0.002), and third-generation TKI (HR = 0.54, p = 0.044) or antiangiogenic drugs (HR = 0.11, p = 0.005) as first/second-line therapy., Conclusions: Upfront brain RT based on first-line EGFR-TKI might improve IC-PFS but not OS in EGFR-mutant lung adenocarcinoma patients, indicating potential survival benefit from brain SRS and early application of drugs with higher intracranial activity., (© 2021 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.)

Glioma is the most common intracranial malignant tumor, with poor prognosis. The new World Health Organization (WHO) integrated classification (2016) for diffuse glioma is mainly based on the status of the isocitrate dehydrogenase (IDH) gene (IDH) mutation and 1p/19q codeletion, with diffuse glioma separated into three distinct molecular categories: chromosome 1p/19q codeletion/IDH mutant, 1p/19q intact /IDH mutant, and IDH wild-type. Gliomas harboring 1p/19q codeletion but without IDH mutation are rare and cannot be classified according to the new revision of the WHO classification. Here we report three high-grade gliomas with this atypical molecular phenotype, and describe their histological and immunohistochemical features, the status of mutations in TERT promopter, H3F3A, HIST1H3B, and BRAF, as well as MGMT promoter methylation, and prognosis. Considering morphology, molecular parameters, and patients prognosis, we found that high-grade gliomas harboring 1p/19q codeletion but without IDH mutation were not typical glioblastoma multiforme (GBM) but were more likely to be GBM than anaplastic oligodendroglioma., (© 2020 Japanese Society of Neuropathology.)

Mutations of isocitrate dehydrogenase 1 (IDH1) or 2 (IDH2) genes have been identified as early molecular events in the development of astrocytomas and oligodendrogliomas. Data regarding the status and prevalence of IDH1/2 mutations in Chinese patients are limited. Herein we report our data from West China Hospital, a major Chinese medical centre. IDH1(R132H) mutation was analysed by immunohistochemistry with the mutation-specific IDH1(R132H) antibody in 1011 patients, including 922 central nervous system (CNS) tumours and 89 non-neoplastic CNS lesions, and PCR-based direct sequencing of IDH1/2 gene mutation in 570 of these samples. Correlation with clinicopathological features and immunohistochemical expression of p53, EGFR, PTEN and Ki-67 was examined. Our data showed that IDH1/2 mutation was present in oligodendrogliomas, anaplastic oligodendrogliomas, diffuse or anaplastic astrocytomas, and glioblastomas, with decreasing frequency, but not in other types of CNS tumours or non-neoplastic lesions examined. IDH1(R132) mutation was most frequent in oligodendrogliomas (57/62, 91.9%), with IDH1(R132H) mutation as the most frequent mutation form. Only one case for each of the rare mutations (R132C, R132G, R132L, and R132S) was identified in the 570 samples analysed by sequencing. Younger age, low expression of p53 and low Ki-67 index were significantly correlated with IDH1 mutation status (p=0.000). All tumours with IDH1(R132) mutations were supratentorial, with frontal lobe as the most frequent site for IDH-mutated gliomas. Only three IDH2(R172) mutation cases were detected in this series. Univariate survival analysis in 459 glioma patients with diffusely infiltrating gliomas showed that IDH1 mutations as well as the more classical prognosticators (age, WHO grade, p53 and Ki-67 index) were of prognostic significance. Multivariate analysis by Cox proportional hazard regression model demonstrated that lack of IDH1 mutation was an independent prognostic factor for both progression-free survival [relative risk (RR)=2.450, 95% confidence interval (CI)=1.351-4.444] and disease-specific survival (RR=2.489, 95%CI=1.155-5.363)., (Copyright © 2016 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.)

The SOX4 (sex-determining region Y-related high-mobility-group box transcription factor 4) gene plays critical roles in embryonic development and cell-fate determination. Recently, SOX4 overexpression has been found in various tumors. However, its expression status and prognostic significance in astrocytoma remain unknown. In this study, SOX4 expression in diffusely infiltrating astrocytoma (WHO grades II-IV) tissues (in comparison with pilocytic astrocytomas) was examined by immunohistochemistry, and its relevance with prognosis was analyzed. Our data showed that SOX4 was over-expressed in diffusely infiltrating astrocytomas and its expression was positively correlated with astrocytoma grade (WHO grades II-IV). Significantly, Kaplan-Meier analysis revealed that SOX4 nuclear overexpression (SOX4-N) was associated with poorer progression-free survival (PFS) and disease-specific survival (DSS) in diffusely infiltrating astrocytoma patients (P < 0.05). Cox regression analysis further showed that nuclear SOX4-N was a significant independent negative prognostic factor for these patients., (© 2015 Japanese Society of Neuropathology.)

Low-grade fibromyxoid sarcoma (LGFMS) is a rare sarcoma typically presenting as a deep soft tissue mass in the lower extremities or trunk. Only four cases of primary intracranial LGFMS have been reported in the literature, but none with molecular/cytogenetic data. We report here a new bona fide case confirmed by the characteristic FUS gene rearrangement, as shown by fluorescence in situ hybridization analysis, in addition to typical histopathological findings. This would be the first genetically confirmed report of the extremely rare occurrence of intracranial LGFMS., (© 2015 Japanese Society of Neuropathology.)

The transcriptional factor AP-2α is a tumor suppressor gene and is downregulated in various neoplasms including glioma. Although the level of AP-2α is negatively associated with the grade of human glioma, the specific functions of AP-2α in glioma are still unknown. In this study, we experimentally showed that artificial overexpression of AP-2α in glioma T98G and U251 cells significantly downregulated the mRNA levels of Bcl-xl, Bcl-2, c-IAP2 and survivin, together with upregulation of the Hrk mRNA levels. Reintroduction of AP-2α also induced downregulation of the protein levels of survivin and VEGF in glioma cells. In biological assays with T98G and U251 cells, AP-2α reduced tumor cell growth, increased cell death, attenuated cell migration and endothelial tube formation. The AP-2α transcription factor may play an important role in suppressing glioma progression.

Background: Alternative splicing of survivin (BIRC5) pre-mRNA generates the common isoform survivin and five additional splice variants: survivin2B, survivinΔEx3, survivin2α, survivin3B and survivin3α. Although the common isoform survivin has been shown to be involved in tumourigenesis and progression of various tumours, including diffusely infiltrating astrocytoma, the expression of other survivin splice variants in astrocytoma has not been fully investigated. Aims To evaluate the expression status and particularly prognostic significance of survivin splice variants in diffusely infiltrating astrocytoma., Methods: mRNA expression of the six survivin variants in 73 diffusely infiltrating astrocytoma and 18 normal brain tissue samples was investigated by using reverse transcription-PCR (RT-PCR), and the total survivin protein expression by western analysis and immunohistochemistry. Association of survivin and its splice variants with tumour grade and prognosis was examined by statistical and survival analysis., Results: The survivin, survivinΔEx3, survivin2B and survivin2α splice variants were significantly elevated in diffusely infiltrating astrocytoma, and were barely detectable or not detectable at all in normal brain tissue. Survivin3B and survivin3α were not detected in these samples. The positive rates of the expressed four variants increased with astrocytoma grade. Significantly, expression of these splice variants was associated with much poorer disease-specific and progression-free survival (Kaplan-Meier analysis, p≤0.002). Cox regression model further indicated survivin2α mRNA expression and nuclear survivin immunostaining to be significant independent negative prognostic factors., Conclusions: The survivin, survivinΔEx3, survivin2B and survivin2α splice variants were significantly elevated in astrocytoma, and were associated with tumour grade and poorer prognosis.

Caspases and inhibitor of apoptosis proteins (IAPs) are antagonizing key apoptosis regulators. Limited studies of a few IAPs indicated their roles in astrocytomas. However, the overall expression status and significance of apoptosis regulators in astrocytomas is not clear. We examined the expression profile of the caspases (CASP3, 6, 7, 8, 9, 10, and 14), APAF1, SMAC, BCL2, the IAPs (BIRC5/survivin, CIAP1, CIAP2, XIAP, and LIVIN), and the proliferation markers Ki67 and PHH3 in 78 diffusely infiltrating astrocytomas and 24 normal brain samples by immunohistochemistry. Western blotting for major caspases and IAPs and reverse transcription-polymerase chain reaction analyses for IAPs were performed on a subset of 27 fresh samples. Our data showed BIRC5 nuclear labeling index (BIRC5-N) was the apoptosis marker most significantly different in World Health Organization grade II to IV astrocytomas and most strongly associated with proliferative activity. Expression level of other apoptosis-related proteins was modest or low in astrocytomas and did not correlate significantly with tumor grade or proliferation. Apoptosis regulators and proliferation markers were not detected in astrocytes of normal brain by immunostaining. This expression profile suggested involvement of apoptosis regulators in astrocytoma tumorigenesis, but tumor progression was more closely associated with proliferative advantages of which BIRC5 nuclear expression appeared to be a manifestation.