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In order to obtain models of gliomas of varying degrees of malignancy, we performed morphological and molecular genetic study of a tissue strain of glioma 10-17-2 (Astrid-17) obtained by intracranial passaging of tumor fragments of chemically induced rat brain tumor, and a cell strain isolated from it. More or less pronounced changes in the expression levels of Mki67, Trp53, Vegfa, and Gfap genes in the tissue and cell strain of glioma 10-17-2 (Astrid-17) compared with intact brain tissue were shown. The tissue model of glioma 10-17-2 (Astrid-17) according to the studied characteristics shows features of grade 3-4 astrocytoma and the cellular model - grade 2-3 astrocytoma., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)

Background: This study analyzed the effectiveness and safety of ultra-low dose fluorescein sodium (FL)-guided malignant glioma resection and its potential to predict the pathological characteristics of glioma., Methods: Sixty patients who underwent FL-guided glioma resection were randomly divided into test (1 mg/kg) and control (5 mg/kg) groups. A retrospective analysis included 30 patients with gliomas who did not undergo FL-guided surgery; these patients were included as a blank control group. Surgical outcomes, Karnofsky performance scores (KPS), and progression-free survival (PFS) at 6 months postoperatively were compared between the 3 groups. The sensitivity and specificity of FL and the relationship between the intensity of FL and Glial fibrillary acidic protein (GFAP) or Ki-67 expression were compared., Results: The total tumor resection rates in the test, control, and blank control groups were 90% (27/30), 86.7% (26/30), and 60% (18/30), respectively. There were significant differences (P < 0.05) in the extent of resection, KPS, and PFS at 6 months after surgery between the test and control groups and the blank control group; however, no significant differences (P > 0.05) were observed between the test and control groups. The intensity of FL and the Ki67 positivity rate (P < 0.05) were directly proportional, but this relationship was not observed with GFAP., Conclusions: Ultra-low-dose FL-guided resection of malignant gliomas is safe and effective. The Ki67 positivity rate was directly proportional to the intensity of FL, indicating its potential to predict gliomas during pathological examination., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Gap junctions are channels between adjacent cells, contributing to the unhindered exchange of metabolites, second messengers, nucleotides, and other molecules. The functional status of gap junctions in brain tumours is underinvestigated. One avenue of research focuses on exploring the expression of polyamines and their co-localisation with the Connexin 43 (Cx43) in the growth zones of glioblastoma multiforme (GBM). The aim of this work was to analyse the expression of Cx43 and spermine in human GBM to reveal their roles in neuro-oncogenesis. Human GBM sample sections were used for the immunochemistry [glial fibrillary acidic protein (GFAP), Cx43, and spermine], confocal laser scanning microscopy, and electron immunohistochemistry. Immunofluorescent analysis revealed that the more extensive processes of GBM cells exhibit GFAP. All GBM samples (n = 10) exhibited positive Cx43 signals in the form of variously sized dots and lines. Cx43 formed dotted lines around cell bodies with segmented transformed nuclei, which were also present in the gliovascular complexes. Furthermore, spermine was overexpressed in all tumour samples (cytoplasm and large and thin tumour processes), including the areas of Cx43 localisation. Merging the Cx43 and spermine signals showed co-expression in the same regions: the membranes of individual cells and individual points on processes in the tumour tissue. Therefore, we established the staining of the co-localisation of Cx43 and the polyamine spermine within glioblastoma, revealing that tumour processes housing the polyamine indeed form gap junctions, suggesting their potential joint interaction. This finding indicates that glioma cells can integrate into the surrounding neural networks, potentially serving as a mechanism to release glycolysis products, relying on gap junction activity facilitated by spermine. Cx43 exhibits sensitivity to polyamines, which play a role in opening gap junctional channels. Furthermore, polyamines have been observed to eliminate the blockades caused by hydrogen ions and calcium, which is crucial for cellular physiology., (© 2024. Oxygen Transport to Tissue International.)

While the fungal metabolite illudin M ( 1 ) is indiscriminately cytotoxic in cancer and non-malignant cells, its retinoate 2 showed a greater selectivity for the former, especially in a cerebral context. Illudin M killed malignant glioma cells as well as primary neurons and astrocytes at similarly low concentrations and destroyed their microtubule and glial fibrillary acidic protein (GFAP) networks. In contrast, the ester 2 was distinctly more cytotoxic in highly dedifferentiated U87 glioma cells than in neurons, which were even stimulated to enhanced growth. This was also observed in co-cultures of neurons with U87 cells where conjugate 2 eventually killed them by induction of differentiation based on the activation of nuclear receptors, which bind to retinoid-responsive elements (RARE). Hence, illudin M retinoate 2 appears to be a promising drug candidate.

Glioma is the most common form of malignant primary brain tumours in adults. Their highly invasive nature makes the disease incurable to date, emphasizing the importance of better understanding the mechanisms driving glioma invasion. Glial fibrillary acidic protein (GFAP) is an intermediate filament protein that is characteristic for astrocyte- and neural stem cell-derived gliomas. Glioma malignancy is associated with changes in GFAP alternative splicing, as the canonical isoform GFAPα is downregulated in higher-grade tumours, leading to increased dominance of the GFAPδ isoform in the network. In this study, we used intravital imaging and an ex vivo brain slice invasion model. We show that the GFAPδ and GFAPα isoforms differentially regulate the tumour dynamics of glioma cells. Depletion of either isoform increases the migratory capacity of glioma cells. Remarkably, GFAPδ-depleted cells migrate randomly through the brain tissue, whereas GFAPα-depleted cells show a directionally persistent invasion into the brain parenchyma. This study shows that distinct compositions of the GFAPnetwork lead to specific migratory dynamics and behaviours of gliomas., (© 2022. The Author(s).)

The 2016 World Health Organization classification of central nervous system tumor firstly introduces molecular diagnosis to glioma, while the molecular features of adult thalamic gliomas (ATGs) in a relatively large sample have not been reported. We aimed at exploring molecular characteristics in ATGs. The data of 97 and 575 newly diagnosed ATGs and superficial gliomas (SGs) patients were collected, and we performed a comparative analysis of molecular characteristics between them. We analyzed expressions of molecules as follow: H3 K27M, isocitrate dehydrogenase1 (IDH1), Ki-67, O6-Methylguanine-DNA methyltransferase (MGMT) promoter, EGFR, p53, ATRX, GFAP, Oligo2, PTEN, MGMT, and MMP9 by immunohistochemistry. Direct gene sequencing was performed to test the H3 K27M, IDH1, and TERT promoter mutation. The median age at diagnosis of ATGs was 36.0 years, and majority of them were high-grade glioma. We found a significant difference in H3 K27M mutation (P = 0.003), IDH1 mutation (P < 0.001), MGMT promoter methylation (P = 0.005), and Ki67 > 0.1 (P < 0.001) between ATGs and SGs. The statuses of IDH1 (P < 0.001), MGMT promoter (P < 0.001), and Ki67 (P < 0.001) were significantly different between these two groups in lower-grade gliomas. And statuses of IDH1 (P < 0.001), Ki67 (P < 0.001), and EGFR (P = 0.032) were different between these two groups in high-grade gliomas. Only Ki67 > 0.1 was differentially expressed between lower- and high-grade gliomas in ATGs (P = 0.014). The high occurrence of H3 K27M mutation and Ki67 > 0.1, rare occurrence of IDH1 mutation, and MGMT promoter methylation in ATGs suggested that ATGs may be a distinct type of glioma entity., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.)

Intraoperative cytological examination and cyto-histologic correlation of papillary glioneuronal tumors have rarely been described in detail in the literature. A 23-year-old female presented at our institution with seizure-like activity, and a 3.0 cm left temporal lobe hypoattenuating lesion. She was accurately diagnosed with papillary glioneuronal tumor on Intraoperative cytology. The patient subsequently proceeded to stealth-guided awake left temporal craniotomy, confirming the diagnosis. In this article, we present a detailed report of papillary glioneuronal tumor (extremely rare central nervous system neoplasm) describing the cytologic and histologic morphologic features, its differential diagnosis with review of the literature., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Primary adherent glioblastoma cell lines are an important tool in investigating cellular and molecular tumor biology, as well as treatment options for patients., Aim: The phenotypical and immunocytochemical characterization of primary cell lines from glioblastoma specimens during establishment is of great importance, in order to reliably identify these cell lines as primary glioblastoma cell lines., Methods and Results: Sixteen primary adherent cell lines out of 34 glioblastoma samples (47%) were established and further characterized. For phenotypical characterization, morphology and growth characteristics of the cells were classified. The cell lines had a high growth rate with a doubling time of 2 to 14 days. Morphologically, the cells displayed spindle-form or polygonal to amorphous shapes and grow as monolayer or in foci without evidence of contact inhibition. The cells were able to migrate and to form colonies. For further characterization, the protein expression of the astrocyte-specific protein glial fibrillary acidic protein (GFAP), the glial marker S100B, the neuronal marker TUBB3, and malignancy marker VIM, as well as the progenitor markers NES and SOX2, the proliferation marker MKI67, and the fibroblast marker TE7 were determined. Based on the immunocytochemical validation criterion of a coexpression of GFAP and S100B, 15 out of these 16 cell lines (94%) were defined as primary glioblastoma cell lines (pGCL). All 15 pGCL expressed TUBB3 and VIM. NES and SOX2 were stained positively in 13/15 and 6/15 pGCL. MKI67 was expressed in 11/15 and TE7 in 2/15 pGCL., Conclusion: These results point out that in self-established primary adherent glioblastoma cell lines, the expression of the specific astrocytic and glial markers GFAP and S100B and of the malignancy and progenitor markers VIM, NES, and SOX2 has to be validated. These data show that primary cell lines of glioblastoma origin with high malignant potential are reliably to establish using standardized validation criteria., (© 2020 The Authors. Cancer Reports published by Wiley Periodicals LLC.)

We report the first case of pineoblastoma in a cow. At necropsy, a soft, gelatinous greyish yellow, 4 × 3 × 2 cm mass was found midsagittally on the dorsal surface of the midbrain. The mass enveloped the brainstem anterior to the cerebellum, extended to the pituitary fossa and was adherent to the ventromedial aspect of the occipital lobes. Histologically, the mass was unencapsulated, with extramedullary proliferation into the lobes and meninges, but was demarcated from the adjacent brain tissue. Histological findings were consistent with a pineoblastoma, as reported in other species, and the neoplasm was strongly immunopositive for synaptophysin. Glial fibrillary acidic protein-positive spindloid astrocytic processes surrounded blood vessels and extended around neoplastic cells., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: It is very important to develop a highly efficient cerebrospinal fluid (CSF) detection system with diagnosis and prediction function, for which the detection of circulating tumor cells (CTCs) in CSF is a good choice. In contrast to the past use of epithelial EpCAM as CTCs separation target, a cytoplasm protein of GFAP antibody was first selected to construct highly-sensitive immunomagnetic liposome beads (IMLs). The validation and efficiency of this system in capturing CTCs for brain tumors were measured both in vitro and in vivo. The associations between the numbers of CTCs in patients with their clinical characteristics were further analyzed., Results: Our data show that CTCs can be successfully isolated from CSF and blood samples from 32 children with brain tumors. The numbers of CTCs in CSF were significantly higher than those in blood. The level of CTCs in CSF was related to the type and location of the tumor rather than its stage. The higher the CTCs number is, the more possibly the patient will suffer from poor prognosis. Genetic testing in GFAP CTC-DNA by sanger sequencing, q-PCR and NGS methods indicated that the isolated CTCs (GFAP+/EGFR+) are the related tumor cell. For example, the high expression of NPR3 gene in CSF CTCs was consistent with that of tumor tissue., Conclusions: The results indicated that GFAP-IML CTCs isolation system, combined with an EGFR immunofluorescence assay of antitumor marker, can serve as a brand-new method for the identification of CTCs for brain tumors. Via lumbar puncture, a minimally invasive procedure, this technique may play a significant role in the clinical diagnosis and drug evaluation of brain tumors.

Background: Metastatic glioblastoma presenting as a solitary osteolytic cervical vertebral mass without primary brain tumor relapse is extremely rare with only 1 reported case in the literature. Because of its rarity, it can be easily overlooked and misdiagnosed, posing a diagnostic dilemma., Case Presentation: A 51-year-old man with right temporal glioblastoma was initially treated by tumor resection, radiotherapy and chemotherapy. Eighteen months after surgery, he was readmitted with complaints of neck pain for 2 weeks. Follow-up magnetic resonance imaging (MRI) and fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) revealed a solitary FDG-avid osteolytic lesion in the 4th cervical vertebral body without other abnormal FDG-uptake in the body and in the absence of local recurrence at the resection cavity. Because of the sudden worsening situation and intractable neck pain, the patient underwent tumor resection. Postoperatively, the pain was obviously reduced and the situation was improved. Interestingly, the immunohistochemical findings of glial fibrillary acidic protein (GFAP) indicated the characteristic of metastatic glioblastoma, despite that the histopathological findings of Hematoxylin & Eosin (H&E) staining was suspicious of osteoclastoma. According to the clinical history, imaging findings, pathological and immunohistochemical results, a final diagnosis of solitary vertebral metastasis from glioblastoma without central nervous system (CNS) relapse was confirmed. Then, the patient received radiotherapy on spine and adjuvant chemotherapy with temozolomide. However, he died suddenly 2 months after the tumor resection, nearly 21 months after the initial diagnosis., Conclusion: We emphasize that metastatic glioblastoma should be considered in the differential diagnosis of a solitary FDG-avid osteolytic vertebral mass on PET/CT. And the diagnosis of extracranial metastasis (ECM) from glioblastoma can be achieved through clinical history, imaging findings, pathological examination, and immunohistochemical staining with GFAP.

An 8-year-old Anglo-European gelding with progressive neurological signs was humanely destroyed and submitted for necropsy examination. The right parietal cortex was disrupted by a well-demarcated, intraparenchymal, 1.5 cm diameter, tan, homogeneous, dense mass. Microscopical examination was consistent with an astrocytoma, which was confirmed on the basis of strong immunohistochemical labelling for glial fibrillary acidic protein. The neoplastic population lacked immunolabelling for oligodendrocyte transcription factor 2. Labelling for ionized calcium binding adaptor molecule 1 highlighted large numbers of reactive microglia throughout the proliferation and in the adjacent neuroparenchyma. While rare, primary brain tumours should be considered as a differential in horses presenting with progressive neurological signs., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The microenvironment and architecture of peritumoral tissue have been suggested to affect permissiveness for infiltration of malignant cells. Astrocytes constitute a heterogeneous population of cells and have been linked to proliferation, migration, and drug sensitivity of glioblastoma (GBM) cells. Through double-immunohistochemical staining for platelet-derived growth factor receptor α (PDGFRα) and glial fibrillary acidic protein (GFAP), this study explored the intercase variability among 45 human GBM samples regarding density of GFAP+ peritumoral astrocytes and a subset of GFAP+ peritumoral astrocyte-like cells also expressing PDGFRα. Large intercase variability regarding the total peritumoral astrocyte density and the density of PDGFRα+/GFAP+ peritumoral astrocyte-like cells was detected. DNA fluorescence in situ hybridization analyses for commonly altered genetic tumor markers supported the interpretation that these cells represented a genetically unaffected host cell subset referred to as PDGFRα+/GFAP+ peritumoral astrocytes. The presence of PDGFRα+/GFAP+ peritumoral astrocytes was significantly positively correlated to older patient age and peritumoral astrocyte density, but not to other established prognostic factors. Notably, presence of PDGFRα+/GFAP+ peritumoral astrocytes, but not peritumoral astrocyte density, was associated with significantly shorter patient overall survival. The prognostic association of PDGFRα+/GFAP+ peritumoral astrocytes was confirmed in multivariable analyses. This exploratory study thus demonstrates previously unrecognized intercase variability and prognostic significance of peritumoral abundance of a novel PDGFRα+ subset of GFAP+ astrocytes. Findings suggest clinically relevant roles of the microenvironment of peritumoral GBM tissue and encourage further characterization of the novel astrocyte subset with regard to origin, function, and potential as biomarker and drug target., (© 2019 Wiley Periodicals, Inc.)

Peripheral metastases of glioblastoma (GBM) are very rare despite the ability of GBM cells to pass through the blood-brain barrier and be disseminated through the peripheral blood. Here, we describe a detailed genetic and immunological characterization of a GBM metastasis in the skeleton, which occurred during anti-PD-1 immune checkpoint therapy. We performed whole genome sequencing (WGS) and 850 K methylation profiling of the primary and recurrent intracranial GBM as well as one of the bone metastases. Copy number alterations (CNA) and mutational profiles were compared to known genomic alterations in the TCGA data base. In addition, immunophenotyping of the peripheral blood was performed. The patient who was primarily diagnosed with IDH-wildtype GBM. After the resection of the first recurrence, progressive intracranial re-growth was again detected, and chemotherapy was replaced by PD-1 checkpoint inhibition, which led to a complete intracranial remission. Two months later MR-imaging revealed multiple osseous lesions. Biopsy confirmed the GBM origin of the skeleton metastases. Immunophenotyping reflected the effective activation of a peripheral T-cell response, with, however, increase of regulatory T cells during disease progression. WGS sequencing demonstrated distinct genomic alterations of the GBM metastasis, with gains along chromosomes 3 and 9 and losses along chromosome 4, 10, and 11. Mutational analysis showed mutations in potentially immunologically relevant regions. Additionally, we correlated tumour-infiltrating lymphocyte and microglia presence to the occurrence of circulating tumour cells (CTCs) in a larger cohort and found a decreased infiltration of cytotoxic T cells in patients positive for CTCs. This study exemplifies that the tumour microenvironment may dictate the response to immune checkpoint therapy. In addition, our study highlights the fact that despite an effective control of intracranial GBM, certain tumour clones have the ability to evade the tumour-specific T-cell response and cause progression even outside of the CNS.

The understanding of the physiology of astrocytes and their role in brain function progresses continuously. Primary astrocyte culture is an alternative method to study these cells in an isolated system: in their physiologic and pathologic states. Cell lines are often used as an astrocyte model, since they are easier and faster to manipulate and cost less. However, there are a few studies evaluating the different features of these cells which may put into question the validity of using them as astrocyte models. The aim of this study was to compare primary cultures (PC) with two cell lines - immortalized astrocytes and C6 cells, in terms of protein characterization, morphology and metabolic functional activity. Our results showed, under the same culture condition, that immortalized astrocytes and C6 are positive for differentiated astrocytic markers (eg. GFAP, S100B, AQP4 and ALDH1L1), although expressing them in less quantities then primary astrocyte cultures. Glutamate metabolism and cell communication are reduced in proliferative cells. However, glucose uptake is elevated in C6 lineage cells in comparison with primary astrocytes, probably due to their tumorigenic origin and high proliferation rate. Immortalized astrocytes presented a lower growth rate than C6 cells, and a similar basal morphology as primary astrocytes. However, they did not prove to be as good reproductive models of some of the classic astrocytic functions, such as S100B secretion and GFAP content, especially while under stimulation. In contrast, C6 cells presented similar results in comparison to primary astrocytes in response to stimuli. Here we provide a functional comparison of three astrocytic models, in an attempt to select the most suitable model for the study of astrocytes, optimizing the research in this area of knowledge., (Copyright © 2019. Published by Elsevier Ltd.)

Introduction: The subventricular zone (SVZ) in the brain is associated with gliomagenesis and resistance to treatment in glioblastoma. In this study, we investigate the prognostic role and biological characteristics of subventricular zone (SVZ) involvement in glioblastoma., Methods: We analyzed T1-weighted, gadolinium-enhanced MR images of a retrospective cohort of 647 primary glioblastoma patients diagnosed between 2005-2013, and performed a multivariable Cox regression analysis to adjust the prognostic effect of SVZ involvement for clinical patient- and tumor-related factors. Protein expression patterns of a.o. markers of neural stem cellness (CD133 and GFAP-δ) and (epithelial-) mesenchymal transition (NF-κB, C/EBP-β and STAT3) were determined with immunohistochemistry on tissue microarrays containing 220 of the tumors. Molecular classification and mRNA expression-based gene set enrichment analyses, miRNA expression and SNP copy number analyses were performed on fresh frozen tissue obtained from 76 tumors. Confirmatory analyses were performed on glioblastoma TCGA/TCIA data., Results: Involvement of the SVZ was a significant adverse prognostic factor in glioblastoma, independent of age, KPS, surgery type and postoperative treatment. Tumor volume and postoperative complications did not explain this prognostic effect. SVZ contact was associated with increased nuclear expression of the (epithelial-) mesenchymal transition markers C/EBP-β and phospho-STAT3. SVZ contact was not associated with molecular subtype, distinct gene expression patterns, or markers of stem cellness. Our main findings were confirmed in a cohort of 229 TCGA/TCIA glioblastomas., Conclusion: In conclusion, involvement of the SVZ is an independent prognostic factor in glioblastoma, and associates with increased expression of key markers of (epithelial-) mesenchymal transformation, but does not correlate with stem cellness, molecular subtype, or specific (mi)RNA expression patterns., Competing Interests: The authors have declared that no competing interests exist.

Objective: To explore related factors that influence time to recurrence and prognosis of gliomas., Methods: A retrospective analysis of pathologic and clinical data of patients with glioma who underwent surgery for the first time and had a recurrence between 2009 and 2018 in West China Hospital was performed. Clinical characteristics of patients were reviewed, and survival analysis was performed to identify prognostic factors for the recurrent time. Molecules with differential changes in the paired samples were included in the survival analysis., Results: A total of 84 patients met our inclusion requirements and were included in the study; other related factors were also considered in detail in the integrated analysis. Significant differences among O 6 -methylguanine-DNA methyltransferase (positive/negative), isocitrate dehydrogenase 1 (positive/negative), and Ki-67 were determined by statistical analysis of paired samples (P = 0.013, P = 0.014, P = 0.017). Univariate analysis demonstrated that Ki-67 (low expression, medium expression, high expression), initial World Health Organization grade (low or high), tumor side (left, right, middle), age (≥50 years, <50 years), and extent of resection were significantly correlated with time to recurrence (log-rank P = 0.008, P < 0.001, P = 0.015, P < 0.001, P = 0.001). Multivariate analysis results showed that Ki-67 lower expression (hazard ratio [HR] = 0.585, 95% confidence interval [CI] = 0.146-2.336, P = 0.448), medium expression (HR = 0.256, 95% CI = 0.084-0.784, P = 0.017), and high expression (HR = 1 as a reference) together with the initial World Health Organization grade (HR = 0.148, 95% CI = 0.029-0.749, P = 0.021) were independent predictive factors for glioma recurrence., Conclusions: This comprehensive analysis revealed that initial World Health Organization grade and Ki-67 proliferative index were independent prognostic factors that predict the time to recurrence of glioma in patients after first surgery., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Sphere formation is an indicator of tumor aggressiveness independent of the tumor grade; however, its relation to progression-free survival (PFS) is less known. This study was designed to assess the neurosphere forming ability among low grade glioma (LGG) and high-grade glioma (HGG), its stem cell marker expression, and correlation to PFS. Tumor samples of 140 patients, including (LGG; n = 67) and (HGG; n = 73) were analyzed. We used sphere forming assay, immunofluorescence, and immunohistochemistry to characterize the tumors. Our study shows that, irrespective of the pathological sub type, both LGG and HGG formed neurospheres in vitro under conventional sphere forming conditions. However, the number of neurospheres formed from tumor tissues were significantly higher in HGG compared to LGG (P < 0.0001). Different grades of glioma were further characterized for the expression of stem cell marker proteins and lineage markers. When neurospheres were analyzed, CD133 positive cells were identified in addition to CD15 and nestin positive cells in both LGG and HGG. When these neurospheres were subjected to differentiation, cells positive for GFAP and β-tubulin III were observed. Expression of stem cell markers and β-tubulin III were prominent in HGG compared to LGG, whereas GFAP expression was higher in LGG than in HGG. Kaplan-Meier survival analysis demonstrated that neurosphere forming ability was significantly associated with shorter PFS (P < 0.05) in both LGG and HGG. Our results supports earlier studies that neurosphere formation may serve as a definitive indicator of stem cell population within the tumor and thus a better predictor of PFS than the tumor grades alone. © 2018 IUBMB Life, 71(1):244-253, 2019., (© 2018 International Union of Biochemistry and Molecular Biology.)

Differentiation is a central key capability of stem cells. Their ability to be multipotent and undergo self-renewal are key identifying features of stem cells. A differentiation assay allows for study of one of the essential features of stem cells, the ability to differentiate into all of the cell types of its lineage, in order to ensure that the cells cultured and utilized in key experiments indeed have stem cell properties. Neural stem cells when plated in differentiation media, differentiate into all three neural lineages: Neurons, Astrocytes, and Oligodendrocytes. Brain tumor initiating cells (BTICs) are cells present in brain tumors that possess stem cell properties and are able to self-renew and differentiate into neural lineages. In the current chapter, we discuss protocols involved in immunofluorescence staining and identification of differentiated cells from BTIC populations.

BACKGROUND Astrocytomas are the most common primary brain neoplasms. Biological indicators of astrocytomas can reflect its biological characteristics. The aim of this study was to assess the expression of the pathological glial fibrillary acidic protein (GFAP) Topo IIα and O⁶-methylguanine-DNA methyltransferase (MGMT) in astrocytomas using magnetic resonance (MR) diffusion kurtosis imaging (DKI) to evaluate the biological characteristics of astrocytomas. MATERIAL AND METHODS Sixty-six patients with pathologically proven astrocytomas were enrolled in this study. All patients underwent conventional MRI head scanning, DKI scanning, and enhanced scanning under the same conditions. Spearman's rank correlation analysis and Bonferroni correction were used to compare the values of DKI and the expression levels of GFAP, Topo IIα, and MGMT between the 2 groups. RESULTS Mean kurtosis (MK) values were negatively correlated with the expression of GFAP (r=-0.836; P=0.03). However, these were positively correlated with the expression of Topo IIα (r=0.896; P=0.01). Moreover, fractional anisotropy (FA) values were not correlated with the expression of GFAP (r=0.366; P=0.05), Topo IIα (r=-0.562; P=0.05), or MGMT (r=-0.153; P=0.10). CONCLUSIONS MK was significantly associated with the expression of GFAP and Topo IIα. To a certain extent, applying DKI may show the biological behavior of tumor cell differentiation, proliferation activity, invasion, and metastasis, and guide individual treatment.

The National Cancer Institute-led multidisciplinary Comparative Brain Tumor Consortium (CBTC) convened a glioma pathology board, comprising both veterinarian and physician neuropathologists, and conducted a comprehensive review of 193 cases of canine glioma. The immediate goal was to improve existing glioma classification methods through creation of a histologic atlas of features, thus yielding greater harmonization of phenotypic characterization. The long-term goal was to support future incorporation of clinical outcomes and genomic data into proposed simplified diagnostic schema, so as to further bridge the worlds of veterinary and physician neuropathology and strengthen validity of the dog as a naturally occurring, translationally relevant animal model of human glioma. All cases were morphologically reclassified according to a new schema devised by the entire board, yielding a majority opinion diagnosis of astrocytoma (43, 22.3%), 19 of which were low-grade and 24 high-grade, and oligodendroglioma (134, 69.4%), 35 of which were low-grade and 99 were high-grade. Sixteen cases (8.3%) could not be classified as oligodendroglioma or astrocytoma based on morphology alone and were designated as undefined gliomas. The simplified classification scheme proposed herein provides a tractable means for future addition of molecular data, and also serves to highlight histologic similarities and differences between human and canine glioma.

Mutations and activation of the PI3K signaling pathway in breast cancer cells have been linked to brain metastases. However, here we describe that in some breast cancer brain metastases samples the protein expression of PI3K signaling components is restricted to the metastatic microenvironment. In contrast to the therapeutic effects of PI3K inhibition on the breast cancer cells, the reaction of the brain microenvironment is less understood. Therefore we aimed to quantify the PI3K pathway activity in breast cancer brain metastasis and investigate the effects of PI3K inhibition on the central nervous system (CNS) microenvironment. First, to systematically quantify the PI3K pathway activity in breast cancer brain metastases, we performed a prospective biomarker study using a reverse phase protein array (RPPA). The majority, namely 30 out of 48 (62.5%) brain metastatic tissues examined, revealed high PI3K signaling activity that was associated with a median overall survival (OS) of 9.41 months, while that of patients, whose brain metastases showed only moderate or low PI3K activity, amounted to only 1.93 and 6.71 months, respectively. Second, we identified PI3K as a master regulator of metastasis-promoting macrophages/microglia during CNS colonization; and treatment with buparlisib (BKM120), a pan-PI3K Class I inhibitor with a good blood-brain-barrier penetrance, reduced their metastasis-promoting features. In conclusion, PI3K signaling is active in the majority of breast cancer brain metastases. Since PI3K inhibition does not only affect the metastatic cells but also re-educates the metastasis-promoting macrophages/microglia, PI3K inhibition may hold considerable promise in the treatment of brain metastasis and the respective microenvironment., (© 2018 Wiley Periodicals, Inc.)

Glioma is the most common primary brain tumor Despite the availability of adjuvant therapies, malignant glioma grows fast and metastasizes via cerebrospinal fluid after tumorectomy or cerebrospinal fluid shunt placement, and the prognosis for patients with glioma remains poor. Our previous study demonstrated that β-asarone has anti-tumor effects on several kinds of cancer cells, especially for glioma cells. In this study, human glioma U251 cells and rat glioma C6 cells were treated with different concentrations of β-asarone. Cultured them for 24 h, 48 h, 72 h and evaluated the IC 50 with the results of Counting Kit-8 assay. Then, cell apoptosis and cell DNA cycles were evaluated with flow cytometry. Apoptosis related mRNA and protein were analyzed In addition, cell migration and invasion were also detected with wound healing and transwell assays, respectively. What is more, glioma specific proteins: GFAP, NRP-1 and NSE an enzyme-linked immunosorbent assay. The corresponding CCK-8 results showed that β-asarone altered cell morphology and inhibited cell proliferation. β-asarone can also induced cell apoptosis, decreased the expression of BCL-2 mRNA and blocked the DNA cycle at the G0/G1 phase for all the two cells. In addition, β-asarone inhibited cell migration and invasion by reducing the expression of GFAP, NRP-1 and NSE. Co-administration with TMZ showed a more pronounced effect. In summary, β-asarone induces cell death and inhibits cell migration and invasion in Glioma U251 and C6 cells., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

The brain microenvironment imposes a particularly intense selective pressure on metastasis-initiating cells, but successful metastases bypass this control through mechanisms that are poorly understood. Reactive astrocytes are key components of this microenvironment that confine brain metastasis without infiltrating the lesion. Here, we describe that brain metastatic cells induce and maintain the co-option of a pro-metastatic program driven by signal transducer and activator of transcription 3 (STAT3) in a subpopulation of reactive astrocytes surrounding metastatic lesions. These reactive astrocytes benefit metastatic cells by their modulatory effect on the innate and acquired immune system. In patients, active STAT3 in reactive astrocytes correlates with reduced survival from diagnosis of intracranial metastases. Blocking STAT3 signaling in reactive astrocytes reduces experimental brain metastasis from different primary tumor sources, even at advanced stages of colonization. We also show that a safe and orally bioavailable treatment that inhibits STAT3 exhibits significant antitumor effects in patients with advanced systemic disease that included brain metastasis. Responses to this therapy were notable in the central nervous system, where several complete responses were achieved. Given that brain metastasis causes substantial morbidity and mortality, our results identify a novel treatment for increasing survival in patients with secondary brain tumors.

Small cell glioblastoma is a high anaplastic variant of GBM characterized by a monomorphic proliferation of small or medium cells with oval nuclei and scanty cytoplasm., Case Study: The cytologic findings of a small cell glioblastoma in 11-year-old male and histologic features of the tumor using immunocytohistochemistry are reported., Conclusion: The accurate preoperative diagnosis of a small cell glioblastoma is crucial to developing a curative surgical plan. Cytology- confirmed by histology- provides a convenient, safe and effective approach to solving a challenging differential diagnosis.

Introduction: Removal of midline paraventricular gliomas is difficult because of their deep localization and invasive character, requiring biopsy for pathologic diagnosis. This study aimed to assess the pathologic findings and clinical course of midline paraventricular gliomas diagnosed using a neuroendoscope., Methods: This study was performed as a retrospective investigation using a neuroendoscope of 26 patients whose tumors were diagnosed as midline paraventricular gliomas. The main loci of the lesions were the thalamus (11 patients), tectum (6 patients), and other areas (9 patients). Of these 26 patients, 21 (81%) had accompanying obstructive hydrocephalus. Surgery was performed via the lateral ventricle using a flexible scope. For patients with obstructive hydrocephalus, we added endoscopic third ventriculostomy, septostomy, and/or plasty of the foramen of Monro. Pathologic diagnosis was determined according to hematoxylin-eosin staining and immunohistochemistry using anti-GFAP, anti-Ki-67, anti-H3-K27M, and anti-IDH1-R132H antibodies., Results: The pathologic diagnoses were grade I (5 patients), grade II (3 patients), grade III (6 patients), and grade IV (4 patients) gliomas. Six patients were diagnosed as having high-grade glioma, which was difficult to distinguish between grade III and grade IV. Two patients were undiagnosable. H3-K27M was strongly positive in 8 of 15 patients with high-grade glioma. All patients with high-grade gliomas died or received best supportive care within 2 years after surgery., Conclusions: Neuroendoscopic surgery is useful for midline paraventricular gliomas in terms of the treatment of obstructive hydrocephalus, as well as pathologic diagnosis and genetic analysis, which are required under the World Health Organization 2016 classification., (Copyright © 2018 Elsevier Inc. All rights reserved.)

MethylCpG binding protein-2 (MeCP2) is an epigenetic regulator and essential for brain development. MeCP2 mutations are associated with a spectrum of neuro-developmental disorders that vary depending on the patient gender, most notably Rett Syndrome. MeCP2 is essential for normal neuronal maturation, and glial cell function in the brain. Besides, its role in neurodevelopmental disorders, MeCP2 is involved in many cancers such as breast, colorectal, lung, liver, and prostate cancer. Glioma is the most lethal form of brain cancer. Studies have shown that dysfunctional epigenetic regulation plays a crucial role in glioma progression. Further, previous studies have suggested a role for MeCP2 in glioma pathogenesis. In this study, we show that MeCP2 may play a critical role in the suppression of glioma progression. Stable overexpression of MeCP2in C6 glioma cells inhibits proliferation, migration, invasion, and adhesion. Moreover, MeCP2 overexpression inhibits pERKand BDNF expression while inducing GFAP expression in C6 glioma. These findings suggest that MeCP2 may play a crucial role in suppression of glioma progression., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Brain tumor patients often experience functional deficits that extend beyond the tumor site. While resting-state functional MRI (rsfMRI) has been used to map such functional connectivity changes in brain tumor patients, the interplay between abnormal tumor vasculature and the rsfMRI signal is still not well understood. Therefore, there is an exigent need for new tools to elucidate how the blood‑oxygenation-level-dependent (BOLD) rsfMRI signal is modulated in brain cancer. In this initial study, we explore the utility of a preclinical model for quantifying brain tumor-induced changes on the rsfMRI signal and resting-state brain connectivity. We demonstrate that brain tumors induce brain-wide alterations of resting-state networks that extend to the contralateral hemisphere, accompanied by global attenuation of the rsfMRI signal. Preliminary histology suggests that some of these alterations in brain connectivity may be attributable to tumor-related remodeling of the neurovasculature. Moreover, this work recapitulates clinical rsfMRI findings from brain tumor patients in terms of the effects of tumor size on the neurovascular microenvironment. Collectively, these results lay the foundation of a preclinical platform for exploring the usefulness of rsfMRI as a potential new biomarker in patients with brain cancer.

The endocannabinoid system plays an important role in the regulation of physiological and pathological conditions, including inflammation and cancer. Hypoxia is a fundamental phenomenon for the establishment and maintenance of the microenvironments in various physiological and pathological conditions. However, the influence of hypoxia on the endocannabinoid system is not fully understood. In the present study, we investigated the effects of hypoxia on the endocannabinoid system in malignant brain tumors. We subjected U-87 MG cells, derived from malignant glioblastoma, to hypoxia (1.5% O2) for 3 days, and evaluated their viability and expression of endocannabinoid-related genes. Hypoxia decreased the expression of cannabinoid receptor 1 and the astrocyte marker glial fibrillary acidic protein, and increased the expression of vascular endothelial growth factor and cyclooxygenase-2, the enzyme responsible for the metabolism of endocannabinoids, in U-87 MG cells. Although cannabinoid receptor (CB) engagement induces cell death in U-87 MG cells in normoxic conditions, CB agonist-induced death was attenuated in hypoxic conditions. These results suggest that hypoxia modifies the endocannabinoid system in glioblastoma cells. Hypoxia-induced inhibition of the endocannabinoid system may aid the development of glioblastoma.

Aim: To compare the uptake of 11 C-deuterodeprenyl ( 11 C-DED) and 11 C-methionine ( 11 C-MET) in three human glioma cell lines and study the relationship with glial fibrillary acid protein (GFAP) and monoamine oxidase B (MAO B) expression. 11 C-DED is used in positron emission tomography imaging as a marker of astrocytosis in various central nervous system pathologies. It binds irreversibly to MAO B, a glial dimeric enzyme with increased activity in some neurological pathologies., Materials and Methods: Binding and internalization studies of 11 C-MET and 11 C-DED were performed in astrocytoma grade III, glioblastoma grade IV, and radio-resistant glioblastoma grade IV cells. Immunofluorescence was used., Results: 11 C-MET specific activity bound to membrane was 9.0%-11.1% and that internalized was 88.9%-91.0%. 11 C-DED specific activity bound to membrane was 34.8%-58.0% and that internalized was 38.7%-65.2%. Immunocytochemistry revealed GFAP and MAO B expression., Conclusions: The expression of MAO B measured by 11 C-DED uptake or immunocytochemistry was not significantly different in grade III or IV cells. The GFAP signal was higher for grade IV compared to grade III. 11 C-MET uptake was high in all the tumor cells. 11 C-DED is a dopamine analogue and the transport across cell membranes is expected to be mediated by DAT receptors present in astrocytes. Reactive astrocytes surround tumor lesions; so the authors suggest that the 11 C-DED uptake might be caused by the reactive astrocytosis and not by MAO B expression in tumor cells.

Gliomas are among the most lethal cancers, being highly resistant to both chemo- and radiotherapy. The expression of junctional adhesion molecule-A (JAM-A) was recently identified on the surface of stem cell-like brain tumor-initiating cells and suggested to function as a unique glioblastoma niche adhesion factor influencing the tumorigenic potential of brain tumor-initiating cells. We have recently identified high JAM-A expression to be associated with poor outcome in glioblastomas, and our aim was to further investigate the expression of JAM-A in gliomas focusing especially on the prognostic value in WHO grade II and III gliomas. JAM-A protein expression was evaluated by immunohistochemistry and advanced quantitative image analysis with continuous estimates of staining intensity. The JAM-A antibody stained tumor cell membranes and cytoplasm to various extent in different glioma subtypes, and the intensity was higher in glioblastomas than low-grade gliomas. We could not detect an association with overall survival in patients with grade II and III tumors. Double-immunofluorescence stainings in glioblastomas revealed co-expression of JAM-A with CD133, SOX2, nestin, and GFAP in tumor cells as well as some co-expression with the microglial/macrophage marker IBA-1. In conclusion, JAM-A expression was higher in glioblastomas compared to low-grade gliomas and co-localized with recognized stem cell markers suggesting an association of JAM-A with glioma aggressiveness. No significant association between JAM-A expression and overall survival was found in grade II and III gliomas. Further research is needed to determine the function and clinical impact of JAM-A in gliomas.

The perivascular niche is critical for intercellular communication between resident cell types in glioblastoma (GBM), and it plays a vital role in maintaining the glioma stem cell (GSC) microenvironment. It is shown in abundant research that different microvascular patterns exist in GBM; and it can be implied that different microvascular patterns are associated with different pathological structures in the perivascular niche. However, the pathological structure of the perivascular niche is still not clear. Here, we investigated the distribution and biological characteristics of different microvascular pattern niches (MVPNs) in GBM by detecting the expression of CD34, CD133, Nestin, α-SMA, GFAP and CD14 in the perivascular niche using multiple -fluorescence. The four basic microvascular patterns are microvascular sprouting (MS), vascular cluster (VC), vascular garland (VG), and glomeruloid vascular proliferation (GVP). By analyzing the proportion of the area of each marker in four types of formations, the results indicated that the expression of CD34, CD133 and Nestin in MS and VC was significantly lower than that in VG and GVP (P<0.05). Furthermore, the results showed that α-SMA expression different in the MS, VC, VG and GVP (P<0.05). However, the expression of GFAP and CD14 in each type of formation exhibited no significant difference (P>0.05). According to the area distributions of different markers, we mapped four precise simulation diagrams to provide an effective foundation for the accurate simulation of glioblastoma in vitro.

Glioblastoma is an aggressive, often recalcitrant disease. In the majority of cases, prognosis is dismal and current therapies only moderately prolong survival. Immunotherapy is increasingly being recognized as an effective treatment modality. CD70 is a transmembrane protein that shows restricted expression in tissue but has been described in various malignancies. Therapeutic targeting of CD70 has demonstrated antitumor efficacy and is in clinical trials. Here, we sought to characterize CD70 expression in a large cohort of gliomas (n = 205) using tissue microarrays. We identified a subset of tumors (n = 18, 8.8% of high-grade gliomas) exhibiting moderate-to-strong immunoreactivity that enriched for the IDH-wild-type glioblastoma variants gliosarcoma (n = 10) and the newly described epithelioid glioblastoma (n = 4). CD70 expression was associated with prolonged survival in gliosarcoma. Analysis of TCGA datasets showed significantly increased CD70 expression in mesenchymal tumors and prolonged survival in recurrent non-G-CIMP high-expressing tumors. In CD70+ gliomas, there was a significant increase in CD68/CD163/HLA-DR+ tumor-associated macrophages, but not CD27+ TIL. These results confirm prior in vitro studies and demonstrate expression in a clinical cohort. The absence of CD70 expression in the post-treatment setting may portend more clinically aggressive disease in gliosarcoma. However, larger-scale studies will be needed to characterize and validate this relationship., (2017 American Association of Neuropathologists, Inc. This work is written by US Government employees and is in the public domain in the US.)

Glioblastoma (GB) is the most common cancer in the brain and with an increasing incidence. Despite major advances in the field, there is no curative therapy for GB to date. Many solid tumors, including GB, experienced metabolic reprogramming in order to sustain uncontrolled proliferation, hypoxic conditions, and angiogenesis. PPARs, member of the steroid hormone receptor superfamily, are particularly involved in the control of energetic metabolism, particularly lipid metabolism, which has been reported deregulated in gliomas. PPARα was previously indicated by us as a potential therapeutic target for this neoplasm, due to the malignancy grade dependency of its expression, being particularly abundant in GB. In this work, we used a new PPARα antagonist on patient-derived GB primary cells, with particular focus on the effects on lipid metabolism and response to radiotherapy. The results obtained demonstrated that blocking PPARα results in cell death induction, increase of radiosensitivity, and decrease of migration. Therefore, AA452 is proposed as a new adjuvant for the gold standard therapies for GB, opening the possibility for preclinical and clinical trials for this class of compounds. J. Cell. Physiol. 232: 1458-1466, 2017. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Neurogenesis is a highly-regulated process occurring in the dentate gyrus that has been linked to learning, memory, and antidepressant efficacy. MicroRNAs (miRNAs) have been previously shown to play an important role in the regulation of neuronal development and neurogenesis in the dentate gyrus via modulation of gene expression. However, this mode of regulation is both incompletely described in the literature thus far and highly multifactorial. In this study, we designed sensors and detected relative levels of expression of 10 different miRNAs and found miR-338-3p was most highly expressed in the dentate gyrus. Comparison of miR-338-3p expression with neuronal markers of maturity indicates miR-338-3p is expressed most highly in the mature neuron. We also designed a viral "sponge" to knock down in vivo expression of miR-338-3p. When miR-338-3p is knocked down, neurons sprout multiple primary dendrites that branch off of the soma in a disorganized manner, cellular proliferation is upregulated, and neoplasms form spontaneously in vivo. Additionally, miR-338-3p overexpression in glioblastoma cell lines slows their proliferation in vitro. Further, low miR-338-3p expression is associated with increased mortality and disease progression in patients with glioblastoma. These data identify miR-338-3p as a clinically relevant tumor suppressor in glioblastoma.

Introduction: Tuberous sclerosis is associated with three central nervous system pathologies: cortical/subcortical tubers, subependymal nodules (SENs), and subependymal giant cell astrocytomas (SEGAs). Tubers are associated with epilepsy, which is often medication-resistant and often leads to resective surgery. Recently, mammalian target of rapamycin inhibitors (mTORi) have been shown to be effective reducing seizure burden in some patients with tuberous sclerosis complex (TSC)-related refractory epilepsy. mTORi have also been shown to be an alternative for surgery treating SEGAs. We describe several cases of resected tubers that contained SEGA tissue without an intraventricular SEGA., Methods: After institutional review board (IRB) protocol approval, we retrospectively reviewed the surgical-pathological data for all TSC patients who underwent cortical resections for treatment of refractory epilepsy at NYU Langone Medical Center and Tel Aviv Medical Center between 2003 and 2013. Data included demographics, epilepsy type, MRI characteristics, epilepsy outcome, and histopathological staining., Results: We reviewed cortical resections from 75 patients with complete pathological studies. In three patients, cortical lesions demonstrated histopathological findings consistent with a SEGA within the resected tuber tissue, with no intraventricular SEGA. All lesions were cortically based and none had any intraventricular extension. No patient had been treated before surgery with an mTORi. Two of the three patients remain Engel grade I-II. All lesions stained positive for glial fibrillary acidic protein (GFAP), synaptophysin, and neuronal nuclear antigen (NeuN)., Conclusion: This is the first description of cortical tubers harboring SEGA tissue. This observation though preliminary may suggest a subgroup of patients with intractable epilepsy in whom mTORi may be considered before surgical intervention.

Epileptogenic tumors affecting children and young adults are a morphologically diverse collection of neuroepithelial neoplasms that, as a group, exhibit varying levels of glial and/or neuronal differentiation. Recent advances in molecular profiling technology, including comprehensive DNA sequencing and methylation analysis, have enabled the application of more precise and biologically relevant classification schemes to these tumors. In this report, we describe a morphologically and molecularly distinct epileptogenic neoplasm, the polymorphous low-grade neuroepithelial tumor of the young (PLNTY), which likely accounts for a sizable portion of oligodendroglioma-like tumors affecting the pediatric population. Characteristic microscopic findings most notably include infiltrative growth, the invariable presence of oligodendroglioma-like cellular components, and intense immunolabeling for cluster of differentiation 34 (CD34). Moreover, integrative molecular profiling reveals a distinct DNA methylation signature for PLNTYs, along with frequent genetic abnormalities involving either B-Raf proto-oncogene (BRAF) or fibroblast growth factor receptors 2 and 3 (FGFR2, FGFR3). These findings suggest that PLNTY represents a distinct biological entity within the larger spectrum of pediatric, low-grade neuroepithelial tumors.

Background: The pathophysiologies underlying meningioma and glioma are distinct. The coexistence of those 2 lesions in the same patient is rare, and at the same location, it is even more exceptional., Case Description: We report a case of a 79-year-old man initially presenting with a meningioma that was treated by complete excision of the lesion. The patient had 2 relapses at the same site, in which glioblastoma was confirmed histopathologically., Conclusions: Glial transformation meningiomas remain a contentious issue, with coincidental occurrence being the most prevalent explanation. Nevertheless, impairment of the same molecular signaling pathways in both tumor types suggests a common origin. Another hypothesis is that perilesional parenchymal damage from radiotherapy or surgery may lead to glial transformation in the tissues surrounding the original meningioma lesion. Further research is needed to determine if the original tumor or surgery has an oncogenic effect on the adjacent tissue., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Pilocytic astrocytoma (PA) is a benign neoplasm that typically occurs in the brain within the pediatric and adolescent age groups and is uncommon in adults. It rarely occurs within the ventricles, and the overall prognosis is favorable. A PA of the brain with spinal metastasis at presentation has never been reported in an adult., Case Description: We report a case of a 47-year-old man presenting with sudden-onset frontal headache associated with nausea and lethargy in addition to a background of a longer history of back pain and headache. Radiologic imaging revealed an acute intraparenchymal hemorrhage in the right parieto-occipital lobes with intraventricular extension within a peripherally enhancing heterogeneous lesion. Magnetic resonance imaging of the spine revealed a sacral intradural tumor. The patient underwent surgical resection of the intracranial mass followed by debulking of the spinal lesion. Histopathologic study revealed that both the cranial and spinal tumors were PA., Conclusions: This case illustrates a unique instance of hemorrhage into a cerebral PA with a spinal metastasis. To our knowledge, this is the first such case reported in an adult. We review the literature on the subject., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The identity of the glioblastoma (GBM) cell of origin and its contributions to disease progression and treatment response remain largely unknown. We have analyzed how the phenotypic state of the initially transformed cell affects mouse GBM development and essential GBM cell (GC) properties. We find that GBM induced in neural stem-cell-like glial fibrillary acidic protein (GFAP)-expressing cells in the subventricular zone of adult mice shows accelerated tumor development and produces more malignant GCs (mGC1 GFAP ) that are less resistant to cancer drugs, compared with those originating from more differentiated nestin- (mGC2 NES ) or 2,'3'-cyclic nucleotide 3'-phosphodiesterase (mGC3 CNP )-expressing cells. Transcriptome analysis of mouse GCs identified a 196 mouse cell origin (MCO) gene signature that was used to partition 61 patient-derived GC lines. Human GC lines that clustered with the mGC1 GFAP cells were also significantly more self-renewing, tumorigenic, and sensitive to cancer drugs compared with those that clustered with mouse GCs of more differentiated origin., (Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.)

Glioblastoma multiforme (GBM) is among the most aggressive of human cancers. Although differentiation therapy has been proposed as a potential approach to treat GBM, the mechanisms of induced differentiation remain poorly defined. Here, we established an induced differentiation model of GBM using cAMP activators that specifically directed GBM differentiation into astroglia. Transcriptomic and proteomic analyses revealed that oxidative phosphorylation and mitochondrial biogenesis are involved in induced differentiation of GBM. Dibutyryl cyclic AMP (dbcAMP) reverses the Warburg effect, as evidenced by increased oxygen consumption and reduced lactate production. Mitochondrial biogenesis induced by activation of the CREB-PGC1α pathway triggers metabolic shift and differentiation. Blocking mitochondrial biogenesis using mdivi1 or by silencing PGC1α abrogates differentiation; conversely, overexpression of PGC1α elicits differentiation. In GBM xenograft models and patient-derived GBM samples, cAMP activators also induce tumor growth inhibition and differentiation. Our data show that mitochondrial biogenesis and metabolic switch to oxidative phosphorylation drive the differentiation of tumor cells., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Oligodendrogliomas are diffuse gliomas characterised by IDH mutation and 1p/19q co-deletion. Classical oligodendrocytes, minigemistocytes, gliofibrillary oligodendrocytes, granular cells, and mucocytes are morphologic cell types described in oligodendroglioma. Even though the occurrence of granular cells in oligodendroglioma is known, exact nature of these cells and their molecular characteristics remain undetermined. We describe a case of oligodendroglioma with granular cells, in which we have attempted to molecularly characterise the granular cells. These granules were stained blue on Luxol fast blue and red on Masson's trichrome. The cells showed a distinct pattern of immunoreactivity to GFAP and IDH1. In addition, they exhibited mitotic activity and increased Ki-67 labelling. Molecularly, both the granular cells and classical oligodendroglial cells in the tumor showed 1p/19q co-deletion which is the diagnostic hallmark of an oligodendroglioma. Thus, we opine that granular cells are neoplastic and represent a morphological variant of neoplastic oligodendrocyte.

Glioneuronal tumor with neuropil-like islands (GTNI) is a rare, recently described neoplasm, whose pathogenesis has not been studied extensively. The role of ATRX mutations, a class-defining alteration in diffuse astrocytic neoplasms, has not been assessed in GTNIs previously. We therefore aimed to assess the status of ATRX, along with IDH1, 1p/19q and p53, in cases of GTNI in order to evaluate the molecular profile of these tumors. All cases of GTNI diagnosed at our Institute were retrieved and clinicopathological features were reviewed. Immunohistochemistry for ATRX, IDH1 and p53 was performed. We identified four cases of GTNI, majority of which occurred in young adults. Loss of ATRX immunoexpression, a surrogate marker for ATRX mutation, was seen in all four cases. All cases were immunopositive for p53, while IDH1 positivity was seen in all three cases assessed. 1p/19q codeletion was absent in the three cases analyzed. These results indicate that the molecular pathogenesis of GTNIs similar to that of diffuse astrocytic tumors. Further, the loss of ATRX expression is seen in both the glial as well as neuronal components, indicating that both arise from the same tumor stem/progenitor cell and that the latter may be a metaplastic change. Thus, loss of ATRX immunoexpression, shown for the first time in these tumors, along with immunopositivity for p53 and IDH1, indicates that these tumors are molecular astrocytomas, and their clinical behaviour is likely to recapitulate that of ATRX-mutant and IDH-mutant diffuse astrocytomas of the same grade.

Although stereotactic radiosurgery (SRS) is effective for central neurocytoma (CN), the long-term outcome of SRS remains unclear. We present a case of recurrent CN that was diagnosed 10years after surgical resection and consecutive stereotactic radiotherapy. The patient was treated with SRS for the recurrent tumor, but underwent two-staged surgery once again due to rapid tumor growth. Histological features of the recurrent tumor were consistent with the diagnosis of CN. However, an increased Ki-67 proliferation index (3.4%), aberrant angiogenesis and glial differentiation of the tumor cells were observed, which were not identified in the initial CN. In addition, vascular endothelial growth factor (VEGF) and VEGF receptor were highly expressed in the recurrent tumor cells, as well as in the vascular endothelial cells. Our case suggests that malignant transition with aberrant angiogenesis and glial differentiation may be attributable to SRS., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objective: To investigate the clinicopathologic features of glioneuronal tumor with neuropil-like island (GTNI)., Methods: Four cases of intracranial and spinal GTNI, including three cases of WHO grade Ⅲ, and one case of WHO grade Ⅱ with grade Ⅲ recurrence. HE and immunohistochemical (IHC) staining were used for pathologic analysis. Fluorescence in situ hybridization (FISH) was used to detect tumor genetic changes. Related literatures were reviewed., Results: Microscopically, neuropil-like islands of varying sizes were seen within a background of glial proliferation, which showed features of astrocytoma or oligoastrocytoma. Neuropil-like islands were focal or circumscribed oval islands of varying sizes. Focally ganglion-like cells were seen. IHC staining revealed that in neuropil-like island area, the neuronal nuclei (Neu-N) as well as the cells around the neuropil-like island expressed oligodendrocyte lineage transcription factor-2 (Olig-2), and synaptophysin. The background glioma cells expressed S-100, glial fibrillary acidic protein (GFAP), vimentin and Olig-2, and the number of p53 positive cells was 10%-50%.In the neuropil-like island area, the Ki-67 labeling index was less than 3%, while in the astrocytoma area it was around 10%-25%.By FISH testing, four cases were no deletion of 1p/19q and PTEN, also no amplification of epidermal growth factor receptor., Conclusions: GTNI is more common in adults. 1p/19q deletions are uncommon in GTNI, only seen in a few cases with background oligodendroglioma. The prognosis is related to WHO grading. GTNI often recurs locally, and the prognosis is not good, especially in the spinal cord GTNI. The recommended treatment includes tumor resection combined with radiotherapy and chemotherapy.

Glioblastoma multiforme (GBM) are the most common primary malignant brain tumor in adults, with a median survival of about one year. This poor prognosis is attributed primarily to therapeutic resistance and tumor recurrence after surgical removal, with the root cause suggested to be found in glioblastoma stem cells (GSCs). Using glial fibrillary acidic protein (GFAP) as a reporter of astrocytic differentiation, we isolated multiple clones from three independent GSC lines which express GFAP in a remarkably stable fashion. We next show that elevated expression of GFAP is associated with reduced clonogenicity in vitro and tumorigenicity in vivo. Utilizing this in vitro cell-based differentiation reporter system we screened chemical libraries and identified the non-depolarizing neuromuscular blocker (NNMB), Atracurium Besylate, as a small molecule which effectively induces astroglial but not neuronal differentiation of GSCs. Functionally, Atracurium Besylate treatment significantly inhibited the clonogenic capacity of several independent patient-derived GSC neurosphere lines, a phenomenon which was largely irreversible. A second NNMB, Vecuronium, also induced GSC astrocytic differentiation while Dimethylphenylpiperazinium (DMPP), a nicotinic acetylcholine receptor (nAChR) agonist, significantly blocked Atracurium Besylate pro-differentiation activity. To investigate the clinical importance of nAChRs in gliomas, we examined clinical outcomes and found that glioma patients with tumors overexpressing CHRNA1 or CHRNA9 (encoding for the AChR-α1 or AChR-α9) exhibit significant shorter overall survival. Finally, we found that ex-vivo pre-treatment of GSCs, expressing CHRNA1 and CHRNA9, with Atracurium Besylate significantly increased the survival of mice xenotransplanted with these cells, therefore suggesting that tumor initiating subpopulations have been reduced.