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The advent of high-dimensional imaging offers new opportunities to molecularly characterize diagnostic cells in disorders that have previously relied on histopathological definitions. One example case is found in tuberous sclerosis complex (TSC), a developmental disorder characterized by systemic growth of benign tumors. Within resected brain tissues from patients with TSC, detection of abnormally enlarged balloon cells (BCs) is pathognomonic for this disorder. Though BCs can be identified by an expert neuropathologist, little is known about the specificity and broad applicability of protein markers for these cells, complicating classification of proposed BCs identified in experimental models of this disorder. Here, we report the development of a customized machine learning pipeline (BAlloon IDENtifier; BAIDEN) that was trained to prospectively identify BCs in tissue sections using a histological stain compatible with high-dimensional cytometry. This approach was coupled to a custom 36-antibody panel and imaging mass cytometry (IMC) to explore the expression of multiple previously proposed BC marker proteins and develop a descriptor of BC features conserved across multiple tissue samples from patients with TSC. Here, we present a modular workflow encompassing BAIDEN, a custom antibody panel, a control sample microarray, and analysis pipelines-both open-source and in-house-and apply this workflow to understand the abundance, structure, and signaling activity of BCs as an example case of how high-dimensional imaging can be applied within human tissues., (© 2024 The Author(s). Cytometry Part B: Clinical Cytometry published by Wiley Periodicals LLC on behalf of International Clinical Cytometry Society.)

Papillary tumor of the pineal region (PTPR) is an uncommon tumor of the pineal region with distinctive histopathologic and molecular characteristics. Experience is limited with respect to its molecular heterogeneity and clinical characteristics. Here, we describe 39 new cases and combine these with 37 previously published cases for a cohort of 76 PTPR's, all confirmed by methylation profiling. As previously reported, two main methylation groups were identified (PTPR-A and PTPR-B). In our analysis we extended the subtyping into three subtypes: PTPR-A, PTPR-B1 and PTPR-B2 supported by DNA methylation profile and genomic copy number variations. Frequent loss of chromosome 3 or 14 was found in PTPR-B1 tumors but not in PTPR-B2. Examination of clinical outcome showed that nearly half (14/30, 47%) of examined patients experienced tumor progression with significant difference among the subtypes (p value = 0.046). Our analysis extends the understanding of this uncommon but distinct neuroepithelial tumor by describing its molecular heterogeneity and clinical outcomes, including its tendency towards tumor recurrence., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Age-related atrophy of skeletal muscle, is characterized by loss of mass, strength, endurance, and oxidative capacity during aging. Notably, bioenergetics and protein turnover studies have shown that mitochondria mediate this decline in function. Although exercise has been the only therapy to mitigate sarcopenia, the mechanisms that govern how exercise serves to promote healthy muscle aging are unclear. Mitochondrial aging is associated with decreased mitochondrial capacity, so we sought to investigate how aging affects mitochondrial structure and potential age-related regulators. Specifically, the three-dimensional (3D) mitochondrial structure associated with morphological changes in skeletal muscle during aging requires further elucidation. We hypothesized that aging causes structural remodeling of mitochondrial 3D architecture representative of dysfunction, and this effect is mitigated by exercise. We used serial block-face scanning electron microscopy to image human skeletal tissue samples, followed by manual contour tracing using Amira software for 3D reconstruction and subsequent analysis of mitochondria. We then applied a rigorous in vitro and in vivo exercise regimen during aging. Across 5 human cohorts, we correlate differences in magnetic resonance imaging, mitochondria 3D structure, exercise parameters, and plasma immune markers between young (under 50 years) and old (over 50 years) individuals. We found that mitochondria we less spherical and more complex, indicating age-related declines in contact site capacity. Additionally, aged samples showed a larger volume phenotype in both female and male humans, indicating potential mitochondrial swelling. Concomitantly, muscle area, exercise capacity, and mitochondrial dynamic proteins showed age-related losses. Exercise stimulation restored mitofusin 2 (MFN2), one such of these mitochondrial dynamic proteins, which we show is required for the integrity of mitochondrial structure. Furthermore, we show that this pathway is evolutionarily conserved as Marf, the MFN2 ortholog in Drosophila , knockdown alters mitochondrial morphology and leads to the downregulation of genes regulating mitochondrial processes. Our results define age-related structural changes in mitochondria and further suggest that exercise may mitigate age-related structural decline through modulation of mitofusin 2., Competing Interests: Competing Interests Disclosure All authors have no competing interests.

Background and Objective: Primary angiitis of the central nervous system (PACNS) is a rare form of vasculitis solely affecting the vessels of the brain, spinal cord, and leptomeninges. A range of magnetic resonance imaging (MRI) features have been associated with PACNS, including cerebral infarction, hemorrhage, and parenchymal or leptomeningeal contrast enhancement., Methods and Results: We describe a 51-year-old man with a case of PACNS manifesting as akinetic mutism with progressive leukoencephalopathy., Discussion: Progressive leukoencephalopathy has not been well defined as a manifestation of PACNS. We review a small number of cases with comparable features, providing additional context on this PACNS manifestation with consideration of clinical subtypes., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Adult IDH-wildtype glioblastoma (GBM) is a highly aggressive brain tumor with no established immunotherapy or targeted therapy. Recently, CD32 + HLA-DR hi macrophages were shown to have displaced resident microglia in GBM tumors that contact the lateral ventricle stem cell niche. Since these lateral ventricle contacting GBM tumors have especially poor outcomes, identifying the origin and role of these CD32 + macrophages is likely critical to developing successful GBM immunotherapies. Here, we identify these CD32 + cells as M_IL-8 macrophages and establish that IL-8 is sufficient and necessary for tumor cells to instruct healthy macrophages into CD32 + M_IL-8 M2 macrophages. In ex vivo experiments with conditioned medium from primary human tumor cells, inhibitory antibodies to IL-8 blocked the generation of CD32 + M_IL-8 cells. Finally, using a set of 73 GBM tumors, IL-8 protein is shown to be present in GBM tumor cells in vivo and especially common in tumors contacting the lateral ventricle. These results provide a mechanistic origin for CD32 + macrophages that predominate in the microenvironment of the most aggressive GBM tumors. IL-8 and CD32 + macrophages should now be explored as targets in combination with GBM immunotherapies, especially for patients whose tumors present with radiographic contact with the ventricular-subventricular zone stem cell niche., Competing Interests: Declaration of interests All authors declare no competing interests.

Therapy resistance and metastatic progression are primary causes of cancer-related mortality. Disseminated tumor cells possess adaptive traits that enable them to reprogram their metabolism, maintain stemness, and resist cell death, facilitating their persistence to drive recurrence. The survival of disseminated tumor cells also depends on their ability to modulate replication stress in response to therapy while colonizing inhospitable microenvironments. In this study, we discovered that the nuclear translocation of AXL, a TAM receptor tyrosine kinase, and its interaction with WRNIP1, a DNA replication stress response factor, promotes the survival of HER2+ breast cancer cells that are resistant to HER2-targeted therapy and metastasize to the brain. In preclinical models, knocking down or pharmacologically inhibiting AXL or WRNIP1 attenuated protection of stalled replication forks. Furthermore, deficiency or inhibition of AXL and WRNIP1 also prolonged metastatic latency and delayed relapse. Together, these findings suggest that targeting the replication stress response, which is a shared adaptive mechanism in therapy-resistant and metastasis-initiating cells, could reduce metachronous metastasis and enhance the response to standard-of-care therapies., Significance: Nuclear AXL and WRNIP1 interact and mediate replication stress response, promote therapy resistance, and support metastatic progression, indicating that targeting the AXL/WRNIP1 axis is a potentially viable therapeutic strategy for breast cancer., (©2024 American Association for Cancer Research.)

Congenital DNA mismatch repair defects (dMMR), such as Lynch Syndrome, predispose patients to a variety of cancers and account for approximately 1% of glioblastoma cases. While few therapeutic options exist for glioblastoma, checkpoint blockade therapy has proven effective in dMMR tumors. Here we present a case study of a male in their 30s diagnosed with dMMR glioblastoma treated with pembrolizumab who experienced a partial response to therapy. Using a multiplex IHC analysis pipeline on archived slide specimens from tumor resections at diagnosis and after therapeutic interventions, we quantified changes in the frequency and spatial distribution of key cell populations in the tumor tissue. Notably, proliferating (KI67+) macrophages and T cells increased in frequency as did other KI67+ cells within the tumor. Therapeutic intervention remodeled the cellular spatial distribution in the tumor leading to a greater frequency of macrophage/tumor cell interactions and T cell/T cell interactions, highlighting impacts of checkpoint blockade on tumor cytoarchitecture and revealing spatial patterns that may indicate advantageous immune interactions in glioma and other solid tumors treated with these agents., Competing Interests: Conflict of Interest Disclosure: DBJ has served on advisory boards or as a consultant for BMS, Catalyst Biopharma, Iovance, Jansen, Mallinckrodt, Merck, Mosaic ImmunoEngineering, Novartis, Oncosec, Pfizer, Targovax, and Teiko, and has received research funding from BMS and Incyte. Declaration of Interests D.B.J. has served on advisory boards or as a consultant for BMS, Catalyst Biopharma, Iovance, Jansen, Mallinckrodt, Merck, Mosaic ImmunoEngineering, Novartis, Oncosec, Pfizer, Targovax, and Teiko, and has received research funding from BMS and Incyte.

This study, utilizing SBF-SEM, reveals structural alterations in mitochondria and myofibrils in human heart failure (HF). Mitochondria in HF show changes in structure, while myofibrils exhibit increased cross-sectional area and branching. Metabolomic and lipidomic analyses indicate concomitant dysregulation in key pathways. The findings underscore the need for personalized treatments considering individualized structural changes in HF., Competing Interests: CONFLICT OF INTEREST The authors declare that they have no conflict of interest.

During aging, muscle gradually undergoes sarcopenia, the loss of function associated with loss of mass, strength, endurance, and oxidative capacity. However, the 3D structural alterations of mitochondria associated with aging in skeletal muscle and cardiac tissues are not well described. Although mitochondrial aging is associated with decreased mitochondrial capacity, the genes responsible for the morphological changes in mitochondria during aging are poorly characterized. We measured changes in mitochondrial morphology in aged murine gastrocnemius, soleus, and cardiac tissues using serial block-face scanning electron microscopy and 3D reconstructions. We also used reverse transcriptase-quantitative PCR, transmission electron microscopy quantification, Seahorse analysis, and metabolomics and lipidomics to measure changes in mitochondrial morphology and function after loss of mitochondria contact site and cristae organizing system (MICOS) complex genes, Chchd3, Chchd6, and Mitofilin. We identified significant changes in mitochondrial size in aged murine gastrocnemius, soleus, and cardiac tissues. We found that both age-related loss of the MICOS complex and knockouts of MICOS genes in mice altered mitochondrial morphology. Given the critical role of mitochondria in maintaining cellular metabolism, we characterized the metabolomes and lipidomes of young and aged mouse tissues, which showed profound alterations consistent with changes in membrane integrity, supporting our observations of age-related changes in muscle tissues. We found a relationship between changes in the MICOS complex and aging. Thus, it is important to understand the mechanisms that underlie the tissue-dependent 3D mitochondrial phenotypic changes that occur in aging and the evolutionary conservation of these mechanisms between Drosophila and mammals., (© 2023 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.)

With sparse treatment options, cardiac disease remains a significant cause of death among humans. As a person ages, mitochondria breakdown and the heart becomes less efficient. Heart failure is linked to many mitochondria-associated processes, including endoplasmic reticulum stress, mitochondrial bioenergetics, insulin signaling, autophagy, and oxidative stress. The roles of key mitochondrial complexes that dictate the ultrastructure, such as the mitochondrial contact site and cristae organizing system (MICOS), in aging cardiac muscle are poorly understood. To better understand the cause of age-related alteration in mitochondrial structure in cardiac muscle, we used transmission electron microscopy (TEM) and serial block facing-scanning electron microscopy (SBF-SEM) to quantitatively analyze the three-dimensional (3-D) networks in cardiac muscle samples of male mice at aging intervals of 3 mo, 1 yr, and 2 yr. Here, we present the loss of cristae morphology, the inner folds of the mitochondria, across age. In conjunction with this, the three-dimensional (3-D) volume of mitochondria decreased. These findings mimicked observed phenotypes in murine cardiac fibroblasts with CRISPR/Cas9 knockout of Mitofilin, Chchd3, Chchd6 (some members of the MICOS complex), and Opa1 , which showed poorer oxidative consumption rate and mitochondria with decreased mitochondrial length and volume. In combination, these data show the need to explore if loss of the MICOS complex in the heart may be involved in age-associated mitochondrial and cristae structural changes. NEW & NOTEWORTHY This article shows how mitochondria in murine cardiac changes, importantly elucidating age-related changes. It also is the first to show that the MICOS complex may play a role in outer membrane mitochondrial structure.

Radiographic contact of glioblastoma (GBM) tumors with the lateral ventricle and adjacent stem cell niche correlates with poor patient prognosis, but the cellular basis of this difference is unclear. Here, we reveal and functionally characterize distinct immune microenvironments that predominate in subtypes of GBM distinguished by proximity to the lateral ventricle. Mass cytometry analysis of isocitrate dehydrogenase wild-type human tumors identified elevated T cell checkpoint receptor expression and greater abundance of a specific CD32+CD44+HLA-DRhi macrophage population in ventricle-contacting GBM. Multiple computational analysis approaches, phospho-specific cytometry, and focal resection of GBMs validated and extended these findings. Phospho-flow quantified cytokine-induced immune cell signaling in ventricle-contacting GBM, revealing differential signaling between GBM subtypes. Subregion analysis within a given tumor supported initial findings and revealed intratumor compartmentalization of T cell memory and exhaustion phenotypes within GBM subtypes. Collectively, these results characterize immunotherapeutically targetable features of macrophages and suppressed lymphocytes in GBMs defined by MRI-detectable lateral ventricle contact.

Disseminated tumor cells with metabolic flexibility to utilize available nutrients in distal organs persist, but the precise mechanisms that facilitate metabolic adaptations remain unclear. Here we show fragmented mitochondrial puncta in latent brain metastatic (Lat) cells enable fatty acid oxidation (FAO) to sustain cellular bioenergetics and maintain redox homeostasis. Depleting the enriched dynamin-related protein 1 (DRP1) and limiting mitochondrial plasticity in Lat cells results in increased lipid droplet accumulation, impaired FAO and attenuated metastasis. Likewise, pharmacological inhibition of DRP1 using a small-molecule brain-permeable inhibitor attenuated metastatic burden in preclinical models. In agreement with these findings, increased phospho-DRP1 expression was observed in metachronous brain metastasis compared with patient-matched primary tumors. Overall, our findings reveal the pivotal role of mitochondrial plasticity in supporting the survival of Lat cells and highlight the therapeutic potential of targeting cellular plasticity programs in combination with tumor-specific alterations to prevent metastatic recurrences., (© 2023. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Astroblastomas (ABs) are rare brain tumors of unknown origin. We performed an integrative genetic and epigenetic analysis of AB-like tumors. Here, we show that tumors traceable to neural stem/progenitor cells (radial glia) that emerge during early to later brain development occur in children and young adults, respectively. Tumors with MN1-BEND2 fusion appear to present exclusively in females and exhibit overexpression of genes expressed prior to 25 post-conception weeks (pcw), including genes enriched in early ventricular zone radial glia and ependymal tumors. Other, histologically classic ABs overexpress or harbor mutations of mitogen-activated protein kinase pathway genes, outer and truncated radial glia genes, and genes expressed after 25 pcw, including neuronal and astrocyte markers. Findings support that AB-like tumors arise in the context of epigenetic and genetic changes in neural progenitors. Selective gene fusion, variable imprinting and/or chromosome X-inactivation escape resulting in biallelic overexpression may contribute to female predominance of AB molecular subtypes., (© 2022. The Author(s).)

HER2+ breast cancer patients are presented with either synchronous (S-BM), latent (Lat), or metachronous (M-BM) brain metastases. However, the basis for disparate metastatic fitness among disseminated tumor cells of similar oncotype within a distal organ remains unknown. Here, employing brain metastatic models, we show that metabolic diversity and plasticity within brain-tropic cells determine metastatic fitness. Lactate secreted by aggressive metastatic cells or lactate supplementation to mice bearing Lat cells limits innate immunosurveillance and triggers overt metastasis. Attenuating lactate metabolism in S-BM impedes metastasis, while M-BM adapt and survive as residual disease. In contrast to S-BM, Lat and M-BM survive in equilibrium with innate immunosurveillance, oxidize glutamine, and maintain cellular redox homeostasis through the anionic amino acid transporter xCT. Moreover, xCT expression is significantly higher in matched M-BM brain metastatic samples compared to primary tumors from HER2+ breast cancer patients. Inhibiting xCT function attenuates residual disease and recurrence in these preclinical models., Competing Interests: Declaration of interests A.B.H. has received research grant support from Takeda and travel support from Puma Biotechnology. C.L.A. receives or has received research grant support from Pfizer, Lilly, and Takeda; holds stock options in Provista and Y-TRAP; and serves or has served in an advisory role to Novartis, Lilly, TAIHO Oncology, Daiichi Sankyo, Merck, AstraZeneca, OrigiMed, Immunomedics, and Susan G. Komen Foundation. R.J.D. is a founder of Atavistik Biosciences and an advisor for Agios Pharmaceuticals, Nirogy Therapeutics, and Vida Ventures., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose: IDH mutations in low-grade gliomas (LGGs) results in improved survival and DNA hypermethylation compared to IDH wild-type LGGs. IDH -mutant LGGs become hypomethylated during progression. It's uncertain if methylation changes occur during IDH wild-type GBM progression and if the methylome can be reprogrammed. This phase I study evaluated the safety, tolerability, efficacy and methylome changes after L-methylfolate (LMF) treatment, in combination with temozolomide and bevacizumab in patients with recurrent high-grade glioma., Patients and Methods: Fourteen patients total, 13 with GBM, one with anaplastic astrocytoma, all IDH wild-type were enrolled in the study. All patients received LMF at either 15, 30, 60, or 90 mg daily plus temozolomide (75mg/m 2 5 days per month) and bevacizumab (10mg/kg every two weeks)., Results: No MTD was identified. LMF treated had mOS of 9.5 months (95% CI, 9.1-35.4) comparable to bevacizumab historical control 8.6 months (95% CI, 6.8-10.8). Six patients treated with LMF survived more than 650 days. Across all treatment doses the most adverse events were diarrhea (7%, 1 patient, grade 2), reflux (7%, 1 patient, grade 2), and dysgeusia (7%, 1 patient, grade 2). In the six brains donated at death, there was a 25% increase in DNA methylated CpGs compared to the paired initial tumor., Conclusions: LMF in combination with temozolomide and bevacizumab was well tolerated in patients with recurrent IDH wild-type high-grade glioma. This small study did not establish a superior efficacy with addition of LMF compared to standard bevacizumab therapy, however, this study did show methylome reprogramming in high-grade glioma., Competing Interests: Disclosure of Potential Conflicts of Interest The authors declare no competing financial interests.

The neural stem cell niche of the ventricular-subventricular zone supports the persistence of stem and progenitor cells in the mature brain. This niche has many notable cytoarchitectural features that affect the activity of stem cells and may also support the survival and growth of invading tumor cells. Histochemical studies of the niche have revealed many proteins that, in combination, can help to reveal stem-like cells in the normal or cancer context, although many caveats persist in the quest to consistently identify these cells in the human brain. Here, we explore the complex relationship between the persistent proliferative capacity of the neural stem cell niche and the malignant proliferation of brain tumors, with a special focus on histochemical identification of stem cells and stem-like tumor cells and an eye toward the potential application of high-dimensional imaging approaches to the field.

Background: We examined the effect of dexamethasone prescribed in the initial 3 postoperative weeks on survival, steroid dependency, and infection in glioblastoma patients., Methods: In this single-center retrospective cohort analysis, we electronically retrieved inpatient administration and outpatient prescriptions of dexamethasone and laboratory values from the medical record of 360 glioblastoma patients. We correlated total dexamethasone prescribed from postoperative day (POD) 0 to 21 with survival, dexamethasone prescription from POD30 to POD90, and diagnosis of an infection by POD90. These analyses were adjusted for age, Karnofsky performance status score, tumor volume, extent of resection, IDH1/2 tumor mutation, tumor MGMT promoter methylation, temozolomide and radiotherapy initiation, and maximum blood glucose level., Results: Patients were prescribed a median of 159 mg [109-190] of dexamethasone cumulatively by POD21. Every 16-mg increment (4 mg every 6 hours/day) of total dexamethasone associated with a 4% increase in mortality (95% confidence interval [CI] 1%-7%, P < .01), 12% increase in the odds of being prescribed dexamethasone from POD30 to POD90 (95% CI 6%-19%, P < .01), and 10% increase in the odds of being diagnosed with an infection (95% CI, 4%-17%, P < .01). Of the 175 patients who had their absolute lymphocyte count measured in the preoperative week, 80 (45.7%) had a value indicative of lymphopenia. In the POD1-POD28 period, this proportion was 82/167 (49.1%)., Conclusions: Lower survival, steroid dependency, and higher infection rate in glioblastoma patients associated with higher dexamethasone administration in the initial 3 postoperative weeks. Nearly half of the glioblastoma patients are lymphopenic preoperatively and up to 1 month postoperatively., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Neuro-Oncology and the European Association of Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: We conducted a segmental volumetric analysis of pre-operative brain magnetic resonance images (MRIs) of glioblastoma patients to identify brain- and tumor-related features that are prognostic of survival., Methods: Using a dataset of 210 single-institutional adult glioblastoma patients, total volumes of the following tumor- and brain-related features were quantified on pre-operative MRIs using a fully automated segmentation tool: tumor enhancement, tumor non-enhancement, tumor necrosis, peri-tumoral edema, grey matter, white matter, and cerebrospinal fluid (CSF). Their association with survival using Cox regression models, adjusting for the well-known predictors of glioblastoma survival. The findings were verified in a second dataset consisting of 96 glioblastoma patients from The Cancer Imaging Archive and The Cancer Genome Atlas (TCIA/TCGA)., Results: CSF volume and edema were independently and consistently associated with overall survival of glioblastoma patients in both datasets. Greater edema was associated with increased hazard or decreased survival [adjusted hazard ratio (aHR) with 95% confidence interval (CI): 1.34 [1.08-1.67], p = 0.008 (institutional dataset); and, 1.44 [1.08-1.93], p = 0.013 (TCIA/TCGA dataset)]. Greater CSF volume also correlated with increased hazard or decreased survival [aHR 1.27 [1.02-1.59], p = 0.035 (institutional dataset), and 1.42 [1.03-1.95], p = 0.032 (TCIA/TCGA dataset)]., Conclusions: Higher brain CSF volume and higher edema levels at diagnosis are independently associated with decreased survival in glioblastoma patients. These results highlight the importance of a broader, quantitative brain-wide radiological analyses and invite investigations to understand tumor-related causes of increased edema and possibly increased CSF volume., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

One goal of precision medicine is to identify mutations within individual tumors to design targeted treatment approaches. This report details the use of genomic testing to select a targeted therapy regimen of erlotinib and rapamycin for a pediatric anaplastic oligodendroglioma refractory to standard treatment, achieving a 33-month sustained response. Immunohistochemical analysis of total and phosphorylated protein isoforms showed abnormal signaling consistent with detected mutations, while revealing heterogeneity in per-cell activation of signaling pathways in multiple subpopulations of tumor cells throughout the course of disease. This case highlights molecular features that may be relevant to designing future targeted treatments., (© 2020 Wiley Periodicals LLC.)

A goal of cancer research is to reveal cell subsets linked to continuous clinical outcomes to generate new therapeutic and biomarker hypotheses. We introduce a machine learning algorithm, Risk Assessment Population IDentification (RAPID), that is unsupervised and automated, identifies phenotypically distinct cell populations, and determines whether these populations stratify patient survival. With a pilot mass cytometry dataset of 2 million cells from 28 glioblastomas, RAPID identified tumor cells whose abundance independently and continuously stratified patient survival. Statistical validation within the workflow included repeated runs of stochastic steps and cell subsampling. Biological validation used an orthogonal platform, immunohistochemistry, and a larger cohort of 73 glioblastoma patients to confirm the findings from the pilot cohort. RAPID was also validated to find known risk stratifying cells and features using published data from blood cancer. Thus, RAPID provides an automated, unsupervised approach for finding statistically and biologically significant cells using cytometry data from patient samples., Competing Interests: NL, JS, AM, SB, AB, KD, AG, KW, RT, LC, BM, RI No competing interests declared, JI was a co-founder and a board member of Cytobank Inc and received research support from Incyte Corp, Janssen, and Pharmacyclics, (© 2020, Leelatian et al.)

Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer that does not respond to endocrine therapy or human epidermal growth factor receptor 2 (HER2)-targeted therapies. Individuals with TNBC experience higher rates of relapse and shorter overall survival compared to patients with receptor-positive breast cancer subtypes. Preclinical discoveries are needed to identify, develop, and advance new drug targets to improve outcomes for patients with TNBC. Here, we report that MYCN, an oncogene typically overexpressed in tumors of the nervous system or with neuroendocrine features, is heterogeneously expressed within a substantial fraction of primary and recurrent TNBC and is expressed in an even higher fraction of TNBCs that do not display a pathological complete response after neoadjuvant chemotherapy. We performed high-throughput chemical screens on TNBC cell lines with varying amounts of MYCN expression and determined that cells with higher expression of MYCN were more sensitive to bromodomain and extraterminal motif (BET) inhibitors. Combined BET and MEK inhibition resulted in a synergistic decrease in viability, both in vitro and in vivo, using cell lines and patient-derived xenograft (PDX) models. Our preclinical data provide a rationale to advance a combination of BET and MEK inhibitors to clinical investigation for patients with advanced MYCN-expressing TNBC., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Chordoid meningioma is a rare WHO grade II histologic variant. Its molecular alterations or their impact on patient risk stratification have not been fully explored. We performed a multicenter, clinical, histological, and genomic analysis of chordoid meningiomas from 30 patients (34 tumors), representing the largest integrated study to date. By NHERF1 microlumen immunohistochemical detection, three epithelial differentiation (ED) groups emerged: #1/fibroblastic-like, #2/epithelial-poorly-differentiated and #3/epithelial-well-differentiated. These ED groups correlated with tumor location and genetic profiling, with NF2 and chromatin remodeling gene mutations clustering in ED group #2, and TRAF7 mutations segregating in ED group #3. Mutations in LRP1B were found in the largest number of cases (36%) across ED groups #2 and #3. Pathogenic ATM and VHL germline mutations occurred in ED group #3 patients, conferring an aggressive or benign course, respectively. The recurrence rate significantly correlated with mutations in NF2 , as single gene, and with mutations in chromatin remodeling and DNA damage response genes, as groups. The recurrence rate was very high in ED group #2, moderate in ED group #3, and absent in ED group #1. This study proposes guidelines for tumor recurrence risk stratification and practical considerations for patient management.

The family of juvenile xanthogranuloma family neoplasms (JXG) with ERK-pathway mutations are now classified within the "L" (Langerhans) group, which includes Langerhans cell histiocytosis (LCH) and Erdheim Chester disease (ECD). Although the BRAF V600E mutation constitutes the majority of molecular alterations in ECD and LCH, only three reported JXG neoplasms, all in male pediatric patients with localized central nervous system (CNS) involvement, are known to harbor the BRAF mutation. This retrospective case series seeks to redefine the clinicopathologic spectrum of pediatric CNS-JXG family neoplasms in the post-BRAF era, with a revised diagnostic algorithm to include pediatric ECD. Twenty-two CNS-JXG family lesions were retrieved from consult files with 64% (n = 14) having informative BRAF V600E mutational testing (molecular and/or VE1 immunohistochemistry). Of these, 71% (n = 10) were pediatric cases (≤18 years) and half (n = 5) harbored the BRAF V600E mutation. As compared to the BRAF wild-type cohort (WT), the BRAF V600E cohort had a similar mean age at diagnosis [BRAF V600E: 7 years (3-12 y), vs. WT: 7.6 years (1-18 y)] but demonstrated a stronger male/female ratio (BRAF V600E: 4 vs WT: 0.67), and had both more multifocal CNS disease ( BRAFV600E: 80% vs WT: 20%) and systemic disease (BRAF V600E: 40% vs WT: none). Radiographic features of CNS-JXG varied but typically included enhancing CNS mass lesion(s) with associated white matter changes in a subset of BRAF V600E neoplasms. After clinical-radiographic correlation, pediatric ECD was diagnosed in the BRAF V600E cohort. Treatment options varied, including surgical resection, chemotherapy, and targeted therapy with BRAF-inhibitor dabrafenib in one mutated case. BRAF V600E CNS-JXG neoplasms appear associated with male gender and aggressive disease presentation including pediatric ECD. We propose a revised diagnostic algorithm for CNS-JXG that includes an initial morphologic diagnosis with a final integrated diagnosis after clinical-radiographic and molecular correlation, in order to identify cases of pediatric ECD. Future studies with long-term follow-up are required to determine if pediatric BRAF V600E positive CNS-JXG neoplasms are a distinct entity in the L-group histiocytosis category or represent an expanded pediatric spectrum of ECD.

Mutations in the torsinA-interacting protein 1 (TOR1AIP1) gene result in a severe muscular dystrophy with minimal literature in the pediatric population. We review a case of TOR1AIP1 gene mutation in a 16-year-old Caucasian female with a long history of muscle weakness. Extensive clinical workup was performed and MRI at time of initial presentation demonstrated no significant muscular atrophy with heterogenous STIR hyperintensity of the lower extremity muscles. MRI findings seven years later included extensive atrophy of the lower extremities, with severe progression, including the gluteal muscles, iliopsoas, rectus femoris, and obturator internus. There was also significant atrophy of the rectus abdominis and internal and external oblique muscles, and iliacus muscles. The MRI findings showed more proximal involvement of lower extremities and no atrophy of the tibialis anterior, making TOR1AIP1 the more likely genetic cause. Muscle biopsy findings supported TOR1AIP1 limb-girdle muscular dystrophy. Though rare, TOR1AIP1 gene mutation occurs in pediatric patients and MRI can aid in diagnosis and help differentiate from other types of muscular dystrophy. Genetic and pathology workup is also crucial to accurate diagnosis and possible treatment of these patients., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Ventricular entry during glioblastoma resection and tumor contact with the subventricular zone (SVZ) have both been shown to associate with development of hydrocephalus, leptomeningeal dissemination, distant parenchymal recurrence, and decreased survival. However, prior studies did not analyze these variables together in a single-patient population; therefore, it is unknown which is an independent predictor of these outcomes., Objective: To conduct a comparative outcome analysis of surgical ventricular entry and SVZ contact by glioblastoma in a retrospective cohort of 232 patients., Methods: Outcomes studied included hydrocephalus, leptomeningeal dissemination, distant tumor recurrences, and progression-free (PFS) and overall (OS) survival. The Cox proportional regression analyses were adjusted for age at diagnosis, preoperative Karnofsky performance status score, extent of resection, temozolomide and radiation treatments, and tumor molecular status (specifically, IDH1/2 mutation and MGMT promoter methylation)., Results: Surgical ventricular entry, SVZ-contacting glioblastoma, hydrocephalus, leptomeningeal dissemination, and distant recurrences were observed in 85 (36.6%), 114 (49.1%), 19 (8.2%), 78 (33.6%), and 59 (25.4%) patients, respectively. Multivariate, adjusted analysis revealed SVZ tumor contact-but not ventricular entry-associated with hydrocephalus (hazard ratio, HR, 4.20 [1.13-15.7], P = .03), leptomeningeal dissemination (HR 1.93 [1.14-3.28], P = .01), PFS (HR 2.10 [1.53-2.88], P < .001), and OS (HR 1.90 [1.35-2.67], P < .001). Distant recurrences were not associated with either. No interaction between the 2 variables was statistically noted., Conclusion: SVZ contact by glioblastoma was independently associated with the development of hydrocephalus, leptomeningeal dissemination, and decreased survival. SVZ tumor contact was associated with ventricular entry during surgical resections, which did not independently correlate with these outcomes., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Checkpoint inhibitors produce durable responses in numerous metastatic cancers, but immune-related adverse events (irAEs) complicate and limit their benefit. IrAEs can affect organ systems idiosyncratically; presentations range from mild and self-limited to fulminant and fatal. The molecular mechanisms underlying irAEs are poorly understood. Here, we report a fatal case of encephalitis arising during anti-programmed cell death receptor 1 therapy in a patient with metastatic melanoma. Histologic analyses revealed robust T cell infiltration and prominent programmed death ligand 1 expression. We identified 209 reported cases in global pharmacovigilance databases (across multiple cancer types) of encephalitis associated with checkpoint inhibitor regimens, with a 19% fatality rate. We performed further analyses from the index case and two additional cases to shed light on this recurrent and fulminant irAE. Spatial and multi-omic analyses pinpointed activated memory CD4 + T cells as highly enriched in the inflamed, affected region. We identified a highly oligoclonal T cell receptor repertoire, which we localized to activated memory cytotoxic (CD45RO + GZMB + Ki67 + ) CD4 cells. We also identified Epstein-Barr virus-specific T cell receptors and EBV + lymphocytes in the affected region, which we speculate contributed to neural inflammation in the index case. Collectively, the three cases studied here identify CD4 + and CD8 + T cells as culprits of checkpoint inhibitor-associated immune encephalitis.

Angiocentric glioma is a rare low-grade neoplasm of the central nervous system which typically presents with medication-refractory seizures in children and young adults. On magnetic resonance imaging, angiocentric glioma is classically T1 hypointense and T2/FLAIR hyperintense. We present the case of a 40-year-old male who had been followed by our institution for 17 years for management of epilepsy. Initial and repeat brain imaging showed an apparent region of cystic encephalomalacia in the right frontal lobe. In an attempt to control his seizures, the lesion was resected. Grossly, the cut surface of the specimen was characterized by multiple small cystic spaces. Microscopically, the lesion was composed of an infiltrative population of glial cells variably arranged in perivascular "pseudorosettes," nodules, and subpial "palisades." The final diagnosis was angiocentric glioma. This is the second reported case of an angiocentric glioma mistaken for encephalomalacia.

Neural stem/progenitor cells (NSPCs) of the ventricular-subventricular zone (V-SVZ) are candidate cells of origin for many brain tumors. However, whether NSPCs in different locations within the V-SVZ differ in susceptibility to tumorigenic mutations is unknown. Here, single-cell measurements of signal transduction intermediates in the mechanistic target of rapamycin complex 1 (mTORC1) pathway reveal that ventral NSPCs have higher levels of signaling than dorsal NSPCs . These features are linked with differences in mTORC1-driven disease severity: introduction of a pathognomonic Tsc2 mutation only results in formation of tumor-like masses from the ventral V-SVZ. We propose a direct link between location-dependent intrinsic growth properties imbued by mTORC1 and predisposition to tumor development., (© 2019 Rushing et al.)

Astroblastoma (AB) is a rare CNS tumor demonstrating abundant astroblastomatous pseudorosettes. Its molecular features have not been comprehensively studied and its status as a tumor entity is controversial. We analyzed a cohort of 27 histologically-defined ABs using DNA methylation profiling, copy number analysis, FISH and site-directed sequencing. Most cases demonstrated mutually exclusive MN1 rearrangements (n = 10) or BRAF V600E mutations (n = 7). Two additional cases harbored RELA rearrangements. Other cases lacked these specific genetic alterations (n = 8). By DNA methylation profiling, tumors with MN1 or RELA rearrangement clustered with high-grade neuroepithelial tumor with MN1 alteration (HGNET-MN1) and RELA-fusion ependymoma, respectively. In contrast, BRAF V600E -mutant tumors grouped with pleomorphic xanthoastrocytoma (PXA). Six additional tumors clustered with either supratentorial pilocytic astrocytoma and ganglioglioma (LGG-PA/GG-ST), normal or reactive cerebrum, or with no defined DNA methylation class. While certain histologic features favored one genetic group over another, no group could be reliably distinguished by histopathology alone. Survival analysis between genetic AB subtypes was limited by sample size, but showed that MN1-rearranged AB tumors were characterized by better overall survival compared to other genetic subtypes, in fact, significantly better than BRAF V600E -mutant tumors (P = 0.013). Our data confirm that histologically-defined ABs are molecularly heterogeneous and do not represent a single entity. They rather encompass several low- to higher-grade glial tumors including neuroepithelial tumors with MN1 rearrangement, PXA-like tumors, RELA ependymomas, and possibly yet uncharacterized lesions. Genetic subtyping of tumors exhibiting AB histology, particularly determination of MN1 and BRAF V600E status, is necessary for important prognostic and possible treatment implications.

Whether patients with glioblastoma that contacts the ventricular-subventricular zone stem cell niche (VSVZ + GBM) have a distinct survival profile from VSVZ - GBM patients independent of other known predictors or molecular profiles is unclear. Using multivariate Cox analysis to adjust survival for widely-accepted predictors, hazard ratios (HRs) for overall (OS) and progression free (PFS) survival between VSVZ + GBM and VSVZ - GBM patients were calculated in 170 single-institution patients and 254 patients included in both The Cancer Genome (TCGA) and Imaging (TCIA) atlases. An adjusted, multivariable analysis revealed that VSVZ contact was independently associated with decreased survival in both datasets. TCGA molecular data analyses revealed that VSVZ contact by GBM was independent of mutational, DNA methylation, gene expression, and protein expression signatures in the bulk tumor. Therefore, while survival of GBM patients is independently stratified by VSVZ contact, with VSVZ + GBM patients displaying a poor prognosis, the VSVZ + GBMs do not possess a distinct molecular signature at the bulk sample level. Focused examination of the interplay between the VSVZ microenvironment and subsets of GBM cells proximal to this region is warranted.

Meningioma is a primary brain tumor arising from the neoplastic transformation of meningothelial cells. Several histological variants of meningioma have been described. Here we show that NHERF1/EBP50, an adaptor protein required for structuring specialized polarized epithelia, can distinguish meningioma variants with epithelial differentiation. NHERF1 decorates the membrane of intracytoplasmic lumens and microlumens in the secretory variant, consistent with a previously described epithelial differentiation of this subtype. NHERF1 also labels microlumens in chordoid meningioma, an epithelial variant not previously known to harbor these structures, and ultrastructural analysis confirmed the presence of microlumens in this variant. NHERF1 associates with the ezrin-radixin-moesin (ERM)-NF2 cytoskeletal proteins, and moesin but not NF2 was detectable in the microlumens. In a meningioma series from 83 patients, NHERF1 revealed microlumens in 87.5% of the chordoid meningioma ( n = 25) and meningioma with chordoid component ( n = 7) cases, and in 100% of the secretory meningioma cases ( n = 12). The most common WHO grade I meningioma variants lacked microlumens. Interestingly, 20% and 66.6% of WHO grades II ( n = 20) and III ( n = 3) meningiomas, respectively, showed microlumen-like NHERF1 staining of ultrastructural tight microvillar interdigitations, mainly in rhabdoid, papillary-like or sheeting areas, revealing a new subset of high grade meningiomas with epithelial differentiation. NHERF1 failed to detect microlumens in 12 additional cases of chordoid glioma of the 3rd ventricle, chordoma and chondrosarcoma, neoplasms that may mimic the histological appearance of chordoid meningioma. This study uncovers features of epithelial differentiation in meningioma and proposes NHERF1 immunohistochemistry as a method of discriminating chordoid meningioma from neoplasms with similar appearance., Competing Interests: CONFLICTS OF INTEREST The authors declare no conflicts of interest.

The presence of the single-nucleotide polymorphism (SNP) rs11554137:C>T in the IDH1 gene is associated with a significantly lower survival in acute myeloid leukemia patients. The impact of its presence in glioblastoma on patient survival is unclear. We retrospectively reviewed 171 adult (> 18 years of age) patients treated at a single, tertiary academic center for supratentorial glioblastoma (WHO grade IV) between 2013 and 2017. We conducted Kaplan-Meier overall and progression free survival analyses based on the IDH1 and IDH2 gene status of patients' glioblastoma (IDH wild type, mutant, and IDH1 rs11554137:C>T SNP). Multivariate Cox survival analyses were conducted accounting for age at diagnosis, preoperative Karnofsky performance status score, treatment (extent of resection, postoperative radiotherapy, and temozolomide), IDH gene variant, and MGMT promoter methylation status. Presence of rs11554137:C>T SNP in glioblastoma samples did not correlate with presence of IDH1 mutation. Patients with rs11554137:C>T SNP did not have histories of prior lower-grade gliomas. Patients with IDH mutant glioblastoma had a distinctly higher survival profile than both rs11554137:C>T SNP and IDH wild type glioblastomas. No survival difference was noted between patients with glioblastoma harboring the SNP and patients with IDH wild type glioblastoma. In this study, clinical prognostication in glioblastoma patients was largely dependent on the classification of IDH mutant and wild type glioblastoma, and not on the presence of IDH1 rs11554137:C>T SNP in the tumor.

Increasing evidence indicates that the adult neurogenic niche of the ventricular-subventricular zone (V-SVZ), beyond serving as a potential site of origin, affects the outcome of malignant brain cancers. Glioma contact with this niche predicts worse prognosis, suggesting a supportive role for the V-SVZ environment in tumor initiation or progression. In this review, we describe unique components of the V-SVZ that may permit or promote tumor growth within the region. Cell-cell interactions, soluble factors, and extracellular matrix composition are discussed, and the role of the niche in future therapies is explored. The purpose of this review is to highlight niche intrinsic factors that may promote or support malignant cell growth and maintenance, and point out how we might leverage these features to improve patient outcome., (Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Background: Mass cytometry measures 36 or more markers per cell and is an appealing platform for comprehensive phenotyping of cells in human tissue and tumor biopsies. While tissue disaggregation and fluorescence cytometry protocols were pioneered decades ago, it is not known whether established protocols will be effective for mass cytometry and maintain cancer and stromal cell diversity., Methods: Tissue preparation techniques were systematically compared for gliomas and melanomas, patient derived xenografts of small cell lung cancer, and tonsil tissue as a control. Enzymes assessed included DNase, HyQTase, TrypLE, collagenase (Col) II, Col IV, Col V, and Col XI. Fluorescence and mass cytometry were used to track cell subset abundance following different enzyme combinations and treatment times., Results: Mechanical disaggregation paired with enzymatic dissociation by Col II, Col IV, Col V, or Col XI plus DNase for 1 h produced the highest yield of viable cells per gram of tissue. Longer dissociation times led to increasing cell death and disproportionate loss of cell subsets. Key markers for establishing cell identity included CD45, CD3, CD4, CD8, CD19, CD64, HLA-DR, CD11c, CD56, CD44, GFAP, S100B, SOX2, nestin, vimentin, cytokeratin, and CD31. Mass and fluorescence cytometry identified comparable frequencies of cancer cell subsets, leukocytes, and endothelial cells in glioma (R = 0.97), and tonsil (R = 0.98)., Conclusions: This investigation establishes standard procedures for preparing viable single cell suspensions that preserve the cellular diversity of human tissue microenvironments. © 2016 International Clinical Cytometry Society., (© 2016 International Clinical Cytometry Society.)

Background: Astroblastomas (ABs) are rare glial tumors showing overlapping features with astrocytomas, ependymomas, and sometimes other glial neoplasms, and may be challenging to diagnose., Methods: We examined clinical, histopathological, and molecular features in 28 archival formalin-fixed, paraffin-embedded AB cases and performed survival analyses using Cox proportional hazards and Kaplan-Meier methods., Results: Unlike ependymomas and angiocentric gliomas, ABs demonstrate abundant distinctive astroblastic pseudorosettes and are usually Olig2 immunopositive. They also frequently exhibit rhabdoid cells, multinucleated cells, and eosinophilic granular material. They retain immunoreactivity to alpha thalassemia/mental retardation syndrome X-linked, are immunonegative to isocitrate dehydrogenase-1 R132H mutation, and only occasionally show MGMT promoter hypermethylation differentiating them from many diffuse gliomas. Like pleomorphic xanthoastrocytoma, ganglioglioma, supratentorial pilocytic astrocytoma, and other predominantly cortical-based glial tumors, ABs often harbor the BRAF V600E mutation, present in 38% of cases tested (n = 21), further distinguishing those tumors from ependymomas and angiocentric gliomas. Factors correlating with longer patient survival included age less than 30 years, female gender, absent BRAF V600E , and mitotic index less than 5 mitoses/10 high-power fields; however, only the latter was significant by Cox and Kaplan-Meier analyses (n = 24; P = .024 and .012, respectively). This mitotic cutoff is therefore currently the best criterion to stratify tumors into low-grade ABs and higher-grade anaplastic ABs., Conclusions: In addition to their own characteristic histological features, ABs share some molecular and histological findings with other, possibly ontologically related, cortical-based gliomas of mostly children and young adults. Importantly, the presence of BRAF V600E mutations in a subset of ABs suggests potential clinical utility of targeted anti-BRAF therapy., (© The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The adaptor protein NHERF1 (Na/H exchanger-3 regulatory factor-1) and its associated ezrin-radixin-moesin-merlin/neurofibromin-2 (ERM-NF2) family proteins are required for epithelial morphogenesis and have been implicated in cancer progression. NHERF1 is expressed in ependymal cells and constitutes a highly sensitive diagnostic marker for ependymoma, where it labels membrane polarity structures. Since NHERF1 and ERM-NF2 proteins show polarized expression in choroid plexus (CP) cells, we tested their diagnostic utility in CP neoplasms. NHERF1 immunohistochemistry in 43 adult and pediatric tumors with papillary morphology revealed strong apical plasma membrane staining in CP papilloma (WHO grade I) and cytoplasmic expression in CP carcinoma (WHO grade III). Ezrin and moesin showed similar but less distinctive staining. NHERF1 also labeled papillary tumors of the pineal region in a microlumen and focal apical membrane pattern, suggestive of a transitional morphology between CP papilloma and ependymoma. CP tumors of all grades could be differentiated from metastatic carcinomas with papillary architecture by NF2, which showed polarized membranous staining in CP tumors. NHERF1 and NF2 immunohistochemistry showed enhanced sensitivity and specificity for CP tumors compared to commonly used markers, including cytokeratins and Kir7.1, emerging as reliable diagnostic tools for the differential diagnosis of papillary tumors of the central nervous system.

Purpose: Aberrant activation of EGFR is a hallmark of glioblastoma. However, EGFR inhibitors exhibit at best modest efficacy in glioblastoma. This is in sharp contrast with the observations in EGFR-mutant lung cancer. We examined whether activation of functionally redundant receptor tyrosine kinases (RTKs) conferred resistance to EGFR inhibitors in glioblastoma., Experimental Design: We collected a panel of patient-derived glioblastoma xenograft (PDX) lines that maintained expression of wild-type or mutant EGFR in serial xenotransplantation and tissue cultures. Using this physiologically relevant platform, we tested the abilities of several RTK ligands to protect glioblastoma cells against an EGFR inhibitor, gefitinib. Based on the screening results, we further developed a combination therapy cotargeting EGFR and insulin receptor (InsR)/insulin-like growth factor 1 receptor (IGF1R)., Results: Insulin and IGF1 induced significant protection against gefitinib in the majority of EGFR-dependent PDX lines with one exception that did not express InsR or IGF1R. Blockade of the InsR/IGF1R pathway synergistically improved sensitivity to gefitinib or dacomitinib. Gefitinib alone effectively attenuated EGFR activities and the downstream MEK/ERK pathway. However, repression of AKT and induction of apoptosis required concurrent inhibition of both EGFR and InsR/IGF1R. A combination of gefitinib and OSI-906, a dual InsR/IGF1R inhibitor, was more effective than either agent alone to treat subcutaneous glioblastoma xenograft tumors., Conclusions: Our results suggest that activation of the InsR/IGF1R pathway confers resistance to EGFR inhibitors in EGFR-dependent glioblastoma through AKT regulation. Concurrent blockade of these two pathways holds promise to treat EGFR-dependent glioblastoma., (©2015 American Association for Cancer Research.)

Primitive neuroectodermal tumors of the central nervous system (CNS-PNETs) are highly aggressive, poorly differentiated embryonal tumors occurring predominantly in young children but also affecting adolescents and adults. Herein, we demonstrate that a significant proportion of institutionally diagnosed CNS-PNETs display molecular profiles indistinguishable from those of various other well-defined CNS tumor entities, facilitating diagnosis and appropriate therapy for patients with these tumors. From the remaining fraction of CNS-PNETs, we identify four new CNS tumor entities, each associated with a recurrent genetic alteration and distinct histopathological and clinical features. These new molecular entities, designated "CNS neuroblastoma with FOXR2 activation (CNS NB-FOXR2)," "CNS Ewing sarcoma family tumor with CIC alteration (CNS EFT-CIC)," "CNS high-grade neuroepithelial tumor with MN1 alteration (CNS HGNET-MN1)," and "CNS high-grade neuroepithelial tumor with BCOR alteration (CNS HGNET-BCOR)," will enable meaningful clinical trials and the development of therapeutic strategies for patients affected by poorly differentiated CNS tumors., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Prolonged treatment with adjuvant valganciclovir has been shown in one retrospective study to exert a significant effect on overall survival (OS) in newly diagnosed patients with glioblastoma multiforme (GBM). However, studies evaluating the effectiveness of valganciclovir in the treatment of recurrent GBM have not been performed. We evaluated the effect of valganciclovir in the recurrent setting in combination with bevacizumab therapy. A retrospective analysis was performed on patients treated for recurrent GBM with off-label valganciclovir and bevacizumab at Vanderbilt University. We identified 13 patients who received valganciclovir plus bevacizumab at some point during their treatment, 8 of whom were started on valganciclovir and bevacizumab concurrently upon first recurrence, whereas 5 had valganciclovir added to their bevacizumab regimen prior to a second recurrence. of these patients, 12 were pathologically confirmed to have GBM, and 1 patient was diagnosed with gliosarcoma. We also identified an institutional cohort of 50 patients who had not been exposed to valganciclovir, but were treated with bevacizumab for first recurrence. The progression-free survival (PFS) at 6 months (PF6) and median OS (mOS) in the valganciclovir plus bevacizumab group was 62% and 13.1 months, respectively, for all 13 patients, and 50% and 11.3 months, respectively, for the 8 concurrently treated patients. In the institutional bevacizumab cohort, the PF6 and mOS were 34% and 8.7 months, respectively. In this retrospective analysis, valganciclovir in combination with bevacizumab exhibited a trend toward improved survival in patients with recurrent GBM. However, given the small sample size and the retrospective nature of this study, a larger prospective study is required to confirm these results.

Background: Metabolic complications such as obesity, hyperglycemia, and type 2 diabetes are associated with poor outcomes in patients with glioblastoma. To control peritumoral edema, use of chronic high-dose steroids in glioblastoma patients is common, which can result in de novo diabetic symptoms. These metabolic complications may affect tumors via profound mechanisms, including activation of insulin receptor (InsR) and the related insulin-like growth factor 1 receptor (IGF1R) in malignant cells., Methods: In the present study, we assessed expression of InsR in glioblastoma surgical specimens and glioblastoma response to insulin at physiologically relevant concentrations. We further determined whether genetic or pharmacological targeting of InsR affected oncogenic functions of glioblastoma in vitro and in vivo., Results: We showed that InsR was commonly expressed in glioblastoma surgical specimens and xenograft tumor lines, with mitogenic isoform-A predominating. Insulin at physiologically relevant concentrations promoted glioblastoma cell growth and survival, potentially via Akt activation. Depletion of InsR impaired cellular functions and repressed orthotopic tumor growth. The absence of InsR compromised downstream Akt activity, but yet stimulated IGF1R expression. Targeting both InsR and IGF1R with dual kinase inhibitors resulted in effective blockade of downstream signaling, loss of cell viability, and repression of xenograft tumor growth., Conclusions: Taken together, our work suggests that glioblastoma is sensitive to the mitogenic functions of insulin, thus significant insulin exposure imposes risks to glioblastoma patients. Additionally, dual inhibition of InsR and IGF1R exhibits promise for treating glioblastoma., (© The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Cerebral amyloid angiopathy (CAA) is the deposition of amyloid proteins in the cerebrovasculature, which can lead to intracerebral hemorrhage. Intracerebral hemorrhage in CAA often presents with microhemorrhages and, less frequently, with more devastating macrohemorrhages. We present a case of CAA-related synchronous bilateral intracerebral macrohemorrhage which, to our knowledge, has yet to be reported in the literature, and postulate its relationship to antiplatelet therapy and transient elevations in blood pressure.

Among brain tumors, the BRAF (V600E) mutation is frequently associated with pleomorphic xanthoastrocytomas (PXAs) and gangliogliomas (GGs). This oncogenic mutation is also detected in ~5 % of other pediatric low-grade gliomas (LGGs) including pilocytic astrocytomas (PAs) and diffuse astrocytomas. In the current multi-institutional study of 56 non-PXA/non-GG diencephalic pediatric LGGs, the BRAF (V600) mutation rate is 36 %. V600-mutant tumors demonstrate a predilection for infants and young children (

Papillary tumor of the pineal region (PTPR) is an uncommon neoplasm with variable biologic behavior. Cytogenetic and molecular diagnostic studies are rare, yielding no definitive genetic signature. We report a case of PTPR with a multicentric presentation and unusual cytogenetic features. A 25-year-old man presented with headache, disconjugate gaze, and confusion. Mass lesions in the pineal and suprasellar regions, with identical imaging characteristics, were identified. The former extended partially into the fourth ventricle. It showed typical PTPR histology and losses of chromosomes 3, 7, 10, 14, 18, and Y with gains of chromosomes 3, 8, and 9. Seventeen months postsurgery, the patient is stable without disease progression after radiation therapy. Synchronous mass lesions at presentation and losses of chromosomes 3, 7, 14, 18, and Y are unusual features, adding to the available data and underscoring the biologic and genetic variability associated with these neoplasms., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Neuroblastoma is a pediatric malignancy of the sympathetic ganglia and adrenal glands, hypothesized to originate from progenitors of the developing sympathetic nervous system. Amplification of the MYCN oncogene is a genetic marker of risk in this disease. Understanding the impact of oncogene expression on sympathoadrenal progenitor development may improve our knowledge of neuroblastoma initiation and progression. We isolated sympathoadrenal progenitor cells from the postnatal murine adrenal gland by sphere culture and found them to be multipotent, generating differentiated colonies of neurons, Schwann cells, and myofibroblasts. MYCN overexpression in spheres promoted commitment to the neural lineage, evidenced by an increased frequency of neuron-containing colonies. MYCN promoted proliferation of both sympathoadrenal progenitor spheres and differentiated neurons derived from these spheres, but there was also an increase in apoptosis. The proliferation, apoptosis, and neural lineage commitment induced by MYCN are tumor-like characteristics and thereby support the hypothesis that multipotent adrenal medullary progenitor cells are cells of origin for neuroblastoma. We find, however, that MYCN overexpression is not sufficient for these cells to form tumors in nude mice, suggesting that additional transforming mutations are necessary for tumorigenesis.