A sensitive and specific histopathologic prognostic marker for H3F3A K27M mutant pediatric glioblastomas

Pediatric glioblastomas (GBM) are highly aggressive and lethal tumors. Recent sequencing studies have shown that ~30 % of pediatric GBM and ~80 % of diffuse intrinsic pontine gliomas show K27M mutations in the H3F3A gene, a variant encoding histone H3.3. H3F3A K27M mutations lead to global reduction in H3K27me3. Our goal was to develop biomarkers for the histopathologic detection of these tumors. Therefore, we evaluated the utility of measuring H3K27me3 global reduction as a histopathologic and prognostic biomarker and tested an antibody directed specifically against the H3.3 K27M mutation in 290 samples. The study cohort included 203 pediatric (including 38 pediatric high-grade astrocytomas) and 38 adult brain tumors of various subtypes and grades and 49 non-neoplastic reactive brain tissues. Detection of H3.3 K27M by immunohistochemistry showed 100 % sensitivity and specificity and was superior to global reduction in H3K27me3 as a biomarker in diagnosing H3F3A K27M mutations. Moreover, cases that stained positive for H3.3 K27M showed a significantly poor prognosis compared to corresponding negative tumors. These results suggest that immunohistochemical detection of H3.3 K27M is a sensitive and specific surrogate for the H3F3A K27M mutation and defines a prognostically poor subset of pediatric GBM. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00401-014-1338-3) contains supplementary material, which is available to authorized users

Recent Advances in the Classification and Treatment of Ependymomas

OPINION STATEMENT: Ependymomas are a subgroup of ependymal glia-derived neoplasms that affect children as well as adults. Arising within any CNS compartment, symptoms at presentation can range from acute onset due to increased intracranial pressure to insidious myelopathy. The overall survival (OS) outcomes in adult patients across the subgroups is heterogeneous with subependymoma having an excellent prognosis often even in the absence of any treatment, whereas supratentorial ependymomas tend to be higher grade in nature and may have an OS of 5 years despite gross total resection and adjuvant radiation. The rarity of ependymal tumors, together still only representing 1.8% of all primary CNS tumors, has been a long-standing challenge in defining optimal treatment guidelines via prospective randomized trials. Retrospective studies have supported maximal safe resection, ideally gross total resection, as the optimal treatment with adjuvant radiation therapy proffering additional tumor control. The evidence for efficacy of chemotherapy and targeted agents in adult ependymomas is minimal. Recent investigations of the molecular, genetic, and DNA methylation profiles of ependymal tumors across all age groups and CNS compartments have identified distinct oncogenic gene products as well as nine molecular subgroups correlating with similar outcomes. The 2016 World Health Organization of Tumors of the Central Nervous System update addresses some of these findings, although their clinical significance has not yet been fully validated. There are inconsistent survival outcomes in retrospective studies for ependymomas graded as II versus III, bringing into question the validity of histologic grading which is subject to high interobserver variability in part due to inconsistent application of mitotic count parameters

Recent Advances in the Classification and Treatment of Ependymomas

OPINION STATEMENT: Ependymomas are a subgroup of ependymal glia-derived neoplasms that affect children as well as adults. Arising within any CNS compartment, symptoms at presentation can range from acute onset due to increased intracranial pressure to insidious myelopathy. The overall survival (OS) outcomes in adult patients across the subgroups is heterogeneous with subependymoma having an excellent prognosis often even in the absence of any treatment, whereas supratentorial ependymomas tend to be higher grade in nature and may have an OS of 5 years despite gross total resection and adjuvant radiation. The rarity of ependymal tumors, together still only representing 1.8% of all primary CNS tumors, has been a long-standing challenge in defining optimal treatment guidelines via prospective randomized trials. Retrospective studies have supported maximal safe resection, ideally gross total resection, as the optimal treatment with adjuvant radiation therapy proffering additional tumor control. The evidence for efficacy of chemotherapy and targeted agents in adult ependymomas is minimal. Recent investigations of the molecular, genetic, and DNA methylation profiles of ependymal tumors across all age groups and CNS compartments have identified distinct oncogenic gene products as well as nine molecular subgroups correlating with similar outcomes. The 2016 World Health Organization of Tumors of the Central Nervous System update addresses some of these findings, although their clinical significance has not yet been fully validated. There are inconsistent survival outcomes in retrospective studies for ependymomas graded as II versus III, bringing into question the validity of histologic grading which is subject to high interobserver variability in part due to inconsistent application of mitotic count parameters

Metformin-induced mitochondrial function and ABCD2 up-regulation in X-linked adrenoleukodystrophy involves AMP-activated protein kinase

X-linked adrenoleukodystrophy (X-ALD) is a progressive neurometabolic disease caused by mutations/deletions in the Abcd1 gene. Similar mutations/deletions in the Abcd1 gene often result in diagonally opposing phenotypes of mild adrenomyeloneuropathy and severe neuroinflammatory cerebral adrenoleukodystrophy (ALD), which suggests involvement of downstream modifier genes. We recently documented the first evidence of loss of AMP-activated protein kinase α1 (AMPKα1) in ALD patient-derived cells. Here, we report the novel loss of AMPKα1 in postmortem brain white matter of patients with ALD phenotype. Pharmacological activation of AMPK can rescue the mitochondrial dysfunction and inhibit the pro-inflammatory response. The FDA approved anti-diabetic drug Metformin, a well-known AMPK activator, induces mitochondrial biogenesis and is documented for its anti-inflammatory role. We observed a dose-dependent activation of AMPKα1 in metformin-treated X-ALD patient-derived fibroblasts. Metformin also induced mitochondrial oxidative phosphorylation and ATP levels in X-ALD patient-derived fibroblasts. Metformin treatment decreased very long chain fatty acid levels and pro-inflammatory cytokine gene expressions in X-ALD patient-derived cells. Abcd2 [adrenoleukodystrophy protein-related protein] levels were increased in metformin-treated X-ALD patient-derived fibroblasts and Abcd1-KO mice primary mixed glial cells. Abcd2 induction was AMPKα1-dependent since metformin failed to induce Abcd2 levels in AMPKα1-KO mice-derived primary mixed glial cells. In vivo metformin (100 mg/Kg) in drinking water for 60 days induced Abcd2 levels and mitochondrial oxidative phosphorylation protein levels in the brain and spinal cord of Abcd1-KO mice. Taken together, these results provide proof-of-principle for therapeutic potential of metformin as a useful strategy for correcting the metabolic and inflammatory derangements in X-ALD by targeting AMPK. There is no effective therapy for inherited peroxisomal disorder X-linked adrenoleukodystrophy (X-ALD). We document the therapeutic potential of FDA approved drug, Metformin, for X-ALD by targeting AMPK. Metformin induced peroxisomal Abcd2 levels in vitro and in vivo. Metformin lowered VLCFA levels, improved mitochondrial function and ameliorated inflammatory gene expression in X-ALD patient-derived cells. Metformin-induced Abcd2 levels were dependent on AMPKα1, a metabolic and anti-inflammatory gene, recently documented by our laboratory to play a putative role in X-ALD pathology. Read the Editorial Highlight for this article on page 10

Metformin-induced mitochondrial function and ABCD2 up-regulation in X-linked adrenoleukodystrophy involves AMP-activated protein kinase

X-linked adrenoleukodystrophy (X-ALD) is a progressive neurometabolic disease caused by mutations/deletions in the Abcd1 gene. Similar mutations/deletions in the Abcd1 gene often result in diagonally opposing phenotypes of mild adrenomyeloneuropathy and severe neuroinflammatory cerebral adrenoleukodystrophy (ALD), which suggests involvement of downstream modifier genes. We recently documented the first evidence of loss of AMP-activated protein kinase α1 (AMPKα1) in ALD patient-derived cells. Here, we report the novel loss of AMPKα1 in postmortem brain white matter of patients with ALD phenotype. Pharmacological activation of AMPK can rescue the mitochondrial dysfunction and inhibit the pro-inflammatory response. The FDA approved anti-diabetic drug Metformin, a well-known AMPK activator, induces mitochondrial biogenesis and is documented for its anti-inflammatory role. We observed a dose-dependent activation of AMPKα1 in metformin-treated X-ALD patient-derived fibroblasts. Metformin also induced mitochondrial oxidative phosphorylation and ATP levels in X-ALD patient-derived fibroblasts. Metformin treatment decreased very long chain fatty acid levels and pro-inflammatory cytokine gene expressions in X-ALD patient-derived cells. Abcd2 [adrenoleukodystrophy protein-related protein] levels were increased in metformin-treated X-ALD patient-derived fibroblasts and Abcd1-KO mice primary mixed glial cells. Abcd2 induction was AMPKα1-dependent since metformin failed to induce Abcd2 levels in AMPKα1-KO mice-derived primary mixed glial cells. In vivo metformin (100 mg/Kg) in drinking water for 60 days induced Abcd2 levels and mitochondrial oxidative phosphorylation protein levels in the brain and spinal cord of Abcd1-KO mice. Taken together, these results provide proof-of-principle for therapeutic potential of metformin as a useful strategy for correcting the metabolic and inflammatory derangements in X-ALD by targeting AMPK. There is no effective therapy for inherited peroxisomal disorder X-linked adrenoleukodystrophy (X-ALD). We document the therapeutic potential of FDA approved drug, Metformin, for X-ALD by targeting AMPK. Metformin induced peroxisomal Abcd2 levels in vitro and in vivo. Metformin lowered VLCFA levels, improved mitochondrial function and ameliorated inflammatory gene expression in X-ALD patient-derived cells. Metformin-induced Abcd2 levels were dependent on AMPKα1, a metabolic and anti-inflammatory gene, recently documented by our laboratory to play a putative role in X-ALD pathology. Read the Editorial Highlight for this article on page 10

Multifocal Intradural Extramedullary Pilocytic Astrocytomas of the Spinal Cord: A Case Report and Review of the Literature

Background and importance: Pilocytic astrocytoma (PA) is among the most common of the central nervous system gliomas in the pediatric population; however, it is uncommon in adults. PAs of the spinal cord in adults are even rarer, with only a few cases found in the literature. We report here the first case in the literature of multifocal intradural extramedullary spinal cord PAs in an adult. Clinical presentation: Our patient is a 56-yr-old female who presented with loss of balance and an ataxic gait. Multiple extramedullary spinal cord tumors were identified intraoperatively, the lesions completely resected, and all diagnosed as PAs. Conclusion: This case illustrates a unique instance of multifocal intradural extramedullary spinal cord PAs in an adult with no previous history of PA during childhood, no known familial syndromes, and no brain involvement

Raman laser damage threshold of rat pial cortex

INTRODUCTION: Raman spectroscopy utilizes a label-free modality of optical imaging that measures scattered photon shifts to give a unique biochemical signature. Its diagnostic capabilities are currently being explored including its applications to intraoperatively identify tissue and oncologic surgical margins. The goal of the present safety study was to assess the threshold at which a 785nM raman laser damages rat pial cortex. METHODS: Sprague Dawley Rats underwent a craniotomy/durotomy and were randomly assigned to either a sham surgery or exposed to a 785nM raman laser. Initial experiments at 100mW failed to show any damage, and the laser was maximally increased to 180mW and exposure time increased to 10 minutes. Animals were then sacrificed immediately, 3 days and 7 days postoperatively and brains processed for pathologic analysis by 2 neuropathologists using H&E, NFAP, GFAP and Luxol fast blue staining. RESULTS: Two neuropathologists examined all slides and did not detect any changes on sham or exposed brains, thus the laser power was increased to 180mW and exposure time to 10 minutes. Even at the increased power and exposure time, there were no observed differences. CONCLUSION: A 785nM 180mW raman laser does not cause thermal damage to the rat pial cortical surface even with 10 minutes of exposure time. Current diagnostic lasers utilize much lower powers and exposure times. Since the absorption of cerebral components is similar in rat and human tissue, these diagnostic tools are likely safe to use intraoperatively. Further studies are needed at higher laser powers, increasing survival times and human tissue to observe delayed changes that may be detected by stains such as NFAP, GFAP and luxol blue

Interdural course of the ophthalmic artery in the optic canal

OBJECTIVE In the current neurosurgical and anatomical literature, the intracanalicular segment of the ophthalmic artery (OphA) is usually described to be within the optic nerve dural sheath (ONDS), implying direct contact between the nerve and the artery inside the optic canal. In the present study, the authors sought to clarify the exact relationship between the OphA and ONDS. METHODS Ten cadaveric heads were subjected to endoscopic endonasal and transcranial exposures of the OphA in the optic canal (5 for each approach). The relationship between the OphA and ONDS was assessed. Histological examination of one specimen of the optic nerve and the accompanying OphA was also performed to confirm the relationship with the ONDS. RESULTS In all specimens, the OphA coursed between the two layers of the dura (endosteal and meningeal) and was not in direct contact with the optic nerve, except for the first few millimeters of the proximal optic canal before it pierced the ONDS. Upon reaching the orbit, the two layers of the dura separated and allowed the OphA to literally float within the orbital fat. The meningeal dura continued as the ONDS, whereas the endosteal dura became the periorbita. CONCLUSIONS This study clarifies the interdural course of the OphA within the optic canal. This anatomical nuance has important neurosurgical implications regarding safe exposure and manipulation of the OphA

Cystic Trophoblastic Tumor in a Primary Central Nervous System Post-Chemotherapy Germ Cell Tumor: The First Case Report

Cystic trophoblastic tumor (CTT) is an uncommon trophoblastic proliferation of germ cell tumor origin, mostly reported in post-chemotherapy metastases of testicular germ cell tumors and rarely primary untreated testicular tumors. To date, we are not aware of occurrence in a non-testicular tumor. A 12-year-old boy presented with limb swelling, increased appetite, weight gain, and precocious puberty. Evaluation revealed right frontal lobe mass and elevated α-fetoprotein and β-human chorionic gonadotrophin. After response to neoadjuvant chemotherapy, the tumor was resected. Microscopically, the resection contained predominantly smooth muscle tissue with scattered small foci of glandular teratoma and CTT. Immunohistochemistry (SALL4, glypican 3) revealed no residual yolk sac tumor. Fluorescence in situ hybridization revealed gain of chromosome 12p. The patient has been disease-free for 13 years. This report expands the spectrum of primary central nervous system germ cell tumors with the occurrence of CTT in this site

Whole genome DNA is distinctly methylated in functioning and non-functioning pituitary macroadenomas

Few somatic mutations or epigenetic alterations were reported to be associated with pituitary adenomas (PA) functional status. In order to evaluate the role of global DNA methylation pattern in Functioning (FPA) and non-functioning PA (NFPA), we profiled the DNA methylome of 14 formalin- fixed paraffin-embedded pituitary specimens (5 non-tumoral, 9 macroadenomas, 6 NFPA; 5 FPA; 5 invasive; 3 large PA, 25±10 mm size) using the Human Illumina EPIC array platform (HM850K). Non-parametric supervised analyses of the methylomes were performed among NFPAs, FPAs and non-tumoral pituitary specimens; differentially methylated probes (DMPs)(