A molecular pathway for cancer cachexia-induced muscle atrophy revealed at single-nucleus resolution.

Cancer cachexia is a prevalent and often fatal wasting condition that cannot be fully reversed with nutritional interventions. Muscle atrophy is a central component of the syndrome, but the mechanisms whereby cancer leads to skeletal muscle atrophy are not well understood. We performed single-nucleus multi-omics on skeletal muscles from a mouse model of cancer cachexia and profiled the molecular changes in cachexic muscle. Our results revealed the activation of a denervation-dependent gene program that upregulates the transcription factor myogenin. Further studies showed that a myogenin-myostatin pathway promotes muscle atrophy in response to cancer cachexia. Short hairpin RNA inhibition of myogenin or inhibition of myostatin through overexpression of its endogenous inhibitor follistatin prevented cancer cachexia-induced muscle atrophy in mice. Our findings uncover a molecular basis of muscle atrophy associated with cancer cachexia and highlight potential therapeutic targets for this disorder.

Extraneural metastatic ependymoma: distant metastasis to the pleura, lungs, lymph nodes and bone.

Ependymomas are neuroepithelial tumours arising from ependymal cells surrounding the cerebral ventricles that rarely metastasise to extraneural structures. This spread has been reported to occur to the lungs, lymph nodes, liver and bone. We describe the case of a patient with recurrent CNS WHO grade 3 ependymoma with extraneural metastatic disease. He was treated with multiple surgical resections, radiation therapy and salvage chemotherapy for his extraneural metastasis to the lungs, bone, pleural space and lymph nodes.

Investigation the mechanism of iron overload-induced colonic inflammation following ferric citrate exposure.

Iron overload occurs due to excessive iron intake compared to the body's demand, leading to iron deposition and impairment of multiple organ functions. Our previous study demonstrated that chronic oral administration of ferric citrate (FC) caused colonic inflammatory injury. However, the precise mechanism underlying this inflammatory response remains unclear. The current study aims to investigate the mechanism by which iron overload induced by FC exposure leads to colonic inflammation. To accomplish this, mice were orally exposed to three different concentrations of FC (71 mg/kg/bw (L), 143 mg/kg/bw (M) and 286 mg/kg/bw (H)) for continuous 16 weeks, with the control group receiving ultrapure water (C). Exposure to FC caused disturbances in the excretory system, altered colonic flora alpha diversity, and enriched pathogenic bacteria, such as Mucispirillum, Helicobacter, Desulfovibrio, and Shigella. These changes led to structural disorders of the colonic flora and an inflammatory response phenotype characterized by inflammatory cells infiltration, atrophy of intestinal glands, and irregular thickening of the intestinal wall. Mechanistic studies revealed that FC-exposure activated the NF-κB signaling pathway by up-regulating TLR4, MyD88, and NF-κB mRNA levels and protein expression. This activation resulted in increased production of pro-inflammatory cytokines, further contributing to the colonic inflammation. Additionally, in vitro experiments in SW480 cells confirmed the activation of NF-κB signaling pathway by FC exposure, consistent with the in vivo findings. The significance of this study lies in its elucidation of the mechanism by which iron overload caused by FC exposure leads to colonic inflammation. By identifying the role of pathogenic bacteria and the NF-κB signaling pathway, this study could potentially offer a crucial theoretical foundation for the research on iron overload, as well as provide valuable insights for clinical iron supplementation.

Myxovirus resistance protein A (MxA) expression in myositides: Sarcoplasmic expression is common in both dermatomyositis and lupus myositis.

INTRODUCTION/AIMS: Myxovirus resistance protein A (MxA) is a type I interferon (IFN1) pathway activation marker and MxA sarcoplasmic expression is currently recognized as a highly specific marker for dermatomyositis (DM). However, we have frequently observed endothelial tubuloreticular inclusions (TRI), another surrogate IFN1 activation marker, in a variety of overlap myositides. The aim of this study was to examine MxA expression in those myositides. METHODS: We retrospectively performed MxA immunostaining on a wide range of myositides. RESULTS: MxA sarcoplasmic expression was present in DM (94.4%, 17/18), active lupus myositis (LM, 80%,16/20), inactive LM (36%, 4/11), antisynthetase syndrome (ASyS, 20%, 2/10), systemic sclerosis (13%, 2/15), Sjogren's syndrome (7.7%, 1/13), and human immunodeficiency virus (HIV) myositis (5.6%, 1/18) and was absent in immune-mediated necrotizing myopathy (IMNM, 0/16) and hydroxychloroquine myopathy (0/5). The sensitivity and specificity of MxA sarcoplasmic expression for LM and DM combined compared with all other myositides were 84.6% (95% CI: 69.5-94.1) and 92.1 (95% CI: 83.6-97.0), respectively, and superior to TRIs. MxA capillary expression was nonspecific. Histologically, 35% of LM cases demonstrated a unique panfascicular necrotizing myopathy pattern. The remainder of the LM cases had significant morphological overlap with DM/ASyS (20%), IMNM (20%), or polymyositis (15%). DISCUSSION: MxA sarcoplasmic expression is highly prevalent in LM and DM and is a useful marker in differentiating DM and LM from other myositides. LM can manifest in various pathology patterns that need to be differentiated from DM, IMNM, ASyS, and polymyositis.

Ectopic PLAG1 induces muscular dystrophy in the mouse.

Even though various genetic mutations have been identified in muscular dystrophies (MD), there is still a need to understand the biology of MD in the absence of known mutations. Here we reported a new mouse model of MD driven by ectopic expression of PLAG1. This gene encodes a developmentally regulated transcription factor known to be expressed in developing skeletal muscle, and implicated as an oncogene in certain cancers including rhabdomyosarcoma (RMS), an aggressive soft tissue sarcoma composed of myoblast-like cells. By breeding loxP-STOP-loxP-PLAG1 (LSL-PLAG1) mice into the MCK-Cre line, we achieved ectopic PLAG1 expression in cardiac and skeletal muscle. The Cre/PLAG1 mice died before 6 weeks of age with evidence of cardiomyopathy significantly limiting left ventricle fractional shortening. Histology of skeletal muscle revealed dystrophic features, including myofiber necrosis, fiber size variation, frequent centralized nuclei, fatty infiltration, and fibrosis, all of which mimic human MD pathology. QRT-PCR and Western blot revealed modestly decreased Dmd mRNA and dystrophin protein in the dystrophic muscle, and immunofluorescence staining showed decreased dystrophin along the cell membrane. Repression of Dmd by ectopic PLAG1 was confirmed in dystrophic skeletal muscle and various cell culture models. In vitro studies showed that excess IGF2 expression, a transcriptional target of PLAG1, phenocopied PLAG1-mediated down-regulation of dystrophin. In summary, we developed a new mouse model of a lethal MD due to ectopic expression of PLAG1 in heart and skeletal muscle. Our data support the potential contribution of excess IGF2 in this model. Further studying these mice may provide new insights into the pathogenesis of MD and perhaps lead to new treatment strategies.

Metabolite analysis of soybean oil on promoting astaxanthin production of Phaffia rhodozyma.

BACKGROUND: Astaxanthin is a carotenoid with strong antioxidant property. In addition, it has anti-cancer, anti-tumor, anti-inflammatory and many other functions. The micro-organisms that mainly produce astaxanthin are Haematococcus pluvialis and Phaffia rhodozyma. Compared with H. pluvialis, P. rhodozyma has shorter fermentation cycle and easier to control culture conditions, but the yield of astaxanthin in P. rhodozyma is low. This article studied how to improve the astaxanthin production of P. rhodozyma. RESULTS: The results showed that when 10 mL L-1 soybean oil was added to the culture medium, astaxanthin production increased significantly, reaching 7.35 mg L-1 , which was 1.4 times that of the control group, and lycopene and ß-carotene contents also increased significantly. Through targeted metabolite analysis, the fatty acids in P. rhodozyma significantly increased under the soybean oil stimulation, especially the fatty acids closely related to the formation of astaxanthin esters, included palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n9), linoleic acid (C18:2n6), α-linolenic acid (C18:3n3) and γ-linolenic acid (C18:3n6), thereby increasing the astaxanthin esters content. CONCLUSION: It showed that the addition of soybean oil can promote the accumulation of astaxanthin by promoting the increase of astaxanthin ester content. © 2022 Society of Chemical Industry.

Epigenetic and genomic profiling of chordoid meningioma: implications for clinical management.

Chordoid meningioma is a morphological variant of meningioma designated as WHO grade 2. However, the recurrence rates varied widely in different case series, and to date, a unifying molecular genetic signature has not been identified. Among 1897 meningiomas resected at our institution, we identified 12 primary chordoid meningiomas from 12 patients. Histologically, all 12 cases had predominant (> 50%) chordoid morphology. Ten were otherwise grade 1, and two were also atypical. We performed DNA global methylation profile, copy number variation analysis, and targeted next-generation sequencing on 11 chordoid meningiomas, and compared to those of 51 non-chordoid, mostly high grade meningiomas. The chordoid meningiomas demonstrated a unique methylation profile in tSNE, UMAP, and hierarchical heatmap clustering analyses of the most differentially methylated CpGs. The most common copy number variation in chordoid meningioma was loss of 1p (7/11, 64%). Three chordoid meningiomas had 2p loss, which was significantly higher than the non-chordoid control cohort (27% vs 7.2%, p = 0.035). 22q loss was only seen in the two cases with additional atypical histological features. Chordoid meningiomas were enriched in mutations in chromatin remodeling genes EP400 (8/11,73%) KMT2C (4/11, 36%) and KMT2D (4/11, 36%), and showed low or absent NF2, TERT, SMO, and AKT1 mutations. Prognosis wise, only one case recurred. This case had atypical histology and high-grade molecular features including truncating NF2 mutation, 1p, 8p, 10, 14, 22q loss, and homozygous deletion of CDKN2A/B. Progression free survival of chordoid, otherwise grade 1 meningioma was comparable to non-chordoid WHO grade 1 meningioma (p = 0.75), and significantly better than chordoid WHO grade 2 meningioma (p = 0.019). Conclusion: the chordoid histology alone may not justify a universal WHO grade 2 designation. Screening for additional atypical histological or molecular genetic features is recommended.

The efficacy of immunohistochemistry in the diagnosis of molecular genetic alterations in central nervous system gliomas: Next-generation sequencing of 212 mutations in 112 patients.

Identification of molecular genetic alterations has become an important part of diagnosis and care of patients with brain tumors. Comparisons of immunohistochemistry (IHC) with DNA sequencing techniques have suggested that IHC is useful for identifying surrogates of mutations in gliomas; however, studies of the efficacy are relatively few. Our aim was to compare IHC in our neuropathology laboratory with a commercially available next-generation sequencing (NGS) platform, Tempus xT. We studied 212 immunohistochemically stained sections of gliomas to identify mutations of isocitrate dehydrogenase (IDH), p53, BRAF, the α-thalassemia/mental retardation syndrome X-linked protein (ATRX), and histone H3. Tempus xT NGS confirmed the IHC diagnosis of IDH1/R132H in 102 of 102 patients (100%), BRAF/V600E in 14 of 14 (100%) patients and H3/K27M in 10 of 10 (100%) patients. For p53, NGS confirmed the IHC diagnosis of mutation in 47 of 53 (87%) patients. For 6 patients, IHC was interpreted as wild-type while NGS indicated a mutation. NGS confirmed the IHC diagnosis of ATRX mutation in 29 of 31 (94%) patients. In 1 patient, IHC predicted a mutation that was not confirmed by NGS, and in another, IHC predicted wild-type, but NGS showed mutant. In 2 other patients, IHC diagnosis of ATRX mutation was equivocal; 1 was mutant and 1 was wild-type by NGS. Our single-center study suggests that IHC for IDH1/R132H, BRAF/V600E, and H3/K27M is highly reliable and may be used confidently in clinical practice. IHC for p53 and ATRX mutations is often reliable but possibly problematic, and genetic studies may be necessary to determine astrocytic or oligodendroglial differentiation.

Preoperative imaging of glioblastoma patients using hyperpolarized 13C pyruvate: Potential role in clinical decision making.

BACKGROUND: Glioblastoma remains incurable despite treatment with surgery, radiation therapy, and cytotoxic chemotherapy, prompting the search for a metabolic pathway unique to glioblastoma cells.13C MR spectroscopic imaging with hyperpolarized pyruvate can demonstrate alterations in pyruvate metabolism in these tumors. METHODS: Three patients with diagnostic MRI suggestive of a glioblastoma were scanned at 3 T 1-2 days prior to tumor resection using a 13C/1H dual-frequency RF coil and a 13C/1H-integrated MR protocol, which consists of a series of 1H MR sequences (T2 FLAIR, arterial spin labeling and contrast-enhanced [CE] T1) and 13C spectroscopic imaging with hyperpolarized [1-13C]pyruvate. Dynamic spiral chemical shift imaging was used for 13C data acquisition. Surgical navigation was used to correlate the locations of tissue samples submitted for histology with the changes seen on the diagnostic MR scans and the 13C spectroscopic images. RESULTS: Each tumor was histologically confirmed to be a WHO grade IV glioblastoma with isocitrate dehydrogenase wild type. Total hyperpolarized 13C signals detected near the tumor mass reflected altered tissue perfusion near the tumor. For each tumor, a hyperintense [1-13C]lactate signal was detected both within CE and T2-FLAIR regions on the 1H diagnostic images (P = .008). [13C]bicarbonate signal was maintained or decreased in the lesion but the observation was not significant (P = .3). CONCLUSIONS: Prior to surgical resection, 13C MR spectroscopic imaging with hyperpolarized pyruvate reveals increased lactate production in regions of histologically confirmed glioblastoma.

SWI/SNF deficient central nervous system neoplasms.

The SWItch/Sucrose Non-Fermentable (SWI/SNF) complexes are ubiquitous ATP dependent chromatin remodeling complexes that provide epigenetic regulation of gene expressions across the genome. Different combination of SWI/SNF subunits allow tissue specific regulation of critical cellular processes. The identification of SMARCB1 inactivation in pediatric malignant rhabdoid tumors provided the first example that the SWI/SNF complex may act as a tumor suppressor. It is now estimated at least 20% of all human tumors contain mutations in the subunits of the SWI/SNF complex. This review summarizes the central nervous system tumors with alterations in the SWI/SNF complex genes. Atypical teratoid/rabdoid tumor (AT/RT) is a highly aggressive embryonal tumor genetically characterized by bi-allelic inactivation of SMARCB1, and immunohistochemically shows complete absence of nuclear expression of its protein product INI1. A small subset of AT/RT show retained INI1 expression but defects in another SWI/SNF complex gene SMARCA4. Embryonal tumors with medulloblastoma, pineoblastoma, or primitive neuroectodermal morphology but loss of INI1 expression are now classified as AT/RT. Cribriform neuroepithelial tumor (CRINET) is an intra or para-ventricular tumor that has similar SMARCB1 alterations as AT/RT but generally has a benign clinical course. Besides AT/RT and CRINET, compete loss of nuclear INI1 expression has also been reported in poorly differentiated chordoma and intracranial myxoid sarcoma within the central nervous system. Families with non-truncating SMARCB1 mutations are prone to develop schwannomatosis and a range of developmental syndromes. The schwannomas in these patients usually demonstrate a mosaic INI1 staining pattern suggestive of partial residual protein function. Finally, clear cell meningioma is a WHO grade II variant meningioma characterized by bi-allelic inactivation of the SMARCE1 gene and immunohistochemically show loss of its protein product BAF57 expression in tumor cell nuclei.

Distinct tissue injury patterns in juvenile dermatomyositis auto-antibody subgroups.

INTRODUCTION: Juvenile dermatomyositis (JDM) can be classified into clinical serological subgroups by distinct myositis-specific antibodies (MSAs). It is incompletely understood whether different MSAs are associated with distinct pathological characteristics, clinical disease activities, or response to treatment. METHODS: We retrospectively reviewed clinicopathological data from consecutive JDM patients followed in the pediatric rheumatology clinic at a single center between October 2016 and November 2018. Demographics, clinical data, and laboratory data were collected and analyzed. Detailed muscle biopsy evaluation of four domains (inflammation, myofiber, vessels, and connective tissue) was performed, followed by statistical analysis. RESULTS: Of 43 subjects included in the study, 26 (60.5%) had a detectable MSA. The most common MSAs were anti-NXP-2 (13, 30.2%), anti-Mi-2 (7, 16.3%), and anti-MDA-5 (5, 11.6%). High titer anti-Mi-2 positively correlated with serum CK > 10,000 at initial visit (r = 0.96, p = 0.002). Muscle biopsied from subjects with high titer anti-Mi-2 had prominent perifascicular myofiber necrosis and perimysial connective tissue damage that resembled perifascicular necrotizing myopathy, but very little capillary C5b-9 deposition. Conversely, there was no positive correlation between the levels of the anti-NXP-2 titer and serum CK (r = - 0.21, p = 0.49). Muscle biopsies from patients with anti-NXP-2 showed prominent capillary C5b-9 deposition; but limited myofiber necrosis. Only one patient had anti-TIF1γ autoantibody, whose muscle pathology was similar as those with anti-NXP2. All patients with anti-MDA-5 had normal CK and near normal muscle histology. CONCLUSIONS: Muscle biopsy from JDM patients had MSA specific tissue injury patterns. These findings may help improve muscle biopsy diagnosis accuracy and inform personalized treatment of JDM.

Multi-Site Optical Monitoring of Spinal Cord Ischemia during Spine Distraction.

Optimal surgical management of spine trauma will restore blood flow to the ischemic spinal cord. However, spine stabilization may also further exacerbate injury by inducing ischemia. Current electrophysiological technology is not capable of detecting acute changes in spinal cord blood flow or localizing ischemia. Further, alerts are delayed and unreliable. We developed an epidural optical device capable of directly measuring and immediately detecting changes in spinal cord blood flow using diffuse correlation spectroscopy (DCS). Herein we test the hypothesis that our device can continuously monitor blood flow during spine distraction. Additionally, we demonstrate the ability of our device to monitor multiple sites along the spinal cord and axially resolve changes in spinal cord blood flow. DCS-measured blood flow in the spinal cord was monitored at up to three spatial locations (cranial to, at, and caudal to the distraction site) during surgical distraction in a sheep model. Distraction was halted at 50% of baseline blood flow at the distraction site. We were able to monitor blood flow with DCS in multiple regions of the spinal cord simultaneously at ∼1 Hz. The distraction site had a greater decrement in flow than sites cranial to the injury (median -40 vs. -7%,). This pilot study demonstrated high temporal resolution and the capacity to axially resolve changes in spinal cord blood flow at and remote from the site of distraction. These early results suggest that this technology may assist in the surgical management of spine trauma and in corrective surgery of the spine.

Utility of copy number variants in the classification of intracranial ependymoma.

Ependymomas are neuroepithelial tumors that differentiate along the ependymal cell lineage, a lining of the ventricles of the brain and the central canal of the spinal cord. They are rare in adults, but account for around 9% of brain tumors in children, where they usually have an aggressive course. Efficient stratification could lead to improved care but remains a challenge even in the genomic era. Recent studies proposed a multivariate classification system based on tumor location, age, and broad genomic findings like global patterns of methylation and copy number variants (CNVs). This system shows improved prognostic utility, but is relatively impractical in the routine clinical setting because it necessitates multiple diagnostic tests. We analyzed 13 intracranial grade II and III ependymoma specimens on a DNA microarray to identify discrete CNVs that could support the existing classification. The loss of chr22 and the gain of 5p15.31 were common throughout our cohort (6 and 11 cases, respectively). Other CNVs correlated well with the previously proposed classification system. For example, gains of chr20 were unique to PF-EPN-B tumors of the posterior fossa and may differentiate them from PF-EPN-A. Given the ease of detecting CNVs using multiple, clinically validated methods, these CNVs should be further studied to confirm their diagnostic and prognostic utility, for incorporation into clinical testing algorithms.

Distinct Expression Patterns of Carbonic Anhydrase IX in Clear Cell, Microcystic, and Angiomatous Meningiomas.

Clear cell, microcytic, and angiomatous meningiomas are 3 vasculature-rich variants with overlapping morphological features but different prognostic and treatment implications. Distinction between them is not always straightforward. We compared the expression patterns of the hypoxia marker carbonic anhydrase IX (CA-IX) in meningiomas with predominant clear cell (n = 15), microcystic (n = 9), or angiomatous (n = 11) morphologies, as well as 117 cases of other World Health Organization recognized histological meningioma variants. Immunostaining for SMARCE1 protein, whose loss-of-function has been associated with clear cell meningiomas, was performed on all clear cell meningiomas, and selected variants of meningiomas as controls. All clear cell meningiomas showed absence of CA-IX expression and loss of nuclear SMARCE1 expression. All microcystic and angiomatous meningiomas showed diffuse CA-IX immunoreactivity and retained nuclear SMARCE1 expression. In other meningioma variants, CA-IX was expressed in a hypoxia-restricted pattern and was highly associated with atypical features such as necrosis, small cell change, and focal clear cell change. In conclusion, CA-IX may serve as a useful diagnostic marker in differentiating clear cell, microcystic, and angiomatous meningiomas.

Dysembryoplastic Neuroepithelial Tumor with Enlarging Heterogeneously Enhancing Organizing Hematoma.

This report portrays an unusual presentation of a dysembryoplastic neuroepithelial tumor characterized by a chronic, enlarging, heterogeneously enhancing organizing hematoma. Differential diagnoses included the malignant transformation of a low-grade glioma, radiation necrosis, and radiation-induced cavernoma. A dysembryoplastic neuroepithelial tumor may have atypical characteristics and behavior, so continued follow-up with serial imaging is recommended.

Role of Nerve and Muscle Biopsies in Pediatric Patients in the Era of Genetic Testing.

BACKGROUND: An operative biopsy is an important component in the diagnosis and treatment of neuromuscular disorders (NMDs). However, recent advances in molecular genetics suggest less invasive genetic testing should be the initial approach. The purpose of our study was to demonstrate the diagnostic value of muscle or nerve biopsy within the pediatric population at a pediatric academic center and offer recommendations for genetic testing in relation to biopsy to achieve the highest diagnostic yield. METHODS: Following institutional review board approval, we retrospectively reviewed the electronic medical record of 221 pediatric patients who underwent muscle and/or nerve biopsy for suspicion of NMD from January 2007 to March 2018. Demographics, family history, clinical presentations, genetic testing results, pathology results, anesthesia complications, clinical diagnoses, and clinic follow-up data were collected. Chi-square analysis was done for statistical significance. RESULTS: A total of 220 underwent muscle biopsy, and 15 underwent nerve biopsy. Not all patients received genetic testing. The average age at biopsy was 7.7 y. Biopsy revealed significant histologic abnormalities in 62.9% (139), directly leading to a specific clinical diagnosis in 33.9% (75). When genetic testing was done before biopsy, definite pathogenic variants were found in 7.6% (9). When genetic testing was done after biopsy, definite pathogenic variants were found in 45.0% (27). Genetic testing yield for pathogenic variants was higher when done after biopsy (P value < 0.00001). CONCLUSIONS: Muscle and nerve biopsies may provide significant diagnostic value. Biopsy helped to rule in or out NMD and guide genetic testing. Our data suggest NMD genetic testing yield was higher when done after biopsy.

A pattern-based approach to the interpretation of skeletal muscle biopsies.

The interpretation of muscle biopsies is complex and provides the most useful information when integrated with the clinical presentation of the patient. These biopsies are performed for workup of a wide range of diseases including dystrophies, metabolic diseases, and inflammatory processes. Recent insights have led to changes in the classification of inflammatory myopathies and have changed the role that muscle biopsies have in the workup of inherited diseases. These changes will be reviewed. This review follows a morphology-driven approach by discussing diseases of skeletal muscle based on a few basic patterns that include cases with (1) active myopathic damage and inflammation, (2) active myopathic damage without associated inflammation, (3) chronic myopathic changes, (4) myopathies with distinctive inclusions or vacuoles, (5) biopsies mainly showing atrophic changes, and (6) biopsies that appear normal on routine preparations. Each of these categories goes along with certain diagnostic considerations and pitfalls. Individual biopsy features are only rarely pathognomonic. Establishing a firm diagnosis therefore typically requires integration of all of the biopsy findings and relevant clinical information. With this approach, a muscle biopsy can often provide helpful information in the diagnostic workup of patients presenting with neuromuscular problems.

The immune-related microRNA miR-146b is upregulated in glioblastoma recurrence.

BACKGROUND: Glioblastoma (GBM) has a high rate of local recurrence despite chemoradiotherapy (CRT). Genome-wide expression profiling was performed on patient tumors before and after chemoradiotherapy to identify genes and gene pathways associated with recurrence. RESULTS: Median time to recurrence was 8.9 months with median time to second surgery of 9.6 months. The microRNA (miRNA) analysis identified 9 oncologic and immune-related miRNAs to be differentially expressed, including the hypoxia-related miR-210 and the immune-modulatory miR-146b. More than 1200 differentially-expressed genes were identified with RNA-sequencing (RNA-seq). Gene set enrichment analysis (GSEA) identified p53 signaling, Notch, Wnt, VEGF, and MEK gene sets enriched in recurrent GBM. Consistent with the miRNA profiling data, the miR-146b target gene set from GSEA analysis was also associated with recurrence. METHODS: Fourteen patients with GBM recurrence after CRT who had available tumor tissue from the initial diagnosis as well as recurrence were selected. Total RNA was isolated from formalin-fixed paraffin-embedded (FFPE) tumor specimens. Genome-wide expression profiling using RT-PCR for miRNA analysis and RNA-seq for messenger RNA (mRNA) analysis were conducted to identify differentially-expressed genes. GSEA was performed on the differential expression data. CONCLUSIONS: Genome-wide expression profiling identifies multiple oncologic and immune-related gene sets associated with GBM recurrence. In particular, immune-related miR-146b is upregulated in recurrence and deserves further investigation.

Diffuse microvascular C5b-9 deposition is a common feature in muscle and nerve biopsies from diabetic patients.

Terminal complement complex deposition in endomysial capillaries detected by a C5b-9 immunostain is considered a diagnostic feature for dermatomyositis. However, we found widespread microvascular C5b-9 reactivity in a substantial subset of muscle biopsies with denervation changes, and in nerve biopsies of peripheral neuropathies, particularly in patients with diabetes. It is unclear whether the presence of C5b-9 deposition signifies active immune-mediated vascular injury that requires immune suppression therapy. We retrospectively identified 63 nerve biopsies in patients with a documented history of diabetes, 26 of which had concomitant muscle biopsies, as well as 54 control nerve biopsies in patients without a documented diabetes history, 18 of which had concomitant muscle biopsies. C5b-9 immunostain was performed on all cases. 87% of the nerve biopsies and 92% of the muscle biopsies from diabetic patients showed microvascular C5b-9 reactivity, compared to 34% and 50% in non-diabetic patients. The differences were statistically significant (p < 0.0001 for nerve and p = 0.002 for muscle). The C5b-9 reactivity was generally proportional to the extent of microvascular sclerosis in diabetic patients, but unrelated to inflammation or vasculitis. C5b-9 deposition in micro-vasculature in both muscle and nerve is therefore a common feature in patients with diabetic neuropathies and may have diagnostic utility. Precaution needs to be taken before using muscle capillary C5b-9 reactivity as evidence of myositis.

Adult Brainstem Gliomas With H3K27M Mutation: Radiology, Pathology, and Prognosis.

Adult brainstem gliomas are difficult to classify based on radiologic and histologic features. A K27M mutation in histone 3 has been described to identify high-grade midline gliomas associated with a particularly unfavorable prognosis. While initially considered a pediatric entity, it is now known that H3K27M-mutant brainstem gliomas occur in all age groups, but they are less well understood in adults. We studied clinical, radiologic, and pathologic features of 25 brainstem gliomas diagnosed at our institution between 1994 and 2017 in subjects at least 18 years old. Seven tumors (28%) were positive for the H3K27M mutation, and their median overall survival was significantly shorter than in the H3-wildtype group (p = 0.004). Although the mutation was invariably associated with a poor prognosis, our study also illustrates the radiologic and pathologic heterogeneity in this molecular tumor subtype. The results showed that H3K27M-mutant status and clinically aggressive course cannot be ruled out based on low-grade histology on the initial biopsy, exophytic growth, only focal or minimal enhancement or an extrapontine location, such as midbrain or medulla. These results favor an integrated approach employing a combination of clinical, radiologic, histologic features as well as H3K27M immunohistochemistry for the diagnostic subclassification of adult brainstem gliomas.