Histone deacetylase inhibitors enhance oncolytic herpes simplex virus therapy for malignant meningioma.

Approximately 20% of meningiomas are not benign (higher grade) and tend to relapse after surgery and radiation therapy. Malignant (anaplastic) meningioma (MM) is a minor subset of high-grade meningioma that is lethal with no effective treatment options currently. Oncolytic herpes simplex virus (oHSV) is a powerful anti-cancer modality that induces both direct cell death and anti-tumor immunity, and has shown activity in preclinical models of MM. However, clinically meaningful efficacy will likely entail rational mechanistic combination approaches. We here show that epigenome modulator histone deacetylase inhibitors (HDACi) increase anti-cancer effects of oHSV in human MM models, IOMM-Lee (NF2 wild-type) and CH157 (NF2 mutant). Minimally toxic, sub-micromolar concentrations of pan-HDACi, Trichostatin A and Panobinostat, substantively increased the infectability and spread of oHSV G47Δ within MM cells in vitro, resulting in enhanced oHSV-mediated killing of target cells when infected at low multiplicity of infection (MOI). Transcriptomics analysis identified selective alteration of mRNA processing and splicing modules that might underlie the potent anti-MM effects of combining HDACi and oHSV. In vivo, HDACi treatment increased intratumoral oHSV replication and boosted the capacity of oHSV to control the growth of human MM xenografts. Thus, our work supports further translational development of the combination approach employing HDACi and oHSV for the treatment of MM.

In Vivo Platelet Detection Using a Glycoprotein IIb/IIIa-Targeted Near-Infrared Fluorescence Imaging Probe.

Platelets play a prominent role in multiple diseases, in particular arterial and venous thrombosis and also in atherosclerosis and cancer. To advance the in vivo study of the biological activity of this cell type from a basic experimental focus to a clinical focus, new translatable platelet-specific molecular imaging agents are required. Herein, we report the development of a near-infrared fluorescence probe based upon tirofiban, a clinically approved small-molecule glycoprotein IIb/IIIa inhibitor (GPIIb/IIIa). Through in vitro experiments with human platelets and in vivo ones in a murine model of deep-vein thrombosis, we demonstrate the avidity of the generated probe for activated platelets, with the added benefit of a short blood half-life, thereby enabling rapid in vivo visualization within the vasculature.

Mesenchymal glioblastoma-induced mature de-novo vessel formation of vascular endothelial cells in a microfluidic device.

High vascularization is a biological characteristic of glioblastoma (GBM); however, an in-vitro experimental model to verify the mechanism and physiological role of vasculogenesis in GBM is not well-established. Recently, we established a self-organizing vasculogenic model using human umbilical vein endothelial cells (HUVECs) co-cultivated with human lung fibroblasts (hLFs). Here, we exploited this system to establish a realistic model of vasculogenesis in GBM. We developed two polydimethylsiloxane (PDMS) devices, a doughnut-hole dish and a 5-lane microfluidic device to observe the contact-independent effects of glioblastoma cells on HUVECs. We tested five patient-derived and five widely used GBM cell lines. Confocal fluorescence microscopy was used to observe the morphological changes in Red Fluorescent Protein (RFP)-HUVECs and fluorescein isothiocyanate (FITC)-dextran perfusion. The genetic and expression properties of GBM cell lines were analyzed. The doughnut-hole dish assay revealed KNS1451 as the only cells to induce HUVEC transformation to vessel-like structures, similar to hLFs. The 5-lane device assay demonstrated that KNS1451 promoted the formation of a vascular network that was fully perfused, revealing the functioning luminal construction. Microarray analysis revealed that KNS1451 is a mesenchymal subtype of GBM. Using a patient-derived mesenchymal GBM cell line, mature de-novo vessel formation could be induced in HUVECs by contact-independent co-culture with GBM in a microfluidic device. These results support the development of a novel in vitro research model and provide novel insights in the neovasculogenic mechanism of GBM and may potentially facilitate the future detection of unknown molecular targets.

Modification of Extracellular Matrix Enhances Oncolytic Adenovirus Immunotherapy in Glioblastoma.

PURPOSE: Extracellular matrix (ECM) component hyaluronan (HA) facilitates malignant phenotypes of glioblastoma (GBM), however, whether HA impacts response to GBM immunotherapies is not known. Herein, we investigated whether degradation of HA enhances oncolytic virus immunotherapy for GBM. EXPERIMENTAL DESIGN: Presence of HA was examined in patient and murine GBM. Hyaluronidase-expressing oncolytic adenovirus, ICOVIR17, and its parental virus, ICOVIR15, without transgene, were tested to determine if they increased animal survival and modulated the immune tumor microenvironment (TME) in orthotopic GBM. HA regulation of NF-κB signaling was examined in virus-infected murine macrophages. We combined ICOVIR17 with PD-1 checkpoint blockade and assessed efficacy and determined mechanistic contributions of tumor-infiltrating myeloid and T cells. RESULTS: Treatment of murine orthotopic GBM with ICOVIR17 increased tumor-infiltrating CD8+ T cells and macrophages, and upregulated PD-L1 on GBM cells and macrophages, leading to prolonged animal survival, compared with control virus ICOVIR15. High molecular weight HA inhibits adenovirus-induced NF-κB signaling in macrophages in vitro, linking HA degradation to macrophage activation. Combining ICOVIR17 with anti-PD-1 antibody further extended the survival of GBM-bearing mice, achieving long-term remission in some animals. Mechanistically, CD4+ T cells, CD8+ T cells, and macrophages all contributed to the combination therapy that induced tumor-associated proinflammatory macrophages and tumor-specific T-cell cytotoxicity locally and systemically. CONCLUSIONS: Our studies are the first to show that immune modulatory ICOVIR17 has a dual role of mediating degradation of HA within GBM ECM and subsequently modifying the immune landscape of the TME, and offers a mechanistic combination immunotherapy with PD-L1/PD-1 blockade that remodels innate and adaptive immune cells.

A Dorsally Located Endodermal Cyst in the Foramen Magnum Mimicking an Arachnoid Cyst: A Case Report.

INTRODUCTION: Endodermal cysts are congenital benign cystic lesions in the central nervous system and cause various symptoms. Although some have been reported in the posterior fossa, endodermal cysts located dorsal to the brainstem are extremely rare. CASE PRESENTATION: The case was of a 10-year-old girl who presented with bilateral upper limb weakness and tremor. Magnetic resonance imaging demonstrated a 4.5-cm cystic lesion with T1-weighted hypointense and T2-weighted hyperintense content in the midline of the cisterna magna dorsal to the medulla oblongata. The cyst was cerebrospinal fluid-like, causing us to suspect a symptomatic arachnoid cyst. The lucent cyst wall had no apparent attachment, and complete recovery ensued following total excision of the cyst wall. Pathology confirmed a diagnosis of endodermal cyst. DISCUSSION/CONCLUSION: Herein, we review the past literature on this rare entity. An endodermal cyst in the cisterna magna tends to be less strongly attached and to show a cerebrospinal fluid-like component on magnetic resonance images that mimics an arachnoid cyst. The characteristics of dorsally located endodermal cysts may differ from those in other locations.

[A Case of Ruptured Cerebral Arteriovenous Malformation Associated with Hereditary Hemorrhagic Telangiectasia].

BACKGROUND: Patients with hereditary hemorrhagic telangiectasia(HHT)are known to have high rates of cerebral arteriovenous malformations(AVMs). Compared to patients with sporadic AVMs, patients with HHT are less likely to present with ruptured AVMs. CASE REPORT: A 14-year-old male patient presented with headache that had lasted for 2 days. CT revealed an intracerebral hemorrhage in the right parietal lobe, and enhanced CT revealed an AVM in the upper part of the hematoma. The size of the nidus was 20 mm, and its feeders were the right superior internal parietal artery and a branch of the anterior cerebral artery. In addition, the AVM had no deep drainer. We also found another AVM in the right temporal lobe and identified telangiectasia of the nose using digital subtraction angiography. We suspected HHT and performed whole body CT, which revealed an arteriovenous fistula in the right lung and a hematoma-like lesion in the spleen. Thus, we diagnosed the patient with HHT. His ruptured AVM was removed electively. CONCLUSION: We report a case of HHT that presented as an intracerebral hemorrhage in a patient. Based on our case study findings, it is necessary to perform long-term follow-up not only for brain AVMs but also for visceral vascular malformations in such patients, as well as perform HHT screening for families. Although such cases are rare, some features of HHT must be considered to accurately diagnose suspected HHT.

A Monoclonal Antibody Against ß1 Integrin Inhibits Proliferation and Increases Survival in an Orthotopic Model of High-Grade Meningioma.

BACKGROUND: High-grade meningiomas (HGMs; World Health Organization [WHO] classification grade II and III) have high relapse rates and poor clinical outcomes despite surgery and radiation treatments. No effective medical therapy currently exists for HGMs, and developing novel therapeutic strategies depends on the identification of molecular drivers. In cancer, ß1 integrin enhances malignant characteristics, including proliferation, invasion, and drug resistance. OBJECTIVE: We conducted this study to investigate whether ß1 integrin could be a therapeutic target in HGMs. PATIENTS AND METHODS: Expression of ß1 integrin was examined in gene array datasets, with proteomics of clinical meningioma specimens, and in patient-derived HGM xenografts. Anti-tumor activity of OS2966, a first-in-class humanized antagonizing monoclonal antibody against ß1 integrin, was tested in vitro and in vivo using an orthotopic mouse model of patient-derived malignant meningioma. RESULTS: ß1 integrin was expressed in meningiomas of all WHO grades and two xenografts tested. In vitro, OS2966 suppressed the viability of NF2-deficient MN3 sphere cells and NF2-wild-type IOMM-Lee malignant meningioma cells only when plated on laminin-coated plastic. While OS2966 decreased phosphorylation of ERK1/2 in both MN3 cells and laminin-grown IOMM-Lee cells, OS2966 only affected the phosphorylation of FAK (Tyr397) in MN3, and of Akt (Ser473) in IOMM-Lee cells, respectively, indicating differential pathway inhibition. Systemic administration of OS2966 in mice bearing orthotopic MN3 HGMs inhibited HGM cell proliferation and significantly extended overall survival of the treated mice. CONCLUSIONS: ß1 Integrin may be a therapeutic target in HGMs, and further preclinical and clinical development of OS2966 for HGM therapy is warranted.

New aspects of glioblastoma multiforme revealed by similarities between neural and glioblastoma stem cells.

Neural stem cells (NSCs) undergo self-renewal and generate neurons and glial cells under the influence of specific signals from surrounding environments. Glioblastoma multiforme (GBM) is a highly lethal brain tumor arising from NSCs or glial precursor cells owing to dysregulation of transcriptional and epigenetic networks that control self-renewal and differentiation of NSCs. Highly tumorigenic glioblastoma stem cells (GSCs) constitute a small subpopulation of GBM cells, which share several characteristic similarities with NSCs. GSCs exist atop a stem cell hierarchy and generate heterogeneous populations that participate in tumor propagation, drug resistance, and relapse. During multimodal treatment, GSCs de-differentiate and convert into cells with malignant characteristics, and thus play critical roles in tumor propagation. In contrast, differentiation therapy that induces GBM cells or GSCs to differentiate into a neuronal or glial lineage is expected to inhibit their proliferation. Since stem cell differentiation is specified by the cells' epigenetic status, understanding their stemness and the epigenomic situation in the ancestor, NSCs, is important and expected to be helpful for developing treatment modalities for GBM. Here, we review the current findings regarding the epigenetic regulatory mechanisms of NSC fate in the developing brain, as well as those of GBM and GSCs. Furthermore, considering the similarities between NSCs and GSCs, we also discuss potential new strategies for GBM treatment.

Synergistic induction of astrocytic differentiation by factors secreted from meninges in the mouse developing brain.

Astrocytes, which support diverse neuronal functions, are generated from multipotent neural stem/precursor cells (NS/PCs) during brain development. Although many astrocyte-inducing factors have been identified and studied in vitro, the regions and/or cells that produce these factors in the developing brain remain elusive. Here, we show that meninges-produced factors induce astrocytic differentiation of NS/PCs. Consistent with the timing when astrocytic differentiation of NS/PCs increases, expression of astrocyte-inducing factors is upregulated. Meningeal secretion-mimicking combinatorial treatment of NS/PCs with bone morphogenetic protein 4, retinoic acid and leukemia inhibitory factor synergistically activate the promoter of a typical astrocytic marker, glial fibrillary acidic protein. Taken together, our data suggest that meninges play an important role in astrocytic differentiation of NS/PCs in the developing brain.

Ruptured Aneurysm of an Aberrant Internal Carotid Artery Successfully Treated with Simultaneous Intervention and Surgery in a Hybrid Operating Room.

BACKGROUND: Aberrant internal carotid artery (aICA) is an anatomic anomaly whereby the internal carotid artery courses through the tympanic cavity without separation by bone. Because aICA is rare, there are no definite treatment strategies for aICA and its complications. CASE DESCRIPTION: We report a case of aICA accompanied by pseudoaneurysm formation and massive bleeding. The patient was a 31-year-old woman with a 2-year history of hearing loss, ear fullness, and pulsatile tinnitus in her left ear. After a diagnosis of otitis media with effusion, she underwent a myringotomy and massive arterial bleeding occurred. After the bleeding was temporarily stopped, aICA and pseudoaneurysm formation on the aICA were shown. To prevent rebleeding, we performed endovascular internal trapping around the pseudoaneurysm after performing common carotid artery to radial artery to middle cerebral artery bypass grafting. After surgery, the aneurysm disappeared. In addition, no new neurologic complications were observed, and the patient's hearing improved and the tinnitus diminished. CONCLUSIONS: This is the first case report of an aICA complicated by pseudoaneurysm formation successfully treated with simultaneous endovascular trapping and high-flow bypass in a hybrid operating room.

Evaluation of carotid artery outward remodeling by T1-weighted magnetic resonance imaging in carotid endarterectomy and stenting.

OBJECTIVE: We evaluated carotid artery outward remodeling and plaque relative signal intensity (rSI) using T1-weighted magnetic resonance imaging (T1-MRI) to investigate their clinical significance in carotid revascularization. METHODS: From 86 patients undergoing carotid endarterectomy (CEA) or carotid artery stenting (CAS), 88 lesions (51 lesions treated with CEA and 37 lesions treated with CAS) were analyzed retrospectively. We evaluated the preoperative carotid artery remodeling index (CRI), determined by a ratio of the external cross-sectional vessel area at maximum stenosis and the reference cross-sectional vessel area at the distal portion of the internal carotid artery, and the plaque rSI, which is quantified as the ratio between the signal intensities of plaque and adjacent muscle using T1-MRI. We divided carotid lesions into four groups using the median values of CRI and rSI: L/L (CRI < 1.8, rSI < 2.5), H/L (CRI ≥ 1.8, rSI < 2.5), L/H (CRI < 1.8, rSI ≥ 2.5), and H/H (CRI ≥ 1.8, rSI ≥ 2.5). The primary end point was detection of acute ipsilateral ischemia on diffusion-weighted imaging (DWI) within 72 hours of treatment. RESULTS: Mean CRI and rSI were significantly higher in lesions treated with CEA than in those treated with CAS. Postoperative DWI abnormalities were observed in 4 CEA cases (7.8%) and 10 CAS cases (27.0%) (P = .01). In the CAS group, the frequency of DWI abnormalities was 5.5% for the L/L, 40.0% for the H/L and L/H, and 55.5% for the H/H group (P = .009). Multivariate analysis showed that the degree of stenosis and H/H lesion were independent risk factors for cerebral embolism. No correlation was found between plaque parameters and postoperative DWI findings in the CEA group. CONCLUSIONS: CRI and rSI provide complementary information for the prediction of high-risk plaques associated with CAS but not with CEA. Preoperative evaluation with T1-MRI facilitates the selection of a treatment strategy for carotid artery stenosis.

[Brain natriuretic peptide in subarachnoid hemorrhage].

Because of the known correlation between the brain natriuretic peptide (BNP) level and the severity of cardiac failure, cardiac function assessment often involves measuring BNP levels. In addition, BNP is produced in the hypothalamus; high BNP levels are reported in patients with subarachnoid hemorrhage (SAH), although the details of this mechanism remain to be clarified. Furthermore, there are unconfirmed reports of high BNP levels during follow up in cases of post-SAH cerebral vasospasm (CVS). In the present study, we retrospectively investigated the correlation between plasma BNP levels and severity of SAH at onset and the utility of the BNP level as a predictor for CVS. Of 149 SAH cases treated as inpatients at our institution between November 2008 and March 2010, our subjects comprised 28 SAH cases in which the plasma BNP level was measured at the time of hospitalization (≦48 hours after SAH onset). There was no significant correlation between BNP levels and SAH severity at the onset, but BNP levels tended to be high in cases accompanied by intracerebral hematoma, particularly in patients with an anterior communicating aneurysm rupture. This is thought to be the result of direct damage to the hypothalamus. The cases with normal BNP levels at the onset of SAH were apt to have favorable outcomes. The incidence of delayed ischemic neurological deficit (DIND) was investigated in 15 cases in which the BNP level was measured multiple times during follow up. The ratio of BNP at SAH onset compared to at days 3 to 7 of the illness was not significant; however, BNP levels tended to be high in cases with DIND complications. BNP levels may constitute a useful early marker for CVS, despite BNP susceptibility to surgical invasion and perioperative management.