Co-expression of midkine and pleiotrophin predicts poor survival in human glioma

The aim of this study was to investigate whether co-expression of midkine (MK) and pleiotrophin (PTN) has prognostic relevance in human gliomas. Immunohistochemistry was used to investigate the expression of MK and PTN proteins in 168 patients with gliomas. The levels of MK and PTN mRNA in glioma tissues and paratumor tissues were evaluated in 45 paired cases by quantitative real-time polymerase chain reaction (qRT-PCR). Kaplan–Meier survival analysis was performed to assess prognostic significance. The expression levels of MK and PTN proteins in glioma tissue were both significantly higher (both p < 0.001) than those in paratumor tissues on immunohistochemistry analysis, which was confirmed by qRT-PCR analysis. Additionally, the overexpression of either MK or PTN was significantly associated with the World Health Organization Grade (p = 0.001 and 0.034, respectively), low Karnofsky Performance Status (KPS) score (p = 0.022 and 0.001, respectively), time to recurrence (p = 0.043 and 0.011, respectively) and poor overall survival (p = 0.018 and 0.001, respectively). Multivariate Cox proportional-hazards regression analysis revealed that increased expressions of MK and PTN were both independent prognostic factors for poor overall survival (p = 0.030 and 0.022, respectively). Furthermore, the co-expression of MK and PTN was more significantly (p = 0.003) associated with adverse prognosis in patients with gliomas than the respective expression of MK or PTN alone. To our knowledge, these findings are the first to indicate that the co-expression of MK and PTN is significantly correlated with prognosis in glioma patients, suggesting that the co-expression of these proteins may be used as both an early diagnostic and independent prognostic marker.     

The influence of carmustine wafer implantation on tumor bed cysts and peritumoral brain edema

The development of perifocal edema and tumor bed cyst has been reported after implantation of biodegradable carmustine wafers for the treatment of malignant gliomas. We retrospectively evaluated these changes in a series of patients; 19 consecutive patients with malignant glioma who received carmustine wafer implantation at our hospital from January 2013 through July 2013, and 28 patients who underwent surgery prior to our institution’s initiation of carmustine wafer implantation, as historical controls. The volume of the tumor bed cyst and perifocal edema was calculated on MRI acquired at four time points: ⩽72 hours after surgery for baseline, and at 1–4, 5–8, and 9–12 weeks after surgery. The volume of the tumor bed cyst in the wafer group increased significantly relative to the control group at all time points (p = 0.04). Opening of the ventricle was inversely correlated with enlargement of the tumor bed cyst in the wafer group (p = 0.04). The change in the volume of perifocal edema in the wafer group was not significantly different (p = 0.48), but exhibited a considerable increase in patients with anaplastic oligodendroglioma relative to glioblastoma patients in the wafer group (p = 0.01). We demonstrated significant enlargement of the tumor bed cyst volume after carmustine wafer implantation, as well as the development of marked perifocal edema in patients with anaplastic oligodendroglioma.     

KPNA2 predicts long term survival in patients with anaplastic oligoastrocytomas

The family of karyopherins comprises importins and exportins which are both involved in nucleocytoplasmic shuttling. Increased levels of karyopherin a2/importin 1 (KPNA2) and chromosome region maintenance protein 1/exportin 1 (CRM1) have been associated with poorer prognosis in patients with infiltrative astrocytomas. Isocitrate dehydrogenase 1 gene (IDH1) R132H mutation status was also recently identified as a prognostic factor for malignant gliomas. We evaluated KPNA2 and CRM1, as well as the IDH1 mutation status, as possible novel biomarkers for World Health Organization grade III anaplastic oligoastrocytomas (AOA). We analyzed nuclear expression of KPNA2 by immunohistochemistry in 72 primary anaplastic gliomas (29 AOA, 24 anaplastic astrocytomas, 19 anaplastic oligodendrogliomas). The IDH1 mutation status was also determined in patients with anaplastic astrocytomas and AOA, and AOA patients were additionally evaluated for CRM1 nuclear expression. Long term survivors (LTS; >8 years) with AOA showed lower KPNA2 expression levels compared to non-LTS (p = 0.005). KPNA2 expression (⩾5% versus <5%, 1–<5%, median) was found to correlate inversely with overall survival (OS) and progression-free survival (PFS) in our overall series as well as in the AOA group (anaplastic gliomas: OS p = 0.017; PFS p = 0.033; AOA: OS p = 0.017, PFS p = 0.040). Mutant IDH1-R132H was detected in 69% of the AOA cohort; a combination of KPNA2 low expression and mutant IDH1-R132H was only seen in LTS (p = 0.050). No differences between the histological subtypes were observed in terms of KPNA2 expression and IDH1-R132H mutation status. To our knowledge this is the first time it has been shown that KPNA2 expression may have potential as a prognostic biomarker for AOA as well.     

Pleomorphic xanthoastrocytomas: Institutional experience of 18 patients

Pleomorphic xanthoastrocytoma (PXA) is a rare, low-grade glioma (World Health Organization Grade II) that most often presents in the first two decades of life. We summarize and present our institutional experience in the management of these tumors. All patients managed for PXA at the University of California San Francisco were retrospectively identified through chart review. Patient demographics, tumor characteristics, management, and follow-up were extracted using medical records. Primary endpoints were overall (OS) and progression-free survival (PFS). In total, nineteen patients were treated for PXA from 1993–2011. Clinical data were available for analysis in 18 patients. Median OS was 209.0 months after date of surgery, with both 5 year and 10 year survival rates of 94%. In this patient cohort, tumor grade (p = 0.07), age (p = 0.32), and extent of resection (p = 0.58) did not predict OS. The majority of tumors (78%) recurred. Median PFS was 21.7 months, with 5 year and 10 year recurrence-free rates of 28% and 22%. On univariate analysis, tumor grade (p = 0.01), but not age (p = 0.51), size (p = 0.30), or extent of resection (p = 0.21), was the only covariate predictive of PFS. In patients presenting with higher tumor grade, however, earlier recurrence was demonstrated. Furthermore, the majority of recurrences (36%) occurred within the first 6 months post-operatively, which indicates the need to closely follow patients for that time.     

An analysis of 170 glioma patients and systematic review to investigate the association between IDH-1 mutations and preoperative glioma-related epilepsy

Seizure is a common presenting symptom of glioma, and many biomarkers have been suggested to be associated with preoperative seizure; however, the relationships between IDH (isocitrate dehydrogenase) mutations and glioma-related epilepsy only recently been studied. The authors aimed to examine the correlations between IDH mutations in glioma patients with preoperative seizures and tumor location. A series of 170 glioma samples were analyzed for IDH1 R132H mutations (amino acid change from arginine to histidine at codon 132) with immunohistochemistry (IHC) staining and for IDH mutations with direct DNA sequencing when the IHC results were negative. If either the IHC or direct DNA sequencing result was positive, the IDH status was defined as mutated. The results of the IDH mutation examinations were used to analyze the relationship between mutations and glioma-related epilepsy. The study population consisted of 64 (37.6%) World Health Organization (WHO) grade II gliomas, 58 (34.1%) grade III, and 48 (28.3%) grade IV gliomas. A total of 84 samples with IDH1 mutations were observed in our study, and 54 of these presented with seizures as the initial symptoms, whereas 28 of the patients with wild-type IDH status presented with seizures (p = 0.043 for the WHO grade II gliomas, p = 0.002 for the grade III gliomas and p = 0.942 for the grade IV gliomas, chi-squared tests). Among the WHO grade II and III gliomas, IDH1 mutations were significantly associated with preoperative seizures, but no significant relationship between IDH mutations and preoperative seizures was found with glioblastoma multiforme.     

Sulforhodamine 101 selectively labels human astrocytoma cells in an animal model of glioblastoma

Sulforhodamine 101 (SR101) is a useful tool for immediate staining of astrocytes. We hypothesized that if the selectivity of SR101was maintained in astrocytoma cells, it could prove useful for glioma research. Cultured astrocytoma cells and acute slices from orthotopic human glioma (n = 9) and lymphoma (n = 6) xenografts were incubated with SR101 and imaged with confocal microscopy. A subset of slices (n = 18) were counter-immunostained with glial fibrillary acidic protein and CD20 for stereological assessment of SR101 co-localization. SR101 differentiated astrocytic tumor cells from lymphoma cells. In acute slices, SR101 labeled 86.50% (±1.86; p < 0.0001) of astrocytoma cells and 2.19% (±0.47; p < 0.0001) of lymphoma cells. SR101-labeled astrocytoma cells had a distinct morphology when compared with in vivo astrocytes. Immediate imaging of human astrocytoma cells in vitro and in ex vivo rodent xenograft tissue labeled with SR101 can identify astrocytic tumor cells and help visualize the tumor margin. These features are useful in studying astrocytoma in the laboratory and may have clinical applications.     

Overexpression of tissue microRNA10b may help predict glioma prognosis

We investigated the relationship between microRNA-10b (miR-10b) expression and prognosis in human glioma patients. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis was used to characterize the expression patterns of miR-10b in 128 glioma and 20 normal brain tissues. Clinical information – age, sex, Karnofsky Performance Status (KPS) and World Health Organization (WHO) grade – were also collected. The associations between miR-10b expression and the clinicopathological factors and outcome of glioma patients were statistically analyzed. Expression levels of miR-10b in glioma tissue were significantly higher than in normal brain tissue (P < 0.001). High-grade glioma (WHO grade III and IV) had much higher miR-10b expression levels than low-grade tumors (WHO grade I and II). Additionally, the increased miR-10b expression in the glioma tissues was significantly associated with a low KPS (P = 0.03). Kaplan–Meier survival curves and Cox regression analyses showed that overexpression of miR-10b (P = 0.01) and high grade (P = 0.02) were independent factors predicting poor outcome for glioma patients. Furthermore, subgroup analyses showed that the miR-10b expression level was significantly associated with poor overall survival in glioma patients with high grades (P < 0.001). Up-regulation of miR-10b may have value in predicting clinical outcome in glioma patients, particularly for those with high pathological grades.     

Relationship among clinical,pathological and bio-molecular features in low-grade epilepsy-associated neuroepithelial tumors

The aim of this study was to evaluate the relationship between molecular markers and clinicopathological features in patients operated on for low-grade epilepsy-associated neuroepithelial tumors. Molecular-genetic signatures are becoming increasingly important in characterizing these lesions, which represent the second most common cause of focal epilepsy in patients undergoing epilepsy surgery. Data from 22 patients operated on for histopathologically confirmed low-grade epilepsy-associated neuroepithelial tumors were retrospectively collected. All specimens were examined for BRAF and IDH mutational status, 1p/19q codeletion and CD34 expression. The relationship between bio-molecular markers and several demographic, clinical and pathological features were analyzed. BRAF mutation was found in 11 (50.0%) patients and CD34 expression in 13 (59.1%). No patients presented IDH mutation or 1p/19q codeletion. Multiple seizure types were present in 5 (45.5%) patients with BRAF mutation and in none of those with BRAF wild type (p = 0.035). Moreover, BRAF mutation was predominant in right-sided lesions (p = 0.004) and CD34 expression was significantly associated with a longer duration of epilepsy (p = 0.027). Several other clinicopathological features, such as association with focal cortical dysplasia and postoperative seizure outcome, showed no significant correlation with molecular markers. Further studies are necessary both to confirm these data in larger cohort of patients and to investigate possible relationships between molecular markers and other clinicopathological features.     

Symptom resolution in infiltrating WHO grade II-IV glioma patients undergoing surgical resection

Past studies of morbidity in patients with infiltrating gliomas have focused on the impact of surgery on quality of life. Surprisingly, little attention has been given to the rate at which the presenting symptoms improve after surgery, even though this is often the patient’s first concern. This study is an initial effort to provide useful information about symptom resolution and factors predicting persistence of symptoms in glioma patients who undergo surgery. We conducted a retrospective analysis on patients who underwent surgery for World Health Organization (WHO) grade II-IV astrocytoma/oligodendroglioma/oligoastrocytoma at our institution. All patients were seen 2–4 months postoperatively, and asked about the persistence of symptoms they experienced preoperatively. Symptoms reported in clinic were assessed against symptoms reported prior to surgery. Our study includes 56 consecutive patients undergoing surgery for gliomas. Of patients who experienced symptoms initially, headache resolved in 18/27 postoperatively, weakness resolved in 8/14 postoperatively, altered mental status resolved in 8/12 postoperatively, vision problems resolved in 7/11 postoperatively, nausea resolved in 5/7 postoperatively, and ataxia resolved in 4/5 postoperatively. Headache was more likely to resolve in patients with frontal or temporal tumors (p = 0.02). Preoperative Karnofsky Performance Scale (KPS) of 70 or less was associated with longer postsurgical hospital stay (p < 0.01). Younger patients were more likely to experience a resolution of altered mental status (p = 0.04). Our analysis provides data regarding the rate at which surgery alleviates patient symptoms and considers variables predicting likelihood of symptom resolution. Some patients will experience symptom resolution following resection of WHO grade II-IV gliomas in the months following surgery.     

Decreased expression of mGluR5 within the dorsolateral prefrontal cortex in autism and increased microglial number in mGluR5 knockout mice: Pathophysiological and neurobehavioral implications

Metabotropic glutamate receptor 5 (mGluR5) and microglial abnormalities have been implicated in autism spectrum disorder (ASD). However, controversy exists as to whether the receptor is down or upregulated in functioning in ASD. In addition, whilst activation of mGluR5 has been shown to attenuate microglial activation, its role in maintaining microglial homeostasis during development has not been investigated. We utilised published microarray data from the dorsolateral prefrontal cortex (DLPFC) of control (n = 30) and ASD (n = 27) individuals to carry out regression analysis to assess gene expression of mGluR5 downstream signalling elements. We then conducted a post-mortem brain stereological investigation of the DLPFC, to estimate the proportion of mGluR5-positive neurons and glia. Finally, we carried out stereological investigation into numbers of microglia in mGluR5 knockout mice, relative to wildtype littermates, together with assessment of changes in microglial somal size, as an indicator of activation status. We found that gene expression of mGluR5 was significantly decreased in ASD versus controls (p = 0.018) as well as downstream elements SHANK3 (p = 0.005) and PLCB1 (p = 0.009) but that the pro-inflammatory marker NOS2 was increased (p = 0.047). Intensity of staining of mGluR5-positive neurons was also significantly decreased in ASD versus controls (p = 0.016). Microglial density was significantly increased in mGluR5 knockout animals versus wildtype controls (p = 0.011). Our findings provide evidence for decreased expression of mGluR5 and its signalling components representing a key pathophysiological hallmark in ASD with implications for the regulation of microglial number and activation during development. This is important in the context of microglia being considered to play key roles in synaptic pruning during development, with preservation of appropriate connectivity relevant for normal brain functioning.     

Hemorrhagic presentation of previously silent brain tumors

Introduction and objectivesAcute presentation with intracranial hemorrhage owing to a previously silent brain tumor (BT) is rare. Although any BT can bleed, the frequency and type of bleeding varies across tumor types.Materials and methodsWe aimed to retrospectively review our experience with 55 patients with BTs presenting with ICH.ResultsSigns of increased intracranial pressure were the most common symptoms. The temporal lobe was the most common lesion site (n = 22). Hemorrhages were mainly confined to the tumor margins (HCTs) (n = 34). Extensive intraparenchymal hemorrhages (EIHs) were mainly associated with moderately/severely decreased levels of consciousness (LOCs) (n = 15/16). High-grade glioma (HGGT) (n = 25) was the leading pathological diagnosis followed by metastasis (MBT) (n = 16/55). The hemorrhage type was associated with the pathological diagnosis of the tumor. Patients with HGGT (n = 19/25) and MBT (n = 9/16) mainly presented with HCTs, whereas low-grade gliomas (LGGT) primarily caused EIHs (n = 6/7).ConclusionsHemorrhagic presentation is a rare occurrence in BTs. Among all, MBT and HGGT are responsible for majority of the cases. Importantly, despite their relatively benign characteristics, LGGTs mainly result in extensive parenchymal destruction once they bleed. Maximum surgical resection of hemorrhagic BTs and decompression of the affected brain regions followed by histological confirmation of the diagnosis should be the main goals of treatment in cases with hemorrhagic BTs.     

Heme oxygenase-1 protects regulatory T cells from hypoxia-induced cellular stress in an experimental mouse brain tumor model

Two characteristic features of malignant gliomas (MG) are the presence of hypoxia and accumulation of regulatory T cells (Tregs). Heme-oxygenase-1 (HO1) is a cytoprotective enzyme expressed in high level by Tregs in glioma. In this study, we show that higher HO1 expression in Tregs is associated with increased survival under hypoxic conditions and that HO1 inhibitor, tin protoporphyrin (SnPP), abrogates the survival benefits. Moreover, SnPP preferentially eliminates Tregs and treatment with SnPP of tumor bearing mice significantly increases survival (23 to 31 days (p < 0.05)). Thus HO1 inhibition provides another alternative way of therapeutically targeting Tregs in MG.     

Experimental colitis triggers the release of substance P and calcitonin gene-related peptide in the urinary bladder via TRPV1 signaling pathways

Clinical data provide evidence of high level of co-morbidity among genitourinary and gastrointestinal disorders characterized by chronic pelvic pain. The objective of this study was to test the hypothesis that colonic inflammation can impact the function of the urinary bladder via activation of TRPV1 signaling pathways followed by alterations in gene and protein expression of substance P (SP) and calcitonin gene-related peptide (CGRP) in sensory neurons and in the bladder. Inflammation was induced by intracolonic instillation of trinitrobenzene sulfonic acid (TNBS, 12.5 mg/kg), and desensitization of TRPV1 receptors was evoked by intracolonic resiniferatoxin (RTX, 10^?7 M). mRNA and protein concentrations of CGRP and SP were measured at 3, 5 and 30 days. RTX instillation in the colon caused 3-fold up-regulation of SP mRNA in the urinary bladder at day 5 (n = 7, p ≤ 0.05) followed by 35-fold increase at day 30 (n = 5, p ≤ 0.05). Likewise, TNBS colitis triggered 15.8-fold up-regulation of SP mRNA 1 month after TNBS (n = 5, p ≤ 0.05). Desensitization of colonic TRPV1 receptors prior to TNBS abolished SP increase in the urinary bladder. RTX led to 4.3-fold increase of CGRP mRNA at day 5 (n = 7, p ≤ 0.05 to control) in the bladder followed by 28-fold increase at day 30 post-RTX (n = 4, p ≤ 0.05). Colitis did not alter CGRP concentration during acute phase; however, at day 30 mRNA level was increased by 17.8 ± 6.9-fold (n = 5, p ≤ 0.05) in parallel with 4-fold increase in CGRP protein (n = 5, p ≤ 0.01) in the detrusor. Protein concentration of CGRP in the spinal cord was diminished by 45–65% (p ≤ 0.05) during colitis. RTX pretreatment did not affect CGRP concentration in the urinary bladder; however, it caused a reduction in CGRP release from lumbosacral DRG neurons during acute phase (3 and 5 days post-TNBS). Our results clearly demonstrate that colonic inflammation triggers the release of pro-inflammatory neuropeptides SP and CGRP in the urinary bladder via activation of TRPV1 signaling mechanisms enunciating the neurogenic nature of pelvic organ cross-sensitization.     

Prognostic factors and survival in primary adult high grade brainstem astrocytoma: A population based study from 1973–2008

Adult brainstem astrocytomas are a rare and heterogeneous group of malignancies. Most reports represent low-grade gliomas. This study used the Surveillance, Epidemiology and End Results (SEER) database to analyze the association between survival and demographic factors, tumor histology, and treatment characteristics among adult patients with high-grade brainstem astrocytoma (HGBSA). Adult patients with histologically confirmed diagnoses of primary HGBSA were studied. In univariate and multivariate analysis, we investigated the effect of demographics, tumor histology and treatment modality on survival. Overall median survival in the cohort of 240 adult patients was 7 months, with 1, 2, 5 and 10 year survival rates of 33.2%, 19.7%, 10.1%, and 8.3%, respectively. Age >50 years (hazard ratio [HR] 1.98, 95% confidence interval [CI] 1.45–2.70, p < 0.001) and grade IV versus grade III tumor (HR 1.61, 95% CI 1.15–2.26, p = 0.006) were associated with statistically significant increased mortality in multivariate analyses. Surgical intervention trended toward association with lower mortality (HR 0.68, 95% CI 0.47–1.01, p = 0.055). Our findings suggest that in patients with HGBSA, younger age and lower-grade histology are associated with better prognosis. Surgical intervention trended towards a significant association with better outcome, while radiation treatment was not associated with a statistically significant benefit in survival.     

Effect of vardenafil on cerebral vasospasm following experimental subarachnoid hemorrhage in rats

We examined the effects of the phosphodiesterase 5 (PDE-5) inhibitor vardenafil on cerebral vasospasm in an experimental rat subarachnoid hemorrhage (SAH) model. Thirty-two albino Wistar rats were divided into five groups: G1, no experimental intervention; G2, administered subarachnoid physiological saline after sham surgery; G3, subjected to SAH; G4, subjected to SAH and administered low-dose (0.5 mg/kg) vardenafil treatment; and G5, subjected to SAH and administered high-dose (5 mg/kg) vardenafil treatment. For animals in G3, G4 and G5, SAH was induced by an injection of autologous non-heparinized blood into the cisterna magna. Immediately after SAH, for animals in G4 and G5, vardenafil was administered by gavage at intervals of 8 hours for 2 days. The rats were then decapitated, and basilar arteries and blood samples were taken for biochemical and histopathological examination. Malonyldialdehyde values in G2 (p = 0.004) and G3 (p = 0.002) were significantly higher than those in G1. G4 and G5 had significantly lower values than G2 and G3 (p = 0.014, G4 v. G2; p = 0.005, G4 v. G3; p = 0.005, G5 v. G2; p = 0.002, G5 v. G3). Total antioxidant capacity (TAC) values in G3 were significantly lower than those in G1 (p = 0.041). TAC values in G4 and G5 were significantly higher than those in G3 (p = 0.043). Mean luminal diameter in G3 was significantly smaller compared with G1 and G2 (p = 0.002), but larger in G4 (p = 0.002) and G5 (p = 0.001) compared with G3. Mean luminal diameter was also significantly larger in G5 than in G2 (p = 0.008) and G4 (p = 0.038). Mean wall thickness in G2 (p = 0.015) and G3 (p = 0.002) was significantly thicker compared with G1. Wall thickness was significantly thinner in G4 and G5 compared with G2 and G3 (p = 0.008, G4 v. G2; p = 0.001, G4 v. G3; p = 0.005, G5 v. G2; p = 0.001, G5 v. G3). Our results confirm that vardenafil may induce vasodilatation and provide potential benefits in SAH therapy by preventing vasospasm.     

Multiplexed protein profiling after aneurysmal subarachnoid hemorrhage: Characterization of differential expression patterns in cerebral vasospasm

Cerebral vasospasm is a major contributor to delayed morbidity following aneurysmal subarachnoid hemorrhage. We sought to evaluate differential plasma protein levels across time in patients with aneurysmal subarachnoid hemorrhage to identify potential biomarkers and to better understand the pathogenesis of cerebral vasospasm. Nine female patients with aneurysmal subarachnoid hemorrhage underwent serial analysis of 239 different serum protein levels using quantitative, multiplexed immunoassays (DiscoveryMAP 250+ v2.0, Myriad RBM, Austin, TX, USA) on post-hemorrhage days 0 and 5. A repeated measures analysis of variance determined that mean protein concentration decreased significantly in patients who developed vasospasm versus those who did not for alpha-2-macroglobulin (F [1.00,7.00] = 16.33, p = 0.005), angiogenin (F [1.00,7.00] = 7.65, p = 0.028), apolipoprotein A-IV (F [1.00,7.00] = 6.308, p = 0.040), granulocyte colony-stimulating factor (F [1.00,7.00] = 9.08, p = 0.020), macrophage-stimulating protein (F [1.00,7.00] = 24.21, p = 0.002), tetranectin (F [1.00,7.00] = 5.46, p < 0.039), vascular endothelial growth factor receptor 3 (F [1.00,7.00] = 6.94, p = 0.034), and significantly increased for vitronectin (F [1.00,7.00] = 5.79, p = 0.047). These biomarkers may be of value in detecting cerebral vasospasm, possibly aiding in the identification of patients at high-risk prior to neurological deterioration.