The NRG3/ERBB4 signaling cascade as a novel therapeutic target for canine glioma.

Canine glioma is a common brain tumor with poor prognosis despite surgery and/or radiation therapy. Therefore, newer and more effective treatment modalities are needed. Neuregulin 3 (NRG3) has known to be a ligand of ERBB4. This study aimed to investigate the usefulness of the NRG3/ERBB4 signaling cascade as a novel therapeutic target in canine glioma. We found out that microRNA (miR)-190a was downregulated in canine brain tumor tissues, including glioma and meningioma. miR-190a directly targeted NRG3 and inhibited the growth of canine glioma cells. The level of p-Akt, which is a downstream target of ERBB4 signaling, was decreased by transfection with miR-190a. NRG3 silencing also suppressed cell growth and decreased the levels of p-Akt and p-ERK1/2, and NRG3 overexpression exhibited opposed effects in canine glioma J3T-1 cells. The mRNA level of erbb4 was significantly upregulated in glioma tissues compared with that in normal brain tissues and meningioma tissues. Furthermore, compared with gefitinib and lapatinib, afatinib exerted a greater inhibitory effect on the growth of canine glioma cells. In conclusion, NRG3/ERBB4 signaling is negatively regulated by miR-190a and contributes to the growth of canine glioma cells, indicating that it may be a promising therapeutic target in canine glioma.

Current Insights into Mesenchymal Signatures in Glioblastoma.

Glioblastoma (GBM) is a fatal primary malignant brain tumor in adults. Despite decades of research, the prognosis for GBM patients is still disappointing. One major reason for the intense therapeutic resistance of GBM is inter- and intra-tumor heterogeneity. GBM-intrinsic transcriptional profiling has suggested the presence of at least three subtypes of GBM: the proneural, classic, and mesenchymal subtypes. The mesenchymal subtype is the most aggressive, and patients with the mesenchymal subtype of primary and recurrent tumors tend to have a worse prognosis compared with patients with the other subtypes. Furthermore, GBM can shift from other subtypes to the mesenchymal subtype over the course of disease progression or recurrence. This phenotypic transition is driven by diverse tumor-intrinsic molecular mechanisms or microenvironmental factors. Thus, better understanding of the plastic nature of mesenchymal transition in GBM is pivotal to developing new therapeutic strategies. In this review, we provide a comprehensive overview of the current understanding of the elements involved in the mesenchymal transition of GBM and discuss future perspectives.

[Subependymal Giant Cell Astrocytoma with Tuberous Sclerosis Complex(TSC-SEGA)].

Subependymal giant cell astrocytoma(SEGA)is a low-grade brain tumor occurring specifically in patients with tuberous sclerosis complex(TSC). TSC is an autosomal dominant genetic disease affecting multiple body systems and with wide variability in presentation. SEGA usually arises around the caudothalamic groove near the foramen of Monro, and can therefore cause life-threatening complications due to hydrocephalus. SEGA develops due to complete loss of function of the TSC1/TSC2 complex through a two-hit mechanism of biallelic inactivation of the TSC1 or TSC2 gene, leading to activation of mammalian target of rapamycin(mTOR). Identification of a pathogenic variant in TSC1 or TSC2 is sufficient for the diagnosis of TSC. Individuals with SEGAs presenting with acute deterioration due to obstructive hydrocephalus should undergo urgent surgical treatment. mTOR inhibitors have been shown to prevent SEGA growth in patients with TSC. Treatment with mTOR inhibitors is primarily recommended for individuals with non-acute symptomatic or asymptomatic growing or large SEGAs and those who are not surgical candidates or prefer medical treatment over surgery. Long-term treatment with mTOR inhibitors efficiently reduced SEGAs and prevented hydrocephalus. The surgical risks, potential side effects of mTOR inhibitors, and effect on other TSC manifestations should be considered so that the best treatment option is selected.

PD-L1 and PD-L2 expression in the tumor microenvironment including peritumoral tissue in primary central nervous system lymphoma.

BACKGROUND: The prevalence of programmed death-ligand 1 (PD-L1) and PD-L2 expression on tumor cells and tumor-infiltrating immune cells in primary central nervous system lymphoma (PCNSL) remains unclear. In the present study, we analyzed needle biopsy and craniotomy specimens of patients with PCNSL to compare the PD-L1 and PD-L2 levels in the tumor and surrounding (peritumoral) tissue. We also assessed the correlation between biological factors and the prognostic significance of PD-L1 and PD-L2 expression. METHODS: We retrospectively analyzed the cases of 70 patients histologically diagnosed with PCNSL (diffuse large B-cell lymphoma). Immunohistochemistry for CD20, CD68, PD-L1, and PD-L2 was performed. In cases with specimens taken by craniotomy, the percentages of PD-L1- and PD-L2-positive macrophages were evaluated in both tumor and peritumoral tissue. The Kaplan-Meier method with log-rank test and Cox proportional hazard model were used for survival analysis. RESULTS: The tumor cells expressed little or no PD-L1 and PD-L2, but macrophages expressed PD-L1 and PD-L2 in most of the patients. The median percentage of PD-L2-positive cells was significantly higher among peritumoral macrophages (32.5%; 95% CI: 0-94.6) than intratumoral macrophages (27.5%; 95% CI: 0-81.1, p = 0.0014). There was a significant correlation between the percentages of PD-L2-positive intratumoral macrophages and PD-L2-positive peritumoral macrophages (p = 0.0429), with very low coefficient correlation (ρ = 0.098535). PD-L1 expression on macrophages was significantly associated with biological factors (intratumoral macrophages: better KPS, p = 0.0008; better MSKCC score, p = 0.0103; peritumoral macrophages: low proportion of LDH elevation, p = 0.0064) and longer OS (for intratumoral macrophages: high PD-L1 = 60 months, 95% CI = 30-132.6; low PD-L1 = 24 months, 95% CI = 11-48; p = 0.032; for peritumoral macrophages: high PD-L1 = 60 months, 95% CI = 30.7-NR; low PD-L1 = 14 months, 95% CI = 3-26). PD-L1 expression on peritumoral macrophages was strongly predictive of a favorable outcome (HR = 0.30, 95% CI = 0.12-0.77, p = 0.0129). CONCLUSIONS: Macrophages in intratumoral and peritumoral tissue expressed PD-L1 and PD-L2 at a higher rate than tumor cells. PD-L1 expression, especially on peritumoral macrophages, seems to be an important prognostic factor in PCNSL. Future comprehensive analysis of checkpoint molecules in the tumor microenvironment, including the peritumoral tissue, is warranted.

Delayed postoperative hyponatremia after endoscopic transsphenoidal surgery for pituitary adenoma.

BACKGROUND: Hyponatremia generally occurs after transsphenoidal surgery (TSS) in a delayed fashion. Most patients with delayed postoperative hyponatremia (DPH) are asymptomatic or only express non-specific symptoms; consequently, DPH is associated with prolonged hospitalization. No consensus has been reached on which patients are at greatest risk of developing DPH. We reviewed patients with DPH and evaluated predictive factors for DPH. METHODS: We retrospectively analyzed 107 consecutive patients who underwent endoscopic TSS for pituitary adenoma (January 2010-December 2016). Patients with DPH (hyponatremia group) and without DPH (normonatremia group) were compared according to their nadir sodium levels on postoperative days 3 to 10. We documented the patients' demographics, clinical features, and postoperative physiological characteristics. RESULTS: Twenty-five (23.4%) patients developed DPH after endoscopic TSS. The patients' mean age was 54 ± 17 years, and 63.6% of the patients were female. The overall prevalence of DPH was 23.4%. The non-parametric χ2 test and the Mann-Whitney U test revealed statistically significant differences in age, use of antihypertensive drugs, nonfunctioning pituitary adenoma, and higher yet normal preoperative thyroid-stimulating hormone level between the hyponatremia and normonatremia groups (P < 0.05). Logistic regression analysis revealed that only older age was a useful independent predictive factor for DPH (odds ratio, 1.05; 95% confidence interval, 1.01-1.08; P = 0.01). The serum sodium levels on postoperative day 2 were significantly lower in the hyponatremia than normonatremia group (P < 0.01) and were negatively correlated with age (r = - 0.25, P < 0.05). The cut-off age for predicting DPH was 55 years. The hospital stay was significantly longer in the hyponatremia than normonatremia group (P < 0.01). CONCLUSIONS: Age of more than 55 years was an independent predictive factor for DPH even after adjusting for potential confounders. Older age was negatively correlated with the serum sodium level on postoperative day 2. Preventing early decreases in the sodium level could reduce the risk of DPH. TRIAL REGISTRATION: 1707-027.

Dynamic Reorganization of Microtubule and Glioma Invasion.

Gliomas are characterized as highly diffuse infiltrating tumors, and currently available treatments such as surgery, radiation and chemotherapy are unfeasible or show limited efficacy against these tumors. Recent genetic and epigenetic analyses of glioma have revealed increasing evidence of the role of driver genetic alterations in glioma development and led to the identification of prognostic factors. Despite these findings, the survival rates of glioma patients remain low, and alternative treatments and novel targets are needed. Recent studies identified neural stem cells as the possible origin of gliomas, and some evidence has revealed shared functions and mechanisms between glioma cells and neurons, also supporting their similarity. The cytoskeleton plays important roles in the migration of normal cells as well as cancer cells. Recent reports have described a role for microtubules, a component of the cytoskeleton, in glioma invasion. Notably, several factors that regulate microtubule functions, such as microtubule-associated proteins, plus-end tracking proteins, or motor proteins, are upregulated in glioma tissues compared with normal tissue, and upregulation of these factors is associated with high invasiveness of glioma cells. In this review, we describe the mechanism of microtubules in glioma invasion and discuss the possibility of microtubule-targeted therapy to inhibit glioma invasion.

[A Trial of Unified Management of Language Tasks Using a Tablet Device for Language Area Mapping].

Language tasks must be based on perioperative neuropsychological evaluation during intraoperative language area mapping for the resection of brain tumor near the language cortex under awake craniotomy. However, flexibility is needed during surgery, because actions during surgery must change based on neurological symptoms and the presence or absence of aphasia. Here, we developed software to assess patients' ability to complete language tasks during surgery by using a tablet device; these language tasks serve as indicators of changes in patient status. We examined its effectiveness through the use of the software. In this case, the patient was a 68-year-old female. Before the surgery, the patient exhibited transcortical sensory aphasia. However, 1 day before the surgery, she exhibited worsening of language symptoms. We prepared a language task on the tablet device based on the patient's ability to complete the task before the surgery. The patient's wakefulness baseline was different from that predicted before the surgery. However, we were able to modify the surgical plan by using the results of the language task on the tablet device. In addition, we were able to finish mapping in approximately 90 minutes.

[Preoperative Embolization for Solid Cerebellar Hemangioblastoma on the Day of Surgery:Two Case Reports].

Surgical resection of solid cerebellar hemangioblastomas can be challenging because of the profuse blood supply and tight space. We report two cases of solid cerebellar hemangioblastomas treated via surgical resection with the aid of preoperative endovascular embolization on the day of surgery. Case 1: A 36-year-old woman presented with a two-month history of headache and vomiting. Magnetic resonance imaging(MRI)revealed a right cerebellar solid mass, mild hydrocephalus, and apparent peritumoral edema. Angiogram showed a highly vascularized mass, three feeding arteries from the superior cerebellar artery(SCA), and a dilated vein draining into the confluence. We performed preoperative embolization of the three feeders with 15% n-butyl-2-cyanoacrylate(NBCA). Final angiogram showed an absence of tumor staining. Tumor resection was performed on the same day, and gross total resection was achieved with no complications. Case 2: A 36-year-old man presented with a four-month history of headache and numbness in the left upper extremity. MRI revealed a right cerebellar solid mass with peritumoral edema. Angiogram showed a highly vascularized mass with two feeding arteries from the right SCA, one from the left posterior inferior cerebellar artery(PICA), and a dilated vein draining into the confluence. Preoperative embolization was performed with 15% NBCA, and complete devascularization was achieved. Tumor resection was performed on the same day, and gross total resection was achieved with no complications. In conclusion, preoperative embolization with NBCA on the day of surgery is a safe and effective adjunctive treatment for solid cerebellar hemangioblastoma.

[Prognostic Impact of Radiation Therapy and Molecular Classification of Infant Atypical Teratoid/Rhabdoid Tumors].

Atypical teratoid/rhabdoid tumor(AT/RT)is a rare and lethal childhood cancer. Although radiation therapy in children less than three years of age is generally deferred because of its neural toxicity, recent studies have shown that multimodal therapies, including radiation therapy, are effective in pediatric patients with AT/RT less than three years of age. We treated four infant AT/RT patients and investigated the impact of radiation therapy and genetic classification on the prognosis. The mean age at the time of the operation was 9.3 months and all patients were female. All patients underwent surgical resection. Of the four patients, two received combined irradiation and chemotherapy. Specifically, one patient received conformal craniospinal radiation therapy and the other received craniospinal irradiation with proton beams. Immunohistochemical analyses of tumor specimens revealed that the two patients were positive for ASCL1, a regulator of Notch signaling. Patients who received radiation therapy and exhibited ASCL1-positive tumors had a better prognosis. We conclude that radiation therapy may prolong survival in AT/RT patients who are less than 3 years of age. However, further study is required to evaluate long-term functional outcomes.

A patient develops transient unique cerebral and cerebellar lesions after unruptured aneurysm coiling.

BACKGROUND: We describe a case of a very unusual complication following a coiling procedure in which the patient developed transient unique cerebral and cerebellar lesions. Lesions were examined not only by magnetic resonance imaging (MRI) but also by positron emission tomography-computed tomography (PET-CT) and proton magnetic resonance spectroscopy ((1)H-MRS). CASE PRESENTATION: A 33-year-old woman presented an incidental 3.7 × 3.3-mm unruptured cerebral aneurysm (CAn) in her basilar artery, which was successfully coiled with balloon assistance. A follow-up brain MRI at 1 and 2 months showed a gradual increase in several white matter hyperintense lesions in the left cerebellar, bilateral occipitotemporal and left parietoccipital lobe during fluid-attenuated inversion recovery (FLAIR). These were the only lesions associated with perfused CAn. However, the patient did not show any additional symptoms such as visual disturbance throughout the entire course. (11)C-methionine-PET (MET-PET) showed an obvious increase in methionine uptake in the lesion corresponding to enhanced areas with gadolinium-enhanced MRI. MRS showed a decrease in the N-acetylaspartate/creatine (NAA/cr) ratio and a slight elevation of the choline/creatine (cho/cr) ratio and a lactate peak in the lesion. A follow-up MRI at 6 and 12 months showed a gradual decrease in the initial hyperintense lesions in FLAIR without any treatment. CONCLUSION: We present a case of an unusual complication after a coiling procedure. Although it is difficult to identify this etiology without a pathological examination, it is importance to increase awareness of such a potential complication arising from coiling procedures, because interventional procedures have become the first choice of treatment for cerebrovascular diseases in many countries.

Assessment of morphology and hemodynamics in a surgically clipped neck of a cerebral aneurysm: illustrative case.

BACKGROUND: Silent magnetic resonance angiography reduces metal artifacts, enabling clear visualization of the clipped neck following surgical clipping of cerebral aneurysms. This study aimed to delineate the morphology of the clipped neck complex in cerebral aneurysms using three-dimensional (3D) multifusion imaging of silent magnetic resonance angiography and fast spin echo magnetic resonance cisternography. Additionally, computational fluid dynamics analysis was utilized to evaluate the hemodynamics of the parent vessel at the clipped neck, allowing for a detailed assessment of hemodynamics at the clipped neck. OBSERVATIONS: The 3D multifusion image enabled visualization of the orientation and shape of the clip within the clipped neck complex, alongside the morphology of the parent vessel. In the hemodynamic analysis of the parent vessel at the clipped neck, areas of high-intensity magnitude of wall shear stress (WSSm) variation corresponding to the clip's contour, along with significant vector of wall shear stress (WSSv) variation related to vector directionality, were visualized in 3D. The intentional residual neck, coated with muscle grafts, was depicted as an area with low WSSm variation values and high WSSv variation values. LESSONS: Three-dimensional multifusion imaging, along with computational fluid dynamics analysis of the parent vessels, facilitated both the morphological and hemodynamic visualization and assessment of the clipped neck complex following neck clipping surgery for cerebral aneurysms. https://thejns.org/doi/10.3171/CASE24194.

The effectiveness of palliative middle meningeal artery embolization prior to craniotomy for large acute epidural hematoma: A case report.

INTRODUCTION AND IMPORTANCE: Acute epidural hematoma is typically managed with craniotomy. However, there are a few reports on transcatheter arterial embolization (TAE) as an adjunctive therapy. CASE PRESENTATION: A 70-year-old female with no obvious history of trauma was transported to our hospital. Computed tomography scan revealed an epidural hematoma of approximately 80 ml with a midline shift of 5 mm. We decided to perform an emergency craniotomy. However, the operating room (OR) was already occupied by a scheduled surgery and it would take 30 min to an hour to prepare it. We opted to wait for our OR, considering that, even if the patient was transferred to another hospital, it would take time for the craniotomy to commence. CLINICAL DISCUSSION: We performed TAE for the middle meningeal artery (MMA) as a palliative measure to prevent hematoma enlargement. The MMA was selectively embolized with 20 % n-butyl-2-cyanoacrylate (NBCA), resulting in no hematoma enlargement or observed complications. The criteria for endovascular treatment of acute epidural hematoma are not yet well-established. This case demonstrates the potential role of endovascular treatment for large acute epidural hematomas in carefully selected patients. CONCLUSION: If there is a time gap before craniotomy, TAE could be considered a viable option for large acute epidural hematomas as a palliative intervention before craniotomy.

Bimodal anti-glioma mechanisms of cilengitide demonstrated by novel invasive glioma models.

Integrins are expressed in tumor cells and tumor endothelial cells, and likely play important roles in glioma angiogenesis and invasion. We investigated the anti-glioma mechanisms of cilengitide (EMD121974), an αvß3 integrin inhibitor, utilizing the novel invasive glioma models, J3T-1 and J3T-2. Immunohistochemical staining of cells in culture and brain tumors in rats revealed positive αvß3 integrin expression in J3T-2 cells and tumor endothelial cells, but not in J3T-1 cells. Established J3T-1 and J3T-2 orthotopic gliomas in athymic rats were treated with cilengitide or solvent. J3T-1 gliomas showed perivascular tumor cluster formation and angiogenesis, while J3T-2 gliomas showed diffuse single-cell infiltration without obvious angiogenesis. Cilengitide treatment resulted in a significantly decreased diameter of the J3T-1 tumor vessel clusters and its core vessels when compared with controls, while an anti-invasive effect was shown in the J3T-2 glioma with a significant reduction of diffuse cell infiltration around the tumor center. The survival of cilengitide-treated mice harboring J3T-1 tumors was significantly longer than that of control animals (median survival: 57.5 days and 31.8 days, respectively, P < 0.005), while cilengitide had no effect on the survival of mice with J3T-2 tumors (median survival: 48.9 days and 48.5, P = 0.69). Our results indicate that cilengitide exerts a phenotypic anti-tumor effect by inhibiting angiogenesis and glioma cell invasion. These two mechanisms are clearly shown by the experimental treatment of two different animal invasive glioma models.

Proteomics-based analysis of invasion-related proteins in malignant gliomas.

One of the insidious biological features of gliomas is their potential to extensively invade normal brain tissue, yet molecular mechanisms that dictate this locally invasive behavior remain poorly understood. To investigate the molecular basis of invasion by malignant gliomas, proteomic analysis was performed using a pair of canine glioma subclones - J3T-1 and J3T-2 - that show different invasion phenotypes in rat brains but have similar genetic backgrounds. Two-dimensional protein electrophoresis of whole-cell lysates of J3T-1 (angiogenesis-dependent invasion phenotype) and J3T-2 (angiogenesis-independent invasion phenotype) was performed. Twenty-two distinct spots were recognized when significant alteration was defined as more than 1.5-fold change in spot intensity between J3T-1 and J3T-2. Four proteins that demonstrated increased expression in J3T-1, and 14 proteins that demonstrated increased expression in J3T-2 were identified using liquid chromatography-mass spectrometry analysis. One of the proteins identified was annexin A2, which was expressed at higher levels in J3T-1 than in J3T-2. The higher expression of annexin A2 in J3T-1 was corroborated by quantitative RT-PCR of the cultured cells and immunohistochemical staining of the rat brain tumors. Moreover, immunohistochemical analysis of human glioblastoma specimens showed that annexin A2 was expressed at high levels in the tumor cells that formed clusters around dilated vessels. These results reveal differences in the proteomic profiles between these two cell lines that might correlate with their different invasion profiles. Thus, annexin A2 may be related to angiogenesis-dependent invasion.

[A case of synovial sarcoma with brain metastasis treated with surgical resection and stereotactic radiosurgery].

Synovial sarcomas compromise between 5 to 10% of all soft tissue sarcomas in adults. Synovial sarcoma commonly occurs in the vicinity of the large joints and cranial metastasis is rare. Here, we describe a case with intracranial metastases of a synovial sarcoma. A 41-year-old woman was admitted to our department with sensory aphasia. She had a history of a left inguinal synovial sarcoma and underwent surgery and chemotherapy for primary and metastatic lesions. Head MRI revealed three gadolinium-enhancing lesions in the left frontal, parietal and parietotemporal lobe. Gross total resection was achieved in the left parietotemporal lesion and pathological diagnosis was synovial sarcoma. Two weeks after surgery, she received cyber-knife radiosurgery and her neurological deficit was almost completely resolved. Intracranial metastatic synovial sarcoma is rare. Surgical resection and stereotaxic radiosurgery was very effective in the present case.

Role of VEGF and matrix metalloproteinase-9 in peritumoral brain edema associated with supratentorial benign meningiomas.

Accumulating evidence indicates that VEGF and matrix metalloproteinase-9 (MMP-9) play a central role in the development of peritumoral brain edema (PTBE) associated with human brain tumors. However, the roles of these proteins, particularly of MMP-9, in PTBE associated with benign meningiomas have not been elucidated. We investigated the association between clinical features and biological factors, such as VEGF and MMP-9, and the incidence of PTBE and edema index (EI) in 60 patients with benign meningiomas. In this study, supratentorial lesions were examined for evaluating the extent of PTBE in the surrounding normal brain tissue. VEGF and MMP-9 expression was immunohistochemically examined. Multivariate analysis revealed that the presence of pial blood supply (odds ratio [OR] 12.250; P = 0.0096) and VEGF (OR 7.683; P = 0.0155), but not MMP-9 (OR 1.178; P = 0.8113), expression are significant factors that independently predict the incidence of PTBE and influence EI. VEGF (P = 0.0397) and MMP-9 (P = 0.0057) expression correlates with the presence of pial blood supply. Moreover, tumors with high VEGF and MMP-9 expression had higher EIs than those with high expression of either (P = 0.030). Our findings suggest that MMP-9 expression was positively related to VEGF expression and pial blood supply and promoted the occurrence of PTBE by inducing the disruption of the arachnoid membrane and formation of pial blood supply.

Cerebral syphilitic gumma mimicking a brain tumor that enlarged temporarily after commencing antibiotic treatment.

In this case report, we describe a 60-year-old man who presented with headaches for 1 year and mild confusion for 3 weeks and was initially diagnosed as having a cerebral tumor on the basis of finding a round lesion in the right lenticular nucleus with ring enhancement on gadolinium-enhanced T1-weighted brain magnetic resonance imaging. However, the discovery of positive serology for Treponema pallidum infection on routine tests on admission prompted analysis of cerebrospinal fluid, which was also positive on Treponema pallidum hemagglutination (TPHA), rapid plasma reagin (RPR), and treponemal antibody absorption (FTA-ABS) tests. Thus, he was diagnosed as having an intracranial syphilitic gumma. After commencing treatment with penicillin G, the lesion temporarily increased in size, but subsequently resolved completely with continuing antibiotic treatment. In the present era of increasing prevalence of syphilitic infection and because they are eminently treatable, syphilitic gummas should be included in the differential diagnosis of apparent brain tumors. Additionally, temporary enlargement of a probable gumma after instituting antibiotic treatment should not prompt cessation or change of the antibiotics.