Yoshihiro Otani

Annexin A2 regulates angiogenesis and invasion phenotypes of malignant glioma

We have established a pair of animal models (J3T-1 and J3T-2) with different invasive and angiogenic phenotypes, and demonstrated that annexin A2 is expressed at higher levels in J3T-1 than J3T-2 cells. The function of annexin A2 in relation to angiogenesis and invasion was investigated using these models. Stable silencing or overexpression of annexin A2 in J3T-1 and J3T-2 cells (J3T-1shA and J3T-2A cells) was established and used. Thirty human glioblastoma samples were evaluated for expression of annexin A2, vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF). Immunohistochemical and quantitative reverse-transcription polymerase chain reaction analyses revealed higher expression of annexin A2, VEGF and PDGF in J3T-1 and J3T-2A cells. Cultured J3T-1 and J3T-2A cells exhibited higher adhesive ability to endothelial cells. Histopathological analysis of animal brain tumors revealed that J3T-1 and J3T-2A tumors displayed marked angiogenesis and invasion along the neovasculature, whereas J3T-2 and J3T-1shA tumors exhibited diffuse, infiltrative invasion without angiogenesis. Positive expression of annexin A2 was observed in tumor cells surrounding dilated vessels in 25/30 human glioblastoma specimens. Our results reveal that the phenotype of glioma invasion is closely related to angiogenesis. We identify annexin A2 as a factor regulating angiogenesis and invasion of malignant gliomas.

Phenotypic Transition as a Survival Strategy of Glioma.

Malignant glioma is characterized by rapid proliferation, invasion into surrounding central nervous system tissues, and aberrant vascularization. There is increasing evidence that shows gliomas are more complex than previously thought, as each tumor comprises considerable intratumoral heterogeneity with mixtures of genetically and phenotypically distinct subclones. Heterogeneity within and across tumors is recognized as a critical factor that limits therapeutic progress for malignant glioma. Recent genotyping and expression profiling of gliomas has allowed for the creation of classification schemes that assign tumors to subtypes based on similarity to defined expression signatures. Also, malignant gliomas frequently shift their biological features upon recurrence and progression. The ability of glioma cells to resist adverse conditions such as hypoxia and metabolic stress is necessary for sustained tumor growth and strongly influences tumor behaviors. In general, glioma cells are in one of two phenotypic categories: higher proliferative activity with angiogenesis, or higher migratory activity with attenuated proliferative ability. Further, they switch phenotypic categories depending on the situation. To date, a multidimensional approach has been employed to clarify the mechanisms of phenotypic shift of glioma. Various molecular and signaling pathways are involved in phenotypic shifts of glioma, possibly with crosstalk between them. In this review, we discuss molecular and phenotypic heterogeneity of glioma cells and mechanisms of phenotypic shifts in regard to the glioma proliferation, angiogenesis, and invasion. A better understanding of the molecular mechanisms that underlie phenotypic shifts of glioma may provide new insights into targeted therapeutic strategies.

Congenital glioblastoma with distinct clinical and molecular characteristics: case reports and a literature review.

BACKGROUND The molecular diagnosis of brain tumors is important in classifying tumors and determining appropriate treatment. Congenital glioblastoma multiforme (GBM) is a rare tumor that occurs in infants, and the prognosis is poor. Approximately 60 patients diagnosed with congenital GBM have been reported. However, few reports have conducted molecular analyses of congenital GBM. CASE DESCRIPTION We describe 2 congenital GBM patients treated in our hospital, and report results of immunohistochemistry, fluorescent in situ hybridization (FISH), direct sequencing, and methylation analyses. Surgery was performed on both patients at 2 months old, and the cases were diagnosed as glioblastoma. Immunohistochemical staining, FISH, and direct sequencing were positive for glial fibrillary acidic protein and ATRX, partially positive for p53, showed no alteration of isocitrate dehydrogenase 1 R132H, H3F3A, HIST1H3B, and BRAF, and indicated no codeletion of 1p and 19q. Methylation analysis of 1 patient identified copy number aberrations of 4 genes: deletions of CDK6 and CDKN2A/B, and a fusion of MET. One patient received chemotherapy consisting of ranimustine, interferon-beta, carboplatin, and etoposide, whereas the other patient received chemotherapy with the modified Childrens Cancer Group study-9921 protocol. Residual tumors in both patients were decreased, and they achieved 18-year- and 9-month progression-free survival, respectively. In addition, we reviewed 65 previously reported congenital GBM patients, and found they have better prognosis than pediatric and adult GBM, and long-term survival can be expected. CONCLUSIONS Congenital GBM demonstrates clinical and molecular characteristics that are different from those of pediatric or adult GBM.

Quantitative analysis of brain edema in patients with malignant glioma treated with BCNU wafers.

BCNU wafers are a form of interstitial chemotherapy that is expected to improve the survival of patients with malignant glioma. However, their adverse events, especially brain edema, sometimes cause significant clinical symptoms. In this study, we performed a volumetric analysis of brain edema after the implantation of BCNU wafers and reported on the clinical course, and exacerbation factors of brain edema. Twelve patients who underwent surgical resection of supratentorial malignant glioma and BCNU wafer implantation, were enrolled. Radiographic quantitative analysis was conducted and compared with a historical control. The volume change in brain edema was divided into three groups and correlation with clinical symptoms was then evaluated. Compared with the control group, the brain edema in the BCNU wafer implantation group was significantly prolonged after surgery. Radiographic volumetric analysis revealed an increase of more than 25% at any time after surgery in four patients (33%) and a reduction of less than 25%, 1month after surgery in three patients (25%). Grade 3 clinical deterioration related to brain edema occurred in two patients and Grade 2 in one patient. Univariate analysis revealed that the radiographic deterioration of brain edema had no correlation with age, sex, diagnosis, tumor grade, preoperative volume of brain edema and tumor, residual tumor volume, or number of BCNU wafers. Radiographic quantitative analysis of brain edema indicated that BCNU wafer implantation may induce the prolongation and enlargement of brain edema with or without neurological deterioration. Brain edema may be controlled by intensive perioperative treatment with diuretics and corticosteroids.

Fibroblast growth factor 13 regulates glioma cell invasion and is important for bevacizumab-induced glioma invasion

Glioblastoma has the poorest prognosis, and is characterized by excessive invasion and angiogenesis. To determine the invasive mechanisms, we previously used two glioma cell lines (J3T-1 and J3T-2) with different invasive phenotypes. The J3T-1 showed abundant angiogenesis and tumor cell invasion around neovasculature, while J3T-2 showed diffuse cell infiltration into surrounding healthy parenchyma. Microarray analyses were used to identify invasion-related genes in J3T-2 cells, and the expressed genes and their intracellular and intratumoral distribution patterns were evaluated in J3T-2 cell lines, human glioma cell lines, human glioblastoma stem cells and human glioblastoma specimens. To determine the role of the invasion-related genes, invasive activities were evaluated in vitro and in vivo. Fibroblast growth factor 13 (FGF13) was overexpressed in J3T-2 cells compared to J3T-1 cells, and in human glioma cell lines, human glioblastoma stem cells and human glioblastoma specimens, when compared to that of normal human astrocytes. Immunohistochemical staining and the RNA-seq (sequencing) data from the IVY Glioblastoma Atlas Project showed FGF13 expression in glioma cells in the invasive edges of tumor specimens. Also, the intracellular distribution was mainly in the cytoplasm of tumor cells and colocalized with tubulin. Overexpression of FGF13 stabilized tubulin dynamics in vitro and knockdown of FGF13 decreased glioma invasion both in vitro and in vivo and prolonged overall survival of several xenograft models. FGF13 was negatively regulated by hypoxic condition. Silencing of FGF13 also decreased in vivo bevacizumab-induced glioma invasion. In conclusion, FGF13 regulated glioma cell invasion and bevacizumab-induced glioma invasion, and could be a novel target for glioma treatment.

Hybrid Microscopic-Endoscopic Surgery for Craniopharyngioma in Neurosurgical Suite: Technical Notes.

OBJECTIVE The best chance of curing craniopharyngioma is achieved by microsurgical total resection; however, its location adjacent to critical structures hinders complete resection without neurologic deterioration. Unrecognized residual tumor within microscopic blind spots might result in tumor recurrences. To improve outcomes, new techniques are necessary to visualize tissue within these blind spots. We examined the success of hybrid microscopic-endoscopic neurosurgery for craniopharyngioma in a neurosurgical suite. METHODS Four children with craniopharyngiomas underwent microscopic resection. When the neurosurgeon was confident that most of the visible tumor was removed but was suspicious of residual tumor within the blind spot, he or she used an integrated endoscope-holder system to inspect and remove any residual tumor. Two ceiling monitors were mounted side by side in front of the surgeon to display both microscopic and endoscopic views and to view both monitors simultaneously. RESULTS Surgery was performed in all patients via the frontobasal interhemispheric approach. Residual tumors were observed in the sella (2 patients), on the ventral surface of the chiasm and optic nerve (1 patient), and in the third ventricle (1 patient) and were resected to achieve total resection. Postoperatively, visual function was improved in 2 patients and none exhibited deterioration related to the surgery. CONCLUSIONS Simultaneous microscopic and endoscopic observation with the use of dual monitors in a neurosurgical suite was ergonomically optimal for the surgeon to perform microsurgical procedures and to avoid traumatizing surrounding vessels or neural tissues. Hybrid microscopic-endoscopic neurosurgery may contribute to safe, less-invasive, and maximal resection to achieve better prognosis in children with craniopharyngioma.

A super gene expression system enhances the anti-glioma effects of adenovirus-mediated REIC/Dkk-3 gene therapy

Reduced expression in immortalized cells/Dickkopf-3 (REIC/Dkk-3) is a tumor suppressor and therapeutic gene in many human cancers. Recently, an adenovirus REIC vector with the super gene expression system (Ad-SGE-REIC) was developed to increase REIC/Dkk-3 expression and enhance therapeutic effects compared with the conventional adenoviral vector (Ad-CAG-REIC). In this study, we investigated the in vitro and in vivo effects of Ad-SGE-REIC on malignant glioma. In U87ΔEGFR and GL261 glioma cells, western blotting confirmed that robust upregulation of REIC/Dkk-3 expression occurred in Ad-SGE-REIC-transduced cells, most notably after transduction at a multiplicity of infection of 10. Cytotoxicity assays showed that Ad-SGE-REIC resulted in a time-dependent and significant reduction in the number of malignant glioma cells attaching to the bottom of culture wells. Xenograft and syngeneic mouse intracranial glioma models treated with Ad-SGE-REIC had significantly longer survival than those treated with the control vector Ad-LacZ or with Ad-CAG-REIC. This study demonstrated the anti-glioma effect of Ad-SGE-REIC, which may represent a promising strategy for the treatment of malignant glioma.

Cerebral Infarction Arising from Takotsubo Cardiomyopathy: Case Report and Literature Review

Although most patients with takotsubo cardiomyopathy have a favorable outcome, complications are not uncommon. Recent studies have reported an increase in incidence of cardioembolic complications; however, the association between takotsubo cardiomyopathy and stroke, in particular thromboembolic cerebral infarction, remains unclear. We reported a 44-year-old woman who had a cerebral infarction resulting from takotsubo cardiomyopathy. She had felt chest discomfort a few days prior to infarction, and later developed left hemiparesis. Head magnetic resonance imaging (MRI) revealed acute infarction in the right insular cortex and occlusion of the right middle cerebral artery at the M2 segment. Echocardiogram revealed a takotsubo-like shape in the motion of the left ventricular wall, and coronary angiography showed neither coronary stenosis nor occlusion. Cerebral infarction resulting from takotsubo cardiomyopathy was diagnosed and treatment with anticoagulant was started. MRI on the eighth day after hospitalization showed recanalization of the right middle cerebral artery and no new ischemic lesions. The findings of the 19 previously published cases who had cerebral infarction resulting from takotsubo cardiomyopathy were also reviewed and showed the median interval between takotsubo cardiomyopathy and cerebral infarction was approximately 1 week and cardiac thrombus was detected in 9 of 19 patients. We revealed that thromboembolic events occurred later than other complications of takotsubo cardiomyopathy and longer observation might be required due to possible cardiogenic cerebral infarction. Anticoagulant therapy is recommended for patients with takotsubo cardiomyopathy with cardiac thrombus or a large area of akinetic left ventricle.

Comparative Histologic and Molecular Analysis of 2 Recurrent Lesions Showing Different Magnetic Resonance Imaging Responses After Bevacizumab Treatment: Report of a Case of Anaplastic Astrocytoma

BACKGROUND We report the case of a patient with anaplastic astrocytoma whose 2 recurrent lesions showed different imaging responses from one another after bevacizumab treatment. Histologic and genetic features of this patient are also described. CASE DESCRIPTION A 31-year-old patient with left temporal anaplastic astrocytoma had surgery, local radiotherapy, and chemotherapy. Recurrent lesions appeared in the cerebellar vermis and left cerebellar hemisphere, and the patient was started on biweekly bevacizumab. Subsequently, the 2 enhanced lesions showed different response patterns on magnetic resonance imaging. Although the lesion in the cerebellar vermis showed an enlargement of enhancing mass, the lesion in the left cerebellar hemisphere showed disappearance of enhancement. We resected the cerebellar vermis lesion and performed biopsy on the cerebellar hemisphere lesion. The specimens were investigated. Both recurrent lesions showed higher Ki-67 labeling indices and pericyte proliferation, and less angiogenesis compared with the initial specimen. Transmission electron microscopy showed a reduction in the distance between the endothelial cells and tumor cells in both recurrent lesions, compared with the initial lesion. However, the tight junctions in the vermian lesion were still disrupted compared with the initial lesion and the cerebellar hemispheric lesion. Genetic analysis of the initial specimen showed proneural signature; however, the recurrent vermian lesion exhibited decreased expression of proneural markers. CONCLUSIONS We report a case of anaplastic astrocytoma with 2 different imaging responses to bevacizumab. Our analysis suggests that differences in tight junctions possibly contributed to the changes on magnetic resonance imaging observed after bevacizumab treatment.

PIK3R1Met326Ile germline mutation correlates with cysteine-rich protein 61 expression and poor prognosis in glioblastoma

Despite therapeutic advances, glioblastoma represents a lethal brain tumor. Recently, research to identify prognostic markers for glioblastoma has intensified. Our previous study demonstrated that median progression-free survival (PFS) and overall survival (OS) of patients with high cysteine-rich protein 61 (CCN1) expression was significantly shorter than that of patients with low CCN1 expression. To understand the molecular mechanisms that regulate CCN1 expression, we examined 147 tumour samples from 80 patients with glioblastoma and 67 patients with lower grade glioma. Next-generation and Sanger sequencing showed that PIK3R1Met326Ile was more frequent in the CCN1 high expression group (10/37 cases, 27.0%) than the CCN1 low expression group (3/38 cases, 7.9%) in glioblastoma. This mutation was also detected in corresponding blood samples. In multivariate analysis, high CCN1 expression and PIK3R1Met326Ile in glioblastoma patients were prognostic factors for OS [HR = 2.488 (1.298–4.769), p = 0.006] and [HR = 2.089 (1.020–4.277), p = 0.0439], respectively. Thus, the PIK3R1Met326Ile germline appears to be correlated with CCN1 expression and poor prognosis in glioblastoma.