Identification of KLRC2 as a candidate marker for brain tumor-initiating cells.

Objective: Brain tumor-initiating cells are characterized by their features of self-renewal, multi-lineage differentiation, and tumorigenicity. We analyzed the gene expression of brain tumor-initiating cells to identify their novel cellular markers. Methods: We performed cDNA microarray, in silico expressed sequence tags (ESTs), RT-PCR, and q-PCR analyses. Results: We identified 10 genes that were more highly expressed in brain tumor-initiating cells than in neural stem cells. In addition, we identified 10 other genes that were more highly expressed in brain tumor-initiating cells than in glioma cell line cells from the cDNA microarray analysis. Using the EST database, we looked to see if the 20 genes were expressed more highly in gliomas, compared with normal adult brains. Among the 20 genes, five (KLRC2, HOXB2, KCNJ2, KLRC1, and COL20A1) were expressed more than twice in glioma samples, compared with normal adult brains, and, therefore, were referred for further evaluation. RT-PCR was conducted using cDNA samples obtained from neural stem cells, normal brain tissue, fetal brain tissue, glioma cell lines, and glioma tumor-initiating cell lines. KLRC2, a transmembrane activating receptor in natural killer cells, was expressed more highly in glioma-initiating cells than in neural stem cell lines or normal adult brain tissue. The q-PCR analysis revealed that expression of KLRC2 was significantly higher in brain tumor-initiating cells compared to normal brain controls. Conclusion: KLRC2 could be a novel cellular marker for brain tumor-initiating cells.

Visualization of spatiotemporal dynamics of human glioma stem cell invasion.

Glioblastoma exhibits phenotypic and genetic heterogeneity, aggressive invasiveness, therapeutic resistance, and tumor recurrence, which can be explained by the existence of glioma stem cells (GSCs). In this study, we visualized the spatiotemporal dynamics of invasion of human GSCs in an orthotopic xenograft mouse model using time-lapse imaging of organotypic brain slice cultures and three-dimensional imaging of optically cleared whole brains. GSCs implanted in the striatum exhibited directional migration toward axon bundles, perivascular area, and the subventricular zone around the inferior horn of the lateral ventricle. GSCs migrated in a helical pattern around axon bundles in the striatum and invaded broadly in both the rostral and caudal directions. GSCs in the corpus callosum migrated more rapidly and unidirectionally toward the contralateral side with pseudopod extension. These characteristics of GSC invasion shared histological features observed in glioblastoma patients. Spatiotemporal visualization techniques can contribute to the elucidation of the mechanisms underlying GSC invasion that may lead to the development of effective therapy for glioblastoma.

Thrombosis of the draining vein causes intracranial haemorrhage in the natural history of brain arteriovenous malformation: case report.

Rupture of arteriovenous malformations (AVM) may be caused by venous outflow restriction, but there is no radiographic evidence of this. We report a case showing only a venous thrombus preceding intracranial haemorrhage from AVM. This is the first evidence that venous thrombus results in AVM rupture in its natural history.

Posterior cerebral artery giant aneurysm associated with bilateral internal carotid artery occlusion in a Klippel-Trenaunay syndrome patient: a case report.

We experienced an extremely rare case of a giant P1-P2 partially thrombosed aneurysm associated with bilateral ICA occlusion in a Klippel-Trenaunay syndrome patient. In our experience, direct surgical clipping via a pterional approach is generally favored for aneurysms located in the junction of the P1-P2 segments, even if they are giant.

Incidental ethmoidal dural arteriovenous fistula coexisting with a pituitary adenoma exacerbating post-transsphenoidal epistaxis.

A 64 year-old man with pituitary adenoma developed massive epistaxis after an uneventful endoscopic transsphenoidal surgery. Angiography showed extravasation from the sphenopalatine artery, to which embolisation was performed. An incidentally coexisting ethmoidal dural arteriovenous fistula supplied by the ophthalmic artery aberrantly originated from the middle meningeal artery caused increased haemorrhage.

Contiguous Metastasis of Pulmonary Adenocarcinoma to Meningioma.

BACKGROUND: Metastasis from one tumor into another is known as tumor-to-tumor metastasis. We report a case of a contiguous occurrence of meningioma and brain cancer metastasis. PATIENT: A 91-year-old woman presented with a sudden onset of weakness in her right limbs and gait disturbance. Fourteen years previously, she had a tumor that was suspected to be a meningioma in the left frontal convexity with no change for several years. One year earlier to presentation she was diagnosed with lung carcinoma in the left lower lobe. RESULTS: Magnetic resonance images revealed enlargement of the tumor with perifocal edema. Histologic examination showed a meningioma with contiguous metastatic poorly differentiated adenocarcinoma, as well as a clearly defined border between the two components. The clinical origin of the metastasis was presumed to be from the left lower lobe of the lung. CONCLUSION: Although our case does not strictly fulfill the definition of tumor-to-tumor metastasis, we suggest a contiguous occurrence develops by the same mechanism and may be a subtype of this process. Although previous reports suggested the loss of epithelial cadherin (E-cadherin) expression in the recipient tumor as the cause of contiguous metastasis, E-cadherin expression was positive in our case and did not seem to be involved in the localization of the metastasis.

Improvement of Respiratory Depression in a Patient with Primary Medullary Hemorrhage Following Removal of Hematoma in the Half-sitting Position.

Primary medullary hemorrhage is a rare event that may result in ataxic respiration. Although it remains controversial whether primary medullary hemorrhage should be managed conservatively or surgically, recent advancements in neuroimaging and microsurgical techniques have shown promise for improving outcomes and prognosis following surgery. The present report discusses the case of a 70-year-old woman admitted to our institution due to sudden-onset nausea and vomiting. The patient underwent surgical removal of a right medullary hematoma for the treatment of daytime respiratory depression and nocturnal apnea while in the half-sitting position. Following surgery, her spontaneous respiration improved, and she was discharged with independent gait. Despite the risk of venous air embolism, accumulating evidence suggests that the half-sitting position is suitable for brainstem surgery because gravity-assisted blood and irrigation drainage from the surgical field allows for cleaner dissection and reduces the need for bipolar coagulation.

Significant antitumor response of disseminated glioblastoma to bevacizumab resulting in long-term clinical remission in a patient with encephalocraniocutaneous lipomatosis: A case report.

The prognosis of recurrent and disseminated glioblastoma is very poor. Bevacizumab is an effective established therapy for recurrent glioblastoma following treatment with radiotherapy plus temozolomide. However, the efficacy of bevacizumab is limited to prolonging progression-free survival, without significant prolongation of the overall survival. We herein report a case of glioblastoma in a 32-year-old female patient with encephalocraniocutaneous lipomatosis (ECCL) that had disseminated following surgical resection and subsequent treatment with temozolomide and radiation therapy. The disseminated tumors disappeared completely after five courses of bevacizumab therapy. Surprisingly, the patient has remained in clinical remission for >2.5 years after dissemination by continuing this therapy. To the best of our knowledge, this is the first case of long-time clinical remission following glioblastoma dissemination and treatment with bevacizumab. In the present case, bevacizumab exerted an atypically strong antitumor effect against disseminated glioblastoma after multidisciplinary treatments had already been applied. Moreover, this is the first report of ECCL associated with a malignant brain tumor.

MIF Maintains the Tumorigenic Capacity of Brain Tumor-Initiating Cells by Directly Inhibiting p53.

Tumor-initiating cells thought to drive brain cancer are embedded in a complex heterogeneous histology. In this study, we isolated primary cells from 21 human brain tumor specimens to establish cell lines with high tumorigenic potential and to identify the molecules enabling this capability. The morphology, sphere-forming ability upon expansion, and differentiation potential of all cell lines were indistinguishable in vitro However, testing for tumorigenicity revealed two distinct cell types, brain tumor-initiating cells (BTIC) and non-BTIC. We found that macrophage migration inhibitory factor (MIF) was highly expressed in BTIC compared with non-BTIC. MIF bound directly to both wild-type and mutant p53 but regulated p53-dependent cell growth by different mechanisms, depending on glioma cell line and p53 status. MIF physically interacted with wild-type p53 in the nucleus and inhibited its transcription-dependent functions. In contrast, MIF bound to mutant p53 in the cytoplasm and abrogated transcription-independent induction of apoptosis. Furthermore, MIF knockdown inhibited BTIC-induced tumor formation in a mouse xenograft model, leading to increased overall survival. Collectively, our findings suggest that MIF regulates BTIC function through direct, intracellular inhibition of p53, shedding light on the molecular mechanisms underlying the tumorigenicity of certain malignant brain cells. Cancer Res; 76(9); 2813-23. ©2016 AACR.

Macrophage migration inhibitory factor (MIF) promotes cell survival and proliferation of neural stem/progenitor cells.

In a previous study, we showed that murine dendritic cells (DCs) can increase the number of neural stem/progenitor cells (NSPCs) in vitro and in vivo. In the present study, we identified macrophage migration inhibitory factor (MIF) as a novel factor that can support the proliferation and/or survival of NSPCs in vitro. MIF is secreted by DCs and NSPCs, and its function in the normal brain remains largely unknown. It was previously shown that in macrophages, MIF binds to a CD74-CD44 complex. In the present study, we observed the expression of MIF receptors in mouse ganglionic-eminence-derived neurospheres using flow cytometry in vitro. We also found CD74 expression in the ganglionic eminence of E14 mouse brains, suggesting that MIF plays a physiological role in vivo. MIF increased the number of primary and secondary neurospheres. By contrast, retrovirally expressed MIF shRNA and MIF inhibitor (ISO-1) suppressed primary and secondary neurosphere formation, as well as cell proliferation. In the neurospheres, MIF knockdown by shRNA increased caspase 3/7 activity, and MIF increased the phosphorylation of Akt, Erk, AMPK and Stat3 (Ser727), as well as expression of Hes3 and Egfr, the products of which are known to support cell survival, proliferation and/or maintenance of NSPCs. MIF also acted as a chemoattractant for NSPCs. These results show that MIF can induce NSPC proliferation and maintenance by multiple signaling pathways acting synergistically, and it may be a potential therapeutic factor, capable of activating NSPC, for the treatment of degenerative brain disorders.

Invasion precedes tumor mass formation in a malignant brain tumor model of genetically modified neural stem cells.

Invasiveness, cellular atypia, and proliferation are hallmarks of malignant gliomas. To effectively target each of these characteristics, it is important to understand their sequence during tumorigenesis. However, because most gliomas are diagnosed at an advanced stage, the chronology of gliomagenesis milestones is not well understood. The aim of the present study was to determine the onset of these characteristics during tumor development. Brain tumor-initiating cells (BTICs) were established by overexpressing H-Ras(V12) in normal neural stem/progenitor cells isolated from the subventricular zone of adult mice harboring a homozygous deletion of the Ink4a/Arf locus. High-grade malignant brain tumors were then created by orthotopic implantation of 10(5) BTICs into the forebrain of 6-week-old wild-type mice. Micewere killed every week for 5 weeks, and tumors were assessed for cellular atypia, proliferation, hemorrhage, necrosis, and invasion. All mice developed highly invasive, hypervascular glioblastoma-like tumors. A 100% penetrance rate and a 4-week median survival were achieved. Tumor cell migration along fiber tracts started within days after implantation and was followed by perivascular infiltration of tumor cells with marked recruitment of reactive host cells. Next, cellular atypia became prominent. Finally, mass proliferation and necrosis were observed in the last stage of the disease. Video monitoring of BTICs in live brain slices confirmed the early onset of migration, as well as the main cell migration patterns. Our results showed that perivascular and intraparenchymal tumor cell migration precede tumor mass formation in the adult brain, suggesting the need for an early and sustained anti-invasion therapy.

Functional analysis of HOXD9 in human gliomas and glioma cancer stem cells.

BACKGROUND: HOX genes encode a family of homeodomain-containing transcription factors involved in the determination of cell fate and identity during embryonic development. They also behave as oncogenes in some malignancies. RESULTS: In this study, we found high expression of the HOXD9 gene transcript in glioma cell lines and human glioma tissues by quantitative real-time PCR. Using immunohistochemistry, we observed HOXD9 protein expression in human brain tumor tissues, including astrocytomas and glioblastomas. To investigate the role of HOXD9 in gliomas, we silenced its expression in the glioma cell line U87 using HOXD9-specific siRNA, and observed decreased cell proliferation, cell cycle arrest, and induction of apoptosis. It was suggested that HOXD9 contributes to both cell proliferation and/or cell survival. The HOXD9 gene was highly expressed in a side population (SP) of SK-MG-1 cells that was previously identified as an enriched-cell fraction of glioma cancer stem-like cells. HOXD9 siRNA treatment of SK-MG-1 SP cells resulted in reduced cell proliferation. Finally, we cultured human glioma cancer stem cells (GCSCs) from patient specimens found with high expression of HOXD9 in GCSCs compared with normal astrocyte cells and neural stem/progenitor cells (NSPCs). CONCLUSIONS: Our results suggest that HOXD9 may be a novel marker of GCSCs and cell proliferation and/or survival factor in gliomas and glioma cancer stem-like cells, and a potential therapeutic target.

Trigeminal schwannomas: experience with 57 cases and a review of the literature.

Trigeminal schwannoma is a mostly benign tumor that can be cured by complete resection. Over the last few decades, several pioneers have developed surgical approaches enabling the total removal of such tumors. We analyzed 57 patients who underwent radical surgery, including 45 patients who underwent skull base surgery as their initial treatment, for removal of trigeminal schwannomas. Here, we report the surgical management of these cases. Since 1990, all such patients have been treated using three main types of middle fossa skull base approaches, which minimize the exposure of the brain: the anterior transpetrosal approach, subtemporal interdural approach (Dolenc), or a combination of these approaches. Before 1990, total tumor removal was achieved in only three of eight patients (38%). After 1990, the tumors were totally removed in 43 patients (90%) and were nearly completely removed in an additional three patients (6%). Among the patients who underwent skull base surgery as their initial treatment, a complete resection was achieved in 93% (42/45 patients) of the cases. However, total surgical removal after surgery and Gamma knife surgery was very difficult because of dense adhesions to the brain stem and cranial nerves. No surgery-related mortalities occurred in this series, and the individual KPS scores were more than 90% among the patients who underwent skull base surgery. No recurrences requiring additional surgery have occurred after an average follow-up period of 4.9 years. Most of the trigeminal schwannomas could be removed totally and safely during a single operation after the introduction of skull base surgery. Therefore, radiosurgery should not be applied as the treatment of first choice for younger patients. A correct anatomical knowledge is critical for minimizing brain exposure and avoiding surgical complications.

Isolation of cancer stem-like cells from a side population of a human glioblastoma cell line, SK-MG-1.

Accumulating evidence suggests that in several types of brain tumors, including glioma, only a phenotypic subset of tumor cells called brain cancer stem cells (BCSCs) may be capable of initiating tumor growth. Recently, the isolation of side population (SP) cells using Hoechst dye has become a useful method for obtaining cancer stem cells in various tumors. In this study, we isolated cancer stem-like cells from human glioma cell lines using the SP technique. Flow cytometry analysis revealed that SK-MG-1, a human glioblastoma cell line, contained the largest number of SP cells among the five glioma cell lines that were analyzed. The SP cells had a self-renewal ability and were capable of forming spheres in a neurosphere culture medium containing EGF and FGF2. Spheres derived from the SP cells differentiated into three different lineage cells: neurons, astrocytes and oligodendrocytes. RT-PCR analysis revealed that the SP cells expressed a neural stem cell marker, Nestin. The SP cells generated tumors in the brains of NOD/SCID mice at 8weeks after implantation, whereas the non-SP cells did not generate any tumors in the brain. These results indicate that SP cells isolated from SK-MG-1 possess the properties of cancer stem cells, including their self-renewal ability, multi-lineage differentiation, and tumorigenicity. Therefore, the SP cells from SK-MG-1 may be useful for analyzing BCSCs because of the ease with which they can be handled and their yield.

De novo development of moyamoya disease in an adult female. Case report.

The origin of moyamoya disease remains unknown. The onset of the angiographically apparent changes of typical moyamoya disease occurs in childhood, but de novo development of the disease has not been confirmed angiographically. The authors report on a case of de novo development of moyamoya disease in a middle-aged female whose cerebral angiography demonstrated no abnormal findings 5 years previously. To the best of the authors' knowledge, this case is the first reported instance of de novo development of definite moyamoya disease verified angiographically. This case demonstrates that the de novo development of moyamoya disease in a middle-aged adult did in fact occur, and angiographically visible features of the disease took < 5 years to complete.

Chromosome arm 1q gain associated with good response to chemotherapy in a malignant glioma. Case report.

The authors describe the case of a patient with a glioblastoma multiforme who showed remarkably good response to chemotherapy. A genetic analysis using comparative genomic hybridization (CGH) revealed that the tumor had a gain on the q arm of chromosome 1 (1q). Using CGH for a series of genetic analyses of more than 180 patients with gliomas, six were found to have a demonstrated 1q gain. Although the tumors in all six of these cases were histopathologically diagnosed as high-grade gliomas, compared with other malignant gliomas they demonstrated a good prognosis because of their favorable chemotherapeutic sensitivity. In immunohistochemical tests, most of the tumor cells in these cases were negative for O6-methylguanine-DNA methyltransferase, which antagonizes the effect of DNA-alkylating chemotherapeutic agents. The authors believed that a gain of 1q could be produced through the genetic events that cause loss of 1p, because these chromosomal aberrations have an imbalance of DNA copy number in common (1p < 1q). A gain of 1q is an infrequent chromosomal aberration and its clinical importance should be investigated in a larger study; however, patients with malignant gliomas demonstrating a 1q gain possibly show longer survival and good response to chemotherapy similar to patients with tumors demonstrating 1p loss. The importance of using genetic analysis for gliomas is emphasized in this report because it may help in selecting cases responsive to chemotherapy and because appropriate treatment for these patients will lead to progress in the treatment of malignant gliomas.

Our method of povidone-iodine ointment and gauze dressings reduced catheter-related infection in serious cases.

In experiment 1, we evaluated our method of catheter care at subclavian vein insertion sites for the control of catheter-related infections in seriously ill neurosurgical patients who needed prolonged catheter placement, compared with an older method. In our method, the insertion site was prepared with 10% povidone-iodine solution, followed by application of 10% povidone-iodine ointment, and covered with sterile gauze and a transparent polyurethane dressing. The older method was based on 1996 guidelines for the prevention of intravascular device-related infections. Catheter colonization and mortality were both found to be significantly reduced with our method (p = 0.0214, p = 0.0379, respectively). In experiment 2, we evaluated whether a regimen of catheter care with 10% povidone-iodine ointment was more effective than that without povidone-iodine ointment for the prevention of infections. This suggested effectiveness of 10% povidone-iodine ointment for reduction of infection. Our method of catheter care was useful even in seriously ill neurosurgical patients.

Povidone-iodine ointment and gauze dressings associated with reduced catheter-related infection in seriously ill neurosurgical patients.

Povidone-iodine ointment and gauze covered by transparent dressings were compared with transparent dressings alone in historical controls (both changed twice weekly) in neurosurgical patients needing catheter placement for prolonged periods. Colonization and bloodstream infection were both reduced with the new method (P < .01 and P = .062, respectively).