Lithium enhances the antitumour effect of temozolomide against TP53 wild-type glioblastoma cells via NFAT1/FasL signalling.

BACKGROUND: We previously showed that activation of the nuclear factor of activated T cells (NFAT)1/Fas ligand (FasL) pathway induces glioma cell death. Lithium (Li) is an inhibitor of glycogen synthase kinase (GSK)-3 that activates NFAT1/FasL signalling. Temozolomide (TMZ) inhibits GSK-3 and activates Fas in tumour protein (TP)53 wild-type (TP53wt) glioma cells. The present study investigated the combinational effects of TMZ and low-dose Li on TP53wt glioma cells. METHODS: The combined effect of TMZ and Li was examined in TP53wt U87 and primary glioma cells and a mouse xenograft model. RESULTS: Combination with 1.2 mM Li potentiated TMZ-induced cell death in TP53wt glioma cells, as determined by neurosphere formation and apoptosis assays. Temozolomide combined with Li treatment inhibited GSK-3 activation, promoted NFAT1 nuclear translocation and upregulated Fas/FasL expression. Targeted knockdown of NFAT1 expression blocked the induction of cell death by TMZ and Li via FasL inhibition. In vivo, combined treatment with TMZ and Li suppressed tumour growth and prolonged the survival of tumour-bearing mice. However, the combination of TMZ and Li did not produce a statistically significant effect in TP53mut glioma cells. CONCLUSIONS: Temozolomide combined with low-dose Li induces TP53wt glioma cell death via NFAT1/FasL signalling. This represents a potential therapeutic strategy for TP53wt glioma treatment.

Frontobasal interhemispheric approach for large superasellar craniopharyngiomas: do the benefits outweigh the risks?

OBJECTIVE: Large suprasellar craniopharyngiomas are surgically challenging. The aim of our study was to explore the therapeutic efficacy of the frontobasal interhemispheric approach for these lesions. METHODS: Twenty-nine consecutive adult patients with large suprasellar craniopharyngiomas (diameter >4 cm) who underwent the frontobasal interhemispheric approach were retrospectively evaluated. Surgical and clinical outcomes were analyzed. RESULTS: Gross total removal was achieved in 23 cases (79.3%) and subtotal removal in 6 cases (20.7%). The mean follow-up period was 76.5 ± 33.2 months (range, 12-132 months). Twenty-four patients (82.7%) had improvement of the visual impairment score (VIS) after surgery. VIS was unchanged in five patients (17.3%), and no patients experienced visual deterioration. Among 23 patients who had preoperative hypopituitarism, 8 (34.8%) had an improvement. Postoperative new or aggravated hypopituitarism was observed in four patients (13.8%). Permanent diabetes insipidus was observed in ten patients (34.4%). Postoperative anosmia occurred in two earlier cases (6.9%). There was no intracranial infection or cerebrospinal fluid fistula. At last follow-up, >9% BMI gain was observed in 34.5% of patients, and 65.5% of patients returned to work. Four patients (13.8%) suffered recurrence. CONCLUSION: Although the frontobasal interhemispheric approach has some disadvantages, it provides ideal access to the suprasellar region and the third ventricle with limited brain retraction. The surgically visible angle is adequate; thus, vital structures can be better protected. For large suprasellar craniopharyngiomas, the benefits of this approach can outweigh its potential risks.

Endoscopic endonasal trans-sphenoidal approach for pituitary adenomas: is one nostril enough?

BACKGROUND: Over the past decade, the endoscopic endonasal trans-sphenoidal approach has been used to resect pituitary adenomas. However, in the use of this procedure, some research teams prefer a two-nostril method, whereas other groups are in favor of the one-nostril method. Here, we present a series of pituitary adenomas and try to confirm whether or not one nostril is enough for endoscopic resection of most pituitary adenomas. METHODS: A total of 250 consecutive patients who underwent an endoscopic endonasal trans-sphenoidal approach were reviewed retrospectively, of which 200 were via the unilateral nostril (group 1) and 50 were via bilateral nostrils (group 2). Surgical and clinical outcomes were analyzed. RESULTS: For microadenomas, intrasellar macroadenomas and macroadenomas with moderate extrasellar extension, the prevalence of gross total resection (GTR), hormonal outcome and visual improvement were similar between the two groups. The one-nostril group had better results for duration of surgery and blood loss, with fewer rhinological complications. However, for macroadenomas with extensive extrasellar invasion, GTR was obtained in two of seven patients in group 2 but none in group 1. CONCLUSION: The one-nostril method, which is relatively fast and minimally invasive, is adequate for endoscopic resection of most pituitary adenomas with moderate extension.

Induction of cytotoxicity by photoexcitation of TiO2 can prolong survival in glioma-bearing mice.

We have investigated the possibility that photoexcited titanium dioxide (TiO2) could inhibit the growth of malignant cells. We studied the anti-glioma effects of nano-TiO2 excited with ultraviolet A (UVA) irradiation both in vitro and in vivo. Transmission electron microscopy demonstrated that glioma cells take up TiO2 by phagocytosis, and vital staining revealed that TiO2 alone has no effect on glioma cell proliferation. However, if TiO2 was combined with UVA irradiation the proliferation rate was decreased significantly compared to controls (P<0.05). RT-PCR suggested that TiO2 induction of glioma cell apoptosis is associated with changes in the expression of genes encoding Bcl-2 family members. We then investigated the in vivo antitumor effects of combined TiO2 plus UVA treatment of established glioma tumors. TiO2 plus UVA led to pronounced areas of necrosis, elevated indices of apoptosis, delayed tumor growth, and increased survival compared with the TiO2-alone control group (P<0.001). Log-rank survival analysis showed that median survival duration was prolonged (P<0.001). These findings suggest that nano-TiO2 based photodynamic therapy has potential in the treatment of glioma.

IL-10 and TGF-ß2 are overexpressed in tumor spheres cultured from human gliomas.

Immune-associated cytokines including IL-10 and TGF-ß2 are thought to play a crucial role in immunosuppression mediated by gliomas. We have investigated the possibility that glioma stem cells are the major source of these cytokines. Tumor spheres, clonal non-adherent cell colonies derived from a single tumor stem cell, were cultured from surgical specimens of eight glioma patients, including two glioblastoma multiformes (grade IV), one anaplastic oligodendroglioma (grade III) and five anaplastic astrocytomas (grade III). Real-time RT-PCR and immunoassay were used to compare the relative expression levels of IL-10 and TGF-ß2 in stem-cell-derived tumor sphere cells (TSCs) and primary cultured glioma cells (PCGCs). TSCs were confirmed to express the brain tumor stem cell marker CD133, and on in vitro differentiation gave rise to cells expressing neuronal or glial markers. RT-PCR and immunoassay revealed that mRNA and protein levels of both IL-10 and TGF-ß2 were significantly higher in TSCs than in PCGCs from the same tumor. Interestingly, the degree of overexpression in TSCs, but not in PCGS, appeared to correlate with the pathological grade of the glioma. These findings suggest that glioma stem cells are likely to be the major tumor source of immunosuppressive cytokines and thereby play a crucial role in determining glioma malignancy.

NFAT1-Mediated Regulation of NDEL1 Promotes Growth and Invasion of Glioma Stem-like Cells.

Glioma stem-like cells (GSC) promote tumor generation and progression. However, the mechanism of GSC induction or maintenance is largely unknown. We previously demonstrated that the calcium-responsive transcription factor nuclear factor of activated T cells-1 (NFAT1) is activated in glioblastomas and regulates the invasion of tumor cells. In this study, we further explored the role of NFAT1 in GSC. We found that NFAT1 expression was associated with an aggressive phenotype and predicted poor survival in gliomas. Compared with normal glioma cells, NFAT1 was upregulated in GSC. NFAT1 knockdown reduced GSC viability, invasion, and self-renewal in vitro and inhibited tumorigenesis in vivo, whereas NFAT1 overexpression enhanced the growth and invasion of GSCs. RNA sequencing showed that NFAT1 depletion was associated with reduced neurodevelopment protein 1-like 1 (NDEL1, a potential downstream target of NFAT1) expression, whereas NFAT1 overexpression induced NDEL1 expression. In addition, NFAT1 regulated the promoter activities of NDEL1, whereas rescue of NDEL1 in NFAT1-silenced GSC partially restored tumor growth and invasion. Upregulation of NFAT1-NDEL1 signaling elevated Erk activation, increased protein levels of stemness markers in GSC, and resulted in de-differentiation of normal neuronal cells and astrocytes. Our results indicate that NFAT1 controls the growth and invasion of GSC partially through regulation of NDEL1. Targeting the NFAT1-NDEL1 axis therefore might be of potential benefit in the treatment of patients with glioma. SIGNIFICANCE: NFAT1 controls the growth and invasion of GSCs, partially by regulating NDEL1. Targeting the NFAT1-NDEL1 axis might provide opportunities in treating patients with glioma.

Primary Central Nervous System Angiosarcoma.

BACKGROUND: Primary angiosarcoma of the brain is an extremely rare malignant tumor that that arises from vascular endothelial cells of the brain or meninges. The presentation, characteristics, and prognosis of this disease are not well understood. Here we report such a case. CASE DESCRIPTION: A 68-year-old Chinese man presented with confusion and progressive impairment of right limb movement. Magnetic resonance imaging (MRI) revealed a hemorrhagic lesion in the left frontal lobe. Exploratory surgery revealed a hematoma-like lesion and extensive superficial hemosiderin deposition. The postoperative pathological diagnosis was angiosarcoma. The tumor recurred at 1 month after the operation, with extensive tumor regrowth in the left hemisphere. The patient died after 4 weeks. CONCLUSIONS: Although accurate preoperative diagnosis of angiosarcoma of the brain is difficult, radiologists and neurosurgeons need to be aware of this rare entity. The prognosis of intracranial angiosarcoma is heterogenous. Intraoperatively, the presence of extensive superficial hemosiderosis may aid in its diagnosis.

Bilateral and symmetric C1-C2 dumbbell ganglioneuromas associated with neurofibromatosis type 1: A case report.

BACKGROUND: Ganglioneuroma (GN) is a rare and benign tumor that originates from autonomic nervous system ganglion cells. The most frequently involved sites are the posterior mediastinum, the abdominal cavity, and the retroperitoneal space. It rarely occurs in the cervical area, compressing the spinal cord. Neurofibromatosis type 1 (NF-1) is an autosomal dominant inheritance disorder, whose prevalence rate approximates one per 3000. CASE SUMMARY: We report an extremely rare case of bilateral and symmetric dumbbell GNs of the cervical spine with NF-1. A 27-year-old man with NF-1 presented with a one-year history of gradually progressive right upper extremity weakness and numbness in both hands. Magnetic resonance imaging showed bilateral and symmetric dumbbell lesions at the C1-C2 levels compressing the spinal cord. We performed total resection of bilateral tumors, and the postoperative histopathological diagnosis of the resected mass was GN. After operation, the preoperative symptoms were gradually relieved without complications. To our knowledge, this is the sixth report of cervical bilateral dumbbell GNs. CONCLUSION: In some cases, cervical bilateral dumbbell GNs could be associated with NF-1. The exact diagnosis cannot be obtained before operation, and pathological outcome is the current gold standard. Surgical resection is the most effective option, and disease outcome is generally good after treatment.

NFAT-1 hyper-activation by methionine enkephalin (MENK) significantly induces cell apoptosis of rats C6 glioma in vivo and in vitro.

The aim of the work was to investigate the effect and possible mechanism of MENK on the growth of rat C6 glioma in vivo or in vitro. Our findings showed that MENK could inhibit the growth of rat C6 glioma, prolong median survival times in tumor-bearing rats, and induce glioma cell apoptosis. Moreover, MENK could increase the activities of caspase-3, caspase-8 and caspase-9. It also increased the expression of Fas, FasL, Bax, while decreased the expression of Bcl-2. We further confirmed that MENK could increase opioid receptors MOR and DOR expressions, Ca2+ influx into the cytoplasm, and a substantial increase of NFAT1accumulation in the nuclei in C6 glioma cell. When we specifically knocked down NFAT1, there was no effect of MENK on the cell viability and FasL up-regulation in NFAT1 knocked-down cell. These results demonstrate that MENK could bind to opioid receptors MOR and DOR on C6 glioma cells and trigger a Ca2+ influx into the cytoplasm, resulting in translocation of NFAT1 into the nucleus. The hyper-activation of NFAT1 may regulate transcription of downstream gene, such as FasL, and induce apoptosis of rat C6 glioma cells.

PMA and ionomycin induce glioblastoma cell death: activation-induced cell-death-like phenomena occur in glioma cells.

Phorbol myristate acetate (PMA) and ionomycin (Io) can induce T cell activation and proliferation. Furthermore, they stimulate activation-induced cell death (AICD) in mature lymphocytes via Fas/Fas ligand (FasL) up-regulation. In this study, we explored the influence of PMA/Io treatment on glioblastoma cells, and found that AICD-like phenomena may also occur in glioma. Using the MTT assay and cell counting, we demonstrated that treatment of PMA/Io significantly inhibited the proliferation of glioma cell lines, U87 and U251. TUNEL assays and transmission electron microscopy revealed that PMA/Io markedly induced U87 and U251 cell apoptosis. Propidium iodide staining and flow cytometry showed that treatment with PMA/Io resulted in an arrestment of cell cycle and an increase in cell death. Using real-time PCR and western blot, we found that PMA/Io up-regulated the expression of Fas and FasL at both mRNA and protein level, which confirmed that PMA/Io induced glioma cell death. Specific knockdown of NFAT1 expression by small hairpin RNA greatly reduced the PMA/Io induced cell death and apoptosis by inhibition of FasL expression. Microarray analysis showed that the expression of NFAT1 significantly correlated with the expression of Fas. The coexistence of Fas with NFAT1 in vivo provides the background for AICD-like phenomena to occur in glioma. These findings demonstrate that PMA/Io can induce glioblastoma cell death through the NFAT1-Fas/FasL pathway. Glioma-related AICD-like phenomena may provide a novel avenue for glioma treatment.

NFAT1 is highly expressed in, and regulates the invasion of, glioblastoma multiforme cells.

Members of the nuclear factor of activated T cells (NFAT) family have been identified as regulators of oncogenic transformation in several human malignancies. A prominent member of this family, NFAT1, is associated with tumor cell survival, apoptosis, migration and invasion. Here, we investigated the role of NFAT1 in glioma cells. In 111 clinical samples, microarray analysis demonstrated that NFAT1 was over-expressed in glioblastoma multiforme (GBM), compared with low-grade gliomas, a result confirmed by RT-PCR in 24 clinical samples and in the U87 and U251 cell lines. Immunohistochemistry and immunofluorescence stain indicated that over-expressed NFAT1 was mainly located in the nucleus, where it acted as a transcription factor. After treatment with the NFAT antagonist cyclosporin A (CsA) and FK506, levels of NFAT1 in the nuclei of U87 GBM cells were dramatically reduced. The invasive potential of U87 cells was reduced by the same treatment, as well as by inhibition of NFAT1 expression using small hairpin RNA. Proliferation of U87 cells was unaffected by CsA, FK506 and NFAT1 shRNA transfection. Clustering analysis and Pearson correlation analysis of microarray data showed that the expression of NFAT1 correlated with the expression of the invasion-related genes cyclooxygenase-2 (COX-2), matrix metalloproteinase-7 (MMP-7) and MMP-9, a result confirmed by in vitro analysis. These findings demonstrate that NFAT1 contributes to the invasive potential but not the proliferation of GBM cells, and suggest that CsA may find application as an adjuvant in combined treatment strategies for GBM.

Differences between generalized q-sampling imaging and diffusion tensor imaging in the preoperative visualization of the nerve fiber tracts within peritumoral edema in brain.

BACKGROUND: Diffusion tensor imaging (DTI) tractography enables the in vivo visualization of white matter tracts inside normal brain tissue, which provides the neurosurgeon important information to plan tumor resections. However, DTI is associated with restrictions in the resolution of crossing fibers in the vicinity of the tumor or in edema. We find that generalized q-sampling imaging (GQI) can overcome these difficulties and is advantageous over DTI for the tractography of the fiber bundle in peritumoral edema. OBJECTIVE: To demonstrate the differences between GQI and DTI in the preoperative mapping of fiber tractography in peritumoral edema of cerebral tumors, and discuss the clinical application of GQI in neurosurgical planning. METHODS: Five patients with brain tumors underwent 3-T magnetic resonance imaging scans, and the data were reconstructed by DTI and GQI. We adjusted the parameters and compared the differences between DTI and GQI in visualizing the fiber tracts in the peritumoral edema of cerebral tumors. RESULTS: GQI and DTI showed substantial differences in displaying the nerve fibers in the edema surrounding the tumor. The GQI tractography method could fully display existing intact fibers in the edema, whereas the fiber tracts in edema displayed by DTI tractography were incomplete, missing, or ruptured. CONCLUSION: GQI can visualize the tracts in the peritumoral edema of cerebral tumors better than DTI. Although GQI has many limitations, its future in the preoperative guidance of brain tumor lesions is promising.

Human brain glioma stem cells are more invasive than their differentiated progeny cells in vitro.

Glioma, the most commonly occurring primary intracranial tumor, remains associated with a dismal outcome, despite the availability of multimodal therapies. Recently, however, the identification of brain glioma stem cells (BGSC) has opened up new avenues for research. BGSC are now accepted as the progenitor cells of gliomas and are thought to determine the biological features of the resulting tumors. Thus, the diffuse invasiveness of gliomas should also be theoretically driven by BGSC. However, little research effort has been directed at understanding the invasiveness of BGSC. In the present study, BGSC from eight surgical glioma specimens were cultured and identified. Using Matrigel invasion assays, the invasiveness of these cells was measured and compared with that of their respective differentiated progeny cells in vitro. For all eight clinical specimens, the BGSC were significantly more invasive than their differentiated progeny cells. These findings indicate a key role for BGSC in glioma infiltration and invasion. We also found that BGSC tended to aggregate and reform into new spheres after travelling into the Matrigel, preserving some of the morphological characteristics of the suspended cells. The invasiveness of the BGSC did not correlate with the pathological grade of glioma in the present study, so further investigations using larger sample sizes are needed to better understand the mechanisms underlying the invasiveness of BGSC.