Although a small uncontrolled nonrandomized trial, this study showed that WT1 vaccine therapy for patients with WT1/HLA-A*2402-positive recurrent GBM was safe and produced a clinical response. Based on these results, further clinical studies of WT1 vaccine therapy in patients with malignant glioma are warranted.

The authors found that incidentally discovered meningiomas did not always follow an exponential growth pattern but often exhibited more complex patterns of growth. Serial monitoring of tumor volumes and regression analysis may reveal the growth pattern of incidental meningiomas and provide information useful for determining treatment strategy.

Background Targeting immune checkpoint proteins has recently gained substantial attention due to the dramatic success of this strategy in clinical trials for some cancers. Inducible T-cell co-stimulator ligand (ICOSLG) is a member of the B7 family of immune regulatory ligands, expression of which in cancer is implicated in disease progression due to regulation of anti-tumor adaptive immunity. Although aberrant ICOSLG expression has been reported in glioma cells, the underlying mechanisms that promote glioblastoma (GBM) progression remain elusive. Methods Here, we investigated a causal role for ICOSLG in GBM progression by analyzing ICOSLG expression in both human glioma tissues and patient-derived GBM sphere cells (GSCs). We further examined its immune modulatory effects and the underlying molecular mechanisms. Results Bioinformatics analysis and GBM tissue microarray showed that upregulation of ICOSLG expression was associated with poor prognosis in patients with GBM. ICOSLG expression was upregulated preferentially in mesenchymal GSCs but not in proneural GSCs in a tumor necrosis factor-α-/NF-ĸB-dependent manner. Furthermore, ICOSLG expression by mesenchymal GSCs promoted expansion of T cells that produced interleukin-10. Knockdown of the gene encoding ICOSLG markedly reduced GBM tumor growth in immune competent mice, with a concomitant downregulation of interleukin-10 levels in the tumor microenvironment. Conclusions Inhibition of the ICOSLG-ICOS axis in GBM may provide a promising immunotherapeutic approach for suppressing a subset of GBM with an elevated mesenchymal signature.

The expression of Wilms' tumor gene WT1 protein was investigated immunohistochemically in 73 glial tumors, including 60 astrocytic tumors, eight oligodendroglial tumors, and five ependymal tumors. WT1 protein was detected in 70 of the 73 glial tumors (95.9%) examined. Almost all glioblastomas, anaplastic astrocytomas, anaplastic ependymomas, and anaplastic oligodendrogliomas expressed high levels of WT1 protein. A significant (p º 0.001) correlation was found between WT1 protein expression and MIB-1 staining index. Histological examination found that WT1 protein was strongly expressed in the anaplastic portions and areas with perivascular proliferation and high cellularity, implying that WT1 gene might be important in glial tumor cell proliferation. WT1 gene is overexpressed in various types of solid tumors and WT1 protein is a target antigen for cancer immunotherapy. This study indicates that many malignant glial tumors are good candidates for cancer immunotherapy targeting WT1 protein and that WT1 protein expression could be used as a proliferation marker in glial tumors.

We investigated the feasibility of using radiologic characteristics to predict the proliferative potential in meningiomas. Our statistical analysis revealed that the presence of peritumoral edema, an ambiguous brain-tumor border, and irregular tumor shape were significantly correlated with a higher MIB-1 staining index (SI) value. We developed the following scoring system for specific features in each tumor: peritumoral edema (tumor with edema = 1, tumor without edema = 0); brain-tumor border (tumor with any ambiguous border = 1, tumor circumscribed by a distinct rim = 0); and tumor shape (tumor with irregular shape = 1, tumor with smooth shape = 0). Using Spearman's correlation coefficient analysis, we found a significant correlation (P < 0.005) between total score calculated for each patient and SI value. Our findings suggest that the proliferative potential of meningiomas can be predicted using a less invasive preoperative examination focusing on the presence of peritumoral edema, ambiguous brain-tumor border, and irregular tumor shape.

Two distinct forms of malignant lymphomas can invade the central nervous system (CNS). Although primary CNS malignant lymphomas (PCNSMLs) invade the brain parenchyma, intravascular lymphomas (IVLs) form tumor cell aggregates in the vasculature and produce stroke-like symptoms and cognitive impairment. Although the tumor cells are mostly of B-cell origin in both types of lymphoma, their biological behavior is different, and the detailed mechanism(s) underlying this difference are not well understood. We studied the expression level of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1) and integrin-beta1 in tumor tissue samples from patients with primary CNS lymphoma (n = 8) and intravascular lymphoma (n = 2) using immunohistochemical analysis. We also assessed the expression of the matrix metalloproteinases (MMP)-2 and MMP-9. ICAM-1 was positive in six and integrin-beta1 was positive in seven patients among eight PCNSML patients. MMP-2 and MMP-9 were expressed in all PCNSML. In contrast, none of them was positive in both IVL cases. Our findings suggest that adhesion molecules and MMPs are essential for malignant lymphoma cell invasion from the vasculature into the brain parenchyma and that they may be the key determinants for malignant lymphoma cells to behave as PCNSML or IVL cells.

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Medulloblastoma (MB) is the most frequent infratentorial malignant brain tumor in children. In contrast, primitive neuroectodermal tumor (PNET) is defined as a supratentorial malignant tumor generated from the cerebral hemisphere. These tumors have considerable histological overlap but have different clinical outcomes including overall survival period, recurrence rate, and chemosensitivity. We investigated the amplification and/or deletion of genes and the chromosomal gain and/or loss in 10 MBs and 3 PNETs with a genomic DNA microarray system. Genes that are frequently amplified in these both these tumors include MSH2, N-myc, AKT3, and EGFR. Amplifications of SNRPN, MYB, and PTEN are observed only in MB. The genes associated with Wnt/APC and Shh/PTCH pathways also have some aberrations. Common chromosomal aberrations include gains at 17q and 7q and losses at 17p. Minor chromosomal losses were also detected at 1p, 8p + q, 11p, 10p + q, 13q, 16q, and Xp + q in MB. SPNETs tend to contain fewer chromosomal and genetic abnormalities than MBs. In conclusion, there are gene expression and chromosomal differences between MBs and SPNETs. These differences may correlate with the prognosis.