PC3-Secreted Microprotein Is Expressed in Glioblastoma Stem-Like Cells and Human Glioma Tissues.

Glioblastoma multiforme (GBM) is the most prevalent malignant primary brain tumor with a high recurrence rate. Despite multimodal therapy including surgical resection, chemotherapy, and radiotherapy, the median survival time after the initial diagnosis of GBM is approximately 14 months. Since cancer stem cells (CSCs) are considered the leading cause of cancer recurrence, glioblastoma stem cell-targeted therapy is a promising strategy for the treatment of GBM. However, because CSC heterogeneity has been implicated in the difficulties of CSC-target therapy, more in-depth knowledge of CSC biology is still required to develop novel therapies. In this study, we established single cell-derived tumorspheres from human glioblastoma U87MG cells. One of these tumorspheres, P4E8 clone, showed CSC-like phenotypes, such as self-renewal capacity, expression of CSC markers, resistance to anti-cancer agents, and in vivo tumorigenicity. Therefore, we used P4E8 cells as a cell-based model of glioblastoma stem cells (GSCs). Gene expression analysis using microarray indicated that the most highly expressed genes in P4E8 cells compared to the parental U87MG were PC3-secreted microprotein (MSMP). Furthermore, MSMP was expressed in patient-derived GSCs and human glioma tissues at the protein level, implying that MSMP might contribute to glioma development and progression.

ICOSLG-mediated regulatory T-cell expansion and IL-10 production promote progression of glioblastoma.

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 antitumor 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/nuclear factor-kappaB-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-inducible co-stimulator axis in GBM may provide a promising immunotherapeutic approach for suppressing a subset of GBM with an elevated mesenchymal signature.

The immunomodulatory-drug, lenalidomide, sustains and enhances interferon-α production by human plasmacytoid dendritic cells.

Background: Lenalidomide (LEN), an immunomodulatory drug (IMiD), is currently used for treatment of multiple myeloma (MM). LEN potentiates T cell and natural killer cell functions. However, the cellular and molecular mechanisms underlying the immunomodulatory effects of LEN remain unclear. We focused on the effects of LEN on human plasmacytoid dendritic cells (pDCs), which are the major source of interferon (IFN)-α in the blood and play a central role in innate immune responses. Results: We found that bortezomib, a proteasome inhibitor used to treat MM, killed pDCs but that 0.1-3 µM LEN (covering clinical plasma concentration range) did not affect pDC survival or CD86 expression. Bortezomib inhibited pDC-derived IFN-α production in a dose-dependent fashion, but 0.1-3 µM LEN sustained pDC-derived IFN-α production when stimulated with an optimal concentration of CpG-ODN 2216 (3 µM). In pDCs stimulated with a low concentration of CpG-ODN (0.1 µM), LEN enhanced IFN-α production. These results indicated that LEN, when used at a clinically relevant concentration, can potentially enhance IFN-α production by pDCs. Conclusion: Collectively, our findings unveiled a novel target of LEN and extend the repertoire of the drug's known immunomodulatory effects. These effects may explain the low incidence of herpes zoster viral infection observed during LEN treatment compared with bortezomib treatment. LEN may function as an IMiD affecting a wide array of immune cells, including pDCs, leading to amplification of a positive immune axis able to eliminate MM cells.

Enlarging pediatric ectopic Rathke's cleft cyst in the prepontine cistern: case report.

Rathke's cleft cyst is a cystic disease that occurs in the sella turcica or, occasionally, in the suprasellar area. An ectopic Rathke's cleft cyst is extremely rare, and its nature is less well understood. The authors report the case of a 14-year-old girl who presented with a growing cystic lesion in the prepontine cistern, immediately behind the dorsum sellae. Preoperative imaging and intraoperative investigation showed part of the cyst wall continuing into the dorsum sellae, to the pituitary gland. The cisternal portion of the cyst wall was totally resected via a right subtemporal approach. Histopathological examination of the cyst wall showed a monolayer of ciliated cells, identical to those of Rathke's cleft cyst. To the best of the authors' knowledge, this represents the first pediatric case of Rathke's cleft cyst occurring in the prepontine cistern.

Establishment of a tumor sphere cell line from a metastatic brain neuroendocrine tumor.

Neuroendocrine tumors are rare, and little is known about the existence of cancer stem cells in this disease. Identification of the tumorigenic population will contribute to the development of effective therapies targeting neuroendocrine tumors. Surgically resected brain metastases from a primary neuroendocrine tumor of unknown origin were dissociated and cultured in serum-free neurosphere medium. Stem cell properties, including self-renewal, differentiation potential, and stem cell marker expression, were examined. Tumor formation was evaluated using intracranial xenograft models. The effect of temozolomide was measured in vitro by cell viability assays. We established the neuroendocrine tumor sphere cell line ANI-27S, which displayed stable exponential growth, virtually unlimited expansion in vitro, and expression of stem-cell markers such as CD133, nestin, Sox2, and aldehyde dehydrogenase. FBS-induced differentiation decreased Sox2 and nestin expression. On the basis of real-time PCR, ANI-27S cells expressed the neuroendocrine markers synaptophysin and chromogranin A. Intracranial xenotransplanted brain tumors recapitulated the original patient tumor and temozolomide exhibited cytotoxic effects on tumor sphere cells. For the first time, we demonstrated the presence of a sphere-forming, stem cell-like population in brain metastases from a primary neuroendocrine tumor. We also demonstrated the potential therapeutic effects of temozolomide for this disease.

5-ALA fluorescence-guided endoscopic surgery for mixed germ cell tumors.

5-Aminolevulinic acid (5-ALA) fluorescence-guided surgery is widely used for detection and planning of resection of malignant gliomas and other brain tumors. However, no reports have described 5-ALA fluorescence-guided surgery or direct visualization of germ cell tumors. Here, we report two cases of germ cell tumors in which a positive 5-ALA fluorescent signal was visualized with a neuroendoscope. Both cases had a tumor in the pineal region that was associated with hydrocephalus. The patients underwent surgery after administration of 5-ALA. After ventricular puncture of the anterior horn, we could observe the ventricular wall and tumor using the Karl Storz Photodynamic diagnosis system endoscope. Then, biopsy of the pineal tumor and endoscopic third ventriculostomy were performed in both cases. In case 1, a 22-year-old man, part of the ventricular wall and tumor tissue showed red fluorescence. In case 2, a 16-year-old man, part of the fornix and infundibular recess showed red fluorescence, and the tumor showed relatively weak red fluorescence. The histopathological diagnosis of both cases was pure germinoma. This is the first report of direct visualization of mixed germinomas with 5-ALA fluorescence-guided endoscopic surgery. This method not only allows visualization of the tumor mass, but may also be useful for detailed observation in the ventricular wall.

Serine/Threonine Kinase MLK4 Determines Mesenchymal Identity in Glioma Stem Cells in an NF-κB-dependent Manner.

Activation of nuclear factor κB (NF-κB) induces mesenchymal (MES) transdifferentiation and radioresistance in glioma stem cells (GSCs), but molecular mechanisms for NF-κB activation in GSCs are currently unknown. Here, we report that mixed lineage kinase 4 (MLK4) is overexpressed in MES but not proneural (PN) GSCs. Silencing MLK4 suppresses self-renewal, motility, tumorigenesis, and radioresistance of MES GSCs via a loss of the MES signature. MLK4 binds and phosphorylates the NF-κB regulator IKKα, leading to activation of NF-κB signaling in GSCs. MLK4 expression is inversely correlated with patient prognosis in MES, but not PN high-grade gliomas. Collectively, our results uncover MLK4 as an upstream regulator of NF-κB signaling and a potential molecular target for the MES subtype of glioblastomas.

Early detection of metachronous brain metastases by biannual brain MRI follow-up may provide patients with non-small cell lung cancer with more opportunities to have radiosurgery.

PURPOSE: Those who have brain metastases smaller than 30 mm in diameter and less than 5 in number can be treated less invasively with radiosurgery. This retrospective study evaluated the optimal brain magnetic resonance image (MRI) follow-up interval for non-small cell lung cancer (NSCLC) patients to detect radiosurgically manageable metachronous brain metastases (MBM). PATIENTS AND METHODS: The records of 551 patients with primary NSCLC, treated in our institute between 2002 and 2007, were reviewed. The initial brain MRI was performed within one month after diagnosis of NSCLC, and the follow-up brain MRI interval was at the discretion of physicians. The interval between the last MRI in which brain metastases were not found and the first MRI in which brain metastases were found was defined as the critical MRIs interval (CMI). The relationship between CMI and the maximum size or number of MBM was evaluated. RESULTS: Among reviewed patients, the initial MRI of 38 patients showed brain metastases and 29 patients were diagnosed as MBM. In these MBM patients, the median interval from diagnosis of NSCLC to diagnosis of brain metastases was 8.9 months. The median CMI was 4.7 (range: 1.6-18.9) months. All brain metastases smaller than 30 mm in maximum diameter were found when CMI was shorter than 6.0 months, although 5 or more brain metastases in number were detected even by shorter CMI than 3 months. CONCLUSION: Early detection of MBM by biannual MRI follow-up may provide NSCLC patients with more opportunities to have less invasive treatment.

Correlation and association of plasma interleukin-6 and plasma platelet-derived microparticles, markers of activated platelets, in healthy individuals.

INTRODUCTION: The aim of this study was to clarify the correlation and association of plasma IL-6 and PDMPs, both of which are associated with metabolic syndrome, in healthy individuals. MATERIALS AND METHODS: We conducted a cross-sectional study of 464 healthy Japanese volunteers (210 men and 254 women, median age 39 and 35years, respectively) who had no signs, symptoms or history of cardiovascular- or cerebrovascular disease and took no medications. We assayed their IL-6 levels with a conventional ELISA kit and their PDMP levels by ELISA and monoclonal antibodies against CD42b and CD42a (glycoprotein Ib and IX). RESULTS: By multivariate analysis, the plasma level of PDMP was correlated with diastolic blood pressure (p=0.015), platelet count (p<0.001), high sensitivity C-reactive protein, and the plasma level of IL-6 (p<0.001) in men (R(2)=0.454, p<0.001) and was correlated with platelet count (p<0.001) and the plasma level of IL-6 (p<0.001) in women (R(2)=0.159, p<0.001). Quartile range of plasma level of IL-6 was associated with plasma level of PDMP after adjustment for diastolic blood pressure, platelet count, and high sensitivity C-reactive protein in men (p<0.001) and associated with plasma level of PDMP after adjustment for platelet count in women (p<0.001). CONCLUSIONS: These results suggest the plasma IL-6 is correlated and associated with the plasma PDMPs, markers of activated platelets in healthy individuals.