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Reduced expression in immortalized cells/Dickkopf-3 (REIC/Dkk-3) is a tumor suppressor and its overexpression has been shown to exert anti-tumor effects as a therapeutic target gene in many human cancers. Recently, we demonstrated the anti-glioma effects of an adenoviral vector carrying REIC/Dkk-3 with the super gene expression system (Ad-SGE-REIC). Anti-vascular endothelial growth factor treatments such as bevacizumab have demonstrated convincing therapeutic advantage in patients with glioblastoma. However, bevacizumab could not improve overall survival in patients with newly diagnosed glioblastoma. In this study, we examined the effects of Ad-SGE-REIC on glioma treated with bevacizumab. Treatment of Ad-SGE-REIC resulted in significant reduced numbers of invasion cells treated with bevacizumab.. Western blot analyses revealed increased expression of several endoplasmic reticulum stress markers in cells treated with both bevacizumab and Ad-SGE-REIC and decreased β-catenin protein levels. Expressions of apoptosis markers were also increased in cells with combination therapy. In malignant glioma mouse models, overall survival was extended in the combination therapy group. These results suggest that the combination therapy of Ad-SGE-REIC and bevacizumab exerts anti-glioma effects by suppressing angiogenesis and invasion of tumors. Combined Ad-SGE-REIC and bevacizumab might indicate a promising strategy for the treatment of malignant glioma.

Glioblastoma (GBM) is the most lethal primary brain tumor characterized by significant cellular heterogeneity, namely tumor cells, including GBM stem-like cells (GSCs) and differentiated GBM cells (DGCs), and non-tumor cells such as endothelial cells, vascular pericytes, macrophages, and other types of immune cells. GSCs are essential to drive tumor progression, whereas the biological roles of DGCs are largely unknown. In this study, we focused on the roles of DGCs in the tumor microenvironment. To this end, we extracted DGC-specific signature genes from transcriptomic profiles of matched pairs of in vitro GSC and DGC models. By evaluating the DGC signature using single cell data, we confirmed the presence of cell subpopulations emulated by in vitro culture models within a primary tumor. The DGC signature was correlated with the mesenchymal subtype and a poor prognosis in large GBM cohorts such as The Cancer Genome Atlas and Ivy Glioblastoma Atlas Project. In silico signaling pathway analysis suggested a role of DGCs in macrophage infiltration. Consistent with in silico findings, in vitro DGC models promoted macrophage migration. In vivo, coimplantation of DGCs and GSCs reduced the survival of tumor xenograft-bearing mice and increased macrophage infiltration into tumor tissue compared with transplantation of GSCs alone. DGCs exhibited a significant increase in YAP/TAZ/TEAD activity compared with GSCs. CCN1, a transcriptional target of YAP/TAZ, was selected from the DGC signature as a candidate secreted protein involved in macrophage recruitment. In fact, CCN1 was secreted abundantly from DGCs, but not GSCs. DGCs promoted macrophage migration in vitro and macrophage infiltration into tumor tissue in vivo through secretion of CCN1. Collectively, these results demonstrate that DGCs contribute to GSC-dependent tumor progression by shaping a mesenchymal microenvironment via CCN1-mediated macrophage infiltration. This study provides new insight into the complex GBM microenvironment consisting of heterogeneous cells.

BACKGROUND Malignant glioma has a poor prognosis and is characterized by excessive proliferation, invasion, and angiogenesis. Previously, we established subclones of glioma cell lines with different invasive phenotypes to investigate the mechanisms of invasion in this malignancy. That study revealed annexin A2 (ANXA2) as an activator of angiogenesis and perivascular invasion. Here, we investigated the molecular mechanism of the phenotypic shift in glioma that is induced by ANXA2. METHODS We identified ANXA2 target genes using microarray analyses of our four established cell lines and RNA-seq data from the IVY Glioblastoma Atlas Project. Co-expression was then confirmed in human glioma cells. Additionally, qRT-PCR, immunoblotting, invasion assays, proliferation assays, and tube formation assays were performed to uncover the specific roles of these angiogenic invasion-related genes. Furthermore, we examined survival times and phenotypic shifts in vivo. RESULTS We identified oncostatin M receptor (OSMR) as an ANXA2-target gene using microarray and RNA-seq, and confirmed its expression correlated with ANXA2 in glioma cells. ANXA2-overexpressing glioma cells showed enhanced OSMR expression and STAT3 phosphorylation, while STAT3 knockdown reduced OSMR expression. When ANXA2 was overexpressed in glioma cells, invasion, angiogenesis, proliferation, and epithelial-mesenchymal transition were promoted; however, silencing OSMR attenuated the ANXA2-induced phenotypic shift. In vivo, ANXA2-overexpressing glioma cells shortened the survival time of tumor-bearing mice, whereas OSMR knockdown increased survival times. CONCLUSIONS We analyzed genes whose expression was regulated by ANXA2 in glioma using invasive glioma models. Through this analysis, we identified that ANXA2 and OSMR regulate a phenotypic shift, suggesting that OSMR could be a promising target to treat and prevent glioma invasion.

INTRODUCTION Invasion of Glioblastoma (GBM) cells into normal brain is the major cause of poor prognosis and requires dynamic reorganization of the actin cytoskeleton, which includes lamellipodial protrusions, focal adhesions, and stress fibers at the leading edge of GBM cells. Therefore, we hypothesized that the inhibition of actin polymerization with existing medication could lead to clinical GBM treatment directly in short time. The Drug Repositioning system is also known as drug repurposing or drug reprofiling and understood as the process of redeveloping a compound for use in a different disease. In this time, we would show the new direction of drug development with drug repositioning. MATERIALS AND METHODS We adopted a drug repositioning system for screening with a pyrene-actin-based actin polymerization assay and identified fluvoxamine, a clinically used antidepressant. Fluvoxamine, selective serotonin reuptake inhibitor, was a potent inhibitor of actin polymerization and confirmed as drug penetration through the blood–brain barrier (BBB) and accumulation of whole brain including brain tumor with no drug toxicity. RESULTS Fluvoxamine inhibited serum-induced ruffle formation, cell migration, and invasion of human GBM and glioma stem cells in vitro by suppressing FAK signaling. Fluvoxamine showed no drug toxicity. Daily treatment of athymic mice bearing human glioma-initiating cells with fluvoxamine blocked tumor cell invasion and prolonged the survival with almost same doze of anti-depressant effect. CONCLUSIONS The SSRI group has big potential for clinical GBM treatment with low cost, short time and low side effect.

INTRODUCTION Expression of the gene encoding reduced expression in immortalized cells/Dickkopf-3 (REIC/Dkk-3) was reported to be reduced in a variety of human cancer cells. We previously examined the antitumor effect of an adenoviral vector carrying REIC/Dkk-3 gene (Ad-CAG-REIC). Recently, a novel adenoviral vector expressing REIC/Dkk-3 has also been developed based on the cytomegalovirus promoter-driven super gene expression system (Ad-SGE-REIC). We evaluated the anti-glioma effect of the Ad-SGE-REIC and planned a clinical trial of Ad-SGE-REIC for malignant glioma. MATERIALS AND METHODS We evaluated a cytotoxicity assay to treatments with Ad-SGE-REIC, Ad-CAG-REIC, or Ad-LacZ (control) using malignant glioma cells. The survival of mice in each group was analyzed by the Kaplan–Meier method. We also performed Good Laboratory Practice (GLP) toxicology tests and prepared a protocol for this clinical trial. RESULTS In the cytotoxicity assay, after treatment with Ad-SGE-REIC, the number of malignant glioma cells attached to the bottom of culture wells was significantly reduced in a time-dependent manner. Mice treated with Ad-SGE-REIC survived significantly longer than those treated with other vectors. We also performed GLP toxicology tests using intracranial injection of higher doses of Ad-SGE-REIC in rats at Shin Nippon Biomedical Laboratories (SNBL Japan) to determine the injection dose of Ad-SGE-REIC for this clinical trial. After finishing the consultation with Pharmaceuticals and Medical Devices Agency (PMDA), we prepared a protocol for a phase I/IIa clinical trial of Ad-SGE-REIC for the treatment of recurrent malignant glioma supported by Japan Agency for Medical Research and Development (AMED). This protocol was reviewed by institution review board (IRB) in March 2019. We submitted a notification of this trial in April 2019. CONCLUSIONS We demonstrated the anti-glioma effect of Ad-SGE-REIC. We will start a phase I/IIa clinical trial of Ad-SGE-REIC for the treatment of recurrent malignant glioma.

Propionibacterium acnes is increasingly known as a causative organism for post-neurosurgical infection; however, no clinical studies have examined the risk factors associated with P. acnes infections. Clinical data obtained from 14 cases of P. acnes infection and 28 controls infected with other pathogens were analyzed. Craniotomy, malignancy, and prolonged duration of operation were significantly associated with the onset of P. acnes infection. No fatal cases were reported.

Boron neutron capture therapy (BNCT) is a tumor selective therapy, the effectiveness of which depends on sufficient 10B delivery to and accumulation in tumors. In this study, we used self-assembling A6K peptide nanotubes as boron carriers and prepared new boron agents by simple mixing of A6K and BSH. BSH has been used to treat malignant glioma patients in clinical trials and its drug safety and availability have been confirmed; however, its contribution to BNCT efficacy is low. A6K nanotube delivery improved two major limitations of BSH, including absence of intracellular transduction and non-specific drug delivery to tumor tissue. Varying the A6K peptide and BSH mixture ratio produced materials with different morphologies-determined by electron microscopy-and intracellular transduction efficiencies. We investigated the A6K/BSH 1:10 mixture ratio and found high intracellular boron uptake with no toxicity. Microscopy observation showed intracellular localization of A6K/BSH in the perinuclear region and endosome in human glioma cells. The intracellular boron concentration using A6K/BSH was almost 10 times higher than that of BSH. The systematic administration of A6K/BSH via mouse tail vein showed tumor specific accumulation in a mouse brain tumor model with immunohistochemistry and pharmacokinetic study. Neutron irradiation of glioma cells treated with A6K/BSH showed the inhibition of cell proliferation in a colony formation assay. Boron delivery using A6K peptide provides a unique and simple strategy for next generation BNCT drugs.

INTRODUCTION Malignant gliomas are one of the most common and aggressive intracranial neoplasms in humans. Expression of the gene encoding reduced expression in immortalized cells/Dickkopf-3 (REIC/Dkk-3) is reduced in a variety of human cancer cells. We previously showed the antitumor effect of an adenoviral vector carrying REIC/Dkk-3 gene (Ad-CAG-REIC). Recently, we have also developed a novel adenoviral vector expressing REIC/Dkk-3 (Ad-SGE-REIC). We assessed the anti-glioma effect of the Ad-SGE-REIC and planned a clinical trial of Ad-SGE-REIC for malignant glioma. MATERIALS AND METHODS We evaluated a cytotoxicity assay to treatments with Ad-SGE-REIC, Ad-CAG-REIC, or Ad-LacZ (control) using malignant glioma cells. The survival of mice in each group was analyzed by the Kaplan-Meier method. We also performed Good Laboratory Practice (GLP) toxicology tests and prepared a protocol for this clinical trial. RESULTS The treatment with Ad-SGE-REIC showed the number of malignant glioma cells attached to the bottom of culture wells was significantly reduced in a time-dependent manner. Mice treated with Ad-SGE-REIC significantly prolonged survival time more than those treated with other vectors. A cGMP product of Ad-SGE-REIC was developed and supplied by a startup biotech company, Momotaro-Gene Inc. We conducted GLP toxicology tests using the intracranial injection of higher doses of Ad-SGE-REIC at Shin Nippon Biomedical Laboratories (SNBL Japan). After finishing the consultation with Pharmaceuticals and Medical Devices Agency (PMDA), we prepared a protocol for a phase I/IIa clinical trial of Ad-SGE-REIC for the treatment of recurrent malignant glioma with our academic research organization (ARO), supported by Japan Agency for Medical Research and Development (AMED). This protocol was reviewed by our institution review board in March 2019. We submitted a notification of this trial in April 2019. CONCLUSIONS We demonstrated the anti-glioma effect of Ad-SGE-REIC. We start a phase I/IIa clinical trial of Ad-SGE-REIC for the treatment of recurrent malignant glioma (https://jrct.niph.go.jp/en-latest-detail/jRCT2063190013).