Cost of medical care for malignant brain tumors at hospitals in the Japan Clinical Oncology Group brain-tumor study group.

BACKGROUND: This study aimed to investigate what treatment are selected for malignant brain tumors, particularly glioblastoma (GBM) and primary central nervous system lymphoma (PCNSL), in real-world Japan and the costs involved. METHODS: We conducted a questionnaire survey regarding treatment selections for newly diagnosed GBM and PCNSL treated between July 2021 and June 2022 among 47 institutions in the Japan Clinical Oncology Group-Brain Tumor Study Group. We calculated the total cost and cost per month of the initial therapy for newly diagnosed GBM or PCNSL. RESULTS: The most used regimen (46.8%) for GBM in patients aged ≤74 years was 'Surgery + radiotherapy concomitant with temozolomide'. This regimen's total cost was 7.50 million JPY (Japanese yen). Adding carmustine wafer implantation (used in 15.0%), TTFields (used in 14.1%), and bevacizumab (BEV) (used in 14.5%) to the standard treatment of GBM increased the cost by 1.24 million JPY for initial treatment, and 1.44 and 0.22 million JPY per month, respectively. Regarding PCNSL, 'Surgery (biopsy) + rituximab, methotrexate, procarbazine, and vincristine (R-MPV) therapy' was the most used regimen (42.5%) for patients of all ages. This regimen incurred 1.07 million JPY per month. The three PCNSL regimens based on R-MPV therapy were in ultra-high-cost medical care (exceeding 1 million JPY per month). CONCLUSIONS: Treatment of malignant brain tumors is generally expensive, and cost-ineffective treatments such as BEV are frequently used. We believe that the results of this study can be used to design future economic health studies examining the cost-effectiveness of malignant brain tumors.

Overcoming immunotherapy resistance and inducing abscopal effects with boron neutron immunotherapy (B-NIT).

Immune checkpoint inhibitors (ICIs) are effective against many advanced malignancies. However, many patients are nonresponders to immunotherapy, and overcoming this resistance to treatment is important. Boron neutron capture therapy (BNCT) is a local chemoradiation therapy with the combination of boron drugs that accumulate selectively in cancer and the neutron irradiation of the cancer site. Here, we report the first boron neutron immunotherapy (B-NIT), combining BNCT and ICI immunotherapy, which was performed on a radioresistant and immunotherapy-resistant advanced-stage B16F10 melanoma mouse model. The BNCT group showed localized tumor suppression, but the anti-PD-1 antibody immunotherapy group did not show tumor suppression. Only the B-NIT group showed strong tumor growth inhibition at both BNCT-treated and shielded distant sites. Intratumoral CD8+ T-cell infiltration and serum high mobility group box 1 (HMGB1) levels were higher in the B-NIT group. Analysis of CD8+ T cells in tumor-infiltrating lymphocytes (TILs) showed that CD62L- CD44+ effector memory T cells and CD69+ early-activated T cells were predominantly increased in the B-NIT group. Administration of CD8-depleting mAb to the B-NIT group completely suppressed the augmented therapeutic effects. This indicated that B-NIT has a potent immune-induced abscopal effect, directly destroying tumors with BNCT, inducing antigen-spreading effects, and protecting normal tissue. B-NIT, immunotherapy combined with BNCT, is the first treatment to overcome immunotherapy resistance in malignant melanoma. In the future, as its therapeutic efficacy is demonstrated not only in melanoma but also in other immunotherapy-resistant malignancies, B-NIT can become a new treatment candidate for advanced-stage cancers.

Pneumocephalus with Inverted Papilloma in the Frontoethmoidal Sinus: Case Report and Literature Review.

Here, we describe the unique case of a pneumocephalus originating from an inverted papilloma (IP) in the frontoethmoidal sinus. A 71-year-old man with diabetes presented with headaches and altered consciousness. Imaging revealed the pneumocephalus together with bone destruction in the left frontal sinus. He underwent simultaneous endoscopic endonasal and transcranial surgery using an ORBEYE exoscope. Pathological diagnosis of the tumor confirmed IP. Post-surgery, the pneumocephalus was significantly resolved and the squamous cell carcinoma antigen level, which had been elevated, decreased. This case underscores the importance of a multidisciplinary approach and innovative surgical methods in treating complex sinonasal pathologies.

Organized Chronic Subdural Hematoma (OCSDH) Mimicking Meningioma.

Organized chronic subdural hematoma (OCSDH) is a relatively rare condition that forms over a longer period of time compared to chronic subdural hematoma and is sometimes difficult to diagnose with preoperative imaging. We resected an intracranial lesion in a 37-year-old Japanese man; the lesion had been increasing in size for >17 years. The preoperative diagnosis based on imaging findings was meningioma; however, pathological findings revealed OCSDH. Clinicians should be aware that OCSDH mimics other tumors and consider surgical strategies for this disease.

Targeting IGF2 to reprogram the tumor microenvironment for enhanced viro-immunotherapy.

BACKGROUND: The FDA approval of oncolytic herpes simplex-1 virus (oHSV) therapy underscores its therapeutic promise and safety as a cancer immunotherapy. Despite this promise, the current efficacy of oHSV is significantly limited to a small subset of patients largely due to the resistance in tumor and tumor microenvironment (TME). METHODS: RNA sequencing (RNA-Seq) was used to identify molecular targets of oHSV resistance. Intracranial human and murine glioma or breast cancer brain metastasis (BCBM) tumor-bearing mouse models were employed to elucidate the mechanism underlying oHSV therapy-induced resistance. RESULTS: Transcriptome analysis identified IGF2 as one of the top-secreted proteins following oHSV treatment. Moreover, IGF2 expression was significantly upregulated in 10 out of 14 recurrent GBM patients after treatment with oHSV, rQNestin34.5v.2 (71.4%; P = .0020) (ClinicalTrials.gov, NCT03152318). Depletion of IGF2 substantially enhanced oHSV-mediated tumor cell killing in vitro and improved survival of mice bearing BCBM tumors in vivo. To mitigate the oHSV-induced IGF2 in the TME, we constructed a novel oHSV, oHSV-D11mt, secreting a modified IGF2R domain 11 (IGF2RD11mt) that acts as IGF2 decoy receptor. Selective blocking of IGF2 by IGF2RD11mt significantly increased cytotoxicity, reduced oHSV-induced neutrophils/PMN-MDSCs infiltration, and reduced secretion of immune suppressive/proangiogenic cytokines, while increased CD8 + cytotoxic T lymphocytes (CTLs) infiltration, leading to enhanced survival in GBM or BCBM tumor-bearing mice. CONCLUSIONS: This is the first study reporting that oHSV-induced secreted IGF2 exerts a critical role in resistance to oHSV therapy, which can be overcome by oHSV-D11mt as a promising therapeutic advance for enhanced viro-immunotherapy.

Genomic landscape of glioblastoma without IDH somatic mutation in 42 cases: a comprehensive analysis using RNA sequencing data.

PURPOSE: Glioblastoma is a malignant brain tumor with a poor prognosis. Genetic mutations associated with this disease are complex are not fully understood and require further elucidation for the development of new treatments. The purpose of this study was to comprehensively analyze genetic mutations in glioblastomas and evaluate the usefulness of RNA sequencing. PATIENTS AND METHODS: We analyzed 42 glioblastoma specimens that were resected in routine clinical practice and found wild-type variants of the IDH1 and IDH2 genes. RNA was extracted from frozen specimens and sequenced, and genetic analyses were performed using the CLC Genomics Workbench. RESULTS: The most common genetic alterations in the 42 glioblastoma specimens were TP53 mutation (28.6%), EGFR splicing variant (16.7%), EGFR mutation (9.5%), and FGFR3 fusion (9.5%). Novel genetic mutations were detected in 8 patients (19%). In 12 cases (28.6%), driver gene mutations were not detected, suggesting an association with PPP1R14A overexpression. Our findings suggest the transcription factors SOX10 and NKX6-2 are potential markers in glioblastoma. CONCLUSION: RNA sequencing is a promising approach for genotyping glioblastomas because it provides comprehensive information on gene expression and is relatively cost-effective.

Combined simultaneous endoscopic endonasal and transcranial surgery using high-definition three-dimensional exoscope for malignant tumors of the anterior skull base.

BACKGROUND: Advanced surgical interventions are required to treat malignancies in the anterior skull base (ASB). This study investigates the utility of endoscopic endonasal and transcranial surgery (EETS) using a high-definition three-dimensional exoscope as an alternative to traditional microscopy. METHODS: Six patients with carcinomas of varying histopathologies underwent surgery employing the EETS maneuver, which synchronized three distinct surgical modalities: harvesting of the anterolateral thigh flap, initiation of the transnasal technique, and initiation of the transcranial procedure. RESULTS: The innovative strategy enabled successful tumor resection and skull base reconstruction without postoperative local neoplastic recurrence, cerebrospinal fluid leakage, or neurological deficits. CONCLUSION: The integration of the exoscope and EETS is a novel therapeutic approach for ASB malignancies. This strategy demonstrates the potential of the exoscope in augmenting surgical visualization, enhancing ergonomics, and achieving seamless alignment of multiple surgical interventions. This technique represents a progressive shift in the management of these complex oncological challenges.

Midline invasion predicts poor prognosis in diffuse hemispheric glioma, H3 G34-mutant: an individual participant data review.

INTRODUCTION: Diffuse hemispheric glioma, H3 G34-mutant (DHGs), is a newly categorized tumor in pediatric-type diffuse high-grade gliomas, World Health Organization grade 4, with a poor prognosis. Although prognostic factors associated with genetic abnormalities have been reported, few reports have examined the clinical presentation of DHGs, especially from the viewpoint of imaging findings. In this study, we investigated the relationship between clinical factors, including imaging findings, and prognosis in patients with DHGs. METHODS: We searched Medline through the PubMed database using two search terms: "G34" and "glioma", between 1 April 2012 and 1 July 2023. We retrieved articles that described imaging findings and overall survival (OS), and added one DHG case from our institution. We defined midline invasion (MI) as invasion to the contralateral cerebrum, brainstem, corpus callosum, thalamus, and basal ganglia on magnetic resonance imaging. The primary outcome was 12-month survival, estimated using Kaplan-Meier curves and logistic regression. RESULTS: A total of 96 patients were included in this study. The median age was 22 years, and the proportion of male patients was 48.4%. Lesions were most frequently located in the frontal lobe (52.6%). MI was positive in 39.6% of all patients. The median OS was 14.4 months. Univariate logistic regression analysis revealed that OS was significantly worse in the MI-positive group compared with the MI-negative group. Multivariate logistic regression analysis revealed that MI was an independent prognostic factor in DHGs. CONCLUSIONS: In this study, MI-positive cases had a worse prognosis compared with MI-negative cases. PREVIOUS PRESENTATIONS: No portion of this study has been presented or published previously.

Combination therapy with hydrogen peroxide and irradiation promotes an abscopal effect in mouse models.

Hydrogen peroxide (H2 O2 ) induces oxidative stress and cytotoxicity, and can be used for treating cancers in combination with radiotherapy. A product comprising H2 O2 and sodium hyaluronate has been developed as a radiosensitizer. However, the effects of H2 O2 on antitumor immunity remain unclear. To investigate the effects of H2 O2 , especially the abscopal effect when combined with radiotherapy (RT), we implanted murine tumor cells simultaneously in two locations in mouse models: the hind limb and back. H2 O2 mixed with sodium hyaluronate was injected intratumorally, followed by irradiation only at the hind limb lesion. No treatment was administered to the back lesion. The H2 O2 /RT combination significantly reduced tumor growth at the noninjected/nonirradiated site in the back lesion, whereas H2 O2 or RT individually did not reduce tumor growth. Flow cytometric analyses of the tumor-draining lymph nodes in the injected/irradiated areas showed that the number of dendritic cells increased significantly with maturation in the H2 O2 /RT combination group. In addition, analyses of tumor-infiltrating lymphocytes showed that the number of CD8+ (cluster of differentiation 8) T cells and the frequency of IFN-γ+ (interferon gamma) CD8+ T cells were higher in the noninjected/nonirradiated tumors in the H2 O2 /RT group compared to those in the other groups. PD-1 (programmed death receptor 1) blockade further increased the antitumor effect against noninjected/nonirradiated tumors in the H2 O2 /RT group. Intratumoral injection of H2 O2 combined with RT therefore induces an abscopal effect by activating antitumor immunity, which can be further enhanced by PD-1 blockade. These findings promote the development of H2 O2 /RT therapy combined with cancer immunotherapies, even for advanced cancers.

Utility of Comprehensive Genomic Profiling for Precise Diagnosis of Pediatric-Type Diffuse High-Grade Glioma.

In the current World Health Organization classification of central nervous system tumors, comprehensive genetic and epigenetic analyses are considered essential for precise diagnosis. A 14-year-old male patient who presented with a cerebellar tumor was initially diagnosed with glioblastoma and treated with radiation and concomitant temozolomide chemotherapy after resection. During maintenance temozolomide therapy, a new contrast-enhanced lesion developed in the bottom of the cavity formed by the resection. A second surgery was performed, but the histological findings in specimens from the second surgery were different from those of the first surgery. Although genome-wide DNA methylation profiling was conducted using frozen tissue for a precise diagnosis, the proportion of tumor cells was insufficient and only normal cerebellum was observed. We then performed comprehensive genetic analysis using formalin-fixed paraffin-embedded sections, which revealed MYCN amplification without alteration of IDH1, IDH2, or Histone H3. Finally, the patient was diagnosed with pediatric-type diffuse high-grade glioma, H3-wildtype and IDH-wildtype. In conclusion, comprehensive genetic and epigenetic analysis should be considered in pediatric brain tumor cases.

IDH-mutant Astrocytoma Arising in the Brainstem with Symptom Improvement by Foramen Magnum Decompression: A Case Report.

Diffusely infiltrative midline gliomas are known to have a poor prognosis. The standard treatment for typical diffuse midline glioma in the pons is local radiotherapy as surgical resection is inappropriate. This case reports a brainstem glioma in which stereotactic biopsy and foramen magnum decompression were concomitantly performed to confirm the diagnosis and improve symptoms. A 23-year-old woman was referred to our department with a chief complaint of headache for six months. Magnetic resonance imaging (MRI) showed diffuse T2 hyperintense swelling of the brainstem with the pons as the main locus. Enlargement of the lateral ventricles was observed because of cerebrospinal fluid obstruction out of the posterior fossa. This was atypical for a diffuse midline glioma in terms of the longstanding slow progression of symptoms and patient age. Stereotactic biopsy was performed for diagnosis, and foramen magnum decompression (FMD) was concomitantly performed to treat the obstructive hydrocephalus. The histological diagnosis was astrocytoma, IDH-mutant. Post-surgery, the patient's symptoms were relieved, and she was discharged on the fifth day after surgery. The hydrocephalus was resolved, and the patient returned to normal life without any symptoms. The tumor size follow-up with MRI demonstrated no marked change for 12 months. Even though diffuse midline glioma is considered to have a poor prognosis, clinicians should contemplate if it is atypical. In atypical cases like the one described herein, surgical treatment may contribute to pathological diagnosis and symptom improvement.

Utility of genome-wide DNA methylation profiling for pediatric-type diffuse gliomas.

Despite the current progress of treatment, pediatric-type diffuse glioma is one of the most lethal primary malignant tumors in the central nervous system (CNS). Since pediatric-type CNS tumors are rare disease entities and highly heterogeneous, the diagnosis is challenging. An accurate diagnosis is essential for the choice of optimal treatment, which leads to precision oncology and improvement of the patient's outcome. Genome-wide DNA methylation profiling recently emerged as one of the most important tools for the diagnosis of CNS tumors, and the utility of this novel assay has been reported in both pediatric and adult patients. In the current World Health Organization classification published in 2021, several new entities are recognized in pediatric-type diffuse gliomas, some of which require methylation profiling. In this review, we investigated the utility of genome-wide DNA methylation profiling in pediatric-type diffuse glioma, as well as issues in the clinical application of this assay. Furthermore, the combination of genome-wide DNA methylation profiling and other comprehensive genomic assays, which may improve diagnostic accuracy and detection of the actionable target, will be discussed.

PKR induces TGF-ß and limits oncolytic immune therapy.

BACKGROUND: Mammalian cells have developed multiple intracellular mechanisms to defend against viral infections. These include RNA-activated protein kinase (PKR), cyclic GMP-AMP synthase and stimulation of interferon genes (cGAS-STING) and toll-like receptor-myeloid differentiation primary response 88 (TLR-MyD88). Among these, we identified that PKR presents the most formidable barrier to oncolytic herpes simplex virus (oHSV) replication in vitro. METHODS: To elucidate the impact of PKR on host responses to oncolytic therapy, we generated a novel oncolytic virus (oHSV-shPKR) which disables tumor intrinsic PKR signaling in infected tumor cells. RESULTS: As anticipated, oHSV-shPKR resulted in suppression of innate antiviral immunity and improves virus spread and tumor cell lysis both in vitro and in vivo. Single cell RNA sequencing combined with cell-cell communication analysis uncovered a strong correlation between PKR activation and transforming growth factor beta (TGF-ß) immune suppressive signaling in both human and preclinical models. Using a murine PKR targeting oHSV, we found that in immune-competent mice this virus could rewire the tumor immune microenvironment to increase the activation of antigen presentation and enhance tumor antigen-specific CD8 T cell expansion and activity. Further, a single intratumoral injection of oHSV-shPKR significantly improved the survival of mice bearing orthotopic glioblastoma. To our knowledge, this is the first report to identify dual and opposing roles of PKR wherein PKR activates antivirus innate immunity and induces TGF-ß signaling to inhibit antitumor adaptive immune responses. CONCLUSIONS: Thus, PKR represents the Achilles heel of oHSV therapy, restricting both viral replication and antitumor immunity, and an oncolytic virus that can target this pathway significantly improves response to virotherapy.

A Case of Radiation-Induced Osteosarcoma with RB1 Gene Alteration Treated by Skull Base Surgery and Craniofacial Reconstruction.

A 35-year-old female presented with headache, photophobia and developed sudden loss of vision after having undergone right-side ophthalmectomy and radiochemotherapy for retinoblastoma in infancy. A neoplastic lesion was found in the left middle cranial fossa and was surgically removed. The diagnosis was radiation-induced osteosarcoma with RB1 gene alteration. Although she received chemotherapy for the residual tumor, it progressed 17 months later. Maximal surgical resection with craniofacial reconstruction was required. We utilized two three-dimensional models for surgical planning. She was discharged without neurological deficits other than loss of light perception subsequent to left ophthalmectomy. In cases where retinoblastoma is treated with radiotherapy, long-term follow-up is necessary to monitor for radiation-induced tumor development.

Age is a major determinant for poor prognosis in patients with pilocytic astrocytoma: a SEER population study.

Background Pilocytic astrocytomas (PAs) are central nervous system tumors with variable prognosis and poorly understood risk factors. Little evidence exists regarding the effect of age on mortality in PA. Therefore, we conducted a thorough characterization of PA in the US. Methods We queried the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2018 to extract age-adjusted incidence rate (AAIR), age-adjusted mortality rate (AAMR), and survival data on PA. The age group comparisons for each measure varied depending on available SEER data. We compared trends in AAIR and AAMR by two age groups (children, 0-19 years; adults, 20 + years) and by sex. The cumulative incidence function and the Fine-Gray competing risk model were applied by 0-19, 20-39, 40-59, and 60 + years of age groups. Results This study included 5211 incident PA and 462 PA-specific deaths between 2000 and 2018. Trends in AAIRs and AAMRs were almost constant between 2000 and 2018. Average AAIRs had a sharp peak in 1-4 years of age groups, whereas AAMRs had a gradual peak in 80-84 years of age groups. Age groups, tumor location, and race/ethnicity were significantly associated with PA-specific death, whereas only age was associated with other cause of deaths. Conclusions Trends in AAIRs and AAMRs were constant regardless of age. PAs in older populations, especially over 60 years old, have higher incidence of death than those in younger populations.

Potent bystander effect and tumor tropism in suicide gene therapy using stem cells from human exfoliated deciduous teeth.

Herpes simplex virus thymidine kinase (HSVTK)/ganciclovir (GCV) suicide gene therapy has a long history of treating malignant gliomas. Recently, stem cells from human exfoliated deciduous teeth (SHED), which are collected from deciduous teeth and have excellent harvestability, ethical aspects, and self-renewal, have been attracting attention mainly in the field of gene therapy. In the present study, we assessed SHED as a novel cellular vehicle for suicide gene therapy in malignant gliomas, as we have previously demonstrated with various cell types. SHED was transduced with the HSVTK gene (SHEDTK). In vitro experiments showed a significant bystander effect between SHEDTK and glioma cell lines in coculture. Furthermore, apoptotic changes caused by caspase 3/7 activation were simultaneously observed in SHEDTK and glioma cells. Mice implanted with a mixture of U87 and SHEDTK and treated with intraperitoneal GCV survived for longer than 100 days. Additionally, tumors in treatment model mice were significantly reduced in size during the treatment period. SHEDTK implanted at the contralateral hemisphere migrated toward the tumor crossing the corpus callosum. These results suggested that SHEDTK-based suicide gene therapy has potent tumor tropism and a bystander-killing effect, potentially offering a new promising therapeutic modality for malignant gliomas.

A Case of Relapsed Primary Central Nervous System Lymphoma Treated with CD19-directed Chimeric Antigen Receptor T Cell Therapy.

Although high-dose methotrexate (HD-MTX) is the standard therapy for primary central nervous system lymphoma (PCNSL), the prognosis remains poor. Because 90% of PCNSL is diffuse large B-cell lymphoma (DLBCL), chimeric antigen receptor (CAR)-T cell therapy is expected to be beneficial. However, there are limited reports on CAR-T cell therapy for PCNSL because of the concern of neurotoxicity. Here, we report a case of relapsed PCNSL treated with anti-CD19 CAR-T cell therapy. A 40-year-old woman presenting with visual disturbance in her left eye was initially diagnosed with bilateral uveitis. Her histological diagnosis was DLBCL, and she was positive for CD19. Although she received chemotherapy including HD-MTX, the tumor relapsed in her right occipital lobe. She underwent remission induction therapy and then anti-CD19 CAR-T cell therapy. Cytokine release syndrome (CRS) grade 2 occurred, but there were no complications of CAR-T cell-related encephalopathy syndrome (CRES). She has achieved complete response for more than 1 year. Anti-CD19 CAR-T cell therapy is a revolutionary immunotherapy for treating relapsed or refractory (R/R) B lineage malignancies. Although there are concerns regarding CRS and CRES in central nervous system lymphoma, the use of anti-CD19 CAR-T cells to treat R/R PCNSL is safe and feasible.

The utility of DNA methylation analysis in elderly patients with pilocytic astrocytoma morphology.

PURPOSE: Pilocytic astrocytoma (PA) is a circumscribed low-grade astrocytic glioma, generally considered to be associated with a good prognosis. However, a subset of PA patients shows unfavorable outcomes. In this study, we retrospectively reviewed PA patients and performed further molecular analysis, such as DNA methylation profiling, to identify prognostic factors. METHODS: We analyzed 29 histologically-confirmed PA patients from a single center from 2002 to 2021 and conducted integrated molecular analyses among elderly PA patients since age was an independent prognostic factor for poor outcomes. RESULTS: The median age at diagnosis was 14 years (range 3-82 years) and 4 patients (14%) were elderly (patients ≥ 60 years old). Age over 60 was associated with poor progression-free survival and overall survival. We performed DNA methylation analysis on 2 of the 4 elderly patients. Both cases were histologically diagnosed as PA, but DNA methylation profiling revealed one as high-grade astrocytoma with piloid features (all methylation class scores were below 0.3 in both v11b4 and v12.5) and the other as glioblastoma, IDH-wildtype (score was over 0.5 in both v11b4 and v12.5), using the German Cancer Research Center methylation profiling classifiers and t-SNE analysis. CONCLUSIONS: Elderly patients with PA morphology showed unfavorable outcomes in this cohort. In those patients, further molecular analysis and DNA methylation profiling revealed the possibility of high-grade astrocytic tumors, including newly defined entities.

Genomic Profiling of a Case of Glioneuronal Tumor with Neuropil-like Islands.

Glioneuronal tumor with neuropil-like islands (GNTNI) is a very rare subtype of glioneuronal tumor. We present a case of a 62-year-old man with GNTNI. Two adjacent lesions in the left parietal lobe were removed by left parietal craniotomy. The histological findings were glial cell proliferation and scattered rosettes consisting of synaptophysin-positive and NeuN-positive cells, leading to the diagnosis of GNTNI. Target sequencing revealed a genetic alteration similar to glioblastoma, IDH-wild type, which suggested adjuvant therapies. There are few previous reports on the treatment of this disease, and the patient should be followed carefully.

Combination of Ad-SGE-REIC and bevacizumab modulates glioma progression by suppressing tumor invasion and angiogenesis.

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 did 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. Ad-SGE-REIC treatment resulted in a significant reduction in the number of invasion cells treated with bevacizumab. Western blot analyses revealed the increased expression of several endoplasmic reticulum stress markers in cells treated with both bevacizumab and Ad-SGE-REIC, as well as decreased ß-catenin protein levels. 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 the angiogenesis and invasion of tumors. Combined Ad-SGE-REIC and bevacizumab might be a promising strategy for the treatment of malignant glioma.