Status of alternative angiogenic pathways in glioblastoma resected under and after bevacizumab treatment

Glioblastoma multiforme (GBM) acquires resistance to bevacizumab (Bev) treatment. Bev affects angiogenic factors other than vascular endothelial growth factor (VEGF), which are poorly understood. We investigated changes in angiogenic factors under and after Bev therapy, including angiopoietin-1 (ANGPT1), angiopoietin-2 (ANGPT2), placental growth factor (PLGF), fibroblast growth factor 2, and ephrin A2 (EphA2). Fifty-four GBM tissues, including 28 specimens from 14 cases as paired specimens from the same patient obtained in three settings: initial tumor resection (naïve Bev), tumors resected following Bev therapy (effective Bev), and recurrent tumors after Bev therapy (refractory Bev). Immunohistochemistry assessed their expressions in tumor vessels and its correlation with recurrent MRI patterns. PLGF expression was higher in the effective Bev group than in the naïve Bev group (p = 0.024) and remained high in the refractory Bev group. ANGPT2 and EphA2 expressions were higher in the refractory Bev group than in the naïve Bev group (p = 0.047 and 0.028, respectively). PLGF expression was higher in the refractory Bev group compared with the naïve Bev group for paired specimens (p = 0.036). PLGF was more abundant in T2 diffuse/circumscribe patterns (p = 0.046). This is the first study to evaluate angiogenic factors other than VEGF during effective and refractory Bev therapy in patient-derived specimens.

An exploratory prospective phase II study of preoperative neoadjuvant bevacizumab and temozolomide for newly diagnosed glioblastoma

PURPOSE

This multi-institutional phase I/II study was conducted to confirm the safety and explore the clinical utility of preoperative Bevacizumab (Bev) for newly diagnosed glioblastoma (GB).

METHODS

Patients were enrolled based on magnetic resonance imaging (MRI) findings typically suggestive of GB. Preoperative Bev and temozolomide (TMZ) were administered at doses of 10 mg/kg on day 0 and 150 mg/m2 on days 1-5, respectively. Surgical resection was performed between days 21 and 30, inclusive. The safety and efficacy were evaluated in a total of 15 cases by progression-free survival (PFS), changes in tumor volume, Karnofsky Performance Scale (KPS) and Mini-Mental State Examination (MMSE) scores after preoperative therapy.

RESULTS

Tumor resection was performed on a mean of day 23.7. Pathological diagnosis was GB, isocitrate dehydrogenase (IDH)-wildtype in 14 cases and GB, IDH-mutant in 1 case. Severe adverse events possibly related to preoperative Bev and TMZ were observed in 2 of the 15 patients, as wound infection and postoperative hematoma and thrombocytopenia. KPS and MMSE scores were significantly improved with preoperative therapy. Tumor volume was decreased in all but one case on T1-weighted imaging with contrast-enhancement (T1CE) and in all cases on fluid-attenuated inversion recovery, with mean volume decrease rates of 36.2% and 54.0%, respectively. Median PFS and overall survival were 9.5 months and 16.5 months, respectively.

CONCLUSION

Preoperative Bev and TMZ is safe as long as the instructions are followed. The strategy might be useful for GB in some patients, not only reducing tumor burden, but also improving patient KPS preoperatively.

TRIAL REGISTRATION NUMBER

UMIN000025579, jRCT1031180233 https://jrct.niph.go.jp/latest-detail/jRCT1031180233 . Registration Date: Jan. 16, 2017.

Gene therapy using genome-edited iPS cells for targeting malignant glioma

Glioblastoma is characterized by diffuse infiltration into the normal brain. Invasive glioma stem cells (GSCs) are an underlying cause of treatment failure. Despite the use of multimodal therapies, the prognosis remains dismal. New therapeutic approach targeting invasive GSCs is required. Here, we show that neural stem cells (NSCs) derived from CRISRP/Cas9-edited human-induced pluripotent stem cell (hiPSC) expressing a suicide gene had higher tumor-trophic migratory capacity compared with mesenchymal stem cells (MSCs), leading to marked in vivo antitumor effects. High migratory capacity in iPSC-NSCs was related to self-repulsive action and pathotropism involved in EphB-ephrinB and CXCL12-CXCR4 signaling. The gene insertion to ACTB provided higher and stable transgene expression than other common insertion sites, such as GAPDH or AAVS1. Ferroptosis was associated with enhanced antitumor immune responses. The thymidylate synthase and dihydroprimidine dehydrogenase expressions predicted the treatment efficacy of therapeutic hiPSC-NSCs. Our results indicate the potential benefit of genome-edited iPS cells based gene therapy for invasive GSCs. Furthermore, the present research concept may become a platform to promote clinical studies using hiPSC.

Correlation between genotype and phenotype with special attention to hearing in 14 Japanese cases of NF2-related schwannomatosis

NF2-related schwannomatosis (NF2) is an autosomal dominant genetic disorder caused by variants in the NF2 gene. Approximately 50% of NF2 patients inherit pathogenic variants, and the remainder acquire de novo variants. NF2 is characterized by development of bilateral vestibular schwannomas. The genetic background of Japanese NF2 cases has not been fully investigated, and the present report performed a genetic analysis of 14 Japanese NF2 cases and examined genotype-phenotype correlations. DNA samples collected from peripheral blood were analyzed by next-generation sequencing, multiplex ligation-dependent probe amplification analysis, and in vitro electrophoresis. Ten cases had pathogenic or likely pathogenic variants in the NF2 gene, with seven truncating variants and three non-truncating variants. The age of onset in all seven cases with truncating variants was < 20 years. The age of onset significantly differed among cases with truncating NF2 variants, non-truncating NF2 variants, and no NF2 variants. However, the clinical course of tumor growth and hearing deterioration were not predicted only by germline pathogenic NF2 variants. The rate of truncating variants was higher in the present study than that of previous reports. Genotype-phenotype correlations in the age of onset were present in the analyzed Japanese NF2 cases.

Clinical, histopathological and molecular risk factors for recurrence of pilocytic astrocytomas: brainstem/spinal location, nestin expression and gain of 7q and 19 are associated with early tumor recurrence

Pilocytic astrocytomas (PAs) are benign tumors. However, clinically aggressive PAs despite benign histology have been reported, and histological and molecular risk factors for prognosis have not been elucidated. 38 PAs were studied for clinical, histological, and molecular factors, including tumor location, extent of resection, post-operative treatment, glioma-associated molecules (IDH1/2, ATRX, BRAF, FGFR1, PIK3CA, H3F3A, p53, VEGF, Nestin, PD-1/PD-L1), CDKN2A/B deletion, and chromosomal number aberrations, to see if there is any correlation with patient's progression-free survival (PFS). Brainstem/spinal location, extent of resection and post-operative treatment, and VEGF-A, Nestin and PD-L1 expression, copy number gain of chromosome 7q or 19, TP53 mutation were significantly associated with shorter PFS. None of the histological parameters was associated with PFS. Multivariate analyses demonstrated that high Nestin expression, gain of 7q or 19, and extent of removal were independently predictive for early tumor recurrence. The brainstem/spinal PAs appeared distinct from those in the other sites in terms of molecular characteristics. Clinically aggressive PAs despite benign histology exhibited high Nestin expression. Brainstem/spinal location, extent of resection and some molecular factors including Nestin expression and gains of 7q and 19, rather than histological parameters, may be associated with early tumor recurrence in PAs.

ACT-1 A PROSPECTIVE MULTICENTER PHASE I/IIA STUDY OF PREOPERATIVE NEOADJUVANT BEVACIZUMAB FOR NEWLY DIAGNOSED GLIOBLASTOMA

Background

Preoperative neoadjuvant bevacizumab (neoBev) reduces enhancement and perifocal edema by inhibition of angiogenesis and vascular permeability for glioblastoma (GBM). The aim of this study was to investigate safety and efficacy of neoBev for newly diagnosed GBM through an exploratory prospective multi-center study.

METHODS & PATIENTS

15 patients with newly diagnosed GBM were enrolled in the present study. Eligibility was a patient with a brain tumor representing with ring-shaped enhancement and perifocal edema on magnetic resonance imaging (MRI). Based on neuroimage of typical GBM, neoBev and temozolomide (TMZ) were administered prior to craniotomy. Two weeks after neoBev, the tumor volume on T1-weighted gadolinium enhancement (T1Gd) and fluid attenuated inversion recovery (FLAIR) were assessed. Three to four weeks after neoBev and TMZ administration, patients underwent surgical resection. The primary endpoint was feasibility and safety, and the secondary endpoint was efficacy. Adverse events including systemic toxicity and wound healing delay during radiation (RT), TMZ, and Bev combined therapy were carefully monitored throughout clinical course including extent of resection.

RESULTS

Average of tumor regression rate two weeks after neoBev on T1Gd and FLAIR were 37.0% and 54.0%, respectively. Cerebral blood flow and cerebral blood volume were reduced after neoBev. Patients underwent surgical resection safely without excess blood loss due to less vascular and less degree of brain swelling. Two patients underwent awake surgery without any complications. Postoperative MRI showed that the all tumors were totally removed except one with multiple invasive tumors. Histological diagnosis of all patients was GBM, IDH-1 wild-type. Postoperative course was uneventful without neurological deficit and adverse effects except one postoperative hematoma in the resection cavity and one wound infection due to wound dehiscence.

CONCLUSION

Preoperative neoBev for newly diagnosed GBM might contribute to safe surgery. Clinical outcome of this therapeutics is now currently under investigation.

P-218 Mitochondria transfer from adipose stem cell ameliorates the development potential of cryopreserved oocytes

Study question

Could autologous adipose stem cell (ASC) mitochondria supplementation restore the post-fertilization development potentialin vitrified-thawed oocytes?

Summary answer

Autologous ASC mitochondria supplementation could rejuvenate the quality of vitrified-thawed oocytes and enhance the embryo’s developmental capacity.

What is known already

Pre- and post-implantation developmental potential of embryos derived from vitrified oocytes are remarkedly lower than those of fresh oocytes. Despite its’ low efficacy, oocyte cryopreservation is becoming prevalent in assisted reproductive technologies to cater the growing demands due to patients' sociological and pathological conditions. Unfavorable effects to mitochondrial membrane potential, mitochondrial structure, ATP production, reactive oxygen species (ROS), meiotic spindle and microfilaments, and Ca2+ ion regulation are reported as detrimental damages in oocytes following the cryopreservation, that adversely affect the development potential. Furthermore, autologous stem cell mitochondria supplementation can rescue the aging-related oocyte mitochondrial damages.

Study design, size, duration

The mature oocytes, autologous ASC, and mitochondria were collected from young mice and analyzed at Osaka City University, Japan. In total, 600 young mouse mature oocytes were occupied in this prospective study.

Participants/materials, setting, methods

Young C57BL/6JJmsmouse (8weeks) mature oocytes that have been pre-vitrified were thawed before the start of the ICSI procedure.ASC specificity and ASC mitochondria function and ultrastructure were pre-analyzed. ASC mitochondria were isolated on the same day and supplemented with intracellular sperm injection (ICSI) and as the control, the mitochondrial buffer was injected. The survival rate, fertilization rate, blastulation, mitochondria function, ROS level in 2 cell embryos, and live birth rates were compared between the 2 groups.

Main results and the role of chance

The ASC mitochondriashowed higher membrane potential compared to the somatic cells and were spherical in shape with low cristae numbers. The survival rate and the fertilization ratewere comparable in both mitochondria supplemented and control groups. However, theASC mitochondria supplementation seemed to havesignificantly improvedthe blastocyst development capacity from 2cell embryos compared to the control group (P &lt; 0.05;56.8% & 38.2%, respectively).And interestingly, a significantly higher ATP level was found in the mitochondria supplemented group’s 2 cell embryos thanin the control group (P &lt; 0.05;905.6pmol & 561.1pmol respectively). And though it was not statistically significant, a higher potential ofgetting live birth was found in the mitochondria supplemented group thanthe control group after 2 cell embryo transfer.

Limitations, reasons for caution

We acknowledge that the absence of compared data with fresh oocytes’ ICSI, the detailed cellular mechanism behind theimprovement of embryo development, and transgenerational safety in offspring developed fromthe mitochondria supplementation werethe limitations of this study.

Wider implications of the findings

With these results, we propose that ASC mitochondria supplementation could rejuvenate the quality of cryopreserved oocytes and enhance the embryo developmental capacity, signifying another possible approach of mitochondrial transplantation therapy.

Trial registration number

not applicable

P-200 An addition of nicotinamide adenine dinucleotide (NAD+) precursor to oocyte maturation medium improves the developmental competence of bovine oocytes after IVF

Study question

Does an increase of nicotinamide adenine dinucleotide (NAD+) level in oocytes lead to an improvement of blastulation after IVF?

Summary answer

The addition of NAD+ precursor to the oocyte maturation medium increased NAD+ levels in the oocytes, improving the developmental competence to the blastocyst after IVF.

What is known already

With maternal ageing, the enzyme that degrades NAD+ (CD38) increases in cells and the amount of NAD+ in cells, including oocytes, decreases. The degradation of NAD+ is also increased when cells are isolated from tissues. NAD+, which is an electron carrier used by all eukaryotes, is reduced to NADH via beta-oxidation of fatty acids and the TCA cycle, enhancing ATP synthesis in the mitochondrial electron transfer system. In addition, an enzyme in the inner mitochondrial membrane donates protons from NADH to NADP+ to synthesize NADPH, which maintains the intracellular redox state.

Study design, size, duration

This study is a prospective study using bovine oocytes retrieved from ovaries obtained from a local slaughterhouse in Osaka city. A total of 2,501 bovine oocytes were used in this study.

Participants/materials, setting, methods

Bovine cumulus-oocyte-complexes (COCs) were matured in vitro in the culture (IVM) medium supplemented with 0-100 μM nicotinamide mononucleotide (NMN). Matured oocytes were inseminated with the washed spermatozoa and cultured to assess the blastulation. Matured oocytes were also used to examine their NAD+, reactive oxygen species (ROS) and ATP levels.

Main results and the role of chance

The addition of NMN to the IVM medium increased intracellular NAD+ levels of bovine mature oocytes at 1 µM and above. As a result, it increased intracellular ATP levels and decreased ROS levels at 10 µM and above. It also improved blastocyst formation rates after IVF at 100 µM (P &lt; 0.05; 35%) compared with control (22.2%). Moreover, the supplementation of NMN to the IVM medium decreased the percentage of apoptotic cells and intracellular ROS levels in cumulus cells surrounding oocytes.

Limitations, reasons for caution

This study was conducted in vitro using bovine oocytes. Thus, studies using human samples should be performed before clinical application.

Wider implications of the findings

By replenishing NAD+, we have found a clue to improving the IVM and IVF outcome, which has been shown to have a lower blastocyst formation rate than conventional IVF methods using in vivo matured oocytes. It may also improve the developmental potential of oocytes retrieved from older women.

Trial registration number

not applicable

TPT1 Supports Proliferation of Neural Stem/Progenitor Cells and Brain Tumor Initiating Cells Regulated by Macrophage Migration Inhibitory Factor (MIF)

One of the key areas in stem cell research is the identification of factors capable of promoting the expansion of Neural Stem Cell/Progenitor Cells (NSPCs) and understanding their molecular mechanisms for future use in clinical settings. We previously identified Macrophage Migration Inhibitory Factor (MIF) as a novel factor that can support the proliferation and/or survival of NSPCs based on in vitro functional cloning strategy and revealed that MIF can support the proliferation of human brain tumor-initiating cells (BTICs). However, the detailed downstream signaling for the functions has largely remained unknown. Thus, in the present study, we newly identified translationally-controlled tumor protein-1 (TPT1), which is expressed in the ventricular zone of mouse embryonic brain, as a downstream target of MIF signaling in mouse and human NSPCs and human BTICs. Using gene manipulation (over or downregulation of TPT1) techniques including CRISPR/Cas9-mediated heterozygous gene disruption showed that TPT1 contributed to the regulation of cell proliferation/survival in mouse NSPCs, human embryonic stem cell (hESC) derived-NSPCs, human-induced pluripotent stem cells (hiPSCs) derived-NSPCs and BTICs. Furthermore, gene silencing of TPT1 caused defects in neuronal differentiation in the NSPCs in vitro. We also identified the MIF-CHD7-TPT1-SMO signaling axis in regulating hESC-NSPCs and BTICs proliferation. Intriguingly, TPT1suppressed the miR-338 gene, which targets SMO in hESC-NSPCs and BTICs. Finally, mice with implanted BTICs infected with lentivirus-TPT1 shRNA showed a longer overall survival than control. These results also open up new avenues for the development of glioma therapies based on the TPT1 signaling pathway.

The Relationship between Family Meals and Mental Health Problems in Japanese Elementary School Children: A Cross-Sectional Study

The relative burden of mental health problems in children is increasing worldwide. Family meals have attracted attention as an effective modifiable factor for preventing children’s mental health problems. We examined the relationship between family meals and mental health problems in Japanese elementary schoolchildren. A cross-sectional, self-administered questionnaire survey was conducted with guardians of children aged 7 to 12 years in Gifu Prefecture, Japan. Frequency of family meals and with whom the child eats breakfast, lunch, and dinner were assessed separately for weekdays and weekends/holidays. Mental health was assessed using the Japanese version of the parent-reported Strengths and Difficulties Questionnaire. Multivariate adjusted odds ratios (ORs) for borderline/abnormal mental health status were calculated using logistic regression analysis. Of the 678 children, 24.9% had borderline/abnormal mental health status. Children eating breakfast with their family less than once a week (adjusted OR, 4.79; 95% confidence interval (CI), 1.51–15.25) and those eating weekend breakfast alone (adjusted OR, 3.61; 95% CI, 1.42–9.23) had a higher prevalence of borderline/abnormal mental health status compared to those eating breakfast seven times a week and weekend breakfast with their family, respectively. These results suggest that family meals, especially breakfast, might be positively associated with better mental health in children.

Gene Therapy Using Neural Stem/Progenitor Cells Derived from Human Induced Pluripotent Stem Cells: Visualization of Migration and Bystander Killing Effect

Glioblastoma is the most aggressive brain tumor characterized by diffuse infiltration into the normal brain parenchyma. Neural stem cells are known to possess the tumor-tropic migratory capacity and thus can be used as cellular vehicles for targeted delivery of therapeutic agents. In the present study, we evaluated the efficacy of herpes simplex virus thymidine kinase (HSV-TK) suicide gene therapy for glioblastoma using neural stem/progenitor cells (NS/PCs) derived from human induced pluripotent stem cells (hiPSCs). Although transduction of hiPSCs is preferable for a safe and stable supply in the clinical setting, high-level and/or constitutive HSV-TK expression was highly cytotoxic to hiPSCs. To overcome this problem, we used the tetracycline-inducible system to control the expression of HSV-TK. hiPSC-derived NS/PCs expressing HSV-TK were transplanted in an orthotopic xenograft mouse model of human glioblastoma. Glioblastoma cell growth in mice was dramatically inhibited following ganciclovir (GCV) administration. Survival of the mice was significantly prolonged with administration of GCV compared with control groups. Time-lapse imaging of organotypic brain slice cultures first demonstrated the directional migration of NS/PCs toward glioblastoma cells and the bystander killing effect upon GCV treatment. hiPSC-derived NS/PCs with HSV-TK/GCV suicide gene system may have considerable therapeutic potential for the treatment of glioblastoma. Color images are available online.

Cell-Based Biohybrid Sensor Device for Chemical Source Direction Estimation

This paper describes a method to estimate the direction from which the signal molecule reaches the sensor by using living cells. In this context, biohybrid sensors that utilize a sophisticated sensing system of cells can potentially offer high levels of chemical-detection sensitivity and selectivity. However, biohybrid-sensor-based chemical-source-direction estimation has not received research attention because the cellular response to chemicals has not been examined in the context of directional information. In our approach, we fabricated a device that can limit the interface between the cell-laden hydrogel and the chemical solution of interest to enhance the time difference over which the chemical solution reaches the cells. Chemical detection by cells that express specific receptors is reflected as the fluorescence of the calcium indicator within the cells. Our device has eight chambers that each house 3D cell-laden collagen hydrogels facing circularly outward. The device also works as a cover to prevent chemicals from permeating the hydrogel from above. In our study, by observing the time course of the fluorescence emission of each chamber, we were able to successfully estimate the chemical-source direction within an error range of 7–13°. Our results suggest that a combination of microstructure devices embedded with living cells can be used to exploit cell functionalities to yield chemical-source directional information.

Quiescent and Activated Fibroblasts in Lateral Ventricular Meningioma With a Dura-like Membrane

BACKGROUND

Lateral ventricular meningioma (LVM) is a rare entity, accounting for 0.5%-5% of all intracranial meningiomas. This type of meningioma arises from meningothelial inclusion bodies in the tela choroidea and/or mesenchymal stroma of the choroid plexus. Although not yet fully characterized, a membranous structure is frequently observed around LVMs. This study analyzed quiescent and activated fibroblast phenotypes in LVMs with focus on the relationship between tumor growth and development of the membranous structure.

METHODS

This retrospective study analyzed 9 LVM cases for which gross total removal was achieved. Expression of the ependymal cell marker (Forkhead Box J1 [FoxJ1]) was histopathologically evaluated. The distribution of quiescent and activated fibroblasts was also analyzed using anti-fibroblast-specific protein-1 (FSP1)/S100A4 antibody and anti-α-smooth muscle actin (αSMA) antibody, respectively. The control group was 5 cases with primary convexity meningioma for which Simpson grade I removal was achieved.

RESULTS

Small LVMs (≤30 mm) were covered by a FoxJ1-positive(+) ependymal cell monolayer; no αSMA(+) cells were detected in the tumor; and a thick membrane capsule was not observed. None of the convexity meningiomas showed FoxJ1(+) cells. Large LVMs (>30 mm) had thick membrane capsules without an ependymal cell monolayer, which resembled dura mater. The FSP1/S100A4(+) and αSM(+) cells were clearly concentrated in the peripheral area just below the thick dura mater-like membrane capsules.

CONCLUSIONS

This study found an association between activated fibroblasts and dura mater-like membrane capsules in LVMs. The characteristics of membranous structure in LVMs may differ depending on tumor size.

Prognostic Significance of Preoperative Neutrophil-to-Lymphocyte Ratio in Patients With Meningiomas

Background

Meningiomas are the most common benign intracranial tumors. However, even WHO grade I meningiomas occasionally show local tumor recurrence. Prognostic factors for meningiomas have not been fully established. Neutrophil-to-lymphocyte ratio (NLR) has been reported as a prognostic factor for several solid tumors. The prognostic value of NLR in meningiomas has been analyzed in few studies.

Materials and Methods

This retrospective study included 160 patients who underwent surgery for meningiomas between October 2010 and September 2017. We analyzed the associations between patients’ clinical data (sex, age, primary/recurrent, WHO grade, extent of removal, tumor location, peritumoral brain edema, and preoperative laboratory data) and clinical outcomes, including recurrence and progression-free survival (PFS).

Results

Forty-four meningiomas recurred within the follow-up period of 3.8 years. WHO grade II, III, subtotal removal, history of recurrence, Ki-67 labeling index ≥3.0, and preoperative NLR value ≥2.6 were significantly associated with shorter PFS (P < 0.001, < 0.001, 0.002, < 0.001, and 0.015, respectively). Furthermore, NLR ≥ 2.6 was also significantly associated with shorter PFS in a subgroup analysis of WHO grade I meningiomas (P = 0.003). In univariate and multivariate analyses, NLR ≥2.6 remained as a significant predictive factor for shorter PFS in patients with meningioma (P = 0.014).

Conclusions

NLR may be a cost-effective and novel preoperatively usable biomarker in patients with meningiomas.

A Pilot Study of the Adverse Events Caused by the Combined Use of Bevacizumab and Vascular Endothelial Growth Factor Receptor-Targeted Vaccination for Patients with a Malignant Glioma

Anti-angiogenic therapy, targeting vascular endothelial growth factor (VEGF)-A/VEGF receptors (VEGFRs), is beneficial for tumor growth prevention in a malignant glioma. A simultaneous blockade using both bevacizumab (Bev), which targets circulating VEGF-A, and a multi-kinase inhibitor on VEGFRs was more effective for advanced solid cancers, including melanoma and renal cell carcinoma. However, previous clinical trials demonstrated a high adverse event rate. Additionally, no studies previously assessed treatment efficacy and safety using both VEGF-A and VEGFR-targeted agents for malignant gliomas. We had conducted clinical trials investigating VEGFRs peptide vaccination in patients with malignant gliomas, in which the treatment exhibited safety and yielded therapeutic effects in some patients. The combined use of Bev and VEGFRs vaccination may enhance the anti-tumor effect in malignant gliomas. In this pilot study, the adverse event profile in patients treated with Bev after the vaccination was investigated to establish this treatment strategy, in comparison to those treated with Bev collected from the published data or treated with the vaccination alone. In our previous clinical studies on patients with malignant gliomas, Bev was administered to 13 patients after VEGFRs vaccinations. One patient had a Grade 4 pulmonary embolism. Two patients had Grade 2 cerebral infarctions. There were no significant differences in the adverse event rates among patients treated with Bev, with the vaccination, or with Bev after the vaccination. Although careful observation is imperative for patients after this combination treatment strategy, VEGFRs-targeted vaccination may coexist with Bev for malignant gliomas.

Central nervous system ganglioneuroblastoma harboring MYO5A-NTRK3 fusion

Central nervous system (CNS) ganglioneuroblastoma is a rare neuroectodermal neoplasm and little is known about its clinical and biological features. Herein, we report a pediatric case of CNS ganglioneuroblastoma harboring MYO5A-NTRK3 fusion. The patient, a 4-year-old boy, underwent a partial resection of a supratentorial tumor that was histopathologically diagnosed as a CNS ganglioneuroblastoma. Treatment with radiotherapy was started per the St Jude Medulloblastoma 03 (SJMB03) protocol; however, the tumor progressed rapidly and radiotherapy was temporally discontinued. Meanwhile, the patient underwent a second surgery, in which a gross total resection was successfully performed, following which he completed the remaining protocol-based therapy. Although an early focal recurrence was detected for which he received additional radiotherapy and oral temozolomide, the patient remained in complete remission for 14 months after the completion of the treatment. A central pathological review and molecular analysis were performed that revealed a MYO5A-NTRK3 fusion. Interestingly, the MYO5A-NTRK3 fusion has been recurrently detected in melanocytic tumors but not in other types of tumors. Therefore, it can be speculated that our case might partly share tumorigenesis mechanisms with MYO5A-NTRK3-positive melanocytic tumors. In addition, our case may enable an improved understanding of the pathogenesis and clinical features of CNS ganglioneuroblastomas.

Novel histopathological classification of meningiomas based on dural invasion

AIMS

Histological invasion into the adjacent brain parenchyma is frequently investigated in meningioma because it is an important morphological criterion for grade II meningioma according to the 2016 WHO classification. However, few studies have focused on dural invasion of meningiomas. Herein, we propose a novel histopathological classification based on dural invasion of meningiomas.

METHODS

Forty-nine cases with WHO grade I meningiomas who underwent Simpson grade I removal were collected. After the meningeal layer (ML) and periosteal layer (PL) of dura mater were visualised by Masson's trichrome stain, we evaluated the depth (to the ML and PL) and the patterns (1, expanding; 2, infiltrating) of dural invasion of meningiomas using serial paraffin sections. Invasion-associated markers, including Ki-67, matrix metalloproteinase (MMP)-1, MMP-9 and MMP-13, aquaporin 1 and Na-K-2Cl cotransporter, were quantitatively analysed by immunohistochemistry.

RESULTS

Thirty-five cases (71.4%) showed the dural invasion. In 27 of these 35 cases (77.1%), dural invasion was localised in ML. Type 1 (expanding type) and type 2 (infiltrating type) invasions were observed in 23 and 12 cases, respectively. The recurrence rate in cases with type 2 invasion was significantly higher than that in cases with type 1 invasion. The percentage of MMP-1-positive tumour cells was also significantly higher in cases with dural invasion than those without, suggesting involvement of MMP-1 in dural invasion.

CONCLUSIONS

We quantitatively evaluated the depth and patterns of dural invasion in meningiomas. The patterns of dural invasion were associated with meningioma recurrence.

Surgical outcomes of anterior cerebellopontine angle meningiomas using the anterior transpetrosal approach compared with the lateral suboccipital approach

BACKGROUND

Anterior transpetrosal approach (ATPA) and lateral suboccipital approach (LSO) are the major surgical approaches for cerebellopontine angle (CPA) meningiomas. Particularly, anterior CPA meningiomas are challenging lesions to be treated surgically. To date, only a few studies have directly compared the outcomes of both approaches focusing on the anterior CPA meningiomas.

METHODS

For the comparative analysis, anterior CPA meningiomas that were eligible for both APTA and LSO were collected in our hospital from April 2005 to March 2017. Anterior CPA meningiomas targeted for this study were defined as follows: (1) without cavernous sinus, clivus, and middle cranial fossa extension, (2) the posterior edge is 1 cm behind the posterior wall of the internal auditory canal, and (3) the inferior edge is above the jugular tuberculum. Based on these criteria, the operative outcomes of 17 patients and 13 patients who were operated via ATPA and LSO were evaluated.

RESULTS

The complication rate of the LSO group was significantly higher than that of the ATPA group (30.7% vs. 0%, p = 0.033). The removal rate did not differ between the ATPA and LSO groups (97.35% vs. 99.23%, p = 0.12). The operative time was significantly shorter in the LSO group than in the ATPA group (304.3 min vs. 405.8 min, p = 0.036).

CONCLUSIONS

Although the LSO is more widely used for CPA meningiomas, ATPA is also considered for these anterior CPA meningiomas.

Clinical and histopathological analyses of VEGF receptors peptide vaccine in patients with primary glioblastoma - a case series

BACKGROUND

The expression of vascular endothelial growth factor (VEGF)-A/ VAGF receptors (VEGFRs) signaling plays a pivotal role in the tumor angiogenesis and the development of the immunosuppressive tumor microenvironment in glioblastomas. We have previously conducted exploratory clinical studies investigating VEGFRs peptide vaccination with and without multiple glioma oncoantigens in patients with recurrent high-grade gliomas. Recently, an exploratory clinical investigation of VEGFRs peptide vaccination was conducted in patients with progressive neurofibromatosis type 2. Those studies suggested that cytotoxic T lymphocytes (CTLs) induced by the vaccination can directly kill a wide variety of cells associated with tumor growth, including tumor vessels, tumor cells, and immunosuppressive cells expressing VEGFR1 and/or 2. In the present study, synergistic activity of the combination of VEGFRs peptide vaccination with chemotherapy was evaluated.

METHODS

We performed the first clinical trial to assess VEGFR1 and 2 vaccination along with temozolomide (TMZ) -based chemoradiotherapy for the patients with primary glioblastomas. Furthermore, histopathological changes after the vaccination were evaluated using paired pre- and post- vaccination specimens.

RESULTS

The disappearance of radiographically enhanced lesion was observed in 2 patients after the vaccination, including one in which the methylation of the O6-methylguanine-DNA methyltransferase (MGMT) promoter was not observed. The histopathological findings of pre- and post-vaccination specimens demonstrated that tumor vessels showed negative or slight VEGFRs expressions after the vaccination and most endothelial cells were covered with PDGFR-β-positive pericytes. Notably, CTLs induced by VEGFRs peptide vaccination attacked not only tumor vessels but also tumor cells and regulatory T cells expressing VEGFRs even in recurrent tumors.

CONCLUSIONS

VEGFR1 and 2 vaccination may have a preliminary synergistic effect when administered with TMZ. The limitation of the present study was the paucity of the number of the samples. Further studies involving more patients are warranted to confirm the findings of this study.

TRIAL REGISTRATION

This study was registered as UMIN000013381 (University Hospital Medical Information Network-Clinical Trial Registry: UMIN-CTR) on 5 March, 2014 and with the Japan Registry of Clinical Trials (jRCT) as jRCTs031180170 on 1 March, 2019.

Alterations of the tumor microenvironment in glioblastoma following radiation and temozolomide with or without bevacizumab

Background

The immunosuppressive tumor microenvironment (TME) contributes to the tumor progression and treatment failure. Our previous study demonstrated alterations in the TME during bevacizumab (Bev) therapy in human glioblastoma (GB) specimens obtained from patients who underwent surgical resection. Continuous Bev administration downregulates the expression of programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1), suppresses the infiltration of tumor associated macrophages (TAMs) and regulatory T cells (Tregs), and increases cytotoxic T lymphocytes (CTLs) infiltration. However, one may argue that these immunosupportive effects might also be induced by radiation therapy (RT) or temozolomide (TMZ), and they cannot necessarily be attributed to Bev alone.

Methods

In the present study, changes in the molecules relevant to the TME were analyzed by immunohistochemistry using paired pre- and post-treatment samples of malignant glioma specimens from 15 patients who received RT and TMZ therapy without Bev.

Results

The expression levels of CD34, vascular endothelial growth factor (VEGF)-A, VEGF receptor 2 (VEGFR2), HIF-1α, CA9, nestin, CD4, CD8, CD163, PD-1, and PD-L1 were not significantly changed after the treatment with RT and TMZ. However, VEGFR1 expression and the number of Foxp3-positive cells tended to be upregulated and increased after the treatment (P=0.058, P=0.082, respectively).

Conclusions

This was the first study to show the alterations of TME following RT and TMZ therapy using paired pre- and post-treatment malignant glioma samples. Long-term treatment of RT and TMZ might worsen immunosuppressive TME in malignant gliomas.

Quantitative assessment and clinical relevance of VEGFRs-positive tumor cells in refractory brain tumors

Vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR)1 and 2 signaling is a potent activator of tumor angiogenesis. Although the expressions of VEGFR1 and VEGFR2 were initially thought to be limited to the endothelial cells, it is now known that both the receptors are expressed in tumor cells. This is the first study wherein VEGFRs-positive tumor cells are quantitatively evaluated for brain tumors with upregulated VEGF/VEGFR signaling. The percentage of VEGFRs-positive tumor cells was quantitatively evaluated in various brain tumors (10 glioblastomas, 22 neurofibromatosis type 2 [NF2]-related schwannomas, 21 sporadic schwannomas, 27 chordomas, 36 meningiomas, 29 hemangioblastomas, 11 hemangiopericytoma, and 13 ependymomas) using immunohistochemistry. VEGF-A expression was also analyzed using quantitative real-time polymerase chain reaction. Double immunofluorescence staining using anti-PDGFR-β and anti-CD34 antibody, microvessel density, and vessel diameter were analyzed to evaluate the vascular characteristics. Chordomas demonstrated an extremely higher percentage of VEGFR1 and VEGFR2-positive tumor cells than other tumors. In contrast, meningiomas and hemangiopericytomas showed few VEGFRs-positive tumor cells. The percentage of positive tumor cells in chordomas, hemangioblastomas, and NF2 schwannomas was associated with clinical courses, such as shorter progression free survival, and growth speed. Glioblastomas and NF2 schwannomas showed larger tumor vessels without pericyte coverage. The present study is the first to quantitatively analyze VEGFR1- and VEGFR2- positive tumor cells in various types of refractory brain tumors. This novel parameter significantly correlated with the progressive clinical courses.

Difference in the hypoxic immunosuppressive microenvironment of patients with neurofibromatosis type 2 schwannomas and sporadic schwannomas

BACKGROUND

Neurofibromatosis type 2 (NF2) patients uniformly develop multiple schwannomas. The tumor-microenvironment (TME) is associated with hypoxia and consists of immunosuppressive cells, including regulatory T cells (Tregs) and tumor-associated macrophages (TAMs). The hypoxic TME of NF2 schwannomas remains unclear. In addition, no comparative study has investigated immunosuppressive cells in NF2 and sporadic schwannomas.

METHODS

In 22 NF2 and 21 sporadic schwannomas, we analyzed the immunohistochemistry for Ki-67, hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor receptor 1 (VEGFR1) and VEGFR2, platelet derived growth factor receptor-beta (PDGFR-β), programmed cell death-1 (PD-1)/ programmed cell death ligand-1 (PD-L1), Foxp3, CD163, CD3, and CD8 to assess the immunosuppressive TME.

RESULTS

Most vessels in sporadic schwannomas exhibited slight or negative VEGFR1 and 2 expressions with pericytes coverage. In contrast, large vessels in NF2 schwannomas exhibited strong VEGFR1 and 2 expressions without pericytes. The number of CD3⁺, CD8⁺, and CD163⁺ cells was significantly higher in NF2 schwannomas than in sporadic ones. The expression of PD-L1 and nestin positive cell ratio was higher in NF2 schwannomas than that in sporadic ones. The number of CD163⁺ cells, nestin positive cell ratio, and HIF-1α expression were significantly associated with shorter progression-free survival in NF2 schwannomas.

CONCLUSIONS

This study presents the clinicopathological features of the differences in immunosuppressive cells and the expression of immune checkpoint molecules between NF2 and sporadic schwannomas. Hypoxic TME was first detected in NF2-schwannomas, which was associated with the tumor progression.

A VEGF receptor vaccine demonstrates preliminary efficacy in neurofibromatosis type 2

The anti-VEGF antibody bevacizumab has shown efficacy for the treatment of neurofibromatosis type 2 (NF2). Theoretically, vascular endothelial growth factor receptors (VEGFRs)-specific cytotoxic T lymphocytes (CTLs) can kill both tumor vessel cells and tumor cells expressing VEGFRs. Here we show an exploratory clinical study of VEGFRs peptide vaccine in seven patients with progressive NF2-derived schwannomas. Hearing improves in 2/5 assessable patients (40%) as determined by international guidelines, with increases in word recognition scores. Tumor volume reductions of ≥20% are observed in two patients, including one in which bevacizumab had not been effective. There are no severe adverse events related to the vaccine. Both VEGFR1-specific and VEGFR2-specific CTLs are induced in six patients. Surgery is performed after vaccination in two patients, and significant reductions in the expression of VEGFRs in schwannomas are observed. Therefore, this clinical immunotherapy study demonstrates the safety and preliminary efficacy of VEGFRs peptide vaccination in patients with NF2.

The anti-vascular endothelial growth factor (VEGF) antibody bevacizumab has shown efficacy for the treatment of neurofibromatosis type 2 (NF2). Here, the authors show that VEGFRs peptide vaccination can improve hearing and reduce tumor volume in NF2 patients, including in previously bevacizumab resistant tumors.

IMT-02 VEGF RECEPTORS EXPRESSION AND REPORT OF CLINICAL TRIAL OF PEPTIDE VACCINE IN SKULL BASE CHORDOMA

Chordoma is a rare refractory neoplasm that arises from the embryological remnants of the notochord. Vascular endothelial growth factor (VEGF) is a potent activator of angiogenesis that is associated with the tumor-immune microenvironment. To evaluate the characteristics of vascular and tumor cells in chordoma, we first analyzed the expression of VEGF receptor (VEGFR) 1, VEGFR2, CD34, and Brachyury in a cell line and 54 tumor tissues. Patients with primary skull base chordomas were divided into the two groups as per the tumor growth rate. The expressions of VEGF-A, VEGFR1, and VEGFR2 on tumor cells; tumor infiltrative immune cells, including regulatory T cells (Tregs) and tumor-associated macrophages (TAMs); and immune-checkpoint molecules (PD-1/PD-L1) were analyzed with the clinical courses. Both VEGFR1 and VEGFR2 were strongly expressed not only on vascular endothelial cells, but also on tumor cells. The recurrent cases showed significantly higher VEGFR1 expressions on tumor cells than the primary cases. The expression of VEGF-A, and the numbers of CD163+ TAMs and Foxp3+ Tregs were significantly higher in the patients with rapid progressive course than the patients with slow progressive course. Based on the present results, VEGFRs-targeted therapy may show efficacy in regulating growth of chordomas.

ANGI-01 ALTERATION IN IMMUNE REGULATORY CELLS BEFORE AND AFTER TREATMENT BY STUPP REGIMEN WITH OR WITHOUT BEVACIZUMAB FOR GLIOBLASTOMA

BACKGROUND

In our previous study, bevacizumab (Bev), a humanized anti- vascular endothelial growth factor monoclonal antibody, downregulated the expression of programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) immune checkpoint molecules, suppressed the infiltration of immunosuppressing cells such as regulatory T cells (Tregs) and tumor-associated macrophages (TAMs), and induces cytotoxic T lymphocytes (CTL) infiltration. To explore the possibility that inhibition of immunosuppressive cell infiltration and induction of CTL were attributed to not only Bev alone but also radiation (RT) or temozolomide (TMZ), we re-evaluated those alterations in the tumor tissue obtained from patients before and after the treatment using Stupp regimen (RT concomitant with TMZ) without Bev therapy.

MATERIALS & METHODS

We analyzed 10 tumor tissues from 5 patients with GBMs, which were paired samples of pre- and post- standard chemoradiotherapy (Stupp regimen: RT plus concomitant and adjuvant TMZ). Immunohistochemical analyses were performed on formalin-fixed, paraffin-embedded tissue of 10 tumors. The sections were stained with anti-Ki-67, anti-VEGF-A, anti-VEGFR1, anti-VEGFR2, anti-CD34, anti-HIF1 alpha, anti-CA9, anti-nestin, anti-PD-1, anti-PD-L1, anti-CD4, anti-CD8, anti-Foxp3, and anti-CD163 antibodies. All expressions were assessed by authors with blinded clinical information.

RESULTS

Immunohistochemical analyses demonstrated that the expression levels of immune regulatory molecules such as Foxp3, CD163, PD-1, PD-L1, CD4, and CD8 were not significantly changed after the treatment using the Stupp regimen, compared with combinational usage of Bev. In addition, expressions of VEGF/VEGFR, hypoxic markers, and stem cell marker were not altered before and after Stupp regimen, either. Bev persistently inhibited immune suppressive cells and immune checkpoint molecules via down-regulation of VEGF pathway. In contrast, Stupp regimen did not affect immune regulations and tumor microenvironment.

CONCLUSION

These results suggested that immunosupportive effect was caused by Bev administration, leading to the novel combinational treatment strategies, in addition to Stupp regimen.

A Comparative Study Between Traditional Microscopic Surgeries and Endoscopic Endonasal Surgery for Skull Base Chordomas

BACKGROUND

Skull base chordomas (SBCs) are rare clinically aggressive neoplasms, developing local recurrences after surgical resection. Although SBCs have traditionally been resected by craniotomy or microscopic transsphenoidal surgery (TSS), the recent development of the endoscopic endonasal approach (EEA) has revolutionized treatment strategies through minimally invasive techniques. This study aimed to evaluate clinical outcomes after traditional microsurgeries or EEAs for SBCs.

METHODS

The present retrospective study investigated 66 patients with primary SBCs who underwent surgery between 1977 and 2019. Resection was performed via EEA in 17 cases, craniotomy in 23, transoral approach in 8, TSS in 12, staged surgery in 4, and others in 2. The median follow-up period for progression-free survival (PFS) was 19.5 months.

RESULTS

There were no significant differences in preoperative tumor volume or resection rate among these approaches. The incidence of postoperative cranial nerve palsy was significantly lower in EEA than that in craniotomy (P < 0.05). Although total resection was observed in 4 cases of EEA expanding into the superior and inferior part of the clivus, no cases of transoral approach or TSS achieved total resection for both parts. No significant difference in PFS was found among these approaches. Multivariate analysis showed that being female and the absence of radiotherapy were significantly associated with shorter PFS (P < 0.05 and P < 0.001, respectively). The resection rate was not associated with PFS.

CONCLUSIONS

EEA is a less invasive surgical approach for SBCs. The development of surgical instruments and postoperative radiotherapy will further improve patients' outcomes.

Evaluation of velopharyngeal function using high-speed cine-magnetic resonance imaging based on T2-weighted sequences: a preliminary study

The objective was to introduce a new technique for visualizing the three-dimensional (3D) movements of velopharyngeal-related muscles using high-speed cine-magnetic resonance imaging (MRI) based on T2-weighted sequences. The evaluation of phonation- and water swallowing-related events was performed in 11 healthy subjects. Specifically, whether cine-MRI could precisely visualize normal velopharyngeal function during these two events was examined. The 3D movements of the soft palate, superior pharyngeal constrictor muscles, and levator veli palatini muscles were visualized in all 11 subjects. A noteworthy finding was that the magnetic resonance signals of the superior constrictor pharyngeal muscles and the levator veli palatini muscles were significantly higher during phonation and during water swallowing than at rest. This initial study suggests that the 3D movements of velopharyngeal-related muscles can be successfully and precisely visualized without side effects. The magnetic resonance signal changes seen in the superior pharyngeal constrictor and levator veli palatini muscles using the technique described here should be useful to develop better methods of evaluation of velopharyngeal function.

Analysis of Temporobasal Vein with Short Subdural Segment for Anterior Transpetrosal Approach

BACKGROUND

The anterior transpetrosal approach (ATPA) is applied to petroclival and brainstem lesions. Although neurosurgeons need to minimize the risk of neurologic complications, brain retraction is necessary for procedures of ATPA. Bridging veins (BVs) limit mobility of the temporal lobe. In the present study, BVs around the petrous bone were analyzed, focusing on the dural entrance and termination points.

METHODS

The relationship between subdural and meningeal segments of temporobasal veins (TBVs) was analyzed by preoperative computed tomography venography in 102 patients who underwent ATPA. TBVs were classified by the dural entrance and termination points.

RESULTS

TBVs mainly entered the transverse sinus and rarely entered transverse-sigmoid sinus (T-S) junction and superior petrosal sinus (SPS). TBVs entered a dural sinus either directly or indirectly through a meningeal vein. The changes in vascular diameter of the lumen, shape, and course were identified between the subdural and meningeal segments. Generally, BVs with long subdural segment do not limit mobility of the temporal lobe. TBVs draining into the T-S junction and SPS tended to be shorter than those draining into the transverse sinus. Furthermore, a few TBVs indirectly entered the dural sinuses through the meningeal vein (early dural entrance). The subdural segment of these TBVs was much shorter.

CONCLUSIONS

TBVs entering the T-S junction or SPS with short subdural segment may limit the mobility of the temporal lobe. Changes in vascular diameter, shape, and course were detected by computed tomography venography, which was helpful to detect the subdural-meningeal transition.

Prognostic significance of VEGF receptors expression on the tumor cells in skull base chordoma

BACKGROUND

Chordoma is a rare refractory neoplasm that arises from the embryological remnants of the notochord, which is incurable using any multimodality therapy. Vascular endothelial growth factor (VEGF) is a potent activator of angiogenesis that is strongly associated with the tumor-immune microenvironment. These factors have not been elucidated for chordomas.

METHODS

To evaluate the characteristics of vascular and tumor cells in chordoma, we first analyzed the expression of VEGF receptor (VEGFR) 1, VEGFR2, CD34, and Brachyury in a cell line and 54 tumor tissues. Patients with primary skull base chordomas were divided into the following two groups as per the tumor growth rate: patients with slow progression (SP: < 3 mm/year) and those with rapid progression (RP: ≥ 3 mm/year). Thus, the expressions of VEGF-A, VEGFR 1, and VEGFR2 on tumor cells; tumor infiltrative immune cells, including regulatory T cells (Tregs) and tumor-associated macrophages (TAMs); and immune-checkpoint molecules (PD-1/PD-L1) were analyzed with the clinical courses, especially in a comparison between the two groups.

RESULTS

In chordomas, both VEGFR1 and VEGFR2 were strongly expressed not only on vascular endothelial cells, but also on tumor cells. The recurrent cases showed significantly higher VEGFR1 expressions on tumor cells than the primary cases. The expression of VEGF-A was significantly higher in RP than that in SP group. The numbers of CD163+ TAMs and Foxp3+ Tregs were higher in RP than that in SP group.

CONCLUSIONS

Expression of VEGFR1 and VEGFR2 on tumor cells and immunosuppressive tumor-microenvironment were related to tumor growth in patients with chordomas.

PITX2 Expression in Non-functional Pituitary Neuroendocrine Tumor with Cavernous Sinus Invasion

Although most pituitary neuroendocrine tumors (PitNETs) show benign behavior, a significant number of PitNETs exhibit an aggressive course including cavernous sinus (CS) invasion. To date, the cause of CS invasion has not been fully elucidated. In this study, we analyzed the relationship between CS invasion in PitNETs and the expression of PITX2 and SNAIL1, which are the transcription factors associated with the morphogenesis of pituitary gland. Sixty cases with non-functional PitNETs were classified into four types: type 1a, none of CS invasion and suprasellar expansion; type 1b, suprasellar expansion without CS invasion; type 2a, CS invasion without suprasellar expansion; and type 2b, CS invasion with suprasellar expansion. We analyzed the expression of PITX2 and SNAIL1 employing quantitative real-time polymerase chain reaction (qPCR) and immunohistochemistry. Other parameters such as mitotic count, Ki-67 index, and p53 expression were also analyzed, which were previously reported as potential tumor proliferative markers in PitNETs. PITX2 expression was significantly higher in PitNETs with CS invasion than PitNETs without CS invasion (P = 0.019). Expression of SNAIL1 was significantly elevated in PitNETs with suprasellar expansion compared with PitNETs without suprasellar expansion (P = 0.02). There was no apparent relationship between CS invasion and mitotic count, Ki-67 index, and p53 expression (mitotic count, P = 0.11; Ki-67 index, P = 0.61; p53, P = 0.66). High PITX2 expression was observed in non-functional PitNETs with CS invasion, suggesting that PITX2 may be involved in CS invasion of PitNETs.

Visualization of spatiotemporal dynamics of human glioma stem cell invasion

Glioblastoma exhibits phenotypic and genetic heterogeneity, aggressive invasiveness, therapeutic resistance, and tumor recurrence, which can be explained by the existence of glioma stem cells (GSCs). In this study, we visualized the spatiotemporal dynamics of invasion of human GSCs in an orthotopic xenograft mouse model using time-lapse imaging of organotypic brain slice cultures and three-dimensional imaging of optically cleared whole brains. GSCs implanted in the striatum exhibited directional migration toward axon bundles, perivascular area, and the subventricular zone around the inferior horn of the lateral ventricle. GSCs migrated in a helical pattern around axon bundles in the striatum and invaded broadly in both the rostral and caudal directions. GSCs in the corpus callosum migrated more rapidly and unidirectionally toward the contralateral side with pseudopod extension. These characteristics of GSC invasion shared histological features observed in glioblastoma patients. Spatiotemporal visualization techniques can contribute to the elucidation of the mechanisms underlying GSC invasion that may lead to the development of effective therapy for glioblastoma.

A Pilot Study of Vaccine Therapy with Multiple Glioma Oncoantigen/Glioma Angiogenesis-Associated Antigen Peptides for Patients with Recurrent/Progressive High-Grade Glioma

High-grade gliomas (HGGs) carry a dismal prognosis despite current treatments. We previously confirmed the safety and immunogenicity of a vaccine treatment targeting tumor angiogenesis with synthetic peptides, for vascular endothelial growth factor receptor (VEGFR) epitopes in recurrent HGG patients. In this study, we evaluated a novel vaccine therapy targeting not only tumor vasculature but also tumor cells, using multiple glioma oncoantigen (GOA)/glioma angiogenesis-associated antigen (GAAA) peptides in HLA-A2402+ recurrent/progressive HGG patients. The vaccine included peptide epitopes from four GOAs (LY6K, DEPDC1, KIF20A, and FOXM1) and two GAAAs (VEGFR1 and VEGFR2). Ten patients received subcutaneous vaccinations. The primary endpoint was the safety of the treatment. T-lymphocyte responses against GOA/GAAA epitopes and treatment response were evaluated secondarily. The treatment was well tolerated without any severe systemic adverse events. The vaccinations induced immunoreactivity to at least three vaccine-targeted GOA/GAAA in all six evaluable patients. The median overall survival time in all patients was 9.2 months. Five achieved progression-free status lasting at least six months. Two recurrent glioblastoma patients demonstrated stable disease. One patient with anaplastic oligoastrocytoma achieved complete response nine months after the vaccination. Taken together, this regimen was well tolerated and induced robust GOA/GAAA-specific T-lymphocyte responses in recurrent/progressive HGG patients.

Persistent restoration to the immunosupportive tumor microenvironment in glioblastoma by bevacizumab

Although vascular endothelial growth factor (VEGF) promotes the immunosuppressive microenvironment, the efficacy of bevacizumab (Bev) on tumor immunity has not been fully investigated. The present study used 47 glioblastoma tissues obtained at 3 different settings: tumors of initial resection (naïve Bev group), tumors resected following Bev therapy (effective Bev group), and recurrent tumors after Bev therapy (refractory Bev group). The paired samples of the initial and post‐Bev recurrent tumors from 9 patients were included. The expression of programmed cell death‐1 (PD‐1)/PD ligand‐1 (PD‐L1), CD3, CD8, Foxp3, and CD163 was analyzed by immunohistochemistry. The PD‐L1+ tumor cells significantly decreased in the effective or refractory Bev group compared with the naïve Bev group (P < .01 for each). The PD‐1+ cells significantly decreased in the effective or refractory Bev group compared with the naïve Bev group (P < .01 for each). The amount of CD3+ and CD8+ T cell infiltration increased in the refractory Bev group compared with the naïve Bev group (CD3, P < .01; CD8, P = .06). Both Foxp3+ regulatory T cells and CD163+ tumor‐associated macrophages significantly decreased in the effective or refractory Bev group compared with the naïve Bev group (Foxp3, P < .01 for each; CD163, P < .01 for each). These findings were largely confirmed by comparing paired initial and post‐Bev recurrent tumors. Bevacizumab restores the immunosupportive tumor microenvironment in glioblastomas, and this effect persists during long‐term Bev therapy.

Identification of specifically reduced Th2 cell subsets in allergic rhinitis patients after sublingual immunotherapy

BACKGROUND

Although Th2 cells are well known to play important roles in allergic diseases including allergic rhinitis (AR), the factors that induce and sustain the pathogenesis of AR remain unclear. The recent development of sublingual immunotherapy (SLIT) is expected to allow changes to the underlying pathogenesis of AR. However, which Th2 cell subsets are important in house dust mite-induced AR (HDM-AR), the influence of SLIT on the pathogenic Th2 cells, and the association of Th2 cell subsets with SLIT efficacy have not been clarified.

METHODS

The cytokine production and frequency of HDM-reactive T-cell subsets in peripheral blood mononuclear cells (PBMCs) were evaluated using flow cytometry in 89 HDM-AR patients (placebo [n = 43] and HDM 300 IR [n = 46]) who participated in a placebo-controlled study of SLIT with HDM tablets. All patients provided samples both before treatment as a baseline and at the end of the 52-week study. The PBMCs were stained with CellTrace™ Violet (CTV) before culture with HDM extract, and HDM-reactive T cells were detected as the proliferated cells with diminished CTV.

RESULTS

HDM-reactive IL-5⁺ IL-13⁺ CD27^- CD161⁺ CD4⁺ cells and ST2⁺ CD45RO⁺ CD4⁺ cells were observed in the peripheral blood from each patient with HDM-AR; these cells significantly decreased after SLIT in the group treated with active tablets. HDM-reactive ST2⁺ CD45RO⁺ CD4⁺ cells were significantly lower in active-responders.

CONCLUSION

Allergen-reactive ST2⁺ CD45RO⁺ CD4⁺ cells or those combined with IL-5⁺ IL-13⁺ CD27^- CD161⁺ CD4⁺ cells may be useful as markers indicating the successful treatment of SLIT. These cells may play a crucial role in the pathogenesis of AR as pathogenic memory Th2 cells.

Difference in Immunosuppressive Cells Between Peritumoral Area and Tumor Core in Glioblastoma

BACKGROUND

Vascular endothelial growth factor (VEGF)-A and VEGF receptor expression in the peritumoral brain zone (PBZ) differs from that in the tumor core (TC) of glioblastoma. To date, no comparative study has investigated the expression of immunosuppressive cells in the PBZ and TC of glioblastoma.

METHODS

In 10 patients with newly diagnosed glioblastoma, we used immunohistochemistry to analyze the expression of VEGF-A, hypoxia-inducible factor-1α, programmed cell death-1 (PD-1), Foxp3, CD163, CD4, and CD8 to assess the immunosuppressive microenvironment.

RESULTS

The number of Foxp3⁺ and CD163⁺ cells was significantly greater in the TC than in the PBZ and correlated with greater expression of hypoxia-inducible factor-1α and VEGF-A in the TC than in the PBZ. The number of CD8⁺ T cells was lower in the TC than in the PBZ, and the TC had more PD-1⁺CD8⁺ T cells compared with the PBZ. These results suggest that the hypoxic condition could be associated with PD-1 expression on lymphocytes, the distribution of Foxp3⁺ regulatory T cells and CD163⁺ tumor-associated macrophages.

CONCLUSIONS

The present study reports the first clinicopathologic features of the differences in immunosuppressive cells and the expression of immune checkpoint molecules between the TC and PBZ of glioblastoma.

Preoperative Assessment of Pathologic Subtypes of Meningioma and Solitary Fibrous Tumor/Hemangiopericytoma Using Dynamic Computed Tomography: A Clinical Research Study

BACKGROUND

Solitary fibrous tumors (SFTs)/hemangiopericytomas (HPCs) are highly vascularized tumors well known for malignant, invasive, and highly vascular features. To date, several studies have reported the preoperative imaging findings of SFTs/HPCs. In this study, computed tomography (CT) tumor values acquired from dynamic CT scan were selected to determine the tumor pathology of highly vascular tumors, such as SFTs/HPCs.

METHODS

We conducted a retrospective study on patients with pathologically diagnosed meningiomas and SFTs/HPCs who had undergone a dynamic contrast CT scan. We assessed and compared the CT values of these tumors according to the pathology.

RESULTS

From a total of 34 patients, 30 patients with meningiomas and 4 patients with HPCs were included. The mean CT values of SFTs/HPCs and angiomatous meningioma were statistically significantly higher than those of the other meningioma subtypes (P = 0.003). We also performed receiver operating characteristic curve analyses to detect an appropriate cutoff point for the CT value to differentiate tumor pathology, and the calculated threshold was 161 Hounsfield units (HU) (sensitivity, 100%; specificity, 75%; area under the curve, 0.87; 95%, CI 0.75-0.99).

CONCLUSIONS

This study showed that obtaining a CT value is useful in determining highly vascular tumor pathology preoperatively. When considering neurosurgical extra-axial tumor removal, and when the CT value of tumors is >161 HU, then highly vascular tumors such as SFTs/HPCs or angiomatous meningiomas are likely, and this should be considered prior to surgical intervention and for risk assessment.

Pathogenicity of memory Th2 cells is linked to stage of allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) consists of three developmental stages that are based on the presence/absence of antigen-specific IgE and symptoms. The pathogenic Th2 (Tpath2) cells constitute a population of Th2 cells with additional potentially pathogenic characteristics. We examined the relationship between Tpath2 cells and the stages of allergic rhinitis by focusing on ST2, which is an IL-33 receptor.

METHODS

Patients with Japanese cedar pollen-induced AR (JCP-AR) and healthy volunteers were divided into "nonsensitized," "asymptomatic sensitized (AS)," and "JCP-AR" groups. We analyzed the ST2 expression and the Th2 function of cultured CD4⁺ T cells. Next, we observed the progress of patients in the AS stage around the time of seasonal pollen dispersal, with the characteristics of Th2 cells.

RESULTS

The ST2 expression of T cells was only upregulated in the AR group. The production of IL-4 and IL-13 was found in CD4⁺ T cells obtained from AS by stimulation with JCP, but reactivity to IL-33 was not observed. Although IL-33 did not induce the elevation of IL-4 production in the JCP-AR group, IL-33 substantially increased the production of IL-5 and IL-13 in comparison with antigen stimulation alone. In newly afflicted patients, the increased expression of ST2 and elevated reactivity to IL-33 was observed, even before the pollen dispersal season.

CONCLUSIONS

Our study demonstrated that the pathogenicity of memory Th2 cells is linked to sensitization and the stage of allergic rhinitis. Therefore, Tpath2 cells may provide useful insights into the mechanism of the onset and progression of allergic rhinitis.