Defining super-enhancers by highly ranked histone H4 multi-acetylation levels identifies transcription factors associated with glioblastoma stem-like properties

BACKGROUND

Super-enhancers (SEs), which activate genes involved in cell-type specificity, have mainly been defined as genomic regions with top-ranked enrichment(s) of histone H3 with acetylated K27 (H3K27ac) and/or transcription coactivator(s) including a bromodomain and extra-terminal domain (BET) family protein, BRD4. However, BRD4 preferentially binds to multi-acetylated histone H4, typically with acetylated K5 and K8 (H4K5acK8ac), leading us to hypothesize that SEs should be defined by high H4K5acK8ac enrichment at least as well as by that of H3K27ac.

RESULTS

Here, we conducted genome-wide profiling of H4K5acK8ac and H3K27ac, BRD4 binding, and the transcriptome by using a BET inhibitor, JQ1, in three human glial cell lines. When SEs were defined as having the top ranks for H4K5acK8ac or H3K27ac signal, 43% of H4K5acK8ac-ranked SEs were distinct from H3K27ac-ranked SEs in a glioblastoma stem-like cell (GSC) line. CRISPR-Cas9-mediated deletion of the H4K5acK8ac-preferred SEs associated with MYCN and NFIC decreased the stem-like properties in GSCs.

CONCLUSIONS

Collectively, our data highlights H4K5acK8ac's utility for identifying genes regulating cell-type specificity.

Haploinsufficiency of NFKBIA reshapes the epigenome antipodal to the IDH mutation and imparts disease fate in diffuse gliomas

Genetic alterations help predict the clinical behavior of diffuse gliomas, but some variability remains uncorrelated. Here, we demonstrate that haploinsufficient deletions of chromatin-bound tumor suppressor NFKB inhibitor alpha (NFKBIA) display distinct patterns of occurrence in relation to other genetic markers and are disproportionately present at recurrence. NFKBIA haploinsufficiency is associated with unfavorable patient outcomes, independent of genetic and clinicopathologic predictors. NFKBIA deletions reshape the DNA and histone methylome antipodal to the IDH mutation and induce a transcriptome landscape partly reminiscent of H3K27M mutant pediatric gliomas. In IDH mutant gliomas, NFKBIA deletions are common in tumors with a clinical course similar to that of IDH wild-type tumors. An externally validated nomogram model for estimating individual patient survival in IDH mutant gliomas confirms that NFKBIA deletions predict comparatively brief survival. Thus, NFKBIA haploinsufficiency aligns with distinct epigenome changes, portends a poor prognosis, and should be incorporated into models predicting the disease fate of diffuse gliomas.

Prediction of Tumor Development and Urine-Based Liquid Biopsy for Molecule-Targeted Therapy of Gliomas

The timing of the acquisition of tumor-specific gene mutations and the systems by which these gene mutations are acquired during tumorigenesis were clarified. Advances in our understanding of tumorigenesis are being made every day, and therapies targeting fundamental genetic alterations have great potential for cancer treatment. Moreover, our research team successfully estimated tumor progression using mathematical modeling and attempted early diagnosis of brain tumors. We developed a nanodevice that enables urinary genetic diagnosis in a simple and noninvasive manner. Mainly on the basis of our research and experience, this review article presents novel therapies being developed for central nervous system cancers and six molecules, which upon mutation cause tumorigenesis and tumor progression. Further understanding of the genetic characteristics of brain tumors will lead to the development of precise drugs and improve individual treatment outcomes.

Mutation detection of urinary cell-free DNA via catch-and-release isolation on nanowires for liquid biopsy

Cell-free DNA (cfDNA) and extracellular vesicles (EVs) are molecular biomarkers in liquid biopsies that can be applied for cancer detection, which are known to carry information on the necessary conditions for oncogenesis and cancer cell-specific activities after oncogenesis, respectively. Analyses for both cfDNA and EVs from the same body fluid can provide insights into screening and identifying the molecular subtypes of cancer; however, a major bottleneck is the lack of efficient and standardized techniques for the isolation of cfDNA and EVs from clinical specimens. Here, we achieved catch-and-release isolation by hydrogen bond-mediated binding of cfDNA in urine to zinc oxide (ZnO) nanowires, which also capture EVs by surface charge, and subsequently we identified genetic mutations in urinary cfDNA. The binding strength of hydrogen bonds between single-crystal ZnO nanowires and DNA was found to be equal to or larger than that of conventional hydrophobic interactions, suggesting the possibility of isolating trace amounts of cfDNA. Our results demonstrated that nanowire-based cancer screening assay can screen cancer and can identify the molecular subtypes of cancer in urine from brain tumor patients through EV analysis and cfDNA mutation analysis. We anticipate our method to be a starting point for more sophisticated diagnostic models of cancer screening and identification.

Easy-to-use machine learning system for the prediction of IDH mutation and 1p/19q codeletion using MRI images of adult-type diffuse gliomas

Adult-type diffuse gliomas are divided into Astrocytoma, IDH-mutant, Oligodendroglioma, IDH-mutant and 1p/19q-codeleted and Glioblastoma, IDH-wildtype based on the IDH mutation, and 1p/19q codeletion status. To determine the treatment strategy for these tumors, pre-operative prediction of IDH mutation and 1p/19q codeletion status might be effective. Computer-aided diagnosis (CADx) systems using machine learning have been noted as innovative diagnostic methods. However, it is difficult to promote the clinical application of machine learning systems at each institute because the support of various specialists is essential. In this study, we established an easy-to-use computer-aided diagnosis system using Microsoft Azure Machine Learning Studio (MAMLS) to predict these statuses. We constructed an analysis model using 258 adult-type diffuse glioma cases from The Cancer Genome Atlas (TCGA) cohort. Using MRI T2-weighted images, the overall accuracy, sensitivity, and specificity for the prediction of IDH mutation and 1p/19q codeletion were 86.9%, 80.9%, and 92.0%, and 94.7%, 94.1%, and 95.1%, respectively. We also constructed an reliable analysis model for the prediction of IDH mutation and 1p/19q codeletion using an independent Nagoya cohort including 202 cases. These analysis models were established within 30 min. This easy-to-use CADx system might be useful for the clinical application of CADx in various institutes.

All-in-One Nanowire Assay System for Capture and Analysis of Extracellular Vesicles from an ex Vivo Brain Tumor Model

Extracellular vesicles (EVs) have promising potential as biomarkers for early cancer diagnosis. The EVs have been widely studied as biological cargo containing essential biological information not only from inside vesicles such as nucleic acids and proteins but also from outside vesicles such as membrane proteins and glycolipids. Although various methods have been developed to isolate EVs with high yields such as captures based on density, size, and immunoaffinity, different measurement systems are needed to analyze EVs after isolation, and a platform that enables all-in-one analysis of EVs from capture to detection in multiple samples is desired. Since a nanowire-based approach has shown an effective capability for capturing EVs via surface charge interaction compared to other conventional methods, here, we upgraded the conventional well plate assay to an all-in-one nanowire-integrated well plate assay system (i.e., a nanowire assay system) that enables charge-based EV capture and EV analysis of membrane proteins. We applied the nanowire assay system to analyze EVs from brain tumor organoids in which tumor environments, including vascular formations, were reconstructed, and we found that the membrane protein expression ratio of CD31/CD63 was 1.42-fold higher in the tumor organoid-derived EVs with a p-value less than 0.05. Furthermore, this ratio for urine samples from glioblastoma patients was 2.25-fold higher than that from noncancer subjects with a p-value less than 0.05 as well. Our results demonstrated that the conventional well plate method integrated with the nanowire-based EV capture approach allows users not only to capture EVs effectively but also to analyze them in one assay system. We anticipate that the all-in-one nanowire assay system will be a powerful tool for elucidating EV-mediated tumor-microenvironment crosstalk.

CD79B Y196 mutation is a potent predictive marker for favorable response to R-MPV in primary central nervous system lymphoma

BACKGROUND

Rituximab, high-dose methotrexate (HD-MTX), procarbazine and vincristine (R-MPV), has significantly prolonged the survival of patients with primary central nervous system lymphoma (PCNSL), but predictive factors for response to R-MPV have not yet been investigated. Herein, we investigated the correlation of MYD88 L265P and CD79B Y196 mutations, which are the most frequently found molecular alterations in PCNSL, with prognosis of patients with PCNSL treated with R-MPV.

METHODS

We investigated the long-term clinical course and status of MYD88 and CD79B genes in 85 patients with PCNSL treated with R-MPV or HD-MTX treatment, and the correlation of these genetic mutations with prognosis.

RESULTS

R-MPV achieved an excellent tumor control rate (61.6% and 69.9% of 5-year progression-free and overall survival rates, respectively). While MYD88 L265P mutation had no significant effect on survival, patients with CD79B Y196 mutations exhibited prolonged survival (p < 0.05). However, the association of CD79B Y196 mutation with a better prognosis was not observed in the HD-MTX cohort, which indicated that CD79B Y196 mutation was a predictive marker for a favorable response to R-MPV. Furthermore, we established an all-in-one rapid genotyping system for these genetic mutations.

CONCLUSIONS

In conclusion, CD79B Y196 mutation is a potent predictive marker for favorable response to R-MPV in PCNSL. The rapid identification of MYD88 L265P and CD79B Y196 mutations can be helpful not only for the accurate molecular diagnosis of PCNSL but also for the prediction of response to R-MPV.

ACT-2 JCOG0911A2 AND ESTABLISHING AN INFRASTRUCTURE FOR RADIOLOGICAL STUDIES FOR JCOG BRAIN TUMOR STUDY GROUP CLINICAL TRIALS

Background

Radiological information is indispensable to understanding the pathology and correctly assessing the treatment response of malignant brain tumors. Clinical trials conducted outside of Japan have vigorously collected and investigated radiological images of the enrolled patients and published many significant findings, such as the RANO criteria. The authors initiated the JCOG0911A2 study, which is an ancillary analysis of JCOG0911, and established an infrastructure for collecting and analyzing raw radiological images of patients enrolled in clinical trials conducted by the JCOG brain tumor study group. JCOG0911A2 study design and infrastructure for radiological image storage: JCOG0911A2 aims to collect all radiological images related to the JCOG0911 study, conduct radiomics analysis, and complete general radiological research. Among 122 registered patients, 2532 series from 118 cases accounting for 237 GB of data were collected as of June 28, 2022. All collected data were anonymized and stored in Osirix MD with triple data backup. JCOG0911A2's treatment response assessment will be performed according to the RANO criteria. Thus, the authors developed a script in MATLAB that enables semi-automatic treatment response assessment according to the investigators' annotations on Osirix MD.

Data Management

The abovementioned “semi-automatic treatment response assessment script” was not necessary until up to a collection of 30 cases. However, manual management became impossible as more case data arrived, and establishing a sophisticated and systematic data management system was inevitable. The data management system developed for JCOG0911A2 is also used with minor modifications for the ongoing JCOG study.

Conclusion

JCOG0911A2 study established a reliable infrastructure capable of handling radiological images from patients enrolled in JCOG brain tumor study group clinical trials.

DDDR-39. IDENTIFICATION OF A NOVEL THERAPEUTIC TARGET THAT IS SYNTHETICALLY LETHAL WITH MUTANT IDH INHIBITOR IN GLIOMA USING THE CRISPR/CAS9 GENOME EDITING TECHNOLOGY

Diffuse glioma is the most frequent and malignant neuroepithelial tumor in the central nervous system. IDH mutations are the most frequent genetic mutations in adult gliomas. The WHO Classification of Tumors, 5th edition, volume 6: Central Nervous System Tumours revised in 2021, defines the presence of IDH mutations in gliomas as astrocytoma IDH-mutant and oligodendroglioma IDH-mutant and 1p/19q-codeleted. In addition, more than 90% of IDH mutations found in gliomas are IDH1 R132H mutation. Several clinical trials of mutant IDH1 inhibitors targeting the IDH1 R132H mutation have shown their efficacy, but it has also been reported that IDH1 inhibitors alone may not provide sufficient tumor suppression. In this study, we performed genome-wide knockout screening using CRISPR/Cas9 genome editing technology to search for new drug targets that are synergistic with the mutant IDH1 inhibitor DS-1001b. The results of CRISPR screening and RNA sequence analysis revealed that several metabolism-related genes are factors that define resistance to mutant IDH inhibitor. In a tumor suppression study, treatment of two IDH1 R132H mutant glioma cell lines (MGG152 and BT142) with mutant IDH1 inhibitor suppressed production of the oncometabolite D2-HG, but did not significantly alter cell growth. However, when mutant IDH1 inhibitor were combined with inhibitor for metabolism-related genes, cell survival was significantly reduced, and the effects were synergistic. In this study, we found that administration of mutant IDH inhibitors to IDH mutant gliomas significantly altered intratumor metabolism using various molecular approaches. We then identified targets that, when combined with mutant IDH inhibitor, provide synergistic tumor suppression. These results are expected to provide a new therapeutic approach for a subset of patients who have difficulty responding to mutant IDH1 inhibitors.

Efficacy of cancer-specific anti-podoplanin CAR-T cells and oncolytic herpes virus G47Δ combination therapy against glioblastoma

Glioblastoma is a devastating malignant brain tumor with a poor prognosis despite standard therapy. Podoplanin (PDPN), a type I transmembrane mucin-like glycoprotein that is overexpressed in various cancers, is a potential therapeutic target for the treatment of glioblastoma. We previously reported the efficacy of chimeric antigen receptor (CAR)-T cells using an anti-pan-PDPN monoclonal antibody (mAb; NZ-1)-based third-generation CAR in a xenograft mouse model. However, NZ-1 also reacted with PDPN-expressing normal cells, such as lymphatic endothelial cells, pulmonary alveolar type I cells, and podocytes. To overcome possible on-target-off-tumor effects, we produced a cancer-specific mAb (CasMab, LpMab-2)-based CAR. LpMab-2 (Lp2) reacted with PDPN-expressing cancer cells but not with normal cells. In this study, Lp2-CAR-transduced T cells (Lp2-CAR-T) specifically targeted PDPN-expressing glioma cells while sparing the PDPN-expressing normal cells. Lp2-CAR-T also killed patient-derived glioma stem cells, demonstrating its clinical potential against glioblastoma. Systemic injection of Lp2-CAR-T cells inhibited the growth of a subcutaneous glioma xenograft model in immunodeficient mice. Combination therapy with Lp2-CAR-T and oncolytic virus G47Δ, a third-generation recombinant herpes simplex virus (HSV)-1, further inhibited the tumor growth and improved survival. These findings indicate that the combination therapy of Lp2-CAR-T cells and G47Δ may be a promising approach to treat glioblastoma.

Microsatellite instability-high is rare events in refractory pediatric solid tumors

Microsatellite instability (MSI)-high status is associated with good responsiveness to immune checkpoint inhibitors. Although MSI-high status has been actively investigated in pediatric brain tumors, studies of other pediatric solid tumors are lacking. Among 334 consecutive pediatric patients with solid tumors, we retrospectively analyzed formalin-fixed paraffin-embedded tumor tissues of 36 of 74 patients (49%) who died of disease. We assessed the MSI status in these tissues using five multiplexed markers. The results revealed that none of the patients had an MSI-high status. These results indicate that MSI-high status is a rare event in pediatric patients with refractory/relapsed solid tumors.Supplemental data for this article is available online at https://doi.org/10.1080/08880018.2021.1998266.

The first-in-human phase I study of a brain-penetrant mutant IDH1 inhibitor DS-1001 in patients with recurrent or progressive IDH1-mutant gliomas

BACKGROUND

Approximately 70% of lower-grade gliomas harbor isocitrate dehydrogenase 1 (IDH1) mutations, resulting in the accumulation of oncometabolite D-2-hydroxyglutarate (D-2-HG); this leads to epigenetic dysregulation, oncogenesis, and subsequent clonal expansion. DS-1001 is an oral brain-penetrant mutant IDH1 selective inhibitor. This first-in-human study investigated the safety, pharmacokinetics, pharmacodynamics, and efficacy of DS-1001.

METHODS

This was a multicenter, open-label, dose-escalation, phase I study of DS-1001 for recurrent/progressive IDH1-mutant (R132) glioma (N = 47) (NCT03030066). DS-1001 was administered orally at 125-1400 mg twice daily. Dose-escalation used a modified continual reassessment method.

RESULTS

The maximum tolerated dose was not reached. Eight patients were continuing treatment at the data cutoff. Most adverse events (AEs) were grade 1-2. Twenty patients (42.6%) experienced at least 1 grade 3 AE. No grade 4 or 5 AEs or serious drug-related AEs were reported. Common AEs (>20%) were skin hyperpigmentation, diarrhea, pruritus, alopecia, arthralgia, nausea, headache, rash, and dry skin. The objective response rates were 17.1% for enhancing tumors and 33.3% for non-enhancing tumors. Median progression-free survival was 10.4 months (95% confidence interval [CI], 6.1 to 17.7 months) and not reached (95% CI, 24.1 to not reached) for the enhancing and non-enhancing glioma cohorts, respectively. Seven on-treatment brain tumor samples showed a significantly lower amount of D-2-HG compared with pre-study archived samples.

CONCLUSIONS

DS-1001 was well tolerated with a favorable brain distribution. Recurrent/progressive IDH1-mutant glioma patients responded to treatment. A study of DS-1001 in patients with chemotherapy- and radiotherapy-naïve IDH1-mutated WHO grade 2 glioma is ongoing (NCT04458272).

Survival Benefit of Supratotal Resection in a Long-term Survivor of IDH-wildtype Glioblastoma: A Case Report and Literature Review

Glioblastoma multiforme (GBM) is an aggressive cancer type, with fewer than 3–5% of patients surviving for more than 3 years. We describe a 48-year-old right-handed man who presented with generalized seizure attacks. Magnetic resonance imaging (MRI) revealed a heterogeneous gadolinium-enhancing lesion in the left inferior parietal lobule. The patient underwent awake surgery, and tumor resection included abnormalities on T2-weighted MRI, with subcortical mapping used to identify the deep functional boundaries. After supratotal resection, the tumor was diagnosed as GBM without isocitrate dehydrogenase (IDH) 1 and 2 mutations. At a follow-up evaluation, 9 years and 2 months after the surgery, the patient appeared healthy, and no relapse or recurrence was observed. We present the case of a long-term survivor of IDH-wildtype GBM. This case suggests that supratotal resection with intraoperative awake brain mapping can improve survival without impairing the patient’s neurological functions.

Long-term effectiveness of Gliadel ® implant for malignant glioma and prognostic factors for survival: 3-year results of a post-marketing surveillance in Japan

Background

Adjuvant treatment with Gliadel wafers may prolong overall survival (OS) for malignant glioma patients without increasing toxicity. In Japan, the long-term OS of these patients treated with Gliadel 7.7 mg implants has not been studied. We evaluated OS and prognostic factors that might affect OS in Japanese patients with malignant glioma who received the Gliadel 7.7 mg implant.

Methods

This observational, long-term, post-marketing surveillance was an extension of a previous surveillance. Data were collected through case report forms at 2 and 3 years after Gliadel implant. Up to 8 Gliadel wafers (61.6 mg of carmustine) were placed over the tumor resection site. Primary endpoints were OS and prognostic factors that may influence OS.

Results

Among the 506 patients analyzed, 62.6% had newly diagnosed disease, and 37.4% had recurrent disease; 79.1% had glioblastoma histological type and 79.6% had World Health Organization Grade IV disease. Patients received a median of 8 wafers. The median OS was 18.0 months; OS rates were 39.8% and 31.5% at 2 and 3 years, respectively. Age ≥65 years (hazard ratio [HR]: 1.456; P = 0.002), lower resection rate (HR: 1.206; P &lt; 0.001), recurrence (HR: 2.418; P &lt; 0.001), and concomitant radiotherapy (HR: 0.588; P &lt; 0.001) were identified as significant prognostic factors.

Conclusions

This study confirmed the 2- and 3-year OS of Japanese malignant glioma patients with varied backgrounds after Gliadel implant. With a careful interpretation of indirect comparisons with previously reported data, the results suggest that prognosis could be improved with Gliadel implants.

MPC-5 Characteristics of H3 G34-mutant gliomas

Introduction: Diffuse hemispheric gliomas, H3 G34-mutant (DHG H3G34-mutant) are newly recognized infiltrating gliomas of the cerebral hemispheres of pediatric and young adult patients. We experienced 6 DHG H3G34-mutant cases. In this study, we describe the clinical, radiological and pathological characteristics of these cases.

Result: Mean age at diagnosis was 16.8 years (range:10–26). Three patients were male. Among six cases, tumors located in cerebral cortex in five cases and multiple sites including basal ganglia and cortex in a case. All tumors showed no or only a faint contrast-enhancement and harbored restriction of diffusion. One patient underwent total resection, four underwent partial resection and one underwent biopsy. Pathological diagnosis were CNS embryonal tumors (n=3/6), glioblastoma, IDH-wildtype (n=2/6) and anaplastic astrocytoma, IDH-wildtype (n=1/5). All cases were negative for Olig2 and positive for GFAP in immunohistochemistry. Mean Ki-67 index was 38% (range: 10–60%). All cases revealed at least one of mitosis, necrosis or microvascular proliferation. Especially, mitosis was the most frequently found (n=5/6). The H3F3A mutations were G34R mutations in all cases. One case revealed a characteristic mutation pattern, therefore now we are performing further examination. Adjuvant chemoradiotherapies were performed for all cases. Mean progression free survival was 10.1 months (range: 1.6–33.1).

Discussion: As published literatures reported, all cases exhibited restriction of diffusion and negative for Olig2. For a cerebral hemispheric tumor of pediatric or young adult patient which shows restriction of diffusion and no contrast-enhancement, and of which pathological findings is malignant and olig2 is negative, genetic analysis of H3F3A gene might be essential.

TB-2 Patient-derived meningioma organoid model demonstrates FOXM1 dependent tumor proliferation

Recent comprehensive studies have revealed several molecular alterations that are frequently found in meningiomas. However, effective treatment reagents targeting specific molecular alterations have not yet been identified because of the limited number of representative research models of meningiomas.

We established 18 organoid models comprising of two malignant meningioma cells (HKBMM and IOMM-Lee), 10 benign meningiomas, four malignant meningiomas, and two solitary fibrous tumors (SFTs). Using immunohistochemistry and molecular analyses consisting of whole exome sequencing, RNA-seq, and DNA methylation analyses, we compared the histological findings and molecular profiling of organoid models with those of parental tumors. The organoids exhibited consistent histological features and molecular profiles with those of the parental tumors. Using a public database of meningioma, we identified that upregulated forkhead box M1 (FOXM1) was correlated with increased tumor proliferation. Overexpression of FOXM1 in benign meningioma organoids increased organoid proliferation; depletion of FOXM1 in malignant organoids decreased proliferation. Additionally, thiostrepton, a FOXM1 inhibitor combined with radiation therapy, significantly inhibited proliferation of malignant meningioma organoid models (P<0.01).

An organoid model for meningioma enabled us to elucidate the tumor biology of meningioma along with potent treatment targets for meningioma.

ML-11 Tirabrutinib treatment for recurrent or refractory PCNSL

Since 2020, tirabrutinib which is a Bruton’s tyrosine kinase (BTK) inhibitor has been available for recurrent or refractory PCNSL cases. The number of studies reporting efficiency and adverse effect of tirabrutinib treatment for recurrent or refractory PCNSL has been limited yet. In this study, we investigated clinical course of eight refractory or recurrent PCNSL cases treated with tirabrutinib in our institute.

Eight PCNSL cases treated with tirabrutinib included four recurrent cases and four refractory cases. Five cases obtained CR or PR after 26.8 days administration of tirabrutinib and other two cases also exhibited obvious improvement of clinical symptoms after 23.5 days administration of tirabrutinib. Among three cases exhibiting intraocular lesions, two cases revealed improvement of visual dysfunction and the other case obtained SD status of intraocular lesion. The most frequently found adverse effect was the skin rash. CTCAE grade 2 (n=2) or 3 (n=2) rash was found after mean 16 days or 94 days of tirabrutinib administration, respectively. Two cases with grade 3 rash could start taking the low-dose tirabrutinib after improvement of rash. Althouth one case experienced shingles, no other case experienced serious adverse effects.

Although adverse effect of rash was frequently found, we could obtain high response rate of tirabrutinib treatment for recurrent or refractory PCNSL cases. We need to establish quantitative assessment method for analysis of treatment response of tirabrutinib for intraocular lesions.

STMO-6 Impact of the extent of resection on the survival of patients with lower grade gliomas using awake brain mapping

Purpose: The aim of this study was to assess the effect of the extent of resection (EOR) of tumors on survival in a series of patients with lower-grade gliomas (LGGs) who underwent awake brain mapping.

Methods: We retrospectively analyzed 126 patients with LGGs in the dominant and non-dominant hemisphere who underwent awake brain surgery at the same institution between December 2012 and May 2020.

Results: The median progression-free survival (PFS) rate of patients with LGGs in the group with an EOR &gt;100 %, including supratotal resection (n = 47; median survival [MS], not reached), was significantly higher than that in the group with an EOR &lt;100% (n = 79; MS, 43.1 months; 95% CI: 37.8–48.4 months; p = 0.04). In patients with diffuse astrocytomas and anaplastic astrocytomas, the group with EOR &gt;100 %, including supratotal resection (n = 25; MS, not reached), demonstrated a significantly better PFS rate than did the group with an EOR &lt;100% (n = 45; MS, 35.8 months; 95% CI: 19.9–51.6 months; p = 0.03). Supratotal or gross total resection was correlated with better PFS in IDH-mutant type of diffuse astrocytomas and anaplastic astrocytomas (n = 19; MS, not reached vs. n = 35; MS, 40.6 months; 95% CI: 22.3–59.0 months; p = 0.02). By contrast, supratotal or gross total resection was not associated with longer PFS rates in patients with IDH-wild type of diffuse astrocytomas and anaplastic astrocytomas.

Conclusions: It is noteworthy that supratotal or gross total resection significantly correlated with better PFS in IDH-mutant type of WHO grade II and III astrocytic tumors. In light of our finding that EOR did not correlate with PFS in patients with aggressive IDH-wild type of diffuse astrocytomas and anaplastic astrocytomas, we suggest treatments that are more intensive will be needed for the control of these tumors.

Reliability of IDH1-R132H and ATRX and/or p53 immunohistochemistry for molecular subclassification of Grade 2/3 gliomas

Since the World Health Organization 2016 classification (2016 WHO), genetic status has been incorporated into the diagnosis of Grade 2/3 gliomas (lower-grade gliomas). Therefore, immunohistochemistry (IHC) of IDH1-R132H, ATRX, and p53 have been used in place of genetic status. We report the associations between histological findings, IHC, and genetic status. We performed IHC of IDH1-R132H, ATRX, and p53 in 76 lower-grade gliomas and discussed its validity based on the 2016 WHO and the upcoming 2021 WHO classification. The sensitivity and specificity of anti-ATRX, p53, and IDH1-R132H IHC were 40.9%/98.1%, 78.6%/85.4%, and 90.5%/84.6%, respectively. Among 21 IDH1-mutant gliomas without 1p/19q codeletion, two gliomas (9.5%) mimicked the so-called classic for oligodendroglioma (CFO) in their morphology. Of the 42 gliomas with 1p/19q codeletion, four cases were difficult to diagnose as oligodendroglioma through morphological examination. Moreover, there were three confusing cases with ATRX mutations but with retained ATRX-IHC positivity. The lessons learned from this study are as follows: (1) ATRX-IHC and p53-IHC should be supplementary to morphological diagnosis, (2) rare IDH mutations other than IDH1 R132H should be considered, and (3) there is no complete alternative test to detect molecular features of glioblastoma under the 2021 WHO classification.

Piecemeal resection of aggressive vertebral hemangioma using real-time navigation-guided drilling technique

Vertebral hemangiomas are the most common benign vertebral tumors and are usually asymptomatic. Aggressive subtypes of the tumor, called aggressive VHs (AVHs), can become symptomatic with extraosseous extensions and require surgical removal. We present a case of AVH in a 36-year-old man presenting with low back pain and right leg pain that persisted for three months. Imaging studies showed a Th12 vertebral tumor that extended into the spinal canal and was squeezing the spinal cord. Computed tomography (CT)-guided biopsy indicated vertebral hemangimoa. Following preoperative arterial embolization, piecemeal gross total resection was attained under navigation guidance. He was left with no neurological deficit and remained well at the 12-month postoperative folow-up. Since AVHs are benign tumor, piecemeal removal of the tumor can be selected. However, disadvantage of the approach include difficulty of making decision how much to remove the front part of the vertebral body close to thoracic descending aorta. Furthermore, when the tumor tissue is too hard to curett, manipulation in tight spaces near the spinal cord carries the risk of damaging it. Navigation-guided drill is highly helpful for real-time monitoring of ongoing tumor resection. It enables safely resection of the tumor especially in the anterior cortical surface of the vertebral body and easily resection even hard tumors. This method results in reducing residual tumor and maintaining safety resection.

St8sia1-deficiency in mice alters tumor environments of gliomas, leading to reduced disease severity

Ganglioside GD3/GD2 are over-expressed in various neuroectoderm-derived tumors. Previous studies indicated that GD3 is involved in the enhancement of cancer properties such as rapid growth and increased invasiveness. However, little is known about the functions of GD3/GD2 in glioma cells and glioma microenvironments. To clarify the functions of GD3/GD2 in gliomas, we used a mouse glioma model based on the RCAS/Gtv-a system. At first, we compared the gliomas size between wild-type (WT) and GD3 synthase (GD3S) knockout (KO) mice, showing a less malignant histology and slower tumor growth in GD3S-KO mice than in WT mice. Immunohistochemistry of glioma sections from WT and GD3S-KO mice revealed that reactive microglia/macrophages showed different localization patterns between the two genetic types of mice. CD68⁺ cells were more frequently stained inside glioma tissues of GD3S-KO mice, while they were stained mainly around glioma tissues in WT mice. The number of CD68⁺ cells markedly increased in tumor tissues of GD3S-KO mice at 2 weeks after injection of transfectant DF-1 cells. Furthermore, CD68⁺ cells in GD3S(-/-) glioma tissues expressed higher levels of inducible nitric oxide synthase. We observed higher expression levels of pro-inflammatory cytokine genes in primary-cultured glioma cells of WT mice than in GD3S-KO mice. DNA microarray data also revealed differential expression levels of various cytokines and chemokines in glioma tissues between WT and GD3S-KO mice. These results suggest that expression of GD3S allows glioma cells to promote polarization of microglia/macrophages towards M2-like phenotypes by modulating the expression levels of chemokines and cytokines.

＜Editors' Choice＞ Indocyanine green emission timing of the recipient artery in revascularization surgery for moyamoya disease

In superficial temporal artery to middle cerebral artery anastomosis with indirect revascularization for patients with moyamoya disease, the optimal method for selecting the most appropriate cortical artery for the recipient in anastomosis has not been established. We investigated the relationship between the fluorescence emission timing of the recipient artery in the preanastomosis indocyanine green videoangiography and operative outcomes. This retrospective study included 51 surgical revascularization procedures for 39 moyamoya disease patients. The enrolled surgical procedures were classified into three groups based on the fluorescence emission timing of the recipient artery in preanastomosis indocyanine green videoangiography: the EARLIEST, the INTERMEDIATE, and the LATEST. Clinical characteristics and operative outcomes were also collected. The occurrence of white thrombus at the anastomosis site and symptomatic hyperperfusion showed significant differences between the groups classified by the fluorescence emission timing of the recipient artery in preanastomosis indocyanine green videoangiography (white thrombus, p = 0.001; symptomatic hyperperfusion, p = 0.026). The development of white thrombi was significantly higher in the LATEST group, and all symptomatic hyperperfusion was observed in the EARLIEST group. These results indicated that the LATEST group had a significantly higher risk for developing white thrombus, and the EARLIEST group was prone to occur symptomatic hyperperfusion. Selecting the recipient artery based on evaluating the fluorescence emission timing in preanastomosis indocyanine green videoangiography may be useful in reducing perioperative complications.

Mathematical Modeling and Mutational Analysis Reveal Optimal Therapy to Prevent Malignant Transformation in Grade II IDH-Mutant Gliomas

Isocitrate dehydrogenase-mutant low-grade gliomas (IDHmut-LGG) grow slowly but frequently undergo malignant transformation, which eventually leads to premature death. Chemotherapy and radiotherapy treatments prolong survival, but can also induce genetic (or epigenetic) alterations involved in transformation. Here, we developed a mathematical model of tumor progression based on serial tumor volume data and treatment history of 276 IDHmut-LGGs classified by chromosome 1p/19q codeletion (IDH^mut/1p19q^codel and IDH^mut/1p19q^noncodel) and performed genome-wide mutational analyses, including targeted sequencing and longitudinal whole-exome sequencing data. These analyses showed that tumor mutational burden correlated positively with malignant transformation rate, and chemotherapy and radiotherapy significantly suppressed tumor growth but increased malignant transformation rate per cell by 1.8 to 2.8 times compared with before treatment. This model revealed that prompt adjuvant chemoradiotherapy prolonged malignant transformation-free survival in small IDHmut-LGGs (≤ 50 cm³). Furthermore, optimal treatment differed according to genetic alterations for large IDHmut-LGGs (> 50 cm³); adjuvant therapies delayed malignant transformation in IDH^mut/1p19q^noncodel but often accelerated it in IDH^mut/1p19q^codel. Notably, PI3K mutation was not associated with malignant transformation but increased net postoperative proliferation rate and decreased malignant transformation-free survival, prompting the need for adjuvant therapy in IDH^mut/1p19q^codel. Overall, this model uncovered therapeutic strategies that could prevent malignant transformation and, consequently, improve overall survival in patients with IDHmut-LGGs. SIGNIFICANCE: A mathematical model successfully estimates malignant transformation-free survival and reveals a link between genetic alterations and progression, identifying precision medicine approaches for optimal treatment of IDH-mutant low-grade gliomas.

Transcriptome-wide analysis of intracranial artery in patients with moyamoya disease showing upregulation of immune response, and downregulation of oxidative phosphorylation and DNA repair

OBJECTIVE

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive occlusion of the internal carotid artery and the secondary formation of collateral vessels. Patients with MMD have ischemic attacks or intracranial bleeding, but the disease pathophysiology remains unknown. In this study, the authors aimed to identify a gene expression profile specific to the intracranial artery in MMD.

METHODS

This was a single-center, prospectively sampled, retrospective cohort study. Microsamples of the middle cerebral artery (MCA) were collected from patients with MMD (n = 11) and from control patients (n = 9). Using microarray techniques, transcriptome-wide analysis was performed.

RESULTS

Comparison of MCA gene expression between patients with MMD and control patients detected 62 and 26 genes whose expression was significantly (p < 0.001 and fold change > 2) up- or downregulated, respectively, in the MCA of MMD. Gene set enrichment analysis of genes expressed in the MCA of patients with MMD revealed positive correlations with genes involved in antigen processing and presentation, the dendritic cell pathway, cytokine pathway, and interleukin-12 pathway, and negative correlations with genes involved in oxidative phosphorylation and DNA repair. Microarray analysis was validated by quantitative polymerase chain reaction.

CONCLUSIONS

Transcriptome-wide analysis showed upregulation of genes for immune responses and downregulation of genes for DNA repair and oxidative phosphorylation within the intracranial artery of patients with MMD. These findings may represent clues to the pathophysiology of MMD.

Newly Established Patient-derived Organoid Model of Intracranial Meningioma

BACKGROUND

Recent comprehensive studies have revealed several molecular alterations that are frequently found in meningiomas. However, effective treatment reagents targeting specific molecular alterations have not yet been identified because of the limited number of representative research models of meningiomas.

METHODS

We performed organoid cultures using meningioma cells and meningioma tumor tissues. Using immunohistochemistry and molecular analyses consisting of whole exome sequencing, RNA-seq, and DNA methylation analyses, we compared the histological findings and molecular profiling of organoid models with those of parental tumors. Further, using these organoid models together with a public database of meningiomas, we explored molecular alterations, which are a potent treatment target for meningioma.

RESULTS

We established 18 organoid models comprising of two malignant meningioma cells (HKBMM and IOMM-Lee), 10 benign meningiomas, four malignant meningiomas, and two solitary fibrous tumors (SFTs). The organoids exhibited consistent histological features and molecular profiles with those of the parental tumors. Using a public database, we identified that upregulated forkhead box M1 (FOXM1) was correlated with increased tumor proliferation. Overexpression of FOXM1 in benign meningioma organoids increased organoid proliferation; depletion of FOXM1 in malignant organoids decreased proliferation. Additionally, thiostrepton, a FOXM1 inhibitor combined with radiation therapy, significantly inhibited proliferation of malignant meningioma organoid models.

CONCLUSIONS

An organoid model for meningioma enabled us to elucidate the tumor biology of meningioma along with potent treatment targets for meningioma.

Lack of GD3 synthase (St8sia1) attenuates malignant properties of gliomas in genetically engineered mouse model

High expression of gangliosides GD3 and GD2 is observed in human gliomas. The functions of GD3 and GD2 in malignant properties have been reported in glioma cells in vitro, but those functions have not yet been investigated in vivo. In this study, we showed that deficiency of GD3 synthase (GD3S, St8sia1) attenuated glioma progression and clinical and pathological features in a platelet-derived growth factor B-driven murine glioma model. Lack of GD3S resulted in the prolonged lifespan of glioma-bearing mice and low-grade pathology in generated gliomas. Correspondingly, they showed reduced phosphorylation levels of Akt, Erks, and Src family kinases in glioma tissues. A DNA microarray study revealed marked alteration in the expression of various genes, particularly in MMP family genes, in GD3S-deficient gliomas. Re-expression of GD3S restored expression of MMP9 in primary-cultured glioma cells. We also identified a transcription factor, Ap2α, expressed in parallel with GD3S expression, and showed that Ap2α was critical for the induction of MMP9 by transfection of its cDNA and luciferase reporter genes, and a ChIP assay. These findings suggest that GD3S enhances the progression of gliomas by enhancement of the Ap2α-MMP9 axis. This is the first report to describe the tumor-enhancing functions of GD3S in vivo.

Necessity for craniospinal irradiation of germinoma with positive cytology without spinal lesion on MR imaging-A controversy

Background

Cerebrospinal fluid (CSF) cytology and spinal MR imaging are routinely performed for staging before treatment of intracranial germinoma. However, the interpretation of the results of CSF cytology poses 2 unresolved clinical questions: (1) Does positive CSF cytology correlate with the presence of spinal lesion before treatment? and (2) Is craniospinal irradiation (CSI) necessary for patients with positive CSF cytology in the absence of spinal lesion?

Methods

Multicenter retrospective analyses were performed based on a questionnaire on clinical features, spinal MR imaging finding, results of CSF cytology, treatments, and outcomes which was sent to 86 neurosurgical and 35 pediatrics departments in Japan. Pretreatment frequencies of spinal lesion on MR imaging were compared between the patients with positive and negative cytology. Progression-free survival (PFS) rates were compared between patients with positive CSF cytology without spinal lesion on MR imaging treated with CSI and with whole brain or whole ventricular irradiation (non-CSI).

Results

A total of 92 germinoma patients from 45 institutes were evaluated by both CSF cytology and spinal MR images, but 26 patients were excluded because of tumor markers, the timing of CSF sampling or incomplete estimation of spinal lesion. Of the remaining 66 germinoma patients, spinal lesions were equally identified in patients with negative CSF cytology and positive cytology (4.9% and 8.0%, respectively). Eleven patients treated with non-CSI had excellent PFS comparable to 11 patients treated with CSI.

Conclusion

CSI is unnecessary for germinoma patients with positive CSF cytology without spinal lesions on MR imaging.

Urinary MicroRNA-Based Diagnostic Model for Central Nervous System Tumors Using Nanowire Scaffolds

There are no accurate mass screening methods for early detection of central nervous system (CNS) tumors. Recently, liquid biopsy has received a lot of attention for less-invasive cancer screening. Unlike other cancers, CNS tumors require efforts to find biomarkers due to the blood-brain barrier, which restricts molecular exchange between the parenchyma and blood. Additionally, because a satisfactory way to collect urinary biomarkers is lacking, urine-based liquid biopsy has not been fully investigated despite the fact that it has some advantages compared to blood or cerebrospinal fluid-based biopsy. Here, we have developed a mass-producible and sterilizable nanowire-based device that can extract urinary microRNAs efficiently. Urinary microRNAs from patients with CNS tumors (n = 119) and noncancer individuals (n = 100) were analyzed using a microarray to yield comprehensive microRNA expression profiles. To clarify the origin of urinary microRNAs of patients with CNS tumors, glioblastoma organoids were generated. Glioblastoma organoid-derived differentially expressed microRNAs (DEMs) included 73.4% of the DEMs in urine of patients with parental tumors but included only 3.9% of those in urine of noncancer individuals, which suggested that many CNS tumor-derived microRNAs could be identified in urine directly. We constructed the diagnostic model based on the expression of the selected microRNAs and found that it was able to differentiate patients and noncancer individuals at a sensitivity and specificity of 100 and 97%, respectively, in an independent dataset. Our findings demonstrate that urinary microRNAs extracted with the nanowire device offer a well-fitted strategy for mass screening of CNS tumors.

So-called bifocal tumors with diabetes insipidus and negative tumor markers: are they all germinoma?

BACKGROUND

The Delphi consensus statements on the management of germ cell tumors (GCTs) failed to reach agreements on the statement that the cases with (i) pineal and neurohypophyseal bifocal lesion, (ii) with diabetes insipidus, and (iii) with negative tumor markers can be diagnosed as germinoma without histological verification. To answer this, multicenter retrospective analysis was performed.

METHODS

A questionnaire on clinical findings, histological diagnosis, and details of surgical procedures was sent to 86 neurosurgical and 35 pediatrics departments in Japan.

RESULTS

Fifty-one institutes reported 132 cases that fulfilled the 3 criteria. Tissue sampling was performed in 91 cases from pineal (n = 44), neurohypophyseal (n = 32), both (n = 6), and distant (n = 9) lesions. Histological diagnosis was established in 89 cases: pure germinoma or germinoma with syncytiotrophoblastic giant cells in 82 (92.1%) cases, germinoma and mature teratoma in 2 cases, and granulomatous inflammation in 2 cases. Histological diagnosis was not established in 2 cases. Although no tumors other than GCTs were identified, 3 (3.4%) patients had non-germinomatous GCTs (NGGCTs). None of the patients developed permanent complications after endoscopic or stereotactic biopsy. Thirty-nine patients underwent simultaneous procedure for acute hydrocephalus without permanent complications, and hydrocephalus was controlled in 94.9% of them.

CONCLUSION

All patients who fulfilled the 3 criteria had GCTs or granulomatous inflammation, but not other types of tumors. However, no fewer than 3.4% of the patients had NGGCTs. Considering the safety and the effects of simultaneous procedures for acute hydrocephalus, biopsy was recommended in such patients.

Ependymoma-like tumor with mesenchymal differentiation harboring C11orf95-NCOA1/2 or -RELA fusion: A hitherto unclassified tumor related to ependymoma

Recurrent fusion genes involving C11orf95, C11orf95‐RELA, have been identified only in supratentorial ependymomas among primary CNS tumors. Here, we report hitherto histopathologically unclassifiable high‐grade tumors, under the tentative label of “ependymoma‐like tumors with mesenchymal differentiation (ELTMDs),” harboring C11orf95‐NCOA1/2 or ‐RELA fusion. We examined the clinicopathological and molecular features in five cases of ELTMDs. Except for one adult case (50 years old), all cases were in children ranging from 1 to 2.5 years old. All patients presented with a mass lesion in the cerebral hemisphere. Histologically, all cases demonstrated a similar histology with a mixture of components. The major components were embryonal‐appearing components forming well‐delineated tumor cell nests composed of small uniform cells with high proliferative activity, and spindle‐cell mesenchymal components with a low‐ to high‐grade sarcoma‐like appearance. The embryonal‐appearing components exhibited minimal ependymal differentiation including a characteristic EMA positivity and tubular structures, but histologically did not fit with ependymoma because they lacked perivascular pseudorosettes, a histological hallmark of ependymoma, formed well‐delineated nests, and had diffuse and strong staining for CAM5.2. Molecular analysis identified C11orf95‐NCOA1, ‐NCOA2, and ‐RELA in two, one, and two cases, respectively. t‐distributed stochastic neighbor embedding analysis of DNA methylation data from two cases with C11orf95‐NCOA1 or ‐NCOA2 and a reference set of 380 CNS tumors revealed that these two cases were clustered together and were distinct from all subgroups of ependymomas. In conclusion, although ELTMDs exhibited morphological and genetic associations with supratentorial ependymoma with C11orf95‐RELA, they cannot be regarded as ependymoma. Further analyses of more cases are needed to clarify their differences and similarities.

Effects of insular resection on interactions between cardiac interoception and emotion recognition

The insular cortex is considered an important region for feeling emotions through interoception. Most studies that report the role of the insula in integrating interoception and emotion have used neuroimaging techniques such as functional magnetic resonance imaging (fMRI); however, there are limited neuropsychological studies. The effects of insular lesions on emotion and interoception have not been suitably investigated. In this study, we examined the role of the insular cortex in cardiac interoception and recognizing emotions from facial expressions by comparing them pre- and post-operatively in patients with glial tumors or brain metastases associated with the insular lobe. Although no significant difference in interoceptive accuracy was observed between the two phases, there were significant associations between the changes in interoceptive accuracy and sensitivity to expressions of anger and happiness. An increased error rate in the heartbeat counting task in the post-operation phase was associated with a decreased accuracy in recognizing anger and happiness. Since most patients had left insula lesions, generalizability of the findings to patients with right lesions is a future subject. To the best of our knowledge, this is the first study to examine the change in interoception and emotion after insular resection in humans. The study results indicate that removal of the insula affects the recognition of emotions such as anger and happiness through interoceptive processing.

Intraoperative seizure outcome of levetiracetam combined with perampanel therapy in patients with glioma undergoing awake brain surgery

OBJECTIVE

This study aimed to evaluate the efficacy of levetiracetam (LEV) combined with perampanel (PER) therapy for intraoperative seizure treatment to determine whether a combination of LEV and PER can aid in the prevention of intraoperative intractable seizures during awake surgery.

METHODS

The authors performed a retrospective cohort study in 78 consecutive patients with glioma who underwent awake surgery using intraoperative direct electrical stimulation mapping. To prevent intraoperative seizures, 50 patients were treated with the antiepileptic drug LEV only (LEV group) from January 2017 to January 2019, while the remaining 28 patients were treated with LEV plus PER (LEV + PER group) between March 2019 and January 2020. LEV (1000-3000 mg) and/or PER (2-4 mg) were administered before the surgery.

RESULTS

Preoperative seizures with International League Against Epilepsy (ILAE) class II-VI occurred in 44% of the patients in the LEV group and in 35.7% of patients in the LEV + PER group, with no significant difference between groups (p = 0.319). Total intraoperative seizures occurred in 18 patients (36.0%) in the LEV therapy group and in 2 patients (7.1%) in the LEV + PER group (p = 0.009). Of these, there were no patients (0%) with intractable seizures in the LEV + PER group. Regarding factors that influence intraoperative seizures in glioma patients during awake brain surgery, multivariate logistic regression models revealed that the occurrence of intraoperative seizures was significantly related to the involvement of motor-related regions (positive vs negative, HR 6.98, 95% CI 1.71-28.56, p = 0.007), preoperative seizure (ILAE class II-VI vs ILAE class I, HR 4.44, 95% CI 1.22-16.11, p = 0.024), and LEV + PER group (positive vs negative, HR 0.07, 95% CI 0.01-0.44, p = 0.005). Treatment-related adverse effects were rare and mild, including sleepiness, tiredness, and dizziness in both treatment groups.

CONCLUSIONS

This study demonstrates that LEV + PER therapy is significantly associated with a lower risk of intraoperative seizures compared with LEV therapy alone in patients with glioma during awake brain mapping. These findings will help neurosurgeons conduct safe and reliable awake surgeries and reduce the rate of intraoperative intractable seizures during such procedures.

Importance of Hydrostatic Pressure and Irrigation for Hemostasis in Neuroendoscopic Surgery

Recently neurosurgical operations have been carried out with water irrigation such as endoscopic third ventriculostomy and tumor resections in ventricles. Water irrigation is one of several published methods that promote hemostasis; however, not enough experimental evidence exists on its efficacy. In this study, we investigate whether hydrostatic pressure and persistent irrigation promote hemostasis in neuroendoscopic surgery. We dissected tails of 12-16-week-old C57BL/6 male mice at 5 mm proximal from the tip and checked for bleeding times under dry and wet conditions at pressures of 0 cmH₂O, 10 cmH₂O, 15 H₂O, and 20 cmH₂O without persistent irrigation to bleeding point and 10 cmH₂O with persistent irrigation. We then examined the dissected edge with hematoxylin-eosin staining and measured the size of vessels. The average bleeding time of each group is as follows: dry: 203.4 sec, wet: 164.4 sec, 5 cmH₂O: 138.6 sec, 10 cmH₂O: 104.6 sec (P <0.001), 20 cmH₂O: 56 sec (P <0.001), and 10 cmH₂O with persistent irrigation: 72.8 sec (P <0.01 compared to 10 cmH₂O without persistent irrigation). The maximum caliber of mice's tail artery was 50-60 μm. Hydrostatic pressure and irrigation are important factors contributing to hemostasis.

LGG-56. INFANTILE HEMISPHERIC BRAIN TUMOR WITH A GOPC-ROS1 FUSION GENE: A CASE REPORT

INTRODUCTION

Infantile hemispheric gliomas with ROS1 fusion genes have been reported to have a relatively poor prognosis. Treatment using a ROS1 inhibitor is expected to generate less toxicity and effective for brain tumors with ROS1 fusion genes. CASE PRESENTATION: A one-month-old female presented with a seizure, and a large hypervascular mass in the right hemisphere was found on MRI. The tumor was not biopsied over concerns of an increased risk for bleeding. The mass was clinically diagnosed as an atypical teratoid rhabdoid tumor. She received neoadjuvant chemotherapy using the modified EU-RHAB protocol. The tumor gradually decreased to 70% of its original size with a reduction of vascularity. A near-total resection (> 95%) was performed at eight months of age. Pathological examination revealed the unusual histology with immunostaining positive for INI-1, GFAP, synaptophysin, neurofilament, and slightly positive for NeuN. MIB-1 labeling index was 6%. The pathological diagnosis was a glioneuronal tumor with desmoplastic infantile ganglioglioma-like features, suggestive of low grade. She received adjuvant chemotherapy with carboplatin and vincristine, which is the standard treatment for low-grade gliomas, and achieved a partial response. The GOPC-ROS1 fusion gene was detected in the tumor by FoundationOne^Ⓡ CDx.

CONCLUSION

Chemotherapy may effectively reduce the size of an infant’s brain tumor which is initially considered to be inoperable. A gene profile should be performed as soon as possible in order to direct appropriate management.

Clinical practice guidance for next-generation sequencing in cancer diagnosis and treatment (edition 2.1)

Background

To promote precision oncology in clinical practice, the Japanese Society of Medical Oncology, the Japanese Society of Clinical Oncology, and the Japanese Cancer Association, jointly published “Clinical practice guidance for next-generation sequencing in cancer diagnosis and treatment” in 2017. Since new information on cancer genomic medicine has emerged since the 1st edition of the guidance was released, including reimbursement for NGS-based multiplex gene panel tests in 2019, the guidance revision was made.

Methods

A working group was organized with 33 researchers from cancer genomic medicine designated core hospitals and other academic institutions. For an impartial evaluation of the draft version, eight committee members from each society conducted an external evaluation. Public comments were also made on the draft. The finalized Japanese version was published on the websites of the three societies in March 2020.

Results

The revised edition consists of two parts: an explanation of the cancer genomic profiling test (General Discussion) and clinical questions (CQs) that are of concern in clinical practice. Particularly, patient selection should be based on the expectation that the patient's post-test general condition and organ function will be able to tolerate drug therapy, and the optimal timing of test should be considered in consideration of subsequent treatment plans, not limited to treatment lines.

Conclusion

We expect that the revised version will be used by healthcare professionals and will also need to be continually reviewed in line with future developments in cancer genome medicine.

TB-03 Newly Established Meningioma Organoid Model Elucidated an Important Role of FOXM1 in Meningioma Progression

Meningioma is the most frequently occurring intracranial neoplasms in adults. Tumor removal surgery and radiotherapy were the widely accepted standard treatment for meningioma. Most meningioma cases were cured by extended total removal. However, some tumors develop in locations less amenable to resection, resulting in tumor recurrence after incomplete tumor removal followed by radiotherapy. Although several comprehensive studies have revealed frequently found molecular alterations of meningiomas, effective treatment reagents targeting specific molecular alterations have not been identified yet because of limited number of representative research models such as tumor cell lines or animal models of meningiomas. Recently developed 3D culture technologies have led to the development of novel cancer models, termed organoid models, due to their quite high efficiency of establishment. In this study, we established primary organoid culture methods using malignant meningioma cell lines (e.g. HKBMM and IOMM-Lee) and patient-derived meningioma tissues. Using this novel method, we have been able to establish six organoid models (four WHO grade I meningiomas, one WHO grade III one and one solitary fibrous tumor (SFT)) using tumor tissues derived from six consecutive patients with 100% success rate. Histological analyses, whole exome sequencing and copy number analyses revealed that these organoids exhibited consistent histological features and molecular profiling with those of parental tumors. Using public database, we identified upregulated FOXM1 was correlated with increased tumor proliferation. Over-expression of FOXM1 in benign meningioma organoids increased organoid proliferation, while depletion of FOXM1 in malignant ones decreased their proliferation. We revealed that novel organoid model for meningioma enable to shed light on the tumor biology of meningioma.

Complete resection and untethering of the cervical and thoracic spinal dermal sinus tracts in adult patients

Dermal sinus tracts (DSTs) of the cervical and thoracic spine are extremely rare, particularly in adult patients because diagnosis is typically made in the early stage after birth by pediatricians. These cases should be treated surgically as soon as possible to prevent neurological sequelae. This report describes two rare adult cases with cervical and thoracic spine DSTs. The first patient presented with back pain and headache, whose skin lesion had been long known, but disregarded since birth. The second patient had long suffered from residual cervical myelopathy from the prior incomplete surgical treatment. Both cases had these sinus tracts excised completely and had spinal cord untethered successfully without any neurological deterioration. There has been a trend toward earlier diagnosis of these entities, but still some cases that were diagnosed in a delayed fashion or underwent incomplete treatment are reported. Improper management during childhood could lead to irreversible neurological deficit caused by spinal cord tethering and/or direct compression due to DSTs-associated tumors. The early detection and prompt surgical intervention improve the chance of a good surgical outcome. Furthermore, complete excision of the sinus tracts and associated tumors could help prevent future bacterial contamination and recurrence.

Surgical outcome and graded prognostic assessment of patients with brain metastasis from adult sarcoma: multi-institutional retrospective study in Japan

BACKGROUND

Brain metastasis (BM) is an uncommon complication of sarcomas with a poor prognosis. Little information is available about the feasibility and prognostic factors of surgical resection of BM from sarcomas.

METHODS

This study involved a retrospective analysis of 22 patients with BM from sarcomas who underwent resection at six institutes in Japan. Prognostic factors were analyzed to develop a graded prognostic assessment (GPA) using the log-rank test and Cox regression analysis. For validation of this GPA, we collected data on 100 surgical cases from 48 published reports.

RESULTS

Postoperative Karnofsky Performance Status (KPS) improved in 50% of our patients. Median overall survival (OS) was 21 months. Multivariate analysis showed age and alveolar soft part sarcoma (ASPS) were significant preoperative prognostic factors (P < 0.05). RTOG-RPA classification had no significant prognostic value. We developed a GPA system for OS after resection of BM. A score of 0 was assigned to patients aged 18-29 years with non-ASPS, 2 to patients aged 18-29 years with ASPS or 30-76 years with non-ASPS, and 4 to patients aged 30-76 years with ASPS. Median OS for patients with GPA scores of 0, 2, and 4 were 6.5, 16.0, and 44.0 months, respectively (P = 0.002). The results were validated by the data of 100 cases compiled (P < 0.001).

CONCLUSION

Median OS of patients with BM from sarcomas was comparable to that from carcinomas after resection. A new sarcoma-specific GPA may help patients and clinicians to select resection as an option for treatment of BM from sarcomas.

Long-term survival in patients with primary intracranial germ cell tumors treated with surgery, platinum-based chemotherapy, and radiotherapy: a single-institution study

OBJECTIVE

The current study aimed to evaluate the treatment outcomes and toxicities of patients with intracranial germ cell tumors (GCTs).

METHODS

This study retrospectively included 110 consecutive patients (70 patients in the germinomatous group and 40 patients in the nongerminomatous GCT [NGGCT] groups) receiving surgery, platinum-based chemotherapy, and radiotherapy for newly diagnosed primary intracranial GCTs. In the authors' protocol, patients with GCTs were further divided into the following four groups: the germinomatous group and the NGGCT groups (mature teratoma, intermediate prognosis, or poor prognosis).

RESULTS

The median overall survival (OS) and progression-free survival (PFS) rates of the patients in the germinomatous group were significantly higher than those in the NGGCT group (p < 0.001). The 5-, 10-, and 20-year OS rates in the germinomatous group were 97.1%, 95.7%, and 93.2%, respectively, with a median follow-up of 11.0 years. On the contrary, the 5-, 10-, and 20-year OS rates in the NGGCT group were 67.3%, 63.4%, and 55.4%, respectively. The 5-, 10-, and 20-year PFS rates were 91.4%, 86.6%, and 86.6%, respectively, in the germinomatous group, whereas those of the NGGCT group were approximately 67.4%, 60.2%, and 53.5%, respectively. Based on the four types of classification in our study, the 5-, 10-, and 20-year OS rates in the NGGCT intermediate prognosis group were 78.9%, 71.8%, and 53.8%, respectively. On the contrary, the 3- and 5-year OS rates in the NGGCT poor prognosis group were 42.9% and 34.3%, respectively. Moreover, toxicities with the treatment of intracranial GCTs were found to be tolerable in the present study population. The multivariate survival models for OS in the NGGCT intermediate prognosis and poor prognosis groups demonstrated that only the alpha-fetoprotein status was significantly associated with worsened OS (HR 3.88, 95% CI 1.29-11.66; p = 0.02).

CONCLUSIONS

The authors found that platinum-based chemotherapy and radiotherapy result in favorable survival outcomes in patients with germinomatous GCTs. Clinical outcomes were still unfavorable in the NGGCT intermediate prognosis and poor prognosis groups; therefore, a new protocol that increases the survival rate of patients belonging in both groups should be considered.

Spontaneous Rupture of a Huge Presacral Tarlov Cyst Leading to Dramatic Neurologic Recovery

BACKGROUND

This manuscript discusses the case of huge presacral Tarlov cysts (TCs) and the substantial neurologic recovery noted in the patient following spontaneous rupture of the most prominent cyst. Perineural or TCs are nerve root cysts, which are usually incidental findings on magnetic resonance imaging (MRI) and are most frequently observed in the sacral spine. Symptomatic lesions are rarely encountered.

CASE DESCRIPTION

In this case, a 44-year-old woman presented with anal and vulva pain on the right side, and bladder and bowel dysfunction. MRI of the lumbosacral spine showed multiple huge bilateral TCs located within the presacral space from S1-3. There was a substantially large right-sided S3 cyst that was presumed to be responsible for her symptoms. Surgical intervention was considered; however, her symptoms improved significantly during the waiting period for surgery because of spontaneous rupture of the right-sided S3 cyst, as confirmed on follow-up MRI. On follow-up over a 1-year period, the patient had been very well with no recurrent symptoms.

CONCLUSIONS

To our knowledge, this is the first report of spontaneous cyst rupture and resultant neurologic improvement in a case of symptomatic presacral TCs.

KHYG-1 Cells With EGFRvIII-specific CAR Induced a Pseudoprogression-like Feature in Subcutaneous Tumours Derived from Glioblastoma-like Cells

BACKGROUND/AIM

We previously established a novel type of epidermal growth factor receptor variant III (EGFRvIII)-specific chimeric antigen receptor (CAR)-expressing natural killer (NK) cell line, designated EvCAR-KHYG-1, which inhibited the growth of glioblastoma (GBM) cells in vitro via apoptosis.

MATERIALS AND METHODS

We investigated the cytokine-producing effect of EvCAR-KHYG-1 cells on GBM-like cell lines and their antitumour effect using in vivo xenograft assays.

RESULTS

EvCAR-KHYG-1 cells produced interleukin-2, interferon-γ, and tumour necrosis factor-α on EGFRvIII-expressing U87MG cells. In vivo xenograft assays showed that EvCAR-KHYG-1 cells did not reduce the volume of subcutaneous tumours derived from EGFRvIII-expressing U87MG cells but did reduce tumour cell occupancy.

CONCLUSION

EvCAR-KHYG-1 cells led to expression of cellular immunity-related cytokines on EGFRvIII-expressing U87MG in vitro but did not inhibit tumour progression due to the induction of a pseudo progression-like pathological feature. Future studies investigating the effect of different conditions in vivo are required to study the inhibition of tumour progression in GBM.

Navigated repetitive transcranial magnetic stimulation as preoperative assessment in patients with brain tumors

We aimed to investigate clinical parameters that affected the results of navigated repetitive transcranial magnetic stimulation (nrTMS) language mapping by comparing the results of preoperative nrTMS language mapping with those of direct cortical stimulation (DCS) mapping. In the prospective, non-randomized study, patients had to meet all of the following inclusion criteria: the presence of left- or right-side brain tumors in the vicinity of or inside the areas anatomically associated with language functions; awake brain surgery scheduled; and age >18 years. Sixty one patients were enrolled, and this study included 42 low-grade gliomas and 19 high-grade gliomas (39 men, 22 women; mean age, 41.1 years, range 18-72 years). The tumor was located in the left and right hemisphere in 50 (82.0%) and 11 (18.0%) patients, respectively. In the 50 patients with left-side gliomas, nrTMS language mapping showed 81.6% sensitivity, 59.6% specificity, 78.5% positive predictive value, and 64.1% negative predictive value when compared with the respective DCS values for detecting language sites in all regions. We then investigated how some parameters, including age, tumor type, tumor volume, and the involvement of anatomical language-related regions, affected different subpopulations. Based on the receiver operating curve statistics, subgroup analysis showed that the non-involvement of language-related regions afforded significantly better the area under the curve (AUC) values (AUC = 0.81, 95% confidence interval (CI): 0.74-0.88) than the involvement of language-related regions (AUC = 0.58, 95% CI: 0.50-0.67; p < 0.0001). Our findings suggest that nrTMS language mapping could be a reliable method, particularly in obtaining responses for cases without tumor-involvement of classical perisylvian language areas.

Genetic analysis in patients with newly diagnosed glioblastomas treated with interferon-beta plus temozolomide in comparison with temozolomide alone

PURPOSE

This study aimed to explore the genetic alterations and to identify good responders in the experimental arm in the tumor samples from newly diagnosed glioblastoma (GBM) patients enrolled in JCOG0911; a randomized phase II trial was conducted to compare the efficacy of interferonβ (IFNβ) plus temozolomide (TMZ) with that of TMZ alone.

EXPERIMENTAL

DESIGN: Of 122 tumors, we performed deep targeted sequencing to determine the somatic mutations, copy number variations, and tumor mutation burden; pyrosequencing for O⁶-methylguanine-DNA methyltransferase (MGMT) promoter methylation; Sanger sequencing for the telomerase reverse transcriptase (TERT) promoter; and microsatellite instability (MSI) testing in 95, 91, 91 and 72 tumors, respectively. We performed a multivariable Cox regression analysis using backward stepwise selection of variables including clinical factors (sex, age, performance status, residual tumor after resection, tumor location) and genetic alterations.

RESULTS

Deep sequencing detected an IDH1 mutation in 13 tumors (14%). The MGMT promoter methylation by quantitative pyrosequencing was observed in 41% of the tumors. A mutation in the TERT promoter was observed in 69% of the tumors. While high tumor mutation burden (> 10 mutations per megabase) was seen in four tumors, none of the tumors displayed MSI-high. The clinical and genetic factors considered as independent favorable prognostic factors were gross total resection (hazard ratio [HR]: 0.49, 95% confidence interval, 0.30-0.81, P = 0.0049) and MGMT promoter methylation (HR: 0.43, 0.21-0.88, P = 0.023). However, tumor location at the temporal lobe (HR: 1.90, 1.22-2.95, P = 0.0046) was an independent unfavorable prognostic factor. No predictive factors specific to the TMZ + IFNβ + Radiotherapy (RT) group were found.

CONCLUSION

This additional sub-analytical study of JCOG0911 among patients with newly diagnosed GBM showed that tumor location at the temporal lobe, gross total resection, and MGMT promoter methylation were significant prognostic factors, although no factors specific to IFNβ addition were identified.

A randomized, double-blind, phase III trial of personalized peptide vaccination for recurrent glioblastoma

BACKGROUND

We conducted a phase III trial of personalized peptide vaccination (PPV) for human leukocyte antigen (HLA)-A24+ recurrent glioblastoma to develop a new treatment modality.

METHODS

We randomly assigned 88 recurrent glioblastoma patients to receive PPV (n = 58) or the placebo (n = 30) at a 2-to-1 ratio. Four of 12 warehouse peptides selected based on preexisting peptide-specific immunoglobulin G levels or the corresponding placebos were injected 1×/week for 12 weeks.

RESULTS

Our trial met neither the primary (overall survival [OS]) nor secondary endpoints. Unfavorable factors for OS of 58 PPV patients compared with 30 placebo patients were SART2-93 peptide selection (n = 13 vs 8, hazard ratio [HR]: 15.9), ≥70 years old (4 vs 4, 7.87), >70 kg body weight (10 vs 7, 4.11), and performance status (PS)3 (8 vs 2, 2.82), respectively. Consequently, the median OS for PPV patients without SART2-93 selection plus one of these 3 favorable factors (<70 y old, ≤70 kg, or PS0-2) was significantly longer than that for the corresponding placebo patients (HR: 0.49, 0.44, and 0.51), respectively. Preexisting immunity against both all 12 warehouse peptides besides SART2-93 and the other cytotoxic T lymphocyte epitope peptides was significantly depressed in the patients with SART2-93 selection (n = 21) compared with that of the patients without SART2-93 selection (n = 67). Biomarkers correlative for favorable OS of the PPV patients were a lower percentage of CD11b+CD14+HLA-DRlow immunosuppressive monocytes and a higher percentage of CD4+CD45RA- activated T cells, the intermediate levels of chemokine C-C ligand 2 (CCL2), vascular endothelial growth factor, interleukin (IL)-6, IL-17, or haptoglobin, respectively.

CONCLUSION

This phase III trial met neither the primary nor secondary endpoints.

Characterization of a novel type NK cell line KHYG-1 carrying EGFRvIII-specific CAR in glioblastoma cells

Background

Natural killer (NK) cells are considered potential antitumor effector cells. The aim of this study was to establish a novel type of a chimeric antigen receptor (CAR)-NK cell line (CAR-KHYG-1) specific for epidermal growth factor receptor variant III (EGFRvIII)-expressing glioblastoma (GBM) cells and investigate the antitumor effects of EGFRvIII-specific-CAR-expressing KHYG-1 (EvCAR-KHYG-1) in vitro and in vivo.

Materials and Methods

EvCAR-KHYG-1 was established by lentiviral-based transduction of the EvCAR gene and magnetic bead-based purification of EvCAR-expressing NK cells. The antitumor effects of EvCAR-KHYG-1 were evaluated using growth inhibition and apoptosis detection assays on GBM cell lines (EGFRvIII-expressing and non-expressing U87MG glioma cells). Cytokine production was determined by cytometric beads array. In vivo xenograft assays were performed in NOG mice subcutaneously implanted with EGFRvIII-expressing U87MG (Ev-U87MG).

Results

EvCAR-KHYG-1 inhibited GBM cell-growth via apoptosis in an EGFRvIII-expression specific manner in vitro. In addition, EvCAR-KHYG-1 produced IL-2, INF-γ and TNF-α on Ev-U87MG cells. In vivo xenograft assays showed that EvCAR-KHYG-1 did not decrease the volume of subcutaneous tumors but inhibited the occupancy of cancer cells in the subcutaneous tumor.

Discussion

EvCAR-KHYG-1 enhanced antitumor effects and produced Th1-type cytokines on EGFRvIII-expressing GBM cells, but did not inhibit progression of subcutaneous GBM cell-derived tumors to induce a pseudo progression pathological phenotype.

Conclusion

A novel type CAR-NK cell line was established. In vivo experiments are required to determine ways it can be used to inhibit tumor progression.

Effect of CRISPR/Cas9-mediated PD-1-disrupted primary human third-generation CAR-T cells targeting EGFRvIII on human glioblastoma cell growth

Glioblastoma (GBM) is the most common and malignant brain tumor. As GBM is resistant to standard treatment, immunotherapy might be a promising alternative. Chimeric antigen receptor (CAR) is an artificially modified fusion protein that can be engineered to direct the specificity and function of T cells against tumor antigens. The antitumor effects of EGFRvIII-targeting CAR-T (EvCAR-T) cells are limited in GBM, on account of the interaction between programmed cell death protein 1 (PD-1) on activated EvCAR-T cells and its ligands on target tumor cells. Antibodies against PD-1 have shown limitations, so permanent deletion of the PD-1 gene in CAR-T cells might be a promising solution. Therefore, in the present study, PD-1-disrupted EvCAR-T cells were established for the first time with the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) gene-editing tool. We determined the disruption efficiency of the human PD-1 gene in EvCAR-T cells and evaluated the antitumor effect of PD-1-disrupted EvCAR-T cells against human GBM cells. The results showed that our designed-sgRNA/Cas9 expression vectors precisely disrupted the target region of PD-1 and inhibited the expression of PD-1 in EvCAR-T cells. Further, the PD-1-disrupted EvCAR-T cells also had a growth inhibitory effect on EGFRvIII-expressing GBM cells. Thus, this study provides a simple, easy, and clinical applicable strategy for inducing PD-1-disrupted EvCAR-T cells, which could potentially be useful for improving the efficacy of EvCAR-T cell-based adoptive immunotherapy for GBM, and even other cancers.

Aberrant Active cis-Regulatory Elements Associated with Downregulation of RET Finger Protein Overcome Chemoresistance in Glioblastoma

RET finger protein (RFP) forms a complex with histone deacetylase 1, resulting in aberrant deacetylation of H3K27ac and dysregulation of cis-regulatory elements. We evaluated the modulatory effects of RFP knockdown on cis-regulatory elements, gene expression, and chemosensitivity to temozolomide both in glioblastoma cells and in an intracranial glioblastoma model. The combination of RFP knockdown and temozolomide treatment markedly suppressed the glioblastoma cell growth due to oxidative stress and aberrant cell cycle and increased survival time in mice with glioblastoma. ChIP-seq and RNA-seq revealed that RFP knockdown increased or decreased activity of numerous cis-regulatory elements that lie adjacent to genes that control functions such as apoptosis, mitosis, DNA replication, and cell cycle: FOXO1, TBP2, and PARPBP. This study suggests that RFP contributes to chemoresistance via aberrant deacetylation of histone H3 at K27, whereas dysregulation of RFP-associated cis-regulatory elements in glioma and RFP knockdown combined with temozolomide is an effective treatment strategy for lethal glioma.

Effect of CRISPR/Cas9-Mediated PD-1-Disrupted Primary Human Third-Generation CAR-T Cells Targeting EGFRvIII on In Vitro Human Glioblastoma Cell Growth

Glioblastoma (GBM), which is the most common malignant brain tumor, is resistant to standard treatments. Immunotherapy might be a promising alternative for the treatment of this cancer. Chimeric antigen receptor (CAR) is an artificially modified fusion protein that can be engineered to direct the specificity and function of T cells against tumor antigens. However, the antitumor effects of EGFRvIII-targeting CAR-T (EvCAR-T) cells in GBM are limited. The inhibitory effect is induced by the interaction between programmed cell death protein 1 (PD-1) on activated EvCAR-T cells and its ligands on GBM cells. In the present study, PD-1-disrupted EvCAR-T cells were established using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9). The sgRNA/Cas9 expression vectors designed precisely disrupted the target region of PD-1 and inhibited the expression of PD-1 in EvCAR-T cells. The PD-1-disrupted EvCAR-T cells had an in vitro growth inhibitory effect on EGFRvIII-expressing GBM cells without altering the T-cell phenotype and the expression of other checkpoint receptors. In the future, the in vivo antitumor effect of this vector should be evaluated in order to determine if it could be applied clinically for improving the efficacy of EvCAR-T cell-based adoptive immunotherapy for GBM.