bluuebunny/crossref_metadata_2025_split huggingface dataset:
BIOL-04. CYTOPLASM PROTEIN GFAP MAGNETIC BEADS CONSTRUCTION AND APPLICATION AS CELL SEPARATION TARGET FOR BRAIN TUMORS
Authors: Zhao Yang , Ma Jie 
Published: June 2021

Abstract

Background
It is very important to develop a highly efficient cerebrospinal fluid (CSF) detection system with diagnosis and prediction function, for which the detection of circulating tumor cells (CTCs) in CSF is a good choice. In contrast to the past use of epithelial EpCAM as CTCs separation target, a cytoplasm protein of GFAP antibody was first selected to construct highly-sensitive immunomagnetic liposome beads (IMLs). The validation and efficiency of this system in capturing CTCs for brain tumors were measured both in vitro and in vivo. The associations between the numbers of CTCs in patients with their clinical characteristics were further analyzed.

Results
Our data show that CTCs can be successfully isolated from CSF and blood samples from 32 children with brain tumors. The numbers of CTCs in CSF were significantly higher than those in blood. The level of CTCs in CSF was related to the type and location of the tumor rather than its stage. The higher the CTCs number is, the more possibly the patient will suffer from poor prognosis. Genetic testing in GFAP CTC-DNA by sanger sequencing, q-PCR and NGS methods indicated that the isolated CTCs (GFAP+/EGFR+) are the related tumor cell. For example, the high expression of NPR3 gene in CSF CTCs was consistent with that of tumor tissue.

Conclusions
The results indicated that GFAP-IML CTCs isolation system, combined with an EGFR immunofluorescence assay of antitumor marker, can serve as a brand-new method for the identification of CTCs for brain tumors. Via lumbar puncture, a minimally invasive procedure, this technique may play a significant role in the clinical diagnosis and drug evaluation of brain tumors.
BIOL-07. MIR-212 FUNCTIONS AS A TUMOR SUPPRESSOR GENE IN GROUP 3 MEDULLOBLASTOMA VIA TARGETING NUCLEAR FACTOR I/B (NFIB)
Authors: Perumal Naveenkumar , Kanchan Ranjana , Doss David , Atri Pranita , Venkata Ramakanth Chirravuri , Thapa Ishwor , Nasser Mohd , Batra Surinder , Mahapatra Sidharth 
Published: June 2021

Abstract
Medulloblastoma (MB), the most frequent malignant pediatric brain tumor is subdivided into four primary subgroups, i.e. wingless-type (WNT), sonic hedgehog (SHH), group 3, and group 4. Haploinsufficiency of chromosome 17p13.3 and c-myc amplification distinguish high-risk group 3 tumors, which are associated with rapid metastasis, recurrence and early mortality. We sought to identify the role of miR-212, which resides on chromosome 17p13.3, in the pathophysiology of group 3 MB. RNA expression analyses revealed dramatically reduced levels of miR-212 in group 3 tumors and cell lines mainly through epigenetic silencing via histone modifications (deacetylation). Restoring in vitro miR-212 expression reduced tumor cell proliferation, colony formation, wound healing, migration and invasion with decreased p-AKT and p-ERK levels in group 3 MB cell lines. Interestingly, a shift in differential c-myc phosphorylation (from serine-62 to threonine-58) was also discovered with miR-212 expression, resulting in reduced total c-myc levels, concurrent with elevated cellular apoptosis. In turn, pro-apoptotic binding partners of c-myc, i.e. Bin-1 and P19ARF, were upregulated in these cells. These findings were recapitulated in stable inducible miR-212 expressing tumor cells. Using a combination of transcriptomic data and a dual luciferase assay, we isolated an important oncogenic target of miR-212, i.e, NFIB, a nuclear transcription factor implicated in metastasis and recurrence. Increased expression of NFIB was confirmed in group 3 tumors, with poor survival shown in high NFIB-expressing patients. As prior, transient NFIB silencing in vitro reduced not only tumor cell proliferation, colony formation, wound healing, migration and invasion, but also medullosphere formation along with decreased expression of stem cell markers (Nanog, Oct4, Sox2, CD133), confirming its role in tumor recurrence possibly via augmenting tumor stemness. Taken together, these results substantiate the tumor suppressive role of miR-212 in group 3 MB and provide a potential new oncogenic target implicated in tumor recurrence, NFIB.
EMBR-01. CLASS I HDAC INHIBITORS AND PLK1 INHIBITORS SYNERGIZE IN MYC-AMPLIFIED MEDULLOBLASTOMA
Authors: Valinciute Gintvile , Ecker Jonas , Selt Florian , Hielscher Thomas , Schmidt Christin , Sigaud Romain , Ridinger Johannes , Gatzweiler Charlotte , Picard Daniel , Oppermann Sina , Blattner-Johnson Mirjam , Jones David T W , Oehme Ina , Kool Marcel , Remke Marc , Pfister Stefan M , Witt Olaf , Milde Till 
Published: June 2021

Abstract

Background
Medulloblastoma (MB) is one of the most common malignant pediatric CNS tumors. Patients with Group 3 MBs harboring MYC amplification exhibit low survival rates. Surviving patients suffer from therapy-induced sequelae, which calls for new targeted therapy strategies. We and others have previously shown the sensitivity of MYC-amplified MB to class I histone deacetylase (HDAC) inhibition. After demonstrating that the MYC target gene PLK1 is significantly downregulated upon class I HDACi treatment, we hypothesized that inhibition of both HDACs and PLK1 could have synergistic effects.

Methods
Cell metabolic activity changes upon HDAC and PLK1 inhibitor treatment were measured in MYC-amplified and non-amplified MB cell lines, as well as in an additional MYC-inducible cell line. The interaction effect of both inhibitors was determined by computation of the combination index (CI) using the Chou-Talalay method. Results were validated assessing cell viability, cell cycle, and apoptosis induction. Transcription profile changes after combination treatment were evaluated.

Results
MYC-amplified MB cell lines were more sensitive than non-amplified cell lines to PLK1i treatment, showing IC50 in clinically achievable concentration ranges. Inhibition of class I HDACs and PLK1 synergistically reduced cell metabolic activity in lower concentrations in MYC-amplified compared to non-amplified MB cell lines. We also observed a significant loss of viability and cells in G1 phase, as well as induction of apoptosis after combination treatment in MYC-amplified cells. MYC target gene sets were significantly downregulated in the MYC-amplified cell line HD-MB03 after treatment with combination. We demonstrated reduction of MYC protein levels upon PLK1i treatment. In vivo evaluation of combination treatment using orthotopic Group 3 MYC-amplified MB PDX models is ongoing.

Conclusion
Our data suggest that MYC-amplification is a predictive marker for PLK1i treatment in MB. The combination of HDACi and PLKi could be a candidate therapy for future clinical trials for MYC-amplified group 3 MB.
EMBR-04. BET INHIBITION TARGETS RADIOTHERAPY RESISTANCE IN H3K27ME3-DEFICIENT GROUP 3 MEDULLOBLASTOMA
Authors: Gabriel Nishanth , Balaji Kumaresh , Inkman Matthew , Jayachandran Kay , Zhang Jin , Dahiya Sonika , Goldstein Michael 
Published: June 2021

Abstract
Medulloblastoma has been categorized into four subgroups based on genetic, epigenetic and transcriptional profiling. However, molecular pathways determining radiotherapy response in this tumor remain elusive. Here, we investigated the role of the EZH2-dependent histone H3K27 tri-methylation in radiotherapy response in medulloblastoma. We demonstrate that 47.2% of group 3 and 4 medulloblastoma patients have H3K27me3-deficient tumors. Loss of H3K27me3 was associated with a radioresistant phenotype, high relapse rates and poor overall survival. We show that an epigenetic switch from H3K27me3 to H3K27ac occurs at specific genomic loci in H3K27me3-deficient medulloblastoma cells altering the transcriptional profile. The resulting up-regulation of EPHA2 (ephrin type-A receptor 2) stimulates an excessive activation of the pro-survival AKT signaling pathway leading to radiotherapy resistance. We show that BET inhibition targets radiation resistance in H3K27me3-deficient medulloblastoma by suppressing H3K27ac levels, blunting EPHA2 overexpression and mitigating the excessive AKT signaling. Additionally, BET inhibition sensitizes medulloblastoma cells to radiation by enhancing apoptotic response through suppression of Bcl-XL and up-regulation of Bim expression. Our work demonstrates a novel mechanism of radiation resistance in medulloblastoma and identifies an epigenetic marker predictive of radiotherapy response. Based on these findings we propose an epigenetically guided treatment approach targeting radiotherapy resistance in medulloblastoma patients.
EMBR-08. CORRELATION OF HISTOPATHOLOGY, CHROMOSOMAL MICROARRAY, AND NANOSTRING BASED 22-GENE ASSAY FOR MEDULLOBLASTOMA SUBGROUP ASSIGNMENT ON “HEAD START” 4 CLINICAL TRIAL
Authors: Dhall Girish , Patel Parth , Blue Megan , Biegel Jaclyn , Almiraz-Suarez Isabel , Hwang Eugene , Pierson Christopher , Boue Daniel , Finlay Jonathan 
Published: June 2021

Abstract
“Head Start” 4 (HS 4) is a prospective randomized clinical trial that tailors treatment based on medulloblastoma molecular subgroups and response to induction chemotherapy to compare the efficacy of one versus three (tandem) cycles of myeloablative therapy. Advances in RNA and DNA profiling have identified four core molecular subgroups of medulloblastoma with prognostic significance: Sonic Hedgehog (SHH) subtype, WNT subtype, Group 3, and Group 4. In HS 4 trial, we utilize a combination of histopathology and immunohistochemistry (pathology/IHC), as well as chromosomal microarray analysis (CMA) utilizing OncoScanTM (Thermo Fisher) to classify medulloblastoma samples into either SHH, WNT, or non-WNT/non-SHH (Group 3/4) subgroups at the time of diagnosis. NanoString based 22-gene assay is performed retrospectively to test concordance. We have pathology/IHC, CMA, and NanoString data on 26 infants and young children with medulloblastoma enrolled on HS 4. Pathology/IHC was able to assign samples to SHH, WNT, and non-WNT/non-SHH subgroups in all but two cases: one case was classified as Group 3, and the second as SHH by both CMA and NanoString. CMA was indeterminate in six cases, of which, pathology/IHC was able to assign all six samples aforementioned three subgroups. NanoString was indeterminate in two cases: one case was classified as SHH by CMA and pathology/IHC, and the second case was indeterminate by CMA but was assigned as non-WNT/non-SHH on pathology/IHC. There is excellent correlation between NanoString and combination of histopathology and CMA for core medulloblastoma subgrouping on HS 4. Methylation studies are ongoing.
EMBR-11. SYNERGISTIC DRUG COMBINATIONS FOR THE TREATMENT OF MYC AMPLIFIED GROUP 3 MEDULLOBLASTOMA
Authors: Zeuner Simon , Vollmer Johanna , Peterziel Heike , Sigaud Romain , Oppermann Sina , ElHarouni Dina , Hielscher Thomas , Witt Olaf , Oehme Ina , Milde Till , Ecker Jonas 
Published: June 2021

Abstract

Background
Medulloblastoma (MB) is a highly aggressive brain tumour in children. Patients with Group 3 MB harbouring a MYC-amplification (subtype II) show a particularly poor outcome despite high-intensity multimodal therapy. We and others have previously shown that MYC amplified Group 3 MB cells are highly susceptible towards treatment with class I histone deacetylase (HDAC) inhibitors such as entinostat. However, in clinical trials HDACi as a monotherapy show only modest efficacy in solid tumours. We propose to increase the efficacy of class I HDACi by drug combinations.

Methods
To identify synergistic drug combinations (entinostat + X) for the treatment of MYC amplified MB we performed a drug screen with a library of n=75 clinically available compounds as single agents and in combination with entinostat in n=3 MYC amplified vs. n=1 MYC-non amplified cell lines. Synergistic behaviour of the six most promising drug combinations was validated by metabolic activity assays, cell count experiments and gene expression profiling. Synergy was assessed by the Loewe additivity model using a combination of ray design and checkerboard matrix.

Results
The drug screen revealed n=20/75 drugs that were particularly effective (drug sensitivity score ≥10) in combination with entinostat treatment in all three MYC amplified cell lines. Synergy assessment of the top n=6 drugs confirmed strong synergistic activity with entinostat for n=2 drugs (navitoclax, irinotecan). The BCL-2 family inhibitor navitoclax showed the most robust synergy with entinostat in subsequent validation experiments.

Conclusion
Several drugs either clinically available or currently in clinical trials, including the BCL-2/Xl/w inhibitor navitoclax, show promising effects in a combination therapy with entinostat for the treatment of MYC amplified Group 3 MB.
EMBR-17. DE-INTENSIFICATION OF RADIOTHERAPY IN RIGOROUSLY DEFINED LOW-RISK WNT-SUBGROUP MEDULLOBLASTOMA IS ASSOCIATED WITH UNACCEPTABLY HIGH RISK OF NEURAXIAL FAILURE: RESULTS FROM THE PROSPECTIVE FOR-WNT STUDY
Authors: Gupta Tejpal , Pervez Shizan , Dasgupta Archya , Chatterjee Abhishek , Krishnatry Rahul , GodaSastri Jayant , Prasad Maya , Chinnaswamy Girish , Epari Sridhar , Sahay Ayushi , Shirsat Neelam , Shetty Prakash , Moiyadi Aliasgar , Shaikh Farnaz , Bano Nazia , Jalali Rakesh 
Published: June 2021

Abstract

Background
Medulloblastoma is a heterogenous disease comprising four molecular subgroups (WNT, SHH, Group 3, and Group 4) with varying outcomes. Excellent long-term survival (&gt;90%) has prompted de-intensification of therapy in WNT-subgroup medulloblastoma globally. FOR-WNT is one such prospective study (CTRI/2017/12/010767) testing the hypothesis that focal conformal radiotherapy (RT) (54Gy/30 fractions/6-weeks) with avoidance of upfront craniospinal irradiation (CSI) followed by standard adjuvant chemotherapy significantly reduces RT-related late toxicity without unduly compromising survival in low-risk WNT-subgroup medulloblastoma (residual tumor &lt;1.5cm2 with no evidence of metastases in children aged between 3–16 years).

Methods
Patients with low-risk WNT-subgroup medulloblastoma were enrolled after written informed consent/assent. To ensure patient safety, stopping rules were devised according to group-sequential method.

Results
Between July 2017 till Feb 2019, seven children of WNT-pathway medulloblastoma were treated with focal conformal RT followed by 6-cycles of adjuvant chemotherapy (cisplatin, cyclophosphamide, and vincristine). One child succumbed to acute renal failure during chemotherapy, while the other 6 patients completed all 6-cycles as planned. Three children were detected with neuraxial failure (supratentorial brain and/or spine) without synchronous local recurrence in the treated tumor-bed on surveillance neuro-imaging between 1.5–2 years from index diagnosis following which the study was terminated prematurely. All 3 children with relapse were treated with salvage CSI (35Gy/21 fractions) with (conformal avoidance of previously treated tumor-bed) plus boost irradiation (10.8-18Gy/6–10 fractions) of metastatic deposits resulting in complete/near complete response and are alive with controlled disease. The other 3 children have not shown any evidence of relapse for over 2-years from index diagnosis and remain on active clinico-radiological surveillance.

Conclusion
In rigorously defined low-risk WNT-subgroup medulloblastoma, avoidance of upfront CSI is associated with unacceptably high risk of neuraxial failure. A successor study (FOR-WNT 2) incorporating low-dose CSI (18Gy/10 fractions) with similar tumor-bed dose and adjuvant systemic chemotherapy is currently underway.
EMBR-19. SHH-DRIVEN MEDULLOBLASTOMA WITH CONCURRENT UNILATERAL RENAL AGENESIS
Authors: Aaroe Ashley , Sarkar Sanila , Sherani Farha , McAleer Mary , Fuller Greg , Zaky Wafik 
Published: June 2021

Abstract

Case Presentation
A 3-year-old female with insignificant past medical history presented with 6 weeks of headaches, emesis, and lethargy. MR imaging identified a heterogeneously enhancing right cerebellar hemispheric mass and obstructive hydrocephalus. Gross total resection was performed without complications; pathology revealed classical WHO grade 4 medulloblastoma (MB). MR imaging of the spine and cerebrospinal fluid testing were negative for disseminated disease. Treatment for standard risk medulloblastoma was initiated, comprising proton craniospinal irradiation with posterior fossa boost and concurrent vincristine, followed by adjuvant chemotherapy with vincristine, lomustine, cisplatin, and cyclophosphamide as standard of care. Next generation sequencing of the tumor tissue performed using a high-multiplex PCR-based NGS panel was negative for alteration of the SMO, PTCH1 and CTBNN1 genes. Further molecular characterization via methylation profiling demonstrated the sonic hedgehog (SHH) molecular subtype. Prior to initiation of chemotherapy, renal ultrasound was performed and identified congenitally absent right kidney; audiology evaluation was unremarkable.

Discussion
In patients with Gorlin syndrome, cases of unilateral renal agenesis in association with germline SHH-pathway mutations have been reported [1]. SHH signaling is implicated in multiple steps in the development of the urinary system [2]. Outside Gorlin syndrome, however, to the best of our knowledge unilateral renal agenesis coinciding with SHH-driven MB has not been reported. Our patient notably lacks any clinical stigmata of Gorlin syndrome (skeletal abnormalities, skin pits, macrocephaly) and does not exhibit the characteristic germline genetic abnormalities that define GS (PTCH1 mutation or 9q22.3 microdeletion). There are important treatment implications for patients with the constellation of abnormalities we describe here, particularly regarding the requisite frequent monitoring of renal function during multi-agent chemotherapy courses. Our patient tolerated chemoradiation well, and is currently on maintenance chemotherapy with favorable course to date.
EMBR-33. YAP1 FUNCTION IN SHH MEDULLOBLASTOMA PROGRESSION AND IMMUNE EVASION
Authors: Abdelfattah Nourhan , Natarajan Sivaraman , Baskin David , Yun Kyuson 
Published: June 2021

Abstract
Our incomplete understanding of the key players in Medulloblastoma (MB) development and progression, and their roles in modulating highly Immune desert-like microenvironment in MBs present major hurdles in successfully applying existing therapies and developing new therapies for MBs. Here, we demonstrate that Yap1 acts as a critical modulator of SHH MB (fSmoM2; GFAPcre (SG) and Ptch;p53 SHH-MB mouse models) progression and immune evasion. Yap1 genetic deletion in SG mice significantly extends survival and normalizes brain development by increasing neuronal differentiation. Both bulk and single-cell RNA sequencing analyses show that Yap1 deleted tumors contain cells with more differentiated molecular signatures similar to late CGNPs and differentiating neurons, and less stem-like cells, compared to SG tumors. Additionally, integrated analyses of ChiPseq, RNAseq, and scRNAq data suggest that Yap1 directly binds to the Super enhancer region containing Sox2 and promotes Sox2 expression in SHH MB cells. We postulate that Yap1 expression is maintained or re-activated in SHH MB cells to generate long-term self-renewing tumor cells. Consistently, Yap1-deleted SHH MB or Verteporfin (a small molecule inhibitor of Yap1) -treated Ptch;p53 MB cells lose self-renewal ability in vitro. Furthermore, we hypothesize that a molecular mechanism underlying this stemness promoting function is mediated through Sox2 expression. Intriguingly, Yap1 deletion in SG MBs is accompanied by a significant change in the immune microenvironment, when compared to age-matched SG MBs. There is a significant increase in the number of bone marrow-derived immune cells (including cytotoxic T-cells, neutrophils, and macrophages). RNAseq analysis of rescued tumors shows marked enrichment of interferon-gamma response genes and pro-inflammatory cytokines. This study highlights Yap1 as a crucial mediator of MB progression and a molecular regulator of inflammatory immune cell infiltration into SHH MBs. Consequently, our work paves the way for improving immunotherapy treatments in brain malignancies.
EPEN-03. ZFTA/C11ORF95 FUSIONS DRIVE SUPRATENTORIAL EPENDYMOMA VIA SHARED ONCOGENIC MECHANISMS
Authors: Zheng Tuyu , Ghasemi David R , Okonechnikov Konstantin , Korshunov Andrey , Maaß Kendra K , Sill Martin , Gojo Johannes , Schüller Ulrich , Milde Till , Mack Stephen C , Gilbertson Richard J , von Deimling Andreas , Jones David T W , Kool Marcel , Pfister Stefan M , Sahm Felix , Kawauchi Daisuke , Pajtler Kristian W 
Published: June 2021

Abstract
The majority of supratentorial ependymomas (ST-EPN) are driven by fusion genes between RELA and zinc finger translocation associated, ZFTA, previously named C11orf95. Apart from fusions with a portion of the Hippo effector YAP1, which affects a small group of infant patients, the oncogenic mechanism of remaining ST-EPNs remains unclear. Aiming at refining the molecular classification of ST-EPNs, we have analyzed methylation profiles, RNA and DNA sequencing results as well as clinical data in a cohort of 613 ST-EPNs. An unbiased approach revealed distinct methylation clusters composed of tumors with ependymal but also various other histological features containing alternative translocations that shared ZFTA as a partner gene. Tumors within these additional clusters were characterized by fusions of ZFTA to numerous fusion partners different from RELA, e.g. MAML2, MAML3, NCOA2 and SS18, implying a general role of ZFTA in tumorigenesis of ST-EPN. Indeed, the transforming capacity of newly identified fusion genes was validated using an electroporation-based in vivo gene transfer technology in mice. All fusion genes themselves were sufficient to drive malignant transformation in the developing cerebral cortex and resulting tumors faithfully recapitulated molecular characteristics of their human counterparts. We found that both, the partner gene and the zinc finger DNA binding domain of ZFTA, were essential to exert tumorigenesis. Together with two additional studies, we performed a comprehensive analysis across datasets to derive a 93 gene signature of ZFTA-RELA-driven tumors, in which the Sonic Hedgehog effector gene GLI2 was identified as a promising downstream target. Subsequent co-expression of ZFTA:RELA and a dominant negative form of Gli2 indeed hampered tumorigenesis. Targeting GLI2 with arsenic trioxide caused extended survival of tumor-bearing animals, indicating GLI2 as a critical regulator of ZFTA fusion-positive tumorigenesis as well as a potential therapeutic vulnerability in these tumors.