bluuebunny/crossref_metadata_2025_split huggingface dataset:
IMMU-12. Exploring and modulating the tumour immune microenvironment to facilitate the selection of immunotherapies for paediatric-type diffuse high-grade glioma
Authors: Cockle Julia , Bjerke Lynn , Mackay Alan , Grabovska Yura , Burford Anna , Molinari Valeria , Pereira Rita , Boult Jessica , Robinson Simon , Carvalho Diana Martins , Clarke Matthew , Titley Ian , Yara Erika , Straathof Karin , Wennerberg Erik , Becher Oren , Castro Maria , Melcher Alan , Jones Chris 
Published: June 2022

Abstract
Immune cells have the potential to selectively eradicate high-risk brain tumours such as paediatric-type diffuse high-grade glioma (PDHGG). We aim to characterize the tumour immune microenvironment (TIME) of intra-cranial syngeneic mouse models of diffuse hemispheric glioma, H3G34 (DHG-H3G34) and diffuse midline glioma, H3K27 (DMG-H3K27). We also demonstrate how an oncolytic reovirus (Reolysin) can “heat-up” the TIME of our syngeneic models. Orthotopic immunocompetent mouse models of DHG-H3G34 (C57BL/6, NRASG12V + shp53 + shATRX +/- H3.3G34R) and DMG-H3K27 (Nestin-Tv-a/p53fl/fl, RCAS-ACVR1R206H + RCAS-H3.1K27M) were profiled using single-cell RNA-sequencing (scRNA-seq) (10x genomics), a 22-colour custom flow cytometry immune panel and spatial transcriptomics. Differential marker expression was validated with immunohistochemistry and immunofluorescence in tissue sections. Syngeneic mouse tumours treated systemically with Reolysin were also profiled to evaluate the effects of the oncolytic virus on the TIME. Cell type predictions in scRNA-seq using singleR, ssGSEA and expression of individual marker genes suggested that the predominant immune cell types within hemispheric tumours were monocytes (11-21%) and macrophages (10-19%) with much smaller proportions of CD4+ and CD8+ T-cells (4-10%). By contrast, much smaller proportions of monocytes (2%) and macrophages (3%) were observed in the H3.1K27M pontine model. Flow cytometry, immunohistochemistry and immunofluorescence validated scRNA-seq immune profiles and characterised signalling of the PD-1/PD-L1 checkpoint pathway. Spatial transcriptomics allowed immune cell populations to be positioned within tumour sections and showed significant co-localization of CD4+ and CD8+ lymphocytes at tumour margins. Treatment of syngeneic mouse tumours with Reolysin resulted in reduced tumour volumes and altered the TIME, in particular increasing cytotoxic T-cell tumour infiltration. Our results highlight immunological heterogeneity within molecular subgroups of PDHGG and demonstrate ability of a systemically delivered oncolytic virus, Reolysin, to “heat-up” the TIME, contributing to a more immune actionable profile. Future work will help to identify optimal combinations for the next generation of immunotherapies in PDHGG.
LGG-07. Novel CRISPR/Cas9 induced KIAA1549:BRAF fusion model for preclinical studies of pediatric gliomas
Authors: Patel Krupesh , Zhao Guisheng , Huang Shih-Ming , Karakousi Triantafyllia , Nicolaides Theodore , Papagiannakopoulos Thales 
Published: June 2022

Abstract
BACKGROUND: Pediatric Low Grade Gliomas (pLGG) are the most common group of central nervous system (CNS) tumors in children and cause significant morbidities. Pilocytic astrocytoma (PA) is the most frequent pLGG. KIAA1549:BRAF fusion is a well-established oncogenic driver in PA. Oncogene induced senescence (OIS) has prevented establishing PA cultures for in vitro and in vivo studies. Here we look at a novel NIH-3T3 fibroblast model harboring KIAA1549:BRAF fusion gene via CRISPR/Cas9 somatic genome engineering technology.
OBJECTIVES: Establishing that the CRISPR/Cas9 edited NIH-3T3 fibroblast model with the KIAA1549:BRAF fusion is valuable for in vitro and in vivo studies without early OIS. DESIGN/METHOD: CRISPR/Cas9 editing technology was used to establish a KIAA1549:BRAF fusion positive cell model. This cell model was studied in vitro with MEK inhibitor cobimetinib (GDC-0973) and using WST-1 viability assay, clonogenic assay, senescence β-galactosidase staining, and western blot. In vivo murine models with subcutaneous fusion positive NIH-3T3 fibroblast tumors were treated with GDC-0973. Survival studies and tissue studies were subsequently done. RESULTS: A fusion positive NIH-3T3 fibroblast model was successfully established. Increased BRAF cDNA expression and higher levels of p-ERK were observed. In vitro studies showed decreased viability with GDC-0973. Clonogenic assay showed qualitative and quantitative decreases in viable cells. P-ERK target inhibition was established without induction of senescence. In vivo studies demonstrated successful subcutaneous tumor implantation, therapy efficacy, and target inhibition. CONCLUSION: CNS tumors, most commonly pLGG, in children cause significant morbidities. KIAA1549:BRAF fusion is an oncogenic driver in PA. In vitro and in vivo studies are important for pre-clinical models. OIS has prevented establishing adequate fusion positive animal cell models. Here we have demonstrated a successful CRISPR/Cas9 edited fusion positive NIH-3T3 fibroblast model.
LGG-10. Evaluation of the chemotherapy efficacy of children with optic pathway glioma in a tertiary hospital in China
Authors: Li Miao , Du Shuxu , Tian Yongji , Zhang Jin , Gao Wenchao , Xiao Jinjing , Gong Xiaojun , Sun Yanling , Wu Wanshui , Sun Liming 
Published: June 2022

Abstract
OBJECTIVE: In order to analyze the chemotherapy efficacy of children with optic pathway glioma (OPG), the clinical, treatment and prognosis factors of children with OPG who received the German International Society of Pediatric Oncology (SIOP) low-grade glioma (LGG) 2004 regimen chemotherapy, were retrospectively analyzed. METHOD: From September 2014 to October 2019, a total of 60 patients with OPG were enrolled and accept LGG 2004 chemotherapy in the Department of Pediatrics, Beijing Shijitan Hospital, Capital Medical University, China. The progression-free survival (PFS) rates and overall survival (OS) rates were analyzed by the Kaplan-Meier method. Both univariate and multivariate analyses were performed using the Cox-proportional hazards model. The test standard α=0.05. RESULTS: Until January 1st, 2022, all children were alive, and the clinical symptoms were improved at any degree, and well tolerated during the whole treatment. The median follow-up time was 3.7 years (range 2.3-7.1 years), the average time of objective response was 6.8 months (range from 2 to 21 months), and the 5 year PFS rates were 73.0 ± 7.24 %. However, about 3 to 8 months later, 8 cases (age &lt;4 years) relapsed which attained partial remission (PR) at the end of the whole therapy. These relapsed cases were performed the LGG 2004 regimen again, and all had an objective response after 4~6 courses of treatment. In addition, two children (age&gt;8 years old) progressed rapidly during treatment, and had to be performed local radiotherapy and reached complete remission (CR). Another two cases with BRAF V600E mutation, reached a significant remission after 3 months of targeted therapy with selumetinib. Furthermore, the COX multivariate analysis shows that spinal metastasis is an independent risk factor of prognosis of children with OPG. CONLUSIONS: Chemotherapy can improve the clinical efficacy of children with OPG, which is better when combining with bevacizumab and/or targeted therapy.
LGG-16. Retrospective and integrative analyses of molecular characteristics and their specific imaging parameters in pediatric grade 1 gliomas.
Authors: Courant Marie , Lhermitte Benoit , Guerin Eric , Chammas Agathe , Reita Damien , Sebastia Consuelo , Douzal Valérie , Gabor Flaviu , Salmon Alexandra , Todeschi Julien , Coca Andres Hugo , Vincent Florence , Entz-Werlé Natacha 
Published: June 2022

Abstract
Pediatric low-grade gliomas (PLGG) are the most common brain tumors diagnosed during childhood and represent a heterogeneous group associating variable molecular abnormalities. To go further and develop specific statistical patterns integrating altogether tumor molecular background, imaging features and patient outcome, a retrospective study was performed in a group of non-NF1 grade 1 PLGGs. So, 78 children, followed from 2004 to 2017, were retrospectively reported. Their therapeutic management comprised surgery or surgery plus chemotherapies (e.g., carboplatin and vincristine). In this population, radiological and molecular patterns were pooled statistically to be able to identify specific prognostic subgroups. Considering all 78 patients, 59 had only a surgical removal and 19 patients were treated with post-operative chemotherapy. Twelve progressions were reported in the partially resected and chemotherapeutic groups, whereas 4 deaths occurred only in the highly treated patients. As expected, PLGG with BRAF pV600E and/or CDKN2A loss exhibited poor outcomes. Nevertheless, we were able to evidence statistically significant associations between molecular characteristics and their specific imaging presentation on diagnostic and 24-week MRIs. In the chemo-treated patients, the molecularly good risk situations were significantly linked to the presence of a large tumor cyst at diagnosis (&gt; 50% of the tumor volume (TV)) and the appearance during treatment of a higher cystic proportion that we called “cystic conversion”. So, additionally to the WHO prognostic molecular patterns, precise MRI characteristics (notably cystic part proportions onto TV) were associated to BRAF p.V600E PLGGs, as well as to the more frequent molecular KIAA1549-BRAF fused PLGGs. To summarize, absence on diagnostic MRI of cystic parts and/or cystic conversion at 6-month chemotherapy time point were significantly linked to a worst prognosis and response to treatment. In future studies, these imaging features might be considered as innovative prognostic markers to use during treatment.
LGG-20. Defining subgroups in low grade gliomas by their immune and stromal microenvironment
Authors: Körner Meik , Spohn Michael , Schüller Ulrich , Bockmayr Michael 
Published: June 2022

Abstract
Immunologic treatment options are still uncommon in low grade gliomas, although such therapies might be beneficial for inoperable and aggressive cases. Knowledge on immune and stromal cells in low grade gliomas, which is a mandatory prerequisite for such approaches, is still scarce. We therefore gathered published gene-expression data from 400 low grade gliomas as well as 302 high grade gliomas in order to quantify 10 microenvironment cell populations. First, we investigated general differences in the microenvironment of low- and high-grade gliomas. Lower-grade and high-grade tumors cluster together, respectively, and show a general similarity within and distinct differences between these groups, the main difference being a higher infiltration of fibroblasts and T-cells in high-grade gliomas. Among the analysed entities, gangliogliomas and pleomorphic xanthoastrocytomas presented the highest overall immune cell infiltration. Further analyses of the low-grade gliomas presented three distinct microenvironmental signatures of immune cell infiltration, which can be divided into T-cell/dendritic/natural killer cell-, neutrophilic/B lineage/natural killer cell-, and monocytic/vascular/stromal-dominated immune clusters. These clusters correlated with tumor location, age, and histological diagnosis, but not with sex or progression-free survival. Our work shows that low- and high-grade gliomas can be characterized and differentiated by their immune cell infiltration. Low grade gliomas cluster into three distinct immunologic tumor microenvironments, which may be of further interest for upcoming immunotherapeutic research.
LGG-29. Use of Bevacizumab in Pediatric Low-grade Glioma: Ten-year experience in a single center
Authors: Rafael Margarida Simão , Cruz Ofelia , Perez-Jaume Sara , Santa-María Vicente , Lavarino Cinzia , Salvador Hector , Muchart Jordi , Hinojosa Jose , Suñol Mariona , Morales Andrés 
Published: June 2022

Abstract
PURPOSE: Pediatric low-grade gliomas (PLGG) have excellent overall survival but frequently need non-surgical therapy at diagnosis or after progression at unresectable sites such as the optic pathway. Chemotherapy side effects have led to the need for better-tolerated regimens with a sustained response. Bevacizumab, a humanized anti-VEGF monoclonal antibody has been used in monotherapy and/or in combination for these entities. Here we present our experience with its use in PLGG. METHODS: A retrospective, observational, single-institution study between 2008-2018 was performed, reporting the short-term outcomes of safety and efficacy of bevacizumab in progressive PLGG. RESULTS: Twenty-six patients with a median age at diagnosis of 3.32 years old [0.12-14.7] and the median age at the treatment of 8.11 years old [0.41-16.82] were included in the study. Nineteen had optic pathway gliomas and chiasmatic-hypothalamic gliomas (73.1%), 9 of them (47.4%) associated with neurofibromatosis type 1 (NF1). Fourteen non-NF1 tumors were molecularly studied, disclosing BRAF-KIAA1549 fusion transcript in 9 and BRAF V600E mutation in 2. Bevacizumab was administered in combination with other agent(s) in 16 of the 35 treatment courses. Responses were assessed at 3, 6, 12 months, and at the end of treatment. Progression-free survival at 12 months was 94%, and no severe adverse events were observed. CONCLUSIONS: In our series, Bevacizumab in PLGG showed short-term clinical efficacy with a favorable toxicity profile. Larger and long-term prospective studies may determine whether the response is conditioned upon different clinical or molecular features.
LGG-31. Pediatric low-grade gliomas with FGFR1 mutations and spontaneous hemorrhage: case series
Authors: Campion Stephani , Aguilar-Bonilla Ana E , Elbabaa Samer , Smith Amy A 
Published: June 2022

Abstract
Pediatric low-grade gliomas (pLGG) are the most common pediatric CNS neoplasms. Thanks to the advent of molecular tumor diagnostics, we have begun exploring the clinical relevance of FGFR1 (c.1632C&gt;A; p.N546K) mutations in the pLGG population. However, the risk of spontaneous hemorrhage in pLGG patients harboring FGFR1 mutations is even less understood. We present four pLGG cases with FGFR1 mutation and hemorrhagic episodes. Patient 1 presented with an intraventricular hemorrhage and leptomeningeal disease. Pathology was consistent with suprasellar pilocytic astrocytoma, FGFR1, and PTPN11 mutations. Initial therapy consisted of Carboplatin/Vinblastine per ADVL0515. The patient has had several recurrences, and treatment regimens have included ACNS0223, Everolimus, and A9952 regimen A. Patient 2 was diagnosed with an optic pathway glioma, and pathology confirmed FGFR1, MEK2, PTPN11, and NF1 splice site mutations. The patient also has a history of Noonan’s Syndrome and has undergone several chemotherapy regimens, including A9952 Regimen A, COG MATCH with Erdafitinib, and Avastin. The best tumor response was seen while on Avastin. The patient has presented with two episodes of intratumoral hemorrhage, both after treatment with Avastin. Patient 3 presented with a sudden brain stem hemorrhage and underwent a biopsy and debulking. The pathology was consistent with a pilocytic astrocytoma with an FGFR1 mutation confirmed by Next-generation sequencing (NGS). Treatment regimens for this patient include A9952 Regimen A and Vinblastine. Patient 4 presented with acute headache and vomiting and was found to have a hemorrhagic suprasellar mass. The patient underwent tumor debulking, and pathology was consistent with low-grade glioma. NGS revealed FGFR1 and KRAS mutations. The patient received therapy as per A9952 Regimen A. Greater surveillance of this molecular and clinical finding is warranted to uncover the association between FGFR1 mutations and hemorrhage in patients with low-grade gliomas.
LGG-35. Dyslipidemia in children treated with BRAF inhibitors for brain tumor, a new side effect? A single center retrospective study
Authors: Crocco Marco , Verrico Antonio , Milanaccio Claudia , Piccolo Gianluca , Gaggero Gabriele , De Marco Patrizia , Iurilli Valentina , Profio Sonia Di , Calevo Maria Grazia , Casalini Emilio , Iorgi Natascia Di 
Published: June 2022

Abstract
The targeted therapies for brain tumors are innovative and promising oncological treatments and as a result their use has expanded widely. BRAF inhibitors (BRAFi) in recent years have played a central role in disease control of unresectable BRAF-mutated pediatric low-grade gliomas (LGG). Understanding the side effects of these drugs is crucial for clinical practice. The aim of the study was to investigate retrospectively the acute and long-term effects of vemurafenib on lipid metabolism in children treated for an LGG. Children (n=6) treated with vemurafenib at the mean age of 8.41±6.1 exhibited early alterations in plasma lipid profile as demonstrated after 1 month (n=4) by high plasma levels of Low-Density Lipoprotein (LDL 139.5±51.5,mg/dL), Total Cholesterol (TC 221.5±42.1,mg/dL) and Triglycerides (TG 107.8±44.4,mg/dL). Despite dietary recommendations, dyslipidemia persisted 3 months later (LDL 148.8±40.2,mg/dL; TC 238±36.5,mg/dL; TG 115±45.6,mg/dL; n=4) and at long distance follow-up (38±23,months) after treatment with vemurafenib: LDL 139.2±49.1,mg/dL; TC 216.5±38.4,mg/dL; TG 129.7±83.4 mg/dL. This potential side effect suddenly resolved itself in the only patient in which a change of therapy was made (to the combination of dabrafenib and trametinib). BMI was compatible with overweight/obesity at baseline (mean BMI-SDS 0.9±1.8) in 2 patient and normal in 4 patients: during follow-up BMI remained stable in 5 patients and increased in 1 patient. Our findings highlight that Vemurafenib could be associated with an increased risk of dyslipidemia independently of weight. This risk should be anticipated by the identification of high-risk patients and managed by close monitoring of metabolic parameters during routinely follow-up. The association of dabrafenib with trametinib seem not be associated to dyslipidemia, yet more data are needed to explore the hypothesis about the possible role to reduce the risk of dyslipidemia.
LGG-47. Single-cell RNA Sequencing Reveals Immunosuppressive Myeloid Cell Diversity During Malignant Progression in Glioma
Authors: Rajendran Sakthi , Peterson Clayton , Canella Alessandro , Hu Yang , Gross Amy , Cam Maren , Serin-Harmanci Akdes , Distefano Rosario , Nigita Giovanni , Wang Wesley , Hester Mark , Miller Katherine , Elemento Olivier , Roberts Ryan , Holland Eric , Rao Ganesh , Mardis Elaine , Rajappa Prajwal 
Published: June 2022

Abstract
Myeloid cells and macrophages have been shown to promote immunosuppression in high-grade gliomas (HGG), however their roles in malignant progression of low-grade glioma (LGG) are poorly understood. Here, we investigated the heterogeneity of the immune microenvironment during glioma progression using a murine model that recapitulates the malignant progression of low to high-grade glioma. To that end, we performed single-cell RNA sequencing on CD45+ immune cells isolated from animals bearing no tumor (NT), LGG, and HGG. We observed an increased infiltration of CD4+ T cells, CD8+ T cells, B cells, and natural killer cells in the tumor microenvironment of LGG, whereas this infiltration was abrogated in HGG. Our study identified two distinct macrophage clusters across all 3 samples, with signatures of bone marrow derived and resident macrophages, respectively. These macrophages showed an immune-activated phenotype (Stat1, Tnf, Cxcl9 and Cxcl10) in LGG, but then evolved to a more immunosuppressive state (Lgals3, Apoc1 and Id2) in HGG, restricting T cell recruitment and activation. In addition, we identified CD74 and macrophage migration inhibition factor (MIF) as potential targets for both these distinct macrophage populations, based on their increased expression in LGG and HGG compared to NT. Targeting these factors during the LGG therapeutic window may inhibit myeloid cells and intra-tumoral macrophages and attenuate their immunosuppressive properties and impair malignant progression.
LGG-50. Human induced pluripotent stem cell engineering establishes a humanized mouse platform for pediatric low-grade glioma modeling
Authors: Anastasaki Corina , Chatterjee Jit , Cobb Olivia , Scheaffer Suzanne , Sanapala Shilpa , Costa Amanda , Wilson Anna , Garbow Joel , Rodriguez Fausto , Gutmann David 
Published: June 2022

Abstract
A major obstacle to identifying improved treatments for pediatric low-grade brain tumors (gliomas) is the inability to reproducibly generate human xenografts. To surmount this barrier, we leveraged human induced pluripotent stem cell (hiPSC) engineering to generate low-grade glioma (LGG) lesions representing the two most common pediatric pilocytic astrocytoma-associated molecular alterations, NF1 loss and KIAA1549:BRAF fusion. Using hiPSCs, we identified the susceptible cells of origin for these tumors, and demonstrated that the resulting tumors retain LGG histologic features for at least 6 months in vivo. Finally, this platform enabled the successful long-term growth of patient-derived pLGGs in vivo. Taken together, these avatars establish tractable experimental humanized platforms to elucidate the pathogenesis of childhood brain tumors.
LGG-52. Volumetry-based response characterization of recurrent pediatric low-grade gliomas in PNOC clinical Neuro-oncology trials
Authors: von Reppert Marc , Lin MingDe , Bousabarah Khaled , Familiar Ariana , Velasco Ryan , Waanders Angela , Vossough Arastoo , Haddock Amanda , Nicolaides Theodore , Swanson Kristin , Kazerooni Anahita , Kline Cassie , Nabavizadeh Ali , Haas-Kogan Daphne , Prados Michael , Rubin Joshua , Mueller Sabine , Aboian Mariam 
Published: June 2022

Abstract
BACKGROUND: Endpoints in clinical trials using novel treatments are evaluated by RANO criteria, which provide an estimate of tumor size from two-dimensional measurements along the most prominent axial slice. However, pediatric low-grade gliomas (pLGG) commonly have variegated shapes with solid and cystic components, potentially resulting in misevaluation of true tumor volume and thus, ultimately, trial outcome. OBJECTIVES: We aim to characterize treatment response through volumetric assessment of progressive/recurrent pLGGs treated with single-agent everolimus on PNOC001 clinical trial. We seek to identify clinically relevant criteria that provide added value to response assessment beyond 2D measurements. METHODS: In a cohort of 44 patients we performed 3D-segmentation of solid, cystic and whole tumor within our PACS-framework and compared results to previously carried-out central imaging review by RANO criteria which had yielded 15 PD, 27 SD, 2 PR and 0 CR. RESULTS: 8 tumors were solid only and 36 had a mixed solid-cystic appearance. When evaluating the entire tumor (i.e. solid and cystic components combined) and using the same RANO cutoff criteria, one case changed from PR to SD, one changed from SD to PR, 3 changed from SD to PD, and 7 changed from PD to SD, resulting in an overall discordance of 27% of cases. CONCLUSION: We propose that incorporation of volumetrics into response assessment provides additional and potentially more accurate information beyond RANO-based measurements. It is crucial to note that the above-reported changes represent numerical discrepancies as opposed to true-to-reality changes in clinical outcome. Determining representative thresholds for the deployment of volumetric measures in clinical trials will be critical. Future work will include data from the PNOC002 clinical trial and evaluate inter-reader agreement and reader discordance. With the availability of PACS-based 3D-tools in neuroradiology practice, well-defined volumetric criteria could be incorporated prospectively into treatment response analysis in clinical trials.