scholarly journals TMOD-02. GEBTO: GENETICALLY ENGINEERED BRAIN TUMOR ORGANOIDS AS A NOVEL PRECLINICAL MODEL

2021 ◽  
Vol 23 (Supplement_1) ◽  
pp. i35-i36
Author(s):  
Jens Bunt ◽  
Mieke Roosen ◽  
Evie Egelmeers ◽  
Joris Maas ◽  
Zelda Ode ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Brain Tumors ◽  
Tumor Biology ◽  
Embryonic Stem ◽  
Pediatric Brain Tumors ◽  
Genetically Engineered ◽  
Preclinical Model ◽  
Cells Of Origin ◽  
Pediatric Brain ◽  
Tumor Organoids

Abstract Background One of the bottlenecks in basic and translational research on pediatric brain tumors, is the lack of suitable and representative preclinical models to study tumor biology and drug sensitivity. Over the last decades, extensive molecular characterization has uncovered many entities and subgroups with their unique oncodriving events. However, this heterogeneity is currently not reflected in the models available, especially not for in vitro models. Objectives We aim to generate genetically engineered brain tumor organoids (GEBTO) to represent the molecular variety of embryonal brain tumors and ependymomas. Method Human brain organoids derived from embryonic stem cells are generated to represent the region of tumor origin. To mimic oncodriving events, DNA plasmids are introduced via electroporation in the organoid cells to knockout tumor suppressor genes or overexpress oncogenes. Results Cerebellar and cerebral forebrain organoids were generated as the tissue of origin for medulloblastoma and supratentorial ependymoma (ST-EPN), respectively. Based on the detection of GFP protein encoded by DNA plasmids, the organoid cells can be manipulated within a wide developmental window, which corresponds with the presence of the proposed cells of origin. Different oncodrivers and combinations thereof are now being tested to see whether they result in ectopic growth in cerebral or cerebellar organoids. When successful, the GEBTOs are histologically and molecularly characterized using (single cell) transcriptomic and epigenomic analyses to see how well they resemble human tumors. Discussion Although further development is required, GEBTOs provide a novel avenue to model especially rare pediatric brain tumors, for which tissue and therefore patient-derived models are limited. It also allows for in-depth analyses of the potential cells of origin and the contribution of different mutations to tumor biology.

scholarly journals SL1 GENETICS OF PEDIATRIC BRAIN TUMORS: RECENT ADVANCES AND FUTURE PERSPECTIVES

2019 ◽  
Vol 1 (Supplement_2) ◽  
pp. ii1-ii1
Author(s):  
David T W Jones
Keyword(s):  
Brain Tumor ◽  
Brain Tumors ◽  
Somatic Hypermutation ◽  
Tumor Biology ◽  
Pediatric Brain Tumor ◽  
Pediatric Brain Tumors ◽  
Braf V600e ◽  
Enhancer Element ◽  
Frequent Mutations ◽  
Pediatric Brain

Abstract The last decade has seen a true revolution in our understanding of the oncogenic mechanisms underlying human tumors, brought about by transformative advances in the technologies available to interrogate the (epi)genetic composition of cancer cells. The dynamic pediatric neuro-oncology community has proven to be very agile in adapting to these changes, and has arguably been at the forefront of some of the most exciting new discoveries in tumor biology in recent years. For example, high-throughput genomic sequencing has revealed highly frequent mutations in histone genes in pediatric glioblastoma; highlighted an ever-expanding role for oncogenic gene fusions in multiple pediatric brain tumor types, and also shed light on novel phenotypic patterns such as chromothripsis (dramatic chromosomal shattering) and somatic hypermutation - the latter being a possible marker for response to novel immunotherapeutic approaches. Epigenetic profiling has also identified a role for ‘enhancer hijacking’ (whereby genomic rearrangement brings an active enhancer element in close proximity to a proto-oncogene) in multiple pediatric brain tumors, and is even pointing towards a fundamentally new way in which tumors may be molecularly classified. In coming years, the major challenge will be to harness the power of these discoveries to more accurately diagnose patients and to identify potential therapeutic targets in a more personalized way, so that these major biological advances can also be translated into substantial clinical benefit. Examples such as the dramatic responses observed in childhood brain tumor sufferers to BRAF V600E and NTRK inhibitors demonstrate the promise that such an approach can hold, but it will require a fundamental shift in the way that clinical trials are planned and conducted in order to optimize patient care. This talk will highlight some of the most striking developments in the field, and look at the challenges that remain before these can lead to improved patient outcomes.

scholarly journals A pediatric brain tumor atlas of genes deregulated by somatic genomic rearrangement

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yiqun Zhang ◽  
Fengju Chen ◽  
Lawrence A. Donehower ◽  
Michael E. Scheurer ◽  
Chad J. Creighton
Keyword(s):  
Brain Tumor ◽  
Brain Tumors ◽  
Tyrosine Kinases ◽  
Pediatric Brain Tumor ◽  
Pediatric Brain Tumors ◽  
Altered Expression ◽  
Critical Pathways ◽  
Cis Regulation ◽  
Or Gene ◽  
Pediatric Brain

AbstractThe global impact of somatic structural variants (SSVs) on gene expression in pediatric brain tumors has not been thoroughly characterised. Here, using whole-genome and RNA sequencing from 854 tumors of more than 30 different types from the Children’s Brain Tumor Tissue Consortium, we report the altered expression of hundreds of genes in association with the presence of nearby SSV breakpoints. SSV-mediated expression changes involve gene fusions, altered cis-regulation, or gene disruption. SSVs considerably extend the numbers of patients with tumors somatically altered for critical pathways, including receptor tyrosine kinases (KRAS, MET, EGFR, NF1), Rb pathway (CDK4), TERT, MYC family (MYC, MYCN, MYB), and HIPPO (NF2). Compared to initial tumors, progressive or recurrent tumors involve a distinct set of SSV-gene associations. High overall SSV burden associates with TP53 mutations, histone H3.3 gene H3F3C mutations, and the transcription of DNA damage response genes. Compared to adult cancers, pediatric brain tumors would involve a different set of genes with SSV-altered cis-regulation. Our comprehensive and pan-histology genomic analyses reveal SSVs to play a major role in shaping the transcriptome of pediatric brain tumors.

scholarly journals DIPG-60. PILOT STUDY OF CIRCULATING TUMOR CELLS IN PEDIATRIC HIGH GRADE BRAIN TUMORS

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii299-iii299
Author(s):  
Wafik Zaky ◽  
Long Dao ◽  
Dristhi Ragoonanan ◽  
Izhar Bath ◽  
Sofia Yi ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Brain Tumors ◽  
Tumor Cells ◽  
Circulating Tumor Cells ◽  
Pediatric Brain Tumor ◽  
Pediatric Brain Tumors ◽  
Disease Assessment ◽  
Liquid Biopsies ◽  
Capture Method ◽  
Pediatric Brain

Abstract BACKGROUND Despite its increasing use, circulating tumor cells (CTCs) have not been studied in pediatric brain tumors. METHODS Cell surface vimentin (CSV) is a marker for CTC detection. We developed an automated CSV-based CTC capture method for pediatric brain tumor using the Abnova Cytoquest platform. PBMCs isolated from blood samples from 52 brain tumor patients were processed to isolate CSV+ CTCs. Captured cells were then stained for CSV and CD45 and scanned to determine the number of CTCs. DIPG samples were additionally examined for H3K27M expression on CSV+ cells. Long term cancer survivors were used as a control cohort. RESULTS 86.4% of all the samples exhibited between 1–13 CSV+ CTCs, with a median of 2 CSV+ CTCs per sample. Using a value of ≥ 1 CTC as a positive result, the sensitivity and specificity of this test was 83.05% and 60.0% respectively. 19 DIPG samples were analyzed and 70% (13 samples) were positive for 1–5 CTCs. Five of these 7 positive CSV+ CTCs DIPG samples were also positive for H3K27M mutations by immunohistochemistry (71%). Mean survival in days for the CTC positive and negative DIPG samples were 114 and 211 days, respectively (p= 0.13). CONCLUSION This is the first study of CTCs in pediatric CNS tumors using an automated approach. Patients with brain tumors can exhibit CSV+ CTCs within peripheral blood. The use of specific molecular markers such as H3K27M can improve the diagnostic capability of liquid biopsies and may enable future disease assessment for personalized therapy.

scholarly journals EXTH-73. HETEROGENEITY IN CELL SURFACE ANTIGEN AND HLA CLASS I EXPRESSION IN PEDIATRIC BRAIN TUMORS AND ITS IMPACT ON T-CELL IMMUNOTHERAPY

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii103-ii103
Author(s):  
Haley Houke ◽  
Xiaoyan Zhu ◽  
Kimberly S Mercer ◽  
Jennifer L Stripay ◽  
Jason Chiang ◽  
...  
Keyword(s):  
T Cells ◽  
Brain Tumor ◽  
T Cell ◽  
Brain Tumors ◽  
Cell Surface ◽  
Hla Class I ◽  
Pediatric Brain Tumors ◽  
Class I ◽  
Car T ◽  
Pediatric Brain

Abstract Immunotherapy with tumor antigen-specific chimeric antigen receptor (CAR) and/or ab (T-cell receptor) TCR T-cells has the potential to improve clinical outcomes of patients with pediatric brain tumors. As a prerequisite for successful T-cell therapies, we must determine which cell surface antigens are expressed and targetable in these tumors, and if HLA Class I is present, which is necessary for ab TCR T-cell recognition. Therefore, in this study we systematically analyzed pediatric patient-derived orthotopic xenograft (PDOX) brain tumor samples for cell surface expression of five known CAR targets: IL13Ra2, HER2, EphA2, B7-H3, and GD2, as well as HLA Class I. We established and validated a flow cytometry-based method of profiling tumor-associated antigens. Fifty-three PDOX samples have been profiled to date, including medulloblastoma, high grade glioma (HGG), diffuse intrinsic pontine glioma (DIPG), atypical teratoid rhabdoid tumor (ATRT), and ependymoma, among others. Our results showed high variability within and between individual samples. B7-H3 was the most consistently expressed, seen in 98% of the samples tested. We validated these results by conventional immunohistochemistry staining for B7-H3 and found comparable RESULTS: HLA Class I was highly expressed on all HGG samples but was undetectable on 47.8% of other brain tumor samples. This suggests that down-regulation of HLA class I is one mechanism by which brain tumors evade conventional T-cells, and that HLA-independent CAR T-cells would be useful therapies. We also compared expression of antigens in fresh patient samples and corresponding PDOX tumors and saw that they were indeed similar. To our knowledge, this is the largest group of pediatric brain tumor PDOX samples methodically analyzed for potential CAR target antigens and HLA Class I. Taken together, our data demonstrate that elimination of tumors by CAR T-cell immunotherapies will require targeting multiple antigens, and our profiling method could inform how to circumvent antigen-negative relapse.

scholarly journals Exploratory Evaluation of MR Permeability with 18F-FDG PET Mapping in Pediatric Brain Tumors: A Report from the Pediatric Brain Tumor Consortium

2013 ◽  
Vol 54 (8) ◽  
pp. 1237-1243 ◽  
Author(s):  
K. A. Zukotynski ◽  
F. H. Fahey ◽  
S. Vajapeyam ◽  
S. S. Ng ◽  
M. Kocak ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Brain Tumors ◽  
Fdg Pet ◽  
Pediatric Brain Tumor ◽  
Pediatric Brain Tumors ◽  
18F Fdg ◽  
Pediatric Brain

scholarly journals Circular RNA expression profiles in pediatric ependymomas

2020 ◽  
Author(s):  
Ulvi Ahmadov ◽  
Meile M. Bendikas ◽  
Karoline K. Ebbesen ◽  
Astrid M. Sehested ◽  
Jorgen Kjems ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Brain Tumors ◽  
Pilocytic Astrocytoma ◽  
Expression Profiles ◽  
Pediatric Brain Tumor ◽  
Pediatric Brain Tumors ◽  
Disease Stage ◽  
Tumor Subtypes ◽  
Pediatric Brain ◽  
Control Samples

Pediatric brain tumors frequently develop in the cerebellum, where ependymoma, medulloblastoma and pilocytic astrocytoma are the most prevalent subtypes. These tumors are currently treated using non-specific therapies, in part because few somatically mutated driver genes are present, and the underlying pathobiology is poorly described. Circular RNAs (circRNAs) have recently emerged as a large class of primarily non-coding RNAs with important roles in tumorigenesis, but so far they have not been described in pediatric brain tumors. To advance our understanding of these tumors, we performed high-throughput sequencing of ribosomal RNA-depleted total RNA from 10 primary ependymoma and 3 control samples. CircRNA expression patterns were determined using two independent bioinformatics algorithms, and correlated to disease stage, outcome, age, and gender. We found a profound global downregulation of circRNAs in ependymoma relative to control samples. Many differentially expressed circRNAs were discovered and circSMARCA5 and circ-FBXW7, which are described as tumor suppressors in glioma and glioblastomas in adults, were among the most downregulated. Moreover, patients with a dismal outcome clustered separately from patients with a good prognosis in unsupervised hierarchical cluster analyses. Next, we performed NanoString nCounter experiments using a custom-designed panel including 66 selected circRNA targets and analyzed formalin-fixed paraffin-embedded (FFPE) samples from a larger cohort of ependymoma patients as well as patients diagnosed with medulloblastoma or pilocytic astrocytoma. These experiments were used to validate our findings and, in addition, indicated that circRNA expression profiles are different among distinct pediatric brain tumor subtypes. In particular, circRMST and a circRNA derived from the LRBA gene were specifically upregulated in ependymomas. In conclusion, circRNAs have profoundly different expression profiles in ependymomas relative to controls and other pediatric brain tumor subtypes.

Diffusion Basis Spectrum Imaging with Deep Neural Network Differentiates Distinct Histology in Pediatric Brain Tumors

2020 ◽  
Author(s):  
Zezhong Ye ◽  
Komal Srinivasa ◽  
Joshua Lin ◽  
Jeffrey D. Viox ◽  
Chunyu Song ◽  
...  
Keyword(s):  
Neural Network ◽  
Brain Tumor ◽  
Brain Tumors ◽  
Deep Neural Network ◽  
Unmet Need ◽  
Pediatric Brain Tumors ◽  
High Grade ◽  
Tumor Histology ◽  
Spectrum Imaging ◽  
Pediatric Brain

AbstractHigh-grade pediatric brain tumors constitute the highest mortality of cancer-death in children. While conventional MRI has been widely adopted for examining pediatric high-grade brain tumor clinically, accurate neuroimaging detection and differentiation of tumor histopathology for improved diagnosis, surgical planning, and treatment evaluation, remains an unmet need in the clinical management of pediatric brain tumor. We employed a novel Diffusion Histology Imaging (DHI) approach that incorporates diffusion basis spectrum imaging (DBSI) and deep neural network. DHI aims to detect, differentiate, and quantify heterogenous areas in pediatric high-grade brain tumors, which include normal white matter (WM), densely cellular tumor (DC tumor), less densely cellular tumor (LDC tumor), infiltrating edge, necrosis, and hemorrhage. Distinct diffusion metric combination would thus indicate the unique distributions of each distinct tumor histology features. DHI, by incorporating DBSI metrics and the deep neural network algorithm, classified pediatric tumor histology with an overall accuracy of 83.3%. Receiver operating analysis (ROC) analysis suggested DHI’s great capability in distinguishing individual tumor histology with AUC values (95%CI) of 0.983 (0.985-0.989), 0.961 (0.957-0.964), 0.993 (0.992-0.994), 0.953 (0.947-0.958), 0.974 (0.970-0.978) and 0.980 (0.977-0.983) for normal WM, DC tumor, LDC tumor, infiltrating edge, necrosis and hemorrhage, respectively. Our results suggest that DBSI-DNN, or DHI, accurately characterized and classified multiple tumor histologic features in pediatric high-grade brain tumors. If further validated in patients, the novel DHI might emerge as a favorable alternative to the current neuroimaging techniques to better guide biopsy and resection as well as monitor therapeutic response in patients with high-grade brain tumors.

scholarly journals Deep Learning-Based Studies on Pediatric Brain Tumors Imaging: Narrative Review of Techniques and Challenges

2021 ◽  
Vol 11 (6) ◽  
pp. 716
Author(s):  
Hala Shaari ◽  
Jasmin Kevrić ◽  
Samed Jukić ◽  
Larisa Bešić ◽  
Dejan Jokić ◽  
...  
Keyword(s):  
Deep Learning ◽  
Brain Tumor ◽  
Brain Tumors ◽  
Tumor Imaging ◽  
Pediatric Brain Tumor ◽  
Pediatric Brain Tumors ◽  
Research Issues ◽  
Functional Changes ◽  
Imaging Results ◽  
Pediatric Brain

Brain tumors diagnosis in children is a scientific concern due to rapid anatomical, metabolic, and functional changes arising in the brain and non-specific or conflicting imaging results. Pediatric brain tumors diagnosis is typically centralized in clinical practice on the basis of diagnostic clues such as, child age, tumor location and incidence, clinical history, and imaging (Magnetic resonance imaging MRI / computed tomography CT) findings. The implementation of deep learning has rapidly propagated in almost every field in recent years, particularly in the medical images’ evaluation. This review would only address critical deep learning issues specific to pediatric brain tumor imaging research in view of the vast spectrum of other applications of deep learning. The purpose of this review paper is to include a detailed summary by first providing a succinct guide to the types of pediatric brain tumors and pediatric brain tumor imaging techniques. Then, we will present the research carried out by summarizing the scientific contributions to the field of pediatric brain tumor imaging processing and analysis. Finally, to establish open research issues and guidance for potential study in this emerging area, the medical and technical limitations of the deep learning-based approach were included.

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