scholarly journals Targeting MYCN in Molecularly Defined Malignant Brain Tumors

2021 ◽  
Vol 10 ◽  
Author(s):  
Anna Borgenvik ◽  
Matko Čančer ◽  
Sonja Hutter ◽  
Fredrik J. Swartling

Misregulation of MYC genes, causing MYC overexpression or protein stabilization, is frequently found in malignant brain tumors highlighting their important roles as oncogenes. Brain tumors in children are the most lethal of all pediatric malignancies and the most common malignant primary adult brain tumor, glioblastoma, is still practically incurable. MYCN is one of three MYC family members and is crucial for normal brain development. It is associated with poor prognosis in many malignant pediatric brain tumor types and is focally amplified in specific adult brain tumors. Targeting MYCN has proved to be challenging due to its undruggable nature as a transcription factor and for its importance in regulating developmental programs also in healthy cells. In this review, we will discuss efforts made to circumvent the difficulty of targeting MYCN specifically by using direct or indirect measures to treat MYCN-driven brain tumors. We will further consider the mechanism of action of these measures and suggest which molecularly defined brain tumor patients that might benefit from MYCN-directed precision therapies.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yiqun Zhang ◽  
Fengju Chen ◽  
Lawrence A. Donehower ◽  
Michael E. Scheurer ◽  
Chad J. Creighton

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.


2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii299-iii299
Author(s):  
Wafik Zaky ◽  
Long Dao ◽  
Dristhi Ragoonanan ◽  
Izhar Bath ◽  
Sofia Yi ◽  
...  

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.


Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Rashad Jabarkheel ◽  
Jonathon J Parker ◽  
Chi-Sing Ho ◽  
Travis Shaffer ◽  
Sanjiv Gambhir ◽  
...  

Abstract INTRODUCTION Surgical resection is a mainstay of treatment in patients with brain tumors both for tissue diagnosis and for tumor debulking. While maximal resection of tumors is desired, neurosurgeons can be limited by the challenge of differentiating normal brain from tumor using only microscopic visualization and tactile feedback. Additionally, intraoperative decision-making regarding how aggressively to pursue a gross total resection frequently relies on pathologic preliminary diagnosis using frozen sections which are both time consuming and fallible. Here, we investigate the potential for Raman spectroscopy (RS) to rapidly detect pediatric brain tumor margins and classify brain tissue samples equivalent to histopathology. METHODS Using a first-of-its-kind rapid acquisition RS device we intraoperatively imaged fresh ex vivo pediatric brain tissue samples (2-3 mm × 2-3 mm × 2-3 mm) at the Lucille Packard Children's Hospital. All imaged samples received standard final histopathological analysis, as RS is a nondestructive imaging technique. We curated a labeled dataset of 575 + unique Raman spectra gathered from 160 + brain samples resulting from 23 pediatric patients who underwent brain tissue resection as part of tumor debulking or epilepsy surgery (normal controls). RESULTS To our knowledge we have created the largest labeled Raman spectra dataset of pediatric brain tumors. We are developing an end-to-end machine learning model that can predict final histopathology diagnosis within minutes from Raman spectral data. Our preliminary principle component analyses suggest that RS can be used to classify various brain tumors similar to “frozen” histopathology and can differentiate normal from malignant brain tissue in the context of low-grade glioma resections. CONCLUSION Our work suggests that machine learning approaches can be used to harness the material identification properties of RS for classifying brain tumors and detecting their margins.


2019 ◽  
Vol 1 (Supplement_2) ◽  
pp. ii1-ii1
Author(s):  
David T W Jones

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.


2007 ◽  
Vol 13 (22) ◽  
pp. 6712-6718 ◽  
Author(s):  
Alberto Broniscer ◽  
Sridharan Gururangan ◽  
Tobey J. MacDonald ◽  
Stewart Goldman ◽  
Roger J. Packer ◽  
...  

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