Pediatric Low-Grade Gliomas

Brain tumors constitute the largest source of oncologic mortality in children and low-grade gliomas are among most common pediatric central nervous system tumors. Pediatric low-grade gliomas differ from their counterparts in the adult population in their histopathology, genetics, and standard of care. Over the past decade, an increasingly detailed understanding of the molecular and genetic characteristics of pediatric brain tumors led to tailored therapy directed by integrated phenotypic and genotypic parameters and the availability of an increasing array of molecular-directed therapies. Advances in neuroimaging, conformal radiation therapy, and conventional chemotherapy further improved treatment outcomes. This article reviews the current classification of pediatric low-grade gliomas, their histopathologic and radiographic features, state-of-the-art surgical and adjuvant therapies, and emerging therapies currently under study in clinical trials

Molecular Heterogeneity and Cellular Diversity: Implications for Precision Treatment in Medulloblastoma

Medulloblastoma, the most common pediatric malignant brain tumor, continues to have a high rate of morbidity and mortality in childhood. Recent advances in cancer genomics, single-cell sequencing, and sophisticated tumor models have revolutionized the characterization and stratification of medulloblastoma. In this review, we discuss heterogeneity associated with four major subgroups of medulloblastoma (WNT, SHH, Group 3, and Group 4) on the molecular and cellular levels, including histological features, genetic and epigenetic alterations, proteomic landscape, cell-of-origin, tumor microenvironment, and therapeutic approaches. The intratumoral molecular heterogeneity and intertumoral cellular diversity clearly underlie the divergent biology and clinical behavior of these lesions and highlight the future role of precision treatment in this devastating brain tumor in children

ABT-737 Synergizes with Bortezomib to Induce Apoptosis, Mediated by Bid Cleavage, Bax Activation, and Mitochondrial Dysfunction in an Akt-Dependent Context in Malignant Human Glioma Cell Lines

ABSTRACT We observed that glioma cells are differentially sensitive t

Promise and challenges of peptide-poly: ICLC vaccines for adult and pediatric gliomas

We currently run phase I studies of subcutaneous vaccinations with synthetic peptides for glioma-associated antigen (GAA) epitopes emulsified in Montanide-ISA-51 and intramuscular administration of poly-ICLC in HLA-A2+ adult and pediatric patients with gliomas. Primary endpoints were safety and CD8+ T-cell responses against vaccine-targeted GAAs: IL-13Rα2, EphA2, Survivin and WT1 (WT1 in adults only). Adults with WHO grade 2 low-grade glioma (LGG) have an extremely high risk for transformation to high-grade glioma (HGG), and most patients eventually die of the disease. Because patients with LGGs may not be as immuno-compromised as patients with HGG, they may exhibit greater immunological response to and benefit from the vaccines. We conducted a phase I vaccine study with: newly diagnosed high-risk LGG without prior radiation therapy (RT) (Cohort 1); newly diagnosed high-risk LGG with prior RT (Cohort 2); or recurrent LGG (Cohort 3). Cohorts 1, 2, and 3 have enrolled 12, 1, and 10 patients, respectively. No regimen-limiting toxicity has been encountered except for one case with Grade 3 fever (Cohort 1). Cohort 1 patients demonstrated significantly higher magnitude of IFN-γ ELISPOT responses than Cohort 3 patients for all 4 GAA epitopes, suggesting that newly diagnosed patients may have better vaccine-responsiveness than recurrent patients. The magnitude of the IFN-γ ELISPOT responses in this study is significantly higher than that observed in our previous phase I/II study in HGG patients. Median progression-free survival (PFS) periods are 21 months (Cohort 1; range 10-44) and 12 months (Cohort 3; range 3-28). In Cohort 1, 3 patients are still progression-free (32, 33 and 44 months to date). The only patient with large astrocytoma in Cohort 2 has been progression-free for over 54 months since diagnosis. There was a positive trend for IFN-γ ELISPOT responses and PFS. Diffuse brainstem gliomas (BSGs) and other HGGs of childhood carry a dismal prognosis. To date, 24 children were enrolled, 14 with newly diagnosed BSG treated with RT, and 10 with newly diagnosed BSG or HGG treated with RT and concurrent chemotherapy. No dose-limiting non-CNS toxicity was encountered. Five children had symptomatic pseudoprogression, which responded to corticosteroids and was associated with prolonged survival. Nineteen had stable disease for > 2 cycles, 2 had partial responses, and 1 had prolonged disease-free status after surgery. Median survival among the BSG cohort exceeded 13 months. ELISPOT analysis in 15 children showed GAA responses in 12, to IL-13Rα2 in 9, EphA2 in 7, and survivin in 7. Careful monitoring and management of pseudoprogression is warranted

A novel SNP analysis method to detect copy number alterations with an unbiased reference signal directly from tumor samples

<p>Abstract</p> <p>Background</p> <p>Genomic instability in cancer leads to abnormal genome copy number alterations (CNA) as a mechanism underlying tumorigenesis. Using microarrays and other technologies, tumor CNA are detected by comparing tumor sample CN to normal reference sample CN. While advances in microarray technology have improved detection of copy number alterations, the increase in the number of measured signals, noise from array probes, variations in signal-to-noise ratio across batches and disparity across laboratories leads to significant limitations for the accurate identification of CNA regions when comparing tumor and normal samples.</p> <p>Methods</p> <p>To address these limitations, we designed a novel "Virtual Normal" algorithm (VN), which allowed for construction of an unbiased reference signal directly from test samples within an experiment using any publicly available normal reference set as a baseline thus eliminating the need for an in-lab normal reference set.</p> <p>Results</p> <p>The algorithm was tested using an optimal, paired tumor/normal data set as well as previously uncharacterized pediatric malignant gliomas for which a normal reference set was not available. Using Affymetrix 250K Sty microarrays, we demonstrated improved signal-to-noise ratio and detected significant copy number alterations using the VN algorithm that were validated by independent PCR analysis of the target CNA regions.</p> <p>Conclusions</p> <p>We developed and validated an algorithm to provide a virtual normal reference signal directly from tumor samples and minimize noise in the derivation of the raw CN signal. The algorithm reduces the variability of assays performed across different reagent and array batches, methods of sample preservation, multiple personnel, and among different laboratories. This approach may be valuable when matched normal samples are unavailable or the paired normal specimens have been subjected to variations in methods of preservation.</p

Six priorities to advance the science and practice of coral reef restoration worldwide

Coral reef restoration is a rapidly growing movement galvanized by the accelerating degradation of the world's tropical coral reefs. The need for concerted and collaborative action focused on the recovery of coral reef ecosystems coalesced in the creation of the Coral Restoration Consortium (CRC) in 2017. In March 2020, the CRC leadership team met for a biennial review of international coral reef restoration efforts and a discussion of perceived knowledge and implementation bottlenecks that may impair scalability and efficacy. Herein we present six priorities wherein the CRC will foster scientific advancement and collaboration to: (1) increase restoration efficiency, focusing on scale and cost-effectiveness of deployment; (2) scale up larval-based coral restoration efforts, emphasizing recruit health, growth, and survival; (3) ensure restoration of threatened coral species proceeds within a population-genetics management context; (4) support a holistic approach to coral reef ecosystem restoration; (5) develop and promote the use of standardized terms and metrics for coral reef restoration; and (6) support coral reef restoration practitioners working in diverse geographic locations. These priorities are not exhaustive nor do we imply that accomplishing these tasks alone will be sufficient to restore coral reefs globally; rather these are topics where we feel the CRC community of practice can make timely and significant contributions to facilitate the growth of coral reef restoration as a practical conservation strategy. The goal for these collective actions is to provide tangible, local-scale advancements in reef condition that offset declines resulting from local and global stressors including climate change

Identification of Candidate Growth Promoting Genes in Ovarian Cancer through Integrated Copy Number and Expression Analysis

Ovarian cancer is a disease characterised by complex genomic rearrangements but the majority of the genes that are the target of these alterations remain unidentified. Cataloguing these target genes will provide useful insights into the disease etiology and may provide an opportunity to develop novel diagnostic and therapeutic interventions. High resolution genome wide copy number and matching expression data from 68 primary epithelial ovarian carcinomas of various histotypes was integrated to identify genes in regions of most frequent amplification with the strongest correlation with expression and copy number. Regions on chromosomes 3, 7, 8, and 20 were most frequently increased in copy number (>40% of samples). Within these regions, 703/1370 (51%) unique gene expression probesets were differentially expressed when samples with gain were compared to samples without gain. 30% of these differentially expressed probesets also showed a strong positive correlation (r≥0.6) between expression and copy number. We also identified 21 regions of high amplitude copy number gain, in which 32 known protein coding genes showed a strong positive correlation between expression and copy number. Overall, our data validates previously known ovarian cancer genes, such as ERBB2, and also identified novel potential drivers such as MYNN, PUF60 and TPX2