bluuebunny/crossref_metadata_2025_split huggingface dataset:
COMP-04. MODELING PRECISION ONCOLOGY FOR GLIOBLASTOMA THROUGH INTEGRATION OF DESCRIPTIVE, FUNCTIONAL, AND NETWORK-BASED GENOMICS
Authors: Hoellerbauer Pia , Kufeld Megan , Arora Sonali , Girard Emily , Olson James , Biery Matthew , Chambwe Nyasha , Paddison Patrick 
Published: November 2019

Abstract
Precision oncology is largely based on the notion that identification and targeting of oncogenic drivers will lead to improved clinical outcomes. However, the promise of precision oncology awaits to be fulfilled for many cancers, including Glioblastoma (GBM), where identification of oncogenic drivers has yet to improve survival rates. Here, we have attempted to systematically identify GBM vulnerabilities by performing genome-wide CRISRP-Cas9 lethality screens in patient-derived GBM stem-like cells (GSCs). In validation studies, we comprehensively retested GSC-specific hits in multiple GSC isolates, which were also genomically profiled (e.g. RNA-seq, exome-seq, CNV), and further integrated these data with CRISPR-Cas9 lethality screens from over 500 human cell lines from the Broad Institute’s CRISPR Avana dataset. As a result, we have begun making GBM dependency predictions and functional associations for top scoring hits, including: tumor developmental subtype; loss of functional redundancy with other genes/proteins; cancer-specific subnetworks of genes involved in mitochondrial protein turnover and membrane trafficking; and genes of unknown function essential for subset of GBMs. A few examples of these categories include the following scenarios. We find ADAR (Adenosine Deaminase RNA Specific) gene dependency is associated with the mesenchymal GBM subtype. The EFR3Agene, which has roles in maintaining active pools of phosphatidylinositol 4-kinase, appears required when the expression of its paralog EFR3Bis low or absent in tumor cells. The F-box protein-encoding gene FBXO42appears non-essential to most human cells lines and neural stem cells, but when knocked out in sensitive GSCs causes mitotic arrest, mitotic catastrophe, and cell death. While still a work in progress, we hope to use these results as a foundation for exploring and illuminating patient-specific molecular vulnerabilities for brain tumors. The results also underscore the need for integration of functional genetic approaches, where gene activities are inhibited, into precision oncology paradigms.
COMP-10. THE MUTATIONAL PROFILE OF GLIOBLASTOMA-DERIVED CELL-FREE DNA IN PLASMA REPRESENTS A DISTINCT SUBSET OF THE SOMATIC MUTATIONS PRESENT IN GLIOBLASTOMA SOLID TUMOR DNA
Authors: Underhill Hunter , Nix David , Davidson Christian , Hellwig Sabine , Fuertes Carrie , Colman Howard , Bronner Mary , Jensen Randy 
Published: November 2019

Abstract
Glioblastoma’s mutational landscape varies widely in the same tumor. Using conventional criteria to identify mutations from a focal tissue specimen (e.g., variant allele frequency > 5%) undersamples glioblastoma’s broad clonal diversity, which may limit detection of glioblastoma-derived circulating cell-free DNA in plasma (i.e., circulating tumor DNA; ctDNA). Here, we sought to enhance somatic variant identification in solid tumor DNA to improve detection and characterize glioblastoma-derived ctDNA. Tumor DNA and plasma cell-free DNA (collected < 24 hours prior to the surgical procedure) were isolated from eight glioblastoma patients. DNA was capture-enriched using a custom-designed, glioblastoma-targeted, next-generation sequencing panel (124 genes, 118 kb) followed by paired-end sequencing. Samples were prepared in duplicate with molecular barcodes to enable detection of very-low frequency variants. Somatic mutations in tumor DNA were identified using variable allele frequency thresholds and were considered positive in ctDNA if present in both duplicate samples. Using a lower allele frequency threshold to identify mutations in tumor DNA significantly increased detection of ctDNA (F(1.04,7.29)=14.81, P=0.006). At a solid tumor allele frequency threshold of ≥ 5%, only a single patient (12.5%) had tumor mutations detected in ctDNA. However, at a threshold ≥ 1%, all patients (100%) had at least one tumor mutation detected in ctDNA. Moreover, at a threshold ≥ 0.5%, 7 out of 8 patients (87.5%) had > 12 tumor mutations present in ctDNA. The increased detection of ctDNA enabled the subsequent discovery that somatic mutations in APC, KIT, MSH6, and NF1 were more likely to be present in ctDNA compared to somatic mutations in ATRX, LZTR1, SLC26A3, and TERT which were absent in ctDNA (χ 2=8.0, P=0.005). Thus, stronger sampling of glioblastoma’s genetic heterogeneity in tumor DNA improves detection of ctDNA allowing comparisons between mutational profiles that may lead to the identification of similarities and differences with key biologic and/or clinical implications.
DDIS-01. NEW DRUG DISCOVERY WITH DRUG RE-POSITIONING SYSTEM TOWARD GBM TREATMENT
Authors: Michiue Hiroyuki , Tsuboi Nobushige , Hayashi Keiichiro , Matsui Hideki , Kurozumi Kazuhiko 
Published: November 2019

Abstract

INTRODUCTION
Invasion of Glioblastoma (GBM) cells into normal brain is the major cause of poor prognosis and requires dynamic reorganization of the actin cytoskeleton, which includes lamellipodial protrusions, focal adhesions, and stress fibers at the leading edge of GBM cells. Therefore, we hypothesized that the inhibition of actin polymerization with existing medication could lead to clinical GBM treatment directly in short time. The Drug Repositioning system is also known as drug repurposing or drug reprofiling and understood as the process of redeveloping a compound for use in a different disease. In this time, we would show the new direction of drug development with drug repositioning.

MATERIALS AND METHODS
We adopted a drug repositioning system for screening with a pyrene-actin-based actin polymerization assay and identified fluvoxamine, a clinically used antidepressant. Fluvoxamine, selective serotonin reuptake inhibitor, was a potent inhibitor of actin polymerization and confirmed as drug penetration through the blood–brain barrier (BBB) and accumulation of whole brain including brain tumor with no drug toxicity.

RESULTS
Fluvoxamine inhibited serum-induced ruffle formation, cell migration, and invasion of human GBM and glioma stem cells in vitro by suppressing FAK signaling. Fluvoxamine showed no drug toxicity. Daily treatment of athymic mice bearing human glioma-initiating cells with fluvoxamine blocked tumor cell invasion and prolonged the survival with almost same doze of anti-depressant effect.

CONCLUSIONS
The SSRI group has big potential for clinical GBM treatment with low cost, short time and low side effect.
DDIS-06. ANTICANCER EFFECTS OF THE SMALL MOLECULE INHIBITOR SB747651A IN GLIOBLASTOMAS
Authors: Knudsen Arnon , Boldt Henning B , Kristensen Bjarne 
Published: November 2019

Abstract

INTRODUCTION
Most glioblastomas harbor several different genetic alterations in major cell signaling pathways, leading to tumor progression and treatment resistance. Single-targeted therapies against these alterations have thus far failed to show major clinical value. The aim of this study was to investigate the anticancer effects of SB747651A, a multi-target small molecule inhibitor, targeting the RAS-MAPK and AKT-PI3K kinases AKT, MSK1/2, RSK1/2 and p70S6K in glioblastomas.

METHODS
Three patient-derived glioblastoma cultures were grown as free-floating spheroids and treated with 5 or 10 µM SB747651A. Exposed cells were subject to assays investigating cell viability (propidium iodide), apoptosis (Caspase 3/7), spheroid formation capacity, chemo sensitivity (temozolomide), and migration. In vivo studies are currently ongoing.

RESULTS
Exposed cells showed increased cell death and apoptosis across all three cell cultures in a dose-dependent manner vs. controls (P=0.001). Combination treatment with SB747651A and temozolomide resulted in a significant dose-dependent synergistic effect on cell death in all cell cultures. The fraction of spheroid-initiating cells was significantly reduced in exposed cells (1 in 12 cells) compared to controls (1 in 5 cells; P=0.001), and the growth rate of treated tumor spheroids was reduced by up to 47% (P=0.001). Exposed spheroids showed reduced cell migration in 2 of 3 cell lines, with a maximum reduction of migration distance by 60.4% (P=0.001).

CONCLUSION
SB747651A treatment has shown promising in vitro results by targeting mechanisms with high relevance for the progression and treatment resistance of glioblastomas. Ongoing in vivo studies are aiming to validate these findings, and to uncover potential use of SB747651A in the clinical setting.
DDIS-21. IN VITRO MICRODIALYSIS RECOVERY OF TRAMETINIB
Authors: Romo Carlos , Anders Nicole , Scardina Morgan , Mukherjee Debraj , Grossman Stuart , O Blakeley Jaishri , Rudek-Renaut Michelle 
Published: November 2019

Abstract

BACKGROUND
Dysregulation of the mitogen-activated protein kinase and phosphoinositide 3-kinase (PI3K) pathways is common in several primary brain tumors and metastatic cancers affecting the central nervous system. Trametinib, and oral MEK1/2 inhibitor, has been effective in preclinical studies against a variety of cell lines and improves survival in select patients with gliomas. Unfortunately, limited and often short-lived benefits are frequently seen in patients. A potential explanation for this is insufficient blood brain barrier penetration at therapeutic concentrations. The primary objective of this study is to measure the in vitro relative recovery of trametinib using microdialysis to establish the feasibility of characterizing its intratumoral pharmacokinetics in vivo using this technique.

METHODS
In vitro recovery experiments were performed utilizing commercially available microdialysis instruments. Two perfusion rates (0.5–1µL/min), the use of iso- and hypertonic perfusates (artificial CSF and 10% bovine serum albumin in PBS), and the addition of dimethyl sulfoxide (DMSO) were evaluated using the extraction efficiency method. Liquid chromatography-tandem mass spectrometry was used to measure the concentrations of trametinib in stock solutions, dialysate samples, and controls over time.

RESULTS
Dialysate was initially collected from a solution spiked with 15ng/mL at a rate of 1µL/min for 60 minutes, the recovery was 0.3ng/mL (0.2%) in two samples and below the limit of quantification (< 0.2ng/mL) in three. Dialysate samples were then collected from a stock solution with 150ng/mL of trametinib, recovery ranged from 0.3–15.3ng/mL (0.2–10.2%) in nine detectable samples out of sixteen. Recovery was greater with the addition of DMSO to the perfusate and with the use of a hypertonic perfusate.

CONCLUSIONS
The poor relative recovery of trametinib using microdialysis suggests that this technique would be unreliable in in vivo studies. Trametinib has poor aqueous solubility, limiting the ability of characterizing its pharmacokinetic profile through microdialysis.
DDIS-24. DECREASE IN GLIOBLASTOMA GROWTH IN VITRO WITH TREATMENT OF NOVEL ANALOGS OF GLUCOSE TRANSPORTER INHIBITORS
Authors: GC Sajina , Libby Catherine , Zhang Sixue , Benavides Gloria , Scott Sarah , Li Yanjie , Tran Anh , Otamias Arphaxad , Darley-Usmar Victor , Napierala Marek , Pathak Vibha , Moukha-Chafiq Omar , Augelli-Szafran Corinne , Zhang Wei , Hjelmeland Anita 
Published: November 2019

Abstract
Despite available treatments including surgical resection, radiation and chemotherapy, glioblastoma (GBM) is incurable with rapid recurrence and low median survival rate of just fourteen months. Development of more effective treatments is difficult due to the highly heterogeneous nature of GBM. One aspect of that heterogeneity involves brain tumor initiating cells (BTICs) that have a stem cell-like ability to self-renew. BTICs can readily alter their metabolism and survive in low nutrient environments due in part to increased GLUT3 expression. We believe that the higher expression of GLUT3 in cancer cells compared to non-tumor cells makes it a therapeutic target, although the potential for toxicity must be considered. In recently accepted studies by Libby et al., we reported on two novel GLUT inhibitors identified by structure based virtual screening (SBVS) using a GLUT3 homology model. We are creating a structure-activity relationship profile and seek to increase the potency, selectivity and stability of the GLUT inhibitors. In this study we have tested a number of novel analogs and identified three that have maintained efficacy against BTICs in vitro. Importantly, these compounds display minimal toxicity against human astrocytes. The novel derivatives have increased stability compared to the lead compounds and are efficacious in the nanomolar range. In the future, we intend to utilize our anti-GLUT compounds alone and in combination with radio- and chemotherapy with the hope of clinical translation.
DDIS-28. A HIGH THROUGHPUT SCREENING PLATFORM TO IDENTIFY RADIOSENSITIZERS FOR DIPG
Authors: Clutter Matt , Romero Megan , Becher Oren 
Published: November 2019

Abstract
Diffuse intrinsic pontine glioma (DIPG) is an incurable brainstem tumor and the leading cause of death in children with brain cancer. Despite numerous clinical trials, no drugs have been found to prolong survival for DIPG patients, suggesting an urgent need to test therapeutics in preclinical models more predictive of clinical activity. To address this gap, we developed a genetically engineered mouse model incorporating the Histone H3.3 K27M mutation, p53 deletion, and PDGFR-α amplification, which co-occur in up to 40% of human DIPG. Here we report the results of a drug screen to identify radiosensitizers of DIPG cells isolated from our mouse model and cultured ex vivo as neurospheres. Although previous clinical trials combining radiotherapy with radiosensitizing agents failed to benefit DIPG patients, they incorporated general radiosensitizers. We hypothesize that searching for radiosynergy using 3-dimensional neurospheres derived from genetically defined primary cell DIPG models will enhance our ability to prioritize clinically relevant radiosensitizers. To identify candidates, we developed high throughput radiation and imaging protocols to quantify the number, size, and viability of neurospheres following treatment. We screened 1,280 FDA-approved drugs and 1,600 molecules with a history of clinical use. Two mechanistic classes of compounds were identified that sensitized DIPG neurospheres to radiotherapy, both targeting epigenetic factors. An HDAC1/3 inhibitor along with several different BET bromodomain inhibitors increased cell death 2–3 fold beyond the effect of radiation with minimal activity from the compounds alone. In addition to optimizing the dosing and timing of these compounds for animal studies, we are investigating whether radiosensitization occurs in H3.3 wildtype neurospheres. In the current molecular era of cancer, genetic features like the H3.3 K27M mutation could present an opportunity to develop therapeutics that preferentially radiosensitize diseased cells relative to normal cells. Such “precision radiosensitizers” would advance radiotherapy by enhancing tumor-specific toxicity while sparing bystander cells.
DDIS-30. EVALUATION OF THE SUSCEPTIBILITY OF NEURONS DERIVED FROM HUMAN INDUCED PLURIPOTENT STEM CELLS TO ANTICANCER DRUGS FOR CNS TUMORS
Authors: Kanemura Yonehiro , Fukusumi Hayato , Handa Yukako , Shofuda Tomoko 
Published: November 2019

Abstract
Various chemical substances, including pharmaceuticals, pose potential risks of inducing acute or delayed neurotoxicity in adults and causing developmental neurotoxicity in fetuses or children. To ensure the safety of chemical substances and drugs, neurotoxicity risk assessment is critical, and an appropriate evaluation platform for neurotoxicity is desired. At present, several anticancer reagents, including temozolomide, cisplatin, and etoposide, are used for treatment of high-grade astrocytic tumors or medulloblastomas. In comparison to lots of information about anti-tumor cells effects of these reagents, their neurotoxicity to normal neurons, especially human derived cells, have been poorly investigated because of the low accessibility of human central nervous system (CNS) tissues, the technical difficulties related to neuron isolation from adult human CNS tissues, and the higher ethical controversy surrounding the use of human CNS tissues and/or fetal cells compared to animal tissues or cells. In this study, to overcome these issues, we made human induced pluripotent stem cells derived neurons (hiPSC-neurons) for preparing alternative assay for in vitro test using primary human neuronal cells, and evaluated their susceptibility to six commonly used anticancer drugs (temozolomide, nimustine, cisplatin, etoposide, mercaptopurine, and methotrexate). Human iPSC-neurons were differentiated using 5-week monolayer culture from hiPSC-derived neural stem/progenitor cells (hiPSC-NSPCs) established by combination the dual SMAD inhibition method with neurosphere culture. In vitro cytotoxic effects of six drugs on hiPSC-neurons and their parental hiPSC-NSPCs were evaluated by ATP assay and immunocytostaining. The hiPSC-neurons were generally more resistant to the anticancer drugs than hiPSC-NSPCs, although a high dose of cisplatin decreased the levels of the neuronal marker protein ELAVL3/4 in the hiPSC-neurons after a 48-h drug treatment. These results suggest that our methodology is potentially applicable for efficient determination of the toxicity of any drug to hiPSC-neurons.
DDIS-31. A NOVEL BRAIN-PERMEANT CHEMOTHERAPEUTIC AGENT FOR THE TREATMENT OF BREAST CANCER LEPTOMENINGEAL METASTASIS
Authors: Deng Jiaojiao , Chernikova Sophia , Fischer Wolf-Nicolas , Koller Kerry , Jandeleit Bernd , Ringold Gordon , Hayden Gephart Melanie 
Published: November 2019

Abstract
Leptomeningeal metastasis (LM), a spread of cancer to the cerebrospinal fluid and meninges, is universally and rapidly fatal due to poor detection and no effective treatment. Breast cancers account for a majority of LMs from solid tumors, with triple-negative breast cancers (TNBCs) having the highest propensity to metastasize to LM. The treatment of LM is challenged by poor drug penetration into CNS and high neurotoxicity. Therefore, there is an urgent need for new modalities and targeted therapies able to overcome the limitations of current treatment options. Quadriga has discovered a novel, brain-permeant chemotherapeutic agent that is currently in development as a potential treatment for glioblastoma (GBM). Recently, we have demonstrated dose-dependent in vitro and in vivo anti-tumor activity with various breast cancer cell lines including the human TNBC cell line MDA-MB-231. To evaluate the in vivo antitumor activity of the compound on LM, we used the mouse model of LM based on the internal carotid injection of luciferase-expressing MDA-MB-231-BR3 cells. Once the bioluminescence signal intensity from the metastatic spread reached (0.2 - 0.5) x 106photons/sec, mice were dosed i.v. (8 mg/kg once a week for nine weeks) or i.p. (4 or 8 mg/kg twice a week for nine weeks). Tumor growth was monitored by bioluminescence. The compound was well tolerated and caused a significant delay in metastatic growth resulting in significant extension of survival. Tumors regressed completely in ~ 28 % of treated animals in the i.p. group. Given that current treatments for LM are palliative with only few studies reporting a survival benefit, Quadriga’s new agent could be effective as a therapeutic for both primary and metastatic brain tumors such as LM. REF: https://onlinelibrary.wiley.com/doi/full/10.1002/pro6.43
DDIS-34. HIGH-THROUGHPUT DRUG SCREENING OF FDA-APPROVED ANTINEOPLASTIC DRUGS FOR THE TREATMENT OF AGGRESSIVE MENINGIOMAS
Authors: Jungwirth Gerhard , Yu Tao , Liu Fang , Warta Rolf , Unterberg Andreas , Herold-Mende Christel 
Published: November 2019

Abstract
Currently, we are facing several challenges in the treatment of meningiomas: only subtotally removable tumors, high rate of recurrence in higher-grade meningiomas, malignancy, and lack of effective chemotherapeutic agents for aggressive or inoperable tumors. For these reasons, there is an urgent need for more successful treatments for aggressive meningiomas. Therefore, we used 147 FDA-approved antineoplastic drugs on two different meningioma cell lines, including the genetically modified cell line Ben-Men-1 (WHO°I) and the newly established anaplastic meningioma cell line NCH93 (WHO°III). The impact of the drugs on proliferation was assessed in a high-throughput 386-well format with CellTiter-Glo (Promega) and further validation was done by crystal-violet assay. Subsequent screening of 147 FDA-approved drugs resulted in the identification of potential 5 drugs, including Bortezomib, Carfilzomib, Omacetaxine, Paclitaxel, and Ponatinib. Dose-curve analysis revealed IC50 values of these drugs in the Ben-Men-1 and NCH93 cell lines as follows: Bortezomib 16.2 and 5.7 nM, Carfilzomib 4.8 and 2.6 nM, Omacetaxine and 5.0 and 8.9 nM, Paclitaxel 2.6 and 1.9 µM, and Ponatinib 278 and 206 nM. Inhibitor dosage of 10xIC50 values and higher lead to an average inhibition of Ben-Men-1 and NCH93 cells by up to 90% on day 2 (P< .001). The impact of the antineoplastic agents on the cell cycle was analyzed by flow cytometry. Percentages of sub-G1 phase were significantly elevated with increasing drug concentrations of all five tested compounds (P< .001). To assess the effects of the drugs on migration scratch assay was performed. Drug concentrations of 10xIC50 values resulted in an inhibition of migration in Ben-Men-1 cells for Bortezomib, Carfilzomib, and Omacetaxine by 49%, 30%, and 23%, respectively (P< .05). In conclusion, we identified 5 promising drugs for the treatment of aggressive meningiomas by applying a high-throughput drug screening of 147 FDA-approved antineoplastic drugs.
EPID-01. SEX DIFFERENCE IN EXPRESSION OF IRON-RELATED GENES AND SURVIVAL IN GLIOBLASTOMA PATIENTS
Authors: Lee Sang , Walter Vonn , Salzberg Anna , Nesterova Darya , Lathia Justin , Rubin Joshua , Berens Michael , Barnholtz-Sloan Jill , Connor James 
Published: November 2019

Abstract
Sex impacts the clinical outcome of glioblastoma (GBM) patients. Iron is a key metabolic driver in glioma biology impacting both the neoplastic cells directly and tumor progression through the immune system. We previously reported the expression of HFE (iron homeostatic) gene has a sexually dimorphic impact on survival in GBM patients. To further interrogate the relationship of iron and sexual dimorphism in GBMs, we expanded our analysis to include the ferrome (profile of genes and proteins involved in iron regulation). These genes were identified using IronChip and then interrogated for sexually dimorphic expression and survival in primary GBM patients using The Cancer Genome Atlas GBM database. Biological pathway analysis indicated that the Toll receptor signaling and immune system signaling pathways are most strongly correlated to sex difference and GBM patient survival. Toll like receptor 4 (TLR4) expression in the bottom quartile is associated with a modest survival benefit for female GBM patients compared to male, but in the top quartile of expression of this gene the survival for males is dramatically greater than that for females (18 months versus 3.6 months). Males expressing top quartile of Dual specificity phosphatases (DUSP1) also known as MKP1 survive 24.2 months whereas females survive 5.8 months. There is no sex effect of DUSP1 in the bottom quartile of expression. These data suggest that top quartile expression of TLR4/DUSP1 are both a benefit for males (extending their survival) and a detriment to females (shortening their survival). Both TLR4 and DUSP1 are richly expressed in macrophages. The data suggest that macrophage infiltration into the tumor could be particularly negatively impactful in females; a finding consistent with our previous reports for the HFE gene. In summary, iron related gene expression is linked to sexual dimorphism in survival and may provide insights on sex specific tumor biology.