bluuebunny/crossref_metadata_2025_split huggingface dataset:
BIOM-60. BIOMARKER EVALUATION FOR IMIPRIDONE ONC206 REVEALS ClpP, ATF4, MYC, EGFR and HIF1 AS KEY PREDICTORS OF ANTI-CANCER EFFICACY
Authors: Morrow Sara , Garnett Mathew , McDermott Ultan , Benes Cyril , Allen Joshua , Prabhu Varun 
Published: December 2020

Abstract
ONC206 is a DRD2 antagonist and ClpP agonist that is a chemical derivative of ONC201, which is in Phase II clinical trials for H3 K27M-mutant glioma. We have previously reported that dopamine receptor expression correlates with ONC201 and ONC206 efficacy. Here, we evaluated additional predictive biomarkers for both agents in the GDSC panel using RNA-seq expression data. ClpP emerged as a strong predictor of efficacy for ONC206 (IC50: p = 1.83E-4, AUC: 9.92E-13). ClpP activation enhances degradation of its substrates, including electron transport chain members responsible for oxidative phosphorylation (OXPHOS). Imipridones activate the integrated stress response involving ATF4 and cause proteasomal degradation of c-myc, which also reduces OXPHOS. Accordingly, high ATF4 (IC50: p = 4.92E-5, AUC: p=2.84E-9) and elevated c-myc correlated with ONC206 efficacy (IC50: p = 6.42E-6, AUC: 3.31E-12). EGFR expression is inversely correlate with DRD2 expression in glioma and its activation is associated with glycolysis. Low EGFR expression correlated with increased ONC206 efficacy (IC50: p = 4.32E-7, AUC: p = 6.44E-20). Loss of HIF1 shunts cellular metabolism toward OXPHOS. Low HIF1 expression correlated with increased anticancer efficacy for ONC206 (IC50: p = 1.96E-3, AUC: p = 1.56E-11). Expression of each of the five markers was significantly different in cell lines that achieved an IC90 with ONC206 (~10%) versus those that did not. A similar analysis for ONC201 revealed that ClpP, MYC and EGFR are more predictive of efficacy relative to ATF4 and HIF1. Combinatorial biomarker analyses revealed MYC/EGFR as the most significant predictor of IC50 for both agents. ClpP/MYC and ClpP/HIF1 were the most significant predictors of AUC for ONC201 and ONC206, respectively. Ongoing studies are further investigating tumor type enrichment of biomarkers. Prediction of innate imipridone sensitivity using biomarkers identified in this study may guide patient and tumor type selection in clinical trials.
CBIO-06. MKlp2 INHIBITION AS A NOVEL ANTIMITOTIC FOR GLIOBLASTOMA
Authors: Schrock Morgan , Scarberry Luke , Stromberg Benjamin , Torres Adrian , Chakravarti Arnab , Venere Monica , Summers Matthew 
Published: December 2020

Abstract
Despite innovations in therapy and surgery, glioblastoma remains one of the deadliest tumor types with a 5-year survival rate of approximately 5%. There is a desperate need for new therapeutic strategies to block the growth and survival of glioblastoma. To circumvent toxicities associated with traditional antimitotics, there has been a growing interest in developing therapies that impede mitosis-specific microtubule functions, such as the inhibition of kinesins, mitotic motor proteins that travel along microtubules. Our work with motor kinesin-like protein 2 (MKlp2), in combination with reports from published literature, suggest a previously undescribed role for MKlp2 in early mitosis that would make its inhibition effective at impeding glioblastoma cell growth without neurologic side effects. The objective of this study was to further define this novel function of MKlp2 and to determine the efficacy of MKlp2 inhibition in glioblastoma. Our data indicate that MKlp2 inhibition induced a spindle assembly checkpoint-mediated arrest, suggesting that function of MKlp2 is important for recovery progression to anaphase in addition to its well-known function in late mitosis. In addition, MKlp2 inhibition with a small molecule MKlp2 inhibitor significantly decreased short-term and long-term survival of human glioblastoma patient-derived lines. Furthermore, our data indicate that it is loss of this early mitotic function that is responsible for the anti-proliferative effects caused by MKlp2 inhibition. Ongoing work will continue to delineate the mechanism of MKlp2 in early mitosis and determine the effect of small molecule MKlp2 inhibition in vivo, all the while exploring a new therapeutic strategy for glioblastoma
CBIO-16. SUPPRESSION OF HISTONE H3.3 MITOTIC PHOSPHORYLATION DRIVES DEVELOPMENT OF H3K27M-MUTANT DIFFUSE MIDLINE GLIOMAS
Authors: Day Charles , Langfald Alyssa , Grigore Florina , Sepaniac Leslie , Stumpff Jason , Vaughan Kevin , Robinson James , Hinchcliffe Edward 
Published: December 2020

Abstract
Pediatric midline gliomas – including DIPG – are lethal brain tumors in children, with poor prognosis and limited treatment options that provide only short-term benefits. The majority have a lysine-to-methionine substitution at residue 27 (H3K27M) in genes expressing histone H3 – predominantly in the H3.3 variant. This causes a global reduction in H3 Lys27 tri-methylation (H3K27Me3), comprehensive epigenetic reprogramming, and is a key driver in gliomagenesis. We show that the H3.3K27M mutation also induces chromosome segregation defects, which in high-grade tumors, results in extensive copy number alterations (CNAs). Ser31 is one of five amino acid substitutions differentiating H3.3 from canonical H3.1. Mitotic phosphorylation of H3.3 Ser31 by Chk1 kinase is restricted to pericentromeric heterochromatin, where it plays a role in chromosome segregation. We show that the K27M mutation affects neighboring Ser31 phosphorylation and pericentromeric heterochromatin organization. We demonstrate that (i) H3.3 K27M protein is defective for Ser31 phosphorylation by Chk1 kinase in vitro; (ii) DIPG cell lines have significantly decreased mitotic Ser31 phosphorylation, and are chromosomally unstable; and (iii) CRISPR-reversion of H3.3K27M to Lys27 restores phospho-Ser31 (and Lys27 tri-methylation) and significantly decreases chromosome instability. Expression of H3.3K27M or non-phosphorylatable H3.3S31A mutants in WT cells results in chromosome missegregation; this is suppressed by co-expression of phospho-mimetic H3.3K27M/S31E. In normal cells, chromosome missegregation stimulates p53-dependent cell cycle arrest in G1 to prevent the proliferation of aneuploid daughters. However, cells expressing H3.3 K27M or S31A failed to arrest following missegregation - despite having WT p53. Finally, in a novel mouse model of glioma, mean survival of mice with tumors induced with H3.3K27M and H3.3S31A was 81 and 68 days: 100% of H3.3S31A mice developed high-grade tumors. H3.3 WT controls developed only low-grade tumors and all survived 100 days. H3.3S31A is WT for Lys27 tri-methylation and thus, loss of Ser31 phosphorylation alone is oncogenic.
CBIO-19. LOW GLOBAL HISTONE H4 ACETYLATION LEVELS REVEAL CANDIDATE QUIESCENT CELL POPULATIONS IN GLIOMA AND DISTINGUISH TUMORS BY GRADE
Authors: Mihalas Anca , Feldman Heather , Patel Anoop , Paddison Patrick 
Published: December 2020

Abstract
Current standard of care therapy for glioblastoma (GBM) includes cytoreduction followed by ablative therapies that target rapidly dividing cell types. However, the presence of quiescent-like/G0 states, therefore, represents a natural reservoir of tumor cells that are resistant to current treatments. Quiescence or G0 phase is a reversible state of “stasis” cells enter in response to developmental or environmental cues. To gain insight into how glioblastoma cells might regulate G0-like states, we performed a genome-wide CRISPR-Cas9 screen in patient-derived GBM stem-like cells (GSCs) harboring a G0-reporter to identify genes that when inhibited trap GSCs in G0-like states. Among the top screen hits were members of the Tip60/KAT5 histone acetyltransferase complex, which targets both histones (e.g., H4) and non-histone proteins for acetylation. NuA4 functions as a transcriptional activator, whose activities are coordinated with MYC in certain contexts, and also participates in DNA double-strand break repair by facilitating chromatin opening. However, currently little is known about the roles for NuA4 complex in GBM biology. Through modeling KAT5 function in GSC in vitro cultures and in vivo tumors, we find that KAT5 inhibition causes cells to arrest in a G0-like state with high p27 levels, G1-phase DNA content, low protein synthesis rates, low rRNA rates, lower metabolic rate, suppression of cell cycle gene expression, and low histone H4 acetylation. Interestingly, partial inhibition of KAT5 activity slows highly aggressive tumor growth, while increasing p27hi H4-aclow populations. Remarkably, we that low grade gliomas have significantly higher H4-aclow subpopulations and generally lower H4-ac levels than aggressive grade IV tumors. Taken together, our results suggest that NuA4/KAT5 activity may play a key role in quiescence ingress/egress in glioma and that targeting its activity in high grade tumors may effectively “down grade” them, thus, increase patient survival.
CBIO-24. KINETOCHORE MISREGULATION IN GLIOBLASTOMA AND OTHER CANCERS
Authors: Herman Jake , Zhu Jun , DeLuca Jennifer , Paddison Patrick 
Published: December 2020

Abstract
Aneuploidy is a hallmark of most late stage cancers and contributes to tumor cell evolution, invasiveness, therapy resistance, and recurrence. A major cause of aneuploidy is lagging anaphase chromosomes that have merotelic kinetochore (KT) attachments in mitosis. In this scenario, a KT (i.e., the proteinaceous structure assembled onto centromeres in mitosis) is bound to microtubules (MTs) emanating from both spindle poles, causing chromosome mis-segregation. “Background” chromosome missegregation likely contributes to the initiation of multiple cancers, including glioblastoma (GBM), where chr 7 gain and chr 10 loss are early events. However, we have found that in GBM and transformed cells activation of the RAS signaling pathway significantly increases lagging anaphase chromosomes, and, as a result, aneuploidy and tumor heterogeneity. However, the underlying mechanism of RAS-induced chromosome instability has remained elusive. Here we present one possible cause: MAPK-driven KT stress. The hallmarks of KT stress include chronic KT-MT attachment instability in mitosis, dramatic changes in KT morphology, and increases in merotelic KT attachments and chromosome segregation errors. KT stress is lethal to cancer cells. However, stressed cells survive by relying on BUB1B/BubR1 activity to strengthen KT-MT attachments. We first observed KT stress in GBM patient isolates, where ~60–70% display its hallmarks. We subsequently found that RAS or MEK activity is sufficient to induce KT stress in both CNS and non-CNS derived cell types. We propose that KT stress is caused by aberrant mitotic RAS/MAPK activity, which likely targets one or more KT proteins resulting in KT-MT attachment defects and chromosome instability. In addition, Dr. Jun Zhu’s lab has also created a computational classifier that can identify KT stressed cells and tumors based on the expression of 838 genes associated with KT stress, which can be also used to identify orthogonal therapeutic sensitivities. We will present these findings as well at this meeting.
COVD-03. ASSESSING THE IMPACT OF CORONAVIRUS 19 PANDEMIC ON NEURO-ONCOLOGY AT GUY’S CANCER CENTRE LONDON
Authors: Little Jessica , Al-Salihi Omar , Brazil Lucy , Swampillai Angela 
Published: December 2020

Abstract

BACKGROUND
Immunosuppressive treatment increases COVID-19 risk. Neuro-oncology patients may not qualify for ITU if they deteriorate, but without oncological treatment, prognosis is poor. The pandemic has seen the introduction of new guidelines; including alternative treatment schedules which balance risks of contracting COVID-19, against safely delivering effective cancer treatment. We assess COVID-19 impact on neuro-oncology treatment at Guy’s Cancer Centre, London.

METHODS
Notes of patients seen March-April 2020 were reviewed. Demographic data, tumour grade, treatment and changes due to COVID-19 recorded.

RESULTS
111 patients were identified (69 male: 42 female, median age 51years). 65 were WHO Grade 4, 24 Grade 3, 17 Grade 2, 2 Grade 1, 1 metastatic-neuroblastoma, 1 anaplastic-medulloblastoma and 1 radiological diagnosis of high-grade-glioma. 14% (32) of consultations were in person (16 new, 7 consents, 9 attending for treatment); 86% (198) were telephone. 8 had concurrent chemo-radiotherapy, 22 radiotherapy alone, 64 chemotherapy alone, 15 had active-surveillance and 2 best-supportive-care. To minimise COVID-19 risk, 22.5% (25) had treatment altered: - A 76-year-old had a radiological diagnosis; - 4 had hypofractionated radiotherapy (30Gy in 6#) to minimise hospital visits; - 7 had no chemotherapy (5 were unmethylated /age, 2 patient choice); - 4 switched from PCV to Lomustine; - 11 stopped chemotherapy early; - 50% (36) were given prophylactic GCS-F; - No patients were recruited for trials. 19 reported possible COVID-19 symptoms – 7 had delays and 3 stopped treatment. 4 tested COVID-19 positive (although not all tested). 1 died of COVID-19 (off treatment). Review of March-April 2020 service showed similar new patient referrals compared to the same time in 2019 (16 and 19 respectively).

CONCLUSION
Despite concern about decreasing new referrals during the pandemic, this wasn’t the case for our service. 77.5% of patients had no treatment changes due to COVID-19 and all 22 patients on trial were able to continue treatment throughout this period.
COVD-09. INVESTIGATION AND SUMMARY OF DIAGNOSIS AND TREATMENT OF NEUROLOGICAL TUMORS DURING COVID-19 IN CHINA
Authors: Liang Zhen , Hu Yuanjun , Chen Zhong-ping 
Published: December 2020

Abstract
In order to realize the condition of diagnosis and treatment of neurological tumors in China during COVID-19, CSNO (China Anti-Cancer Association Neuro-Oncology Professional Committee) organized this questionnaire survey. The survey was conducted online from June 3rd to 16th in 2020. A total of 373 replies were received and 370 were confirmed valid questionnaires. The respondents were mainly neurosurgeons, as well as radiotherapists and pathologists in general hospitals and specialized hospitals in 29 provinces and municipalities in China. The survey results are summarized as follows. Firstly, the number of outpatient and inpatient of neurological tumors significantly declined during the epidemic compared with the same period last year in more than 90% of hospitals surveyed, and a few specialized hospitals even stopped treatment due to the outbreak of COVID-19. Compelled by illness was the main reason for most of the patients to go to hospital. As the epidemic prevention and controlling, the normal treatment process for each patient was tedious than that for the same period before, and the costing time also turned longer. Most patients might feel poor medical experience, but they also expressed understanding for the hospital and cooperated with the diagnosis and treatment works. Secondly, during the epidemic period, the participation in academic conferences or MDT decreased significantly for most doctors, and scientific research work even stopped in some hospitals. Online tools have risen as the primary means of communication, not only for academic communication but also for diagnosis and treatment works. More than 90% of doctors believe the style of online communication was a new mode in this special period, with advantages such as convenient and quick. It could be an effective supplement to daily work and would be utilized into work in future.
CSIG-04. ROLE OF c-Met/β1 INTEGRIN COMPLEX IN THE METASTATIC CASCADE
Authors: Sudhir Sweta , Lau Darryl , Wadhwa Harsh , Jain Saket , Chandra Ankush , Nguyen Alan , Spatz Jordan , Shah Sumedh , Cheng Justin , Safaee Michael , Yagnik Garima , Jahangiri Arman , Aghi Manish 
Published: December 2020

Abstract
Metastases cause 90% of human cancer deaths. The metastatic cascade involves 5 steps: local invasion, intravasation, extravasation, metastatic site colonization, and proliferation. While individual mediators of these processes have been investigated, interactions between these mediators remain less well defined. We previously identified a structural complex between receptor tyrosine kinase c-Met and β1 integrin in metastases that form under certain biological and therapeutic inducers, including bevacizumab. Using novel cell culture and in vivo assays, we found that c-Met/β1 complex induction promotes breast cancer intravasation and adhesion to the vessel wall but does not increase extravasation. These effects may be driven by the ability of the c-Met/β1 complex to increase mesenchymal and stem cell characteristics in breast cancer cells. Multiplex transcriptomic analysis revealed upregulated Wnt and hedgehog pathways after c-Met/β1 complex induction in breast cancer cells. We subsequently used CRISPR to introduce a β1 integrin point mutation that prevented binding to c-Met and led to reduced intravasation, confirming the importance of c-Met/β1 integrin binding for the metastatic cascade. OS2966, a therapeutic B1 integrin blocking antibody, disrupted c-Met/β1 binding as well, and decreased invasion, mesenchymal gene expression, and mesenchymal morphology of breast cancer cells. Bone-seeking breast cancer cells exhibited higher c-Met/β1 complex levels than parental controls and preferentially adhere to tissue-specific matrix. Patient bone metastases demonstrated higher c-Met/β1 complex levels than brain metastases. Thus, our research suggests the c-Met/β1 complex drives breast cancer cell intravasation and preferential affinity for bone tissue-specific matrix. Pharmacological targeting of the complex may prevent metastases, particularly osseous metastases.
CSIG-15. INNOVATIVE COMPUTATIONAL PLATFORM ADDRESSES PROSTAGLANDIN E RECEPTOR 3 AS THE MASTER REGULATOR MEDIATING RESISTANCE TO TUMOR TREATING FIELDS IN GLIOBLASTOMA CELLS
Authors: Chen Dongjiang , Le Son , Hutchinson Tarun , Tran David 
Published: December 2020

Abstract

OBJECTIVES
Tumor Treating Fields (TTFields) are approved in combination with temozolomide for newly diagnosed glioblastoma (GBM). TTFields are low-intensity alternating electric fields that are thought to disturb mitotic macromolecules’ assembly. The addition of TTFields resulted in a significant improvement in overall survival. However, most GBM patients eventually develop resistance to TTFields and the mechanism remains unexplored.

METHODS
Multiple GBM cell lines were treated continuously at clinically approved frequency of 200 kHz using an in vitro TTFields system until cells with relative resistance to the cytotoxic effects of TTFields. A systems approach aided by innovative network ranking computational algorithms were utilized to analyze global gene expression profiles and identify resistance pathways, which were subsequently validated experimentally.

RESULTS
TTFields-induced chromosomal instability is preserved in resistant cells, indicating that TTFields resistance is mediated through a non-biophysical mechanism. This acquired TTFields resistance phenotype is associated with a transition of GBM cells to a stem-like state as determined by a neurosphere assay, stemness markers such as CD44 and increased tumorigenesis when implanted into mouse brain. Using an innovative computational platform-NETZEN, we methodically dissected this stemness program in resistant cells. 3 networks were found disrupted and all play critical roles in GBM stemness. Mechanistically, Prostaglandin E Receptor 3 (PTGER3) is the top ranked regulator responsible for resistance. PTGER3 is rapidly upregulated both in vitro and in vivo upon exposure to TTFields and further increases with prolonged treatment as resistance sets in. Immunofluorescence staining shows PTGER3’s nuclear translocation along with Lamin A/C disruption in response to TTFields. Pharmacological inhibition of PTGER3 using aspirin or PTGER3-specific inhibitors resensitized or prevent cells becoming resistance to TTFields.

CONCLUSIONS
We have identified a novel regulator PTGER3 at the apex that plays a critical role in TTFields resistance. This is a potential therapeutic target to reduce resistance to TTFields therapy in GBM.
CTIM-07. IDENTIFICATION OF A BASELINE BIOMARKER ASSOCIATED WITH TUMOR RESPONSES IN A PHASE I/IIa TRIAL OF A THERAPEUTIC CMV VACCINE AGAINST RECURRENT GLIOBLASTOMA (GBM)
Authors: Wen Patrick , Reardon David , Forst Deborah , Lee Eudocia , Iwamoto Fabio , Diaz-Mitoma Francisco , Anderson David , Lassman Andrew 
Published: December 2020

Abstract
Cytomegalovirus (CMV) antigens have been reported in over 90% of GBM tumors. CD4+ and CD8+ T cells are most frequently directed against the gB and pp65 antigens, respectively, and are immunogenic targets in a CMV-based GBM vaccine. We enrolled 10 patients (6 women, 4 men) with KPS at least 70 and first recurrence of GBM to a trial (Phase IIa extension) of gB/pp65 enveloped virus-like particles (eVLPs) with GM-CSF. Intradermal vaccination was administered every 4 weeks, with serologic immune-monitoring 2 weeks after each vaccination and surveillance brain MRI scans every 6 weeks. Median age was 59 years (range 33–67). Among 8 response-evaluable patients, we observed 1 SD and 1 PR. Among all patients treated on phase I and II (n=26), a normal baseline ratio of CD4/CD8 T cells in peripheral blood predicted response (n=6). Other baseline peripheral blood markers did not correlate with efficacy, including total white blood cell, lymphocyte percentage, and absolute lymphocyte count. During treatment, the peripheral blood of responders demonstrated dynamic losses followed by subsequent reappearance and expansion of CMV-specific CD4+ effector memory T cells. Based on these encouraging results, a new arm is enrolling subjects combining gB/pp65 eVLPs (at the same dose) formulated with adjuvant intramuscular AS01B and results will be presented.
CTIM-08. COMBINATION OF THE IMA950/POLY-ICLC MULTIPEPTIDE VACCINE WITH PEMBROLIZUMAB IN RELAPSING GLIOBLASTOMA PATIENTS
Authors: Dutoit Valérie , Marinari Eliana , Dietrich Pierre-Yves , Migliorini Denis 
Published: December 2020

Abstract
The IMA950 peptide vaccine is composed of 9 HLA-A2-restricted peptides eluted from the surface of GBM samples and of two HLA class II-binding peptides1. It was tested in combination with poly-ICLC in patients with newly diagnosed GBM, demonstrating safety. The vaccine was able to elicit CD4 and CD8 T cell responses in the peripheral blood in the majority of patients, with however an overall low magnitude of T cell responses and suboptimal migration of elicited T cells to the brain, probably limiting clinical efficacy2,3. With the aim to improve homing of vaccine-specific T cell to the tumor, we are conducting a phase II clinical trial in patients with recurrent GBM testing the IMA950/poly-ICLC multipeptide vaccine with or without the anti-PD1 antibody pembrolizumab (NCT03665545). 24 patients will be included (12 patients in each arm) and pre- and post-vaccination tumor sample will be available, allowing assessing effect of the vaccine at the tumor site. The primary objective of this trial is safety of IMA950/poly-ICLC given together with pembrolizumab. Secondary objectives include (i) estimation of 6, 9 and 12-month progression-free survival (PFS), (ii) overall survival, (iii) analysis of patient quality of life and (iv) of the synergy/immunogenicity of IMA950/poly-ICLC and pembrolizumab. Immunomonitoring will include measure of vaccine-induced immune responses, IHC for immune cell markers, RNA/TCR sequencing and methylome analysis, to assess vaccine-induced T cell responses, immune modulation and potential signatures predictive of response. Thus far, 6 patients have been included (3 in each arm). Preliminary results show CD4 and CD8 T cell responses to the vaccine are detected in both groups in the peripheral blood. Analysis at the tumor site and comparison between arms will be performed once all patients have been included. 1. Dutoit, V. et al. Brain (2012); 2. Migliorini, D. et al. Neuro Oncol (2019); 3. Rampling, R. et al. Clin Cancer Res(2016)