bluuebunny/crossref_metadata_2025 huggingface dataset:
DDDR-12. THE ROLE OF CASEIN KINASE 1 EPSILON IN TEMOZOLOMIDE SENSITIVITY IN GLIOBLASTOMA STEM CELLS
Authors: Bilton Shawna , Sheng Zhi
Published: November 2022

A major hurdle in effectively treating glioblastoma is the resistance to current chemotherapy temozolomide (TMZ), exhibited intrinsically in glioblastoma stem cells (GSCs). GSCs are a population of tumor cells that are self-renewing, highly resilient and capable of forming genetically heterogeneous and difficult-to-treat tumors. Therefore, overcoming TMZ resistance holds significant promise in the treatment of glioblastoma. Casein kinase 1 ε (CK1ε) has been identified as a stem cell factor that is important for GSCs to self-renew. However, whether CK1ε confers TMZ resistance in GSCs remains elusive.

METHODS

To test the role of CK1ε in the chemoresistance of GSCs, we treated GSC adherent cell lines with TMZ, CK1ε inhibitor IC261, and a combination of TMZ plus IC261. Cell viability was assessed with MTS viability assay or CellTiter-Blue viability assay.

RESULTS

Cell viability was significantly decreased in GSCs treated with 0.8μM IC261 combined with 100μM TMZ as compared to cells treated with either 0.8μM IC261 or 100μM TMZ alone (p < 0.05). We assessed synergistic drug effects using the Bliss independence model to yield Excess Over Bliss (EOB) scores. EOB > 0% indicates a synergistic effect; EOB = 0% indicates additive effect; and EOB < 0% indicates antagonistic effect. Cells treated with 0.8μM IC261 together with 100μM TMZ yielded EOB of > 0%.

CONCLUSIONS

Previous work has identified CK1ε as an important stem cell factor in the survival GSCs, but there lacked studies testing the role of CK1ε in TMZ chemoresistance in vitro. We demonstrate synergistic inhibition of cell viability in GSCs treated with CK1ε inhibitor IC261 in combination with TMZ. Based on these results, CK1ε is suggested to play an important role in the chemoresistance of GSCs to TMZ.
DDDR-13. MGMT FUNCTION DETERMINES THE DIFFERENTIAL RESPONSE OF ATR AND PARP INHIBITORS WITH DNA DAMAGING AGENTS FOR GBM THERAPY
Authors: Koul Dimpy , Wu Shaofang , Li Xaolong , Khan Sabbir , Balasubramaniyan Veerakumar , Yung W K Alfred
Published: November 2022

The most common cancer therapies including chemo- and radiation therapy are designed to induce cell death by DNA damage. However, DNA damage response (DDR) repair pathways initiated by tumor cells can resist the effect of anticancer drugs thus providing the rationale for combining DNA repair pathway inhibitors with radiation and DNA damaging anticancer drugs. The reliance of different cancer to different DDR mechanism can guide for targeted use of specific DDR inhibitor to maximize tumor cell killing. Here, we show the differential activities of two classes of DDR pathway inhibitors, Ataxia Telangiectasia- and Rad3-related kinase (ATRi) and poly(ADP-ribose) polymerases inhibitors (PARPi) across 20 glioma stem cell (GSC) lines. Using a panel of 3 ATRi, we identified a subgroup of GSCs, showing significant synergism with TMZ combination but resistant to ATRi single agent monotherapy. Interestingly, majority of the synergistic cell lines are associated with MGMT promoter methylation, suggesting that only tumor cells with no MGMT repair will benefit from ATR inhibition. Moreover, we also observe that PARPi + TMZ showed synergism only in MGMT unmethylated GSC cells suggesting that this synergism is a result of the dual function of PARPi in blocking BER repair and blocking MGMT PARylation thus abolishing MGMT mediated repair. Altogether, we believe MGMT methylation status in primary GBM could function as a strong biomarker for patient selection for ATRi or PARPi combination with TMZ in the clinic. We are currently exploring the activity of the triple combination of TMZ + PARPi + ATRi for the small subgroup of GSCs that do not show response to either TMZ + ATRi or PARPi + TMZ combinations.
DDDR-14. YAP/TAZ TRANSCRIPTIONAL CO-ACTIVATORS DRIVE NEURO-GLIAL STEM/PROGENITOR CELL IDENTITY IN HIGH GRADE GLIOMAS
Authors: Read Renee , Oh Se-Yeong , Vigneswaran Krishanthan , Boyd Nathaniel , Young Elizabeth , Read William , Olson Jeffrey
Published: November 2022

High-grade gliomas (HGGs), neoplasms derived from neuro-glial stem/progenitor cells, are the most common and lethal malignant primary brain tumors diagnosed in adults and children, with a median survival time of 14 months with current treatments. HGG tumorigenicity is often driven by genetic aberrations in receptor tyrosine kinases (RTKs), such as EGFR, and the Pi-3 kinase (PI3K) signaling pathway. Using Drosophila, mouse, and human HGG model systems of RTK-PI3K mutant HGGs, we identified the YAP and TAZ transcription co-activators, which regulate gene expression via TEAD co-factors, as key drivers of HGG tumorigenicity downstream of oncogenic RTK signaling. YAP and TAZ are highly expressed in RTK-mutant human HGG cells, and regulate TEAD-mediated transcription of several transcription factors, neurodevelopmental genes, and receptors, including the EGFR RTK, that together create a feedforward loop with RTKs to maintain a radial-glia-like stem/progenitor cell fate in HGG cells. Inhibition of YAP and TAZ in self-renewing stem-cell-like RTK mutant HGG cells can inhibit proliferation, block stem/progenitor cell fate, and elicit apoptosis. In particular, the benzoporphyrin derivative verteporfin, a disruptor of YAP/TAZ-TEAD mediated transcription, specifically induced apoptosis of cultured patient-derived HGG cells, suppressed expression of YAP/TAZ transcriptional targets, including RTKs, and conferred significant survival benefit in an orthotopic xenograft HGG model. Our efforts led us to initiate phase 0 and phase 1/2 clinical trials of Visudyne, an FDA-approved liposomal formulation of verteporfin, in which we have verified verteporfin uptake into tumor cells and are now testing the therapeutic efficacy of verteporfin in human patients. Finally, we have examined mechanisms of response and resistance to verteporfin, and we have evidence that stem-like HGG cells can escape the effects of YAP/TAZ inhibition by recapitulating neuro-glial developmental cell fate transitions. Together, our data indicate that targeting YAP/TAZ functionality is a promising therapeutic approach for HGG.
DDDR-25. CO-INHIBITION OF KINASE SIGNALING PATHWAYS AND EPIGENETIC REGULATORS OVERCOMES COMPENSATORY EFFECTS IN PEDIATRIC HIGH-GRADE GLIOMAS
Authors: Adams Jack , Stitzlein Lea , Singh Melissa , Su Xiaoping , Lu Yue , Bailey Cavan , Monje Michelle , Whitehead Christopher , Sebolt-Leopold Judith , Chandra Joya
Published: November 2022

Pediatric high-grade gliomas (pHGG) confer poor survival outcomes with minimal treatment options due to a high rate of therapeutic resistance and few surgical options. One subgroup of pHGG is diffuse intrinsic pontine glioma (DIPG). Patient-derived cell lines, such as SU-DIPG-XIII, SU-DIPG-VI, and SU-DIPG-IV, recapitulate epigenetic mutations seen in patients. In these lines, lysine-specific demethylase 1 (LSD1) is overexpressed and knockdown/inhibition slows growth, therefore, optimizing LSD1 inhibitor treatment regimens is promising. In other models, MEK kinase activation acts as a mechanism of resistance to LSD1 inhibitors. This is relevant to DIPG due to the frequency of dysregulated and mutated upstream kinase pathways. Thus, we sought to identify the connection between LSD1 and kinase signaling as a therapeutic co-inhibition strategy in DIPG. Pharmacologically relevant catalytic LSD1 inhibitors were assessed using the alamarBlue viability assay and demonstrated wide ranges of IC₅₀ values with ORY-1001(19 μM to > 150 μM), ORY-2001( > 50 μM), GSK-LSD1(134 μM to > 500 μM), and IMG-7289(1.6 μM-179 μM) in the SU-DIPG lines. Resistance mechanisms from kinase modulation were investigated via Western Blot to determine if kinase inhibition could sensitize these cells to LSD1 inhibition. We discovered that LSD1 inhibition caused an unexpected increase in pAKT and pERK, suggesting enhanced activity of protumorigenic kinases. To overcome kinase activation from LSD1 inhibition, MEK or PI3K inhibitors, including selumetinib, trametinib, and BKM120, were tested. A novel dual kinase inhibitor directed against EGFR and PI3K, MTX-241F, was also assessed. Several combinations caused a significant increase in efficacy measured by cell viability. We further observed that the addition of kinase inhibitors with LSD1 inhibition decreased phosphorylated kinases. Overall, the combination enhanced in vitro efficacy in contrast to single-agent inhibition supporting an interplay between LSD1 and kinase signaling in pHGG. Future studies will assess this combination utilizing orthotopic xenograft models of DIPG
EOLP-02. THE EFFECT OF CLINICAL TRIAL ENROLLMENT ON SPECIALTY PALLIATIVE CARE RECEIPT IN PEDIATRIC AND YOUNG ADULT PATIENTS WITH HIGH GRADE GLIOMAS
Authors: Roberts Holly , Franson Andrea , Wang Yujie
Published: November 2022

BACKGROUND

Palliative care has been shown to provide numerous benefits to children with cancer. Pediatric patients with high grade glioma (HGG) are particularly well suited for early involvement of palliative care given their high symptom burden and relatively poor prognosis. However, a recent study revealed that pediatric patients with primary central nervous system malignancies missed multiple opportunities for appropriate palliative care involvement. We hypothesize that clinical trial enrollment may adversely impact palliative care involvement for children and young adults with HGG.

METHODS

We identified a cohort of 43 deceased patients with HGG treated at our institution. IRB exemption was obtained. For each patient, the electronic medical record was reviewed to collect demographic, diagnostic, clinical trial, treatment, and palliative care information. Statistical analysis was performed, employing Fisher exact and t tests.

RESULTS

Overall, 72% (31/43) of patients had at least one visit with a specialty palliative care provider. 56% (24/43) of patients enrolled in a clinical trial with HGG-directed therapy, with 71% (17/24) of patients who enrolled in a clinical trial receiving specialty palliative care compared to 74% (14/19) of patients who were not on a trial (p = 1.000). Among patients who received palliative care, there was no statistically significant difference in the timing of palliative care involvement, measured from the date of first palliative care contact to date of death, for patients who enrolled in a clinical trial (mean = 177 days) compared to those who did not (mean = 113 days, p = 0.180).

CONCLUSIONS

As our understanding of the genomic landscape of pediatric brain tumors increases, it can be expected that patients electing to enroll in targeted therapy clinical trials will also increase. As such, it is reassuring that our data suggest trial participation does not adversely impact the receipt of palliative care in children with HGG.
EPID-11. NATIONAL EPIDEMIOLOGY AND SURVIVAL OF ADULT-TYPE DIFFUSE GLIOMAS IN THE UNITED STATES BY IDH, 1P/19Q, MGMT, AND WHO CNS GRADE
Authors: Iorgulescu Bryan , Sun Chuxuan , Cioffi Gino , Neff Corey , Shoaf Madison , Waite Kristin , Kruchko Carol , Wen Patrick Y , Brat Daniel , Ostrom Quinn , Barnholtz-Sloan Jill
Published: November 2022

BACKGROUND

Histomolecularly-defined adult-type diffuse gliomas—including IDH-wildtype glioblastoma, IDH-mutant astrocytoma, and IDH-mutant 1p/19q-codeleted oligodendroglioma—were incorporated into U.S. cancer registry reporting for individuals with brain tumors beginning in 2018. We therefore assessed their epidemiology and overall survival (OS) patterns.

METHODS

Individuals histopathologically diagnosed with diffuse gliomas in 2018 and had brain molecular marker data were identified within the National Cancer Database; Surveillance, Epidemiology, and End Results Incidence; and Central Brain Tumor Registry of the United States databases. Age-adjusted incidence rates per 100,000 population with 95% confidence intervals (95CI) were estimated. OS was estimated using Kaplan Meier methods and stratified by WHO CNS grade, age, sex, tumor size, treatment, extent of resection, and MGMT promoter methylation. WHO CNS grade was additionally examined among individuals with IDH-wildtype diffuse astrocytic gliomas.

RESULTS

IDH-wildtype glioblastomas’ incidence rate was 1.74 (95CI = 1.69-1.78); as compared to 0.14 (95CI = 0.12-0.15), 0.15 (95CI = 0.14-0.16), and 0.07 (95CI: 0.06-0.08) WHO grade 2, 3, and 4 IDH-mutant astrocytomas. Irrespective of grade, IDH mutation prevalence was highest in adolescents & young adults, and IDH-mutant astrocytomas were more frequently MGMT promoter methylated. For OS analysis, 8,651 individuals were identified: one-year OS was 53.7% for WHO grade 4 IDH-wildtype glioblastomas (95CI = 52.5-54.9); 98.0% (95CI = 96.1-99.0), 92.4% (95CI = 89.6-94.5), and 76.3% (95CI = 70.1-81.3) for grade 2, 3, and 4 IDH-mutant astrocytomas; 97.9% (95CI = 95.9-98.9) and 94.4% (95CI = 90.9-96.6) for grade 2 and 3 IDH-mutant 1p/19q-codeleted oligodendrogliomas. Among IDH-wildtype glioblastomas, median OS was 17.1 months (95CI = 16.1-18.6) and 12.4 months (95CI = 12.0-12.9) for methylated and unmethylated MGMT promoters. IDH-wildtype diffuse astrocytic gliomas reported as WHO grade 2 or 3 demonstrated longer adjusted OS compared to grade 4 tumors (both p < 0.001). A significant association was not observed between chemotherapy and OS (HRadjusted 0.95, 95CI = 0.41-2.22, p = 0.91) for radiotherapy-treated grade 3 IDH-wildtype diffuse astrocytic gliomas.

CONCLUSIONS

Our findings provide the initial U.S. epidemiological estimates for histomolecularly-defined adult-type diffuse gliomas.
EPID-24. TIMING OF STANDARD-OF-CARE CHEMO-RADIATION THERAPY FOLLOWING SURGICAL RESECTION OR STEREOTACTIC BIOPSY
Authors: Zhu Ping , Chen Clark
Published: November 2022

OBJECT

The literature examining the optimal timing for initiating post-surgical therapy after glioblastoma surgery is brimming with inconsistencies, with reports of both deleterious effects and benefits in the delay of post-surgical therapy at various time intervals. Moreover, there is currently limited data pertinent to the post-Stupp regimen era. Here, we use the National Cancer Database (NCDB) to explore this matter, with a focus on patients who underwent the standard-of-care (SOC) Stupp regimen.

METHODS

The study cohort included newly glioblastoma patients from the NCDB, with exclusion of patients age < 40 [as proxy for isocitrate dehydrogenase (IDH) mutated astrocytoma] and stratified for Methyl-guanine-methyl transferase (MGMT) promotor methylation. Timing of initiating SOC was grouped by 0-2, 2-4, 4-6, 6-8, and > 8 weeks from surgery. Biopsy and craniotomy patients were analyzed separately. The Kaplan-Meier method and Cox proportional hazards regression were applied for survival analysis.

RESULTS

We identified 6511 glioblastoma patients who underwent SOC therapy with available MGMT methylation status. SOC was initiated in 228 (3.5%), 2478 (38.1%), 2954 (45.4%), 646 (9.9%), and 205 (3.2%) patients at 0-2, 2-4, 4-6, 6-8, and >8 weeks after surgery. For craniotomy patients, initiation of SOC at 0-2 weeks was associated with an increased risk of death relative to SOC initiation at 4-6 weeks (HR: 1.19, p = 0.036). These results remain robust after controlling for the extent of resection, tumor size, and tumor location (HR: 1.19, p = 0.044). Such association was not observed in patients who underwent stereotactic biopsy (HR: 1.27, p = 0.148). Patients who received SOC at 6-8 weeks post-craniotomy (HR: 0.96, p = 0.420) or biopsy (HR: 0.93, p = 0.628) did not appear to worsen survival outcomes.

CONCLUSION

Optimal timing for initiation of SOC differ for craniotomy and needle biopsy patients. Initiating SOC within 2 weeks after craniotomy could lead to worse survival outcomes for GBM patients.
EPCO-08. CONSERVED FEATURES OF TERT PROMOTER DUPLICATIONS REVEAL AN ACTIVATION MECHANISM THAT MIMICS HOTSPOT MUTATIONS IN CANCER
Authors: Suwala Abigail , Barger Carter , Soczek Katarzyna M , Wang Albert S , Kim Min Y , Hong Chibo , Doudna Jennifer A , Chang Susan M , Phillips Joanna J , Solomon David A , Costello Joseph F
Published: November 2022

Mutations in the TERT promoter are the single most common non-coding mutation in cancer and represent the genetic underpinnings of tumor cell immortality. Beyond the two most common point mutations, G228A and G250A, which selectively recruit the ETS factor GABP to activate TERT, the significance of other variants in the TERT promoter are unknown. We identified duplications of wildtype sequence within the core promoter region of TERT in 7 different cancer types that have strikingly similar features including size, insertion position, and inclusion of one of the native ETS motifs. Each duplication activates the TERT promoter to a similar level as G228A and G250A and is critically dependent on the insertion site. The GABP tetramer binds to the TERT duplicated promoter sequence by virtue of the native ETS motif and its duplicated version with precise spacing, and it is necessary for the transcriptional activation by all duplications tested. Spatiotemporal analysis in a multifocal glioblastoma shows the duplication is clonal and its activation of TERT is readily detectable at the single cell level and in bulk tumor tissue. We conclude that recurrent TERT promoter duplications of the native ETS sequence are functionally and mechanistically equivalent to the hotspot mutations that confer tumor cell immortality. The shared mechanism of these divergent somatic genetic alterations suggests a strong selective pressure for recruitment of the GABP tetramer to activate TERT.
EPCO-11. GATEKEEPER INACTIVATION DRIVES TUMOR PROGRESSION TO GRADE IV ASTROCYTOMA
Authors: Hartewig Anja , Granberg Kirsi , Jaatinen Serafiina , Tiihonen Aliisa , Annala Matti , Vuorinen Elisa , Kivinen Anni , Rauhala Minna , Maass Kendra , Pajtler Kristian , Yli-Harja Olli , Helén Pauli , Haapasalo Joonas , Zhang Wei , Haapasalo Hannu , Nykter Matti
Published: November 2022

IDH-mutant low-grade diffuse astrocytomas frequently progress to grade IV astrocytomas with implications for patient prognosis. To better understand this process, we applied whole-genome and transcriptome sequencing to matched tumor samples collected before and after progression to grade IV astrocytomas from five patients. All tumors carried an IDH1 mutation. The number of chromosomal rearrangements was increased between 1.3 and 3.5-fold in the tumors upon progression, with the exception of one case, in which the increase was only 1.03-fold. This case exhibited a hypermutation signature caused by homozygous deletion of the MSH2 gene, which encodes a member of the DNA mismatch repair complex. The most common genomic alterations acquired at progression were homozygous deletions in the CDKN2A/ RB1 -pathway or hemizygous deletion of PTEN. Additionally, PDGFRA was amplified in two grade IV tumors, with concordantly increased expression. For one of these cases, a PDGFRA-amplified subclone is likely to be present already in the low-grade astrocytoma. We further detected intrachromosomal rearrangements closeby the genes NRG3 in the progressed tumors as well as in the The Cancer Genome Atlas (TCGA) cohort. The expression of NRG3 decreased with increasing grade in the TCGA cohort and the gene was frequently deleted. Lower NRG3 expression was associated with shorter survival in the TCGA cohort. Several miRNAs showed differential expression upon progression. For two miRNAs the predicted targets were associated with cell cycle regulation and we detected inverse correlation between miRNA and target mRNA expression. While progression seems to occur via different pathways, the predicted outcome for many of the alterations was the inactivation of tumor suppressor genes and further dysregulation of cell proliferation.
EPCO-24. MULTI-OMIC PROFILING OF PATIENT-DERIVED SUBCLONES IDENTIFIES AGGRESSIVE CELLULAR SUBPOPULATIONS IN PAEDIATRIC DIFFUSE HIGH GRADE GLIOMAS (PDHGGS)
Authors: Kessler Ketty , Grabovska Yura , Burford Anna , Temelso Sara , Tari Haider , Molinari Valeria , Crampsie Shauna , Yu Lu , Choudhary Jyoti , Proszek Paula , Hubank Mike , Mackay Alan , Jones Chris
Published: November 2022

Paediatric-type diffuse high-grade gliomas are classified into distinct subgroups based upon their location and defining molecular alterations, with very poor clinical outcomes in patients >3yrs. This extensive inter-tumour heterogeneity is further complicated by a wide diversity of genotypically- and phenotypically-distinct subclonal populations within individual tumours, providing a substantial barrier to developing effective treatments. We aimed to understand the dynamic cellular make-up of PDHGGs such that novel strategies aimed at targeting specific subpopulations based upon their contribution to disease progression as whole may be employed. Two complementary approaches have been undertaken to address this – first by carrying out single-cell profiling of bulk specimens, and the second isolation and propagation of single-cell-derived stem cell-like cultures in vitro. To-date we have studied 10 cases and a total of 218 subclonal colonies from both DMG-H3K27 and DHG-WT. In a spinal metastatic case of DMG-H3K27, lpWGS/FISH highlighted subpopulations driven by mis-segregation of amplified oncogenic ecDNA, and mutually exclusive subpopulations defined by MYCN, PDGFRA and CCND1. Through integrated analysis of scRNA-seq and scATAC-seq, we show distinct chromatin accessibility profiles to underlie gene expression signatures defining unique subpopulations of cells. In addition to cycling populations and those associated with lineage-specificity, we identified ‘aggressive’ subpopulations defined by significant upregulation of immediate early response genes such as FOS/FOSL1/JUN, those associated with promotion of invasion/migration such as SERPINs and MMPs. These subpopulations could be mapped to isolated single-cell-derived subclones with highly proliferative and/or motile phenotypes, defined by comprehensive profiling of expressed and secreted proteins. Differential cis-regulation driving cell identity/tumorigenesis was found in one example to occur via a trans-histone mechanism mediated by an H4-lysine-methyltransferase, KMT5B. Application of functionally-defined interventional strategies aimed at disrupting the interactions between these subpopulations based upon evolutionary biology principles may offer a novel approach to treat these otherwise incurable tumours in children and young adults.
EPCO-31. AI-BASED PROGNOSTIC STRATIFICATION OF GLIOBLASTOMA USING H&E-STAINED WHOLE SLIDE IMAGES
Authors: Baheti Bhakti , Nasrallah MacLean , Bakas Spyridon
Published: November 2022

BACKGROUND

Glioblastoma is the most common and aggressive malignant adult brain tumor, with median overall survival (OS) of 14 months. Despite optimizations in the treatment regime and technological advancements, patient OS has remained unchanged for the last 20 years. Here we seek the prognostic stratification of glioblastoma patients, by virtue of distinct morphological patterns apparent in histopathology H&E-stained whole slide images (WSI) alone.

METHODS

We selected 271 (ntraining/nhold-out-test= 216/55) frozen digitized tissue sections, at 10x magnification, of untreated primary glioblastoma (IDH-wildtype) adult cases from the TCGA-GBM collection, without history of previous glioma and with post-operative OS > 30 days. The median OS across cases was used to divide them into short- (< 324 days) and long- ( > 390 days) survivors, after excluding 5 percentiles of cases around this median. Each WSI was partitioned in non-overlapping 256x256 patches. A pre-trained VGG16 AI model automatically extracted a 512-dimensional feature vector from each patch. Dimensionality was reduced, from 512 to 8, using principal component analysis, and distinct groups of morphological patterns were identified with unsupervised clustering. The number of distinct groups was decided based on the silhouette coefficient, assessing goodness of clustering. The proportions of these patterns within each WSI, describing the tumor’s spatial heterogeneity, were used to distinguish between short- and long-survivors using gradient boosting.

RESULTS

We identified morphological patterns of 5 distinct groups, descriptive of cellularity differences as well as artifactual content. Quantification of these patterns’ proportions resulted in a classification accuracy of 72.72% (short- vs long-survivors).

CONCLUSIONS

We identified morphologic patterns within a WSI, associated with shorter and longer OS. These may allow the clinical neuropathologist to i) provide additional prognostic information gleaned during microscopic assessment to the treating team, and ii) suggest avenues for further biological investigations towards contributing to our mechanistic understanding and potentially treating of glioblastoma.
EPCO-37. IDENTIFICATION OF KEY EPIGENETIC REGULATORS FOR MEDULLOBLASTOMA INVASION AND METASTASIS
Authors: Jangde Nitish , Walter T Jordan , Ruiz Luz , Ayad Nagi
Published: November 2022

Medulloblastoma (MB) is most common type of pediatric brain cancer. It starts from the hind brain or cerebellum. It is actually an embryonic malignant cancer of the cerebellum is mainly reported over 20% of all central nervous system (CNS) neoplasms in children. MB frequently affected the 3.8-6.9 per million children population in North America and Europe. MB embracing four subgroups: Sonic Hedgehog, Wingless, Group 3, and Group 4. However, the molecular and cellular factors and their mechanism in compelling the maintenance of malignancy are have not well understood. Invasion of tumor cells across the extracellular matrix to the other neighboring tissues is main key event critical for metastasis of the medulloblastoma metastasis. Several factors affect the medulloblastoma genesis, progression, invasion and metastasis. But epigenetic regulators are the crucial regulators MB progression, invasion and metastasis. In order to identify the key regulators for medulloblastoma progression, invasion and metastasis we are doing CRISPR epigenome library screening targeting more than 500 epigenetic genes and 4 guide RNAs targeting each for brain medulloblastoma cells (ONS76 and D425 cells). Initially we have transduced cells with epigenome CRISPR library with different titers to determine the effective viral titer to transfect 30% or lesser number of cells. So that each transduced cell has each guide RNA targeting each gene. Further the transduction was scaled up and after selection the cells were expanded. Further in vitro invasion assay the invaded and un-invaded cells were collected across the Matrigel matrix coated membrane. Along with further enrichment and expansion of these cells we isolated the genomic DNA and sequenced them. The present CRISPR epigenome sequencing analysis targeting invasion property of medulloblastoma cells may provide novel key epigenetic factors affecting the medulloblastoma invasion and eventually metastasis might be the novel and more effective therapeutic target for medulloblastoma treatment.
DISP-06. POPULATION-LEVEL DETERMINANTS OF SOCIO-DEMOGRAPHIC, TUMOR, AND TREATMENT FACTORS IN GLIOBLASTOMA USING SEER DATABASE (1997-2016)
Authors: Yoo Wonsuk , Garcia Michael , Kennedy William , Sanai Nader
Published: November 2022

BACKGROUND

Although socio-demographic and treatment factors have been separately linked to impact on prognosis in several GBM studies, no studies to date have collectively evaluated many potential individual patient and treatment-related factors and their impact on survival in GBM in a comprehensive, multi-institutional, population-based manner. The purpose of this study is to identify sociodemographic, tumor, treatment, and clinical characteristics affecting survival in GBM using a large cancer registry database, the Surveillance Epidemiology End Results (SEER) registry, and identify strategies to reduce risk and disparities for patients with GBM.

METHODS

Individual-level data were obtained from SEER 18 program (1997-2016) using SEER*Stat software. New variables on urban-rural area and treatment combination among surgery, radiotherapy, and chemotherapy were created to comprehensively identify determinants affecting survival in GBM. Univariate and multivariate survival analyses were performed to estimate median survival time using Kaplan-Meier methods and to evaluate the relative risks of potential determinants using Cox hazard methods.

RESULTS

(1) The important determinants include age, gender, race, rural-urban area, diagnostic confirmation, tumor size, resection type, metastases, laterality, treatment effects and combined effects. (2) In addition to the standard treatment on GBM, the socio-demographic and clinical factors like rural-urban area (access to hospital), diagnostic conformation, and report type were important to reduce the risk to GBM patients. (3) Coming to modern times, survival time and survival rate have improved, especially in terms of socio-economic factors of people living in metro areas and married people (HR = 0.897 to 0.813 for metro area and HR = 0.999 to 0.918 for married status).

CONCLUSIONS

Our findings of higher risk determinants in GBM might lead to better prognosis in GBM with socio-demographic and clinical factors affecting the survival in GBM. The future investigation including MGMT promoter methylation might be beneficial with better understanding of determinants affecting risk in GBM.
DISP-07. SURVIVAL ANALYSIS OF GLIOBLASTOMA PATIENTS IN PENNSYLVANIA ACCORDING TO AREA DEPRIVATION INDEX AND IDH STATUS
Authors: Baroz Angel , Stahl Caleb , Bhanja Debarati , Wilding Hannah , Mansouri Alireza
Published: November 2022

INTRODUCTION

Glioblastoma (GBM) is the most aggressive primary brain tumor with a universally poor prognosis. Living in disadvantaged neighborhoods is associated with poor health outcomes, including increased cancer incidence. This study was designed to elucidate the relationship between GBM patients’ survival, isocitrate dehydrogenase (IDH) mutation status, and residential areas of deprivation in the state of Pennsylvania.

METHODS

Patients from Pennsylvania with a pathological diagnosis of GBM WHO Grade IV between January 2007 and December 2018 were retrospectively reviewed in the Penn State Health database. Demographic variables and molecular features were assessed. Area Deprivation Index (ADI) is a validated measure of regional socioeconomic deprivation that indexes neighborhoods by percentile, with low ADI scores representing less deprivation. Patients were assigned to low ( < 50) or high ( ≥ 51) ADI groups. Survival was measured against IDH status and ADI score; log-rank tests were performed.

RESULTS

121 GBM WHO Grade IV patients were identified (median age at diagnosis: 63, 39.7% female, 60.3% male, 93.4% of white race). Among those, 64 (52.9%) had low ADI, and 57 (47.1%) had high ADI. Patients with high ADI had similar overall survival (OS) rates and progression free survival (PFS) at 18 months (56% OS, 95% confidence interval [CI]: 48-64%; 37.4% PFS, 95%CI: 30-44%; P=0.27) compared to patients with low ADI (50% OS, 95%CI: 43-57%; 32.4% PFS, 95%CI: 26-39%; P = 0.27). Further classification by IDH status resulted in 17 (14%) IDH mutant (IDHm) and 104 (86%) IDH wildtype (IDHwt) patients. Survival analysis demonstrated no significant difference in OS between IDHwt and IDHm patients, regardless of ADI score.

CONCLUSION

The aggressive nature of GBM requires early diagnostic approaches to impact survival. Living in socioeconomic disadvantaged areas may diminish survival outcomes; however, our data indicate that GBM may be too aggressive for ADI to have a significant impact on prognosis.
DISP-12. RACIAL DISPARITY IN LENGTH OF STAY FOLLOWING CRANIOTOMY FOR PRIMARY BRAIN GLIOMA
Authors: Lockard Gavin , Gordon Jonah , Alayli Adam , Tran Nam
Published: November 2022

Introduction

The racial disparities of opportunity to receive the appropriate surgical intervention and insurance coverage for adjuvant care may result in surgical outcome and survival disparities among different races. Length of stay (LOS) is an important quality metric measure for determining the distribution of medical resources and their consumption. This study aims to provide a perspective on racial disparities in the overall length of stay and complications for patients undergoing craniotomy for primary brain glioma.

METHODS

The authors performed a retrospective chart review of all patients who underwent craniotomies for resection of primary brain tumors at the Moffitt Cancer Center from 2004-2018. Patients age, race, tumor type, comorbidities, length of stay and complications were reviewed.

RESULTS

A total of 701 patients underwent craniotomies for primary brain glioma, but 66 were excluded due to insufficient follow-up or incomplete records. The racial categories include Caucasians, African American, Asian, Hispanic, and other. Due to the prevalence of Caucasians, the minorities groups were pooled as non-Caucasians. Both cohorts were similar in baseline comorbidities, KPS, tumor characteristics, and surgical factors. Mean LOS remained lower for Caucasians versus non-Caucasians (3.6 vs. 5.5 d). The differences in LOS remain among different tumor types, including GBM (4 vs. 6.7 d), anaplastic astrocytoma (2 vs. 4.4 d), and oligodendroglioma (2.3 vs. 3.7 d). Interestingly, among astrocytoma, Caucasians had a longer LOS (3 vs 1.2 d).

CONCLUSION

Our results highlight disparate treatment patterns that reflect in LOS among patients undergoing craniotomies for primary brain gliomas. These findings warrant further investigation regarding current health-care practices and policies.
DISP-16. NUTRITIONAL SCREENING OF PEDIATRIC CENTRAL NERVOUS SYSTEM TUMOR SURVIVORS REVEALS HIGH PREVALENCE OF MALNOURISHMENT WITH SOCIODEMOGRAPHIC AND CLINICAL RISK FACTORS
Authors: Wilson Rebekah , Soja Jacqueline , Yunker Alexandra , Aziz-Bose Rahela , Gordon Erin , Dieli-Conwright Christina , Cooney Tab
Published: November 2022

Adult survivors of pediatric central nervous system (CNS) tumors are at the highest risk for morbidity and late mortality among all childhood cancers, partially due to chronic health conditions intersected with environmental and lifestyle factors. We aimed to study the prevalence of and risk factors for malnourishment (underweight, overweight, obese) amongst adult survivors of pediatric CNS tumors. We conducted a cross-sectional study assessing young adults (18-39 years) previously treated for pediatric CNS tumors who were followed in our survivorship clinic during 2016-2021. Sociodemographic, clinical, and treatment information was extracted from medical records with BMI status, per CDC guidelines, obtained from the most recent clinic visit. Data was assessed using one-way ANOVA, fishers exact test, and multivariable logistical regression. We identified 198 survivors (53% female, 84.3% white) categorized as underweight (4.0%), normal weight (40.9%), overweight (26.8%), obese (20.2%), and severely obese (8.1%). Patients were median age 8 years [4-12] at diagnosis and 24 years [20-28] at follow-up. Most common primary diagnosis and tumor location was low grade glioma (50.5%) and posterior fossa (39.4%) with 90.4% receiving surgery, 51.5% chemotherapy, and 52.5% radiotherapy. Male sex (OR 2.376, p = 0.006), hypothalamic/optic pathway tumor location (OR 2.362, P = 0.031), and radiation therapy (OR 2.844, p = 0.005) were associated with increased overweight/obesity risk, while chemotherapy (OR 0.363, p = 0.006) was associated with decreased risk. Male sex (OR 0.511, p = 0.007) and white ‘race’ (OR 0.166, p = 0.022) were associated with decreased underweight risk. The majority of young adult survivors seen in our clinic were not healthy weight by BMI, and the distribution of BMI groups appears comparable to contemporary studies of the general young adult U.S. population. The prevalence of malnourishment amongst PNO survivors warrants universal screening efforts with more accurate determinants of body composition than BMI, risk stratification, as well as targeted interventions.
IMMU-03. ANALYSIS OF EXPRESSION SIGNATURES OF MATCHED PRIMARY GASTROINTESTINAL CANCER AND BRAIN METASTASES USING NANOSTRING NCOUNTER TECHNOLOGY
Authors: Cheko Azad , Burnside Georgiana , Vogel Hannes , Gephart Melanie Hayden , Petritsch Claudia
Published: November 2022

BACKGROUND

Brain metastases from the gastrointestinal tract are a rare event (less than 10% of all brain lesions), but their impact on prognosis is remarkable. Their incidence is increasing due to earlier diagnosis and prolonged survival because of more effective treatment modalities. Because of the lack of evidence-based recommendations, no optimal treatment strategy has been defined. Hope might come from the discovery of new prognostic and predictive factors and their biological inhibitors. The aim of this study was to create a repository of matched primary cancer and brain metastases samples for clinicopathologic and molecular correlations of gastrointestinal tumors and to analyze changes in expression signatures between both samples. The main goal was to study the metastatic process and characterize the immune response by characterizing features such as invasiveness, vascular co-option, proliferation, stemness and cell-type heterogeneity between the matched tissues.

METHODS

We searched for patients at Stanford hospital with matched brain metastases from gastrointestinal tumors from 2008 to 2020 using the STARR database (The STAnford Research Repository, or STARR, is Stanford Medicine's approved resource for working with clinical data for research purposes.). Matched specimens mean that both brain metastases and gastrointestinal tumors were studied at Stanford University. FFPE blocks from these matched patients were sectioned and sections analyzed for gene expression analysis using nanoString nCounter technology and the immune-oncology panel.

RESULTS

Expression data from 32 matched patients with primary tumor and brain metastases will be discussed at the meeting.

CONCLUSION

We believe that analysis of changes in expression signatures between the matched primary gastrointestinal cancer and brain metastases will provide novel insights into the role for tumor factors, such as invasiveness, proliferation and stemness, and the tumor microenvironment in progression.
IMMU-10. EXPLORING THE IMMUNOLOGIC CONSEQUENCES OF ATRX DEFICIENCY IN GLIOMA
Authors: Whitfield Benjamin , Huse Jason , Irvin David , Dharmaiah Sharvari , Malgulwar Prit Benny , Roberts Hannah
Published: November 2022

ATRX is a key chromatin regulator, which is mutated in large subsets of both adult and pediatric gliomas. Despite being a common mutation, little is known about the biological ramifications of ATRX deficiency. Recently, it has been demonstrated that ATRX deficiency drives increased replication stress, DNA damage, and global epigenetic dysregulation. Despite these advances, little is known about the impact of ATRX deficiency on the tumor microenvironment (TME). In order to explore the impact of ATRX deficiency on the TME we utilized the RCAS/nTVa system to generate a novel murine model of ATRX deficient glioma. Mice bearing allografts of these tumors displayed significantly increased survival relative to the ATRX intact lines. This survival benefit persisted in Nu/nu mice, which lack an adaptive immune system, but not in SCID mice, which lack both adaptive and innate immunity. Bulk RNA sequencing revealed the ATRX deficient tumors displayed increased expression of inflammatory and innate immune gene sets, and western blotting revealed increased phosphorylation of tank binding kinase 1 (TBK1), a key innate immune regulator. Multiplex cytokine analysis of conditioned media also revealed increased expression of inflammatory cytokines such as CCL2, CCL5, and CXCL10 in the supernatant of ATRX deficient cell lines. Taken together, these results indicate that ATRX deficiency can drive innate immune activation, and that this activation can increase survival in vivo. Further exploration is needed to characterize the upstream drivers of TBK1 activation and elucidate alterations to immune cell infiltration in ATRXdeficient tumors.
IMMU-11. NONO IS A NEW ADENOVIRUS SENSOR: IMPLICATION FOR VIROTHERAPY
Authors: Gillard Andrew , Shin Dong Ho , Laspidea Virginia , Singh Sanjay K , Jiang Hong , Kim Debora , Fan Xuejun , Yi Yanhua , Lang Frederick , Alonso Marta M , Fueyo Juan , Gomez-Manzano Candelaria
Published: November 2022

The median survival for GBM patients is 15 months with a five-year survival rate of less than 10%. Current conventional and experimental treatments, including immune checkpoint blockade, have not improved outcomes in the vast majority of glioma patients. Oncolytic viruses (OVs) are designed to specifically infect and lyse cancer cells to elicit an anti-tumor immune response. In a clinical trial developed by the MDACC team, 20% of GBM patients treated with the oncolytic adenovirus Delta-24-RGD showed complete response and survival longer than three years (NCT00805376). Although these studies have shown that robust immune responses can be invoked using oncolytic virotherapy, the molecular mechanisms underlying OV-mediated anti-tumor immunity remain elusive. Exposure to viruses by innate immune sensors induces protective antiviral immunity. Using bulk RNA sequencing of cells infected with adenovirus we identified the main upstream regulators of the innate immune response including IFN gamma, Interferon responsive genes 3 and 7, and STAT3. However, RNAseq unexpectedly uncovered NONO (Non-POU Domain Containing Octamer Binding) as the most relevant upstream regulator. In agreement with the RNAseq data, Protein analyses demonstrated the upregulation of NONO after adenovirus infection. In addition, immunofluorescence and confocal microscopy examination of the infected cells showed the overexpression and translocation to the nucleus of NONO upon virus infection. We are the first laboratory that has identified NONO as a sensor of adenovirus infection, which may have great significance for the future development of oncolytic viruses. Importantly, we discovered the network of proteins that are upregulated after NONO activation and, finally, we have established that changes in the expression level and subcellular localization of NONO are coincident in time during the infection of cultured cells. Future work is focused on examining the immunomodulatory functions of NONO in adenoviral infected tumors and subsequent generation of NONO-resistant oncolytic adenovirus.
IMMU-32. SPERMIDINE DRIVES GLIOBLASTOMA PROGRESSION VIA SELECTIVE MODULATION OF THE IMMUNE SYSTEM
Authors: Kay Kristen , Bayik Defne , Wang Zeneng , Brown J Mark , Hazen Stanley , Lathia Justin
Published: November 2022

Glioblastoma (GBM) is incurable despite aggressive standard of care treatments (maximal safe surgical resection, radiation, chemotherapy). GBM therapeutic resistance is due to multiple factors, including tumor heterogeneity and a highly immunosuppressive environment. Naturally occurring polyamines have been identified as a putative therapeutic target in other cancers based on their increased presence and function in normal conditions; they are critical for cell growth and proliferation and cellular functions including autophagy and apoptosis. While polyamines are increased in GBM patients, little is known about their impact on GBM growth. In syngeneic immune competent mouse glioma models (GL261, SB28), mass spectrometry data revealed that spermidine (SPD) – a member of the polyamine family – is increased in tumor tissue as compared to non-neoplastic control brain tissue (sham implanted animals). To test the impact of SPD on tumor growth, we treated mouse glioma models with exogenous SPD and found treatment significantly decreased survival. However, in immunocompromised host mice, no such difference was observed, indicating the mechanism through which SPD is driving GBM progression likely involves immune system alterations. Depletion of myeloid derived suppressor cells in vivo via anti-Gr-1 antibody rescues the decrease in survival caused by exogenous SPD, indicating that SPD drives GBM by affecting immune-suppressive cell subsets, namely MDSCs. To assess if SPD is associated with more aggressive GBM growth in human patients, we are currently analyzing polyamine levels in human GBM samples of long vs short term survivors. We are also exploring the effect of dietary polyamines on GBM via the gut-brain-microbiome axis, as polyamines are enriched in many foods and produced by a subset of commensal gut microbes. Understanding the interactions between polyamines, the tumor microenvironment, and the immune response provide a new mechanism for GBM regulation and identify opportunities to alter the environment in the body to enhance immunotherapeutic efficacy.
INNV-03. THE YIELD OF SCREENING MRI AMONG STAGE IV NON SMALL CELL LUNG CANCER PATIENTS
Authors: Waizman Efraim , Lavie Inbar , Amiel Alexandra , Siegal Tali , Dudnick Elizabeth , Yust-Katz Shlomit
Published: November 2022

BACKGROUND

Brain metastases are a common complication of non small cell lung cancer (NSCLC). Approximately 10 percent of newly diagnosed patients with advanced NSCLC have brain metastases. The purpose of this study was to determine whether using magnetic resonance imaging (MRI) for early screening of brain metastases can improve survival. Material and

METHODS

A retrospective analysis of newly diagnosed stage IV NSCLC treated at Davidoff Cancer Center, Israel, between the years 2019-2020. Only patients who were neurologically asymptomatic were included in the study. The study population was divided into two groups. Group A included patients who underwent screening MRI within 12 weeks form diagnosis and group B included those who did not undergo screening MRI. Clinical and radiographic data were collected form the medical records.

RESULTS

379 patients were included in the study, of whom 170 underwent screening MRI. Of the patients who underwent screening MRI 54 were diagnosed with brain metastases. On univariate analysis screening MRI was corelated with better survival [group A median survival 24 month, group B median survival 18 month, p=0.003 HR 1.4 CI 1.12-1.75]. On multivariate analysis that included functional status (ECOG 0-2 compared to 3 and above) and age- screening MRI corelated with survival (p=0.04 HR 1.28 CI 1.02-1.6). Subgroup analysis according to molecular subgroup will be presented in the conference.

CONCLUSION

In this study screening MRI among stage IV NSCLC correlated with better survival even when adjusted to functional status and age.