Adult High-grade Gliomas Research Articles

EXTH-20. EXPLORING EUPHOL’S THERAPEUTIC EFFECT IN ADULT AND PEDIATRIC BRAZILIAN HIGH-GRADE GLIOMAS PRE-CLINICAL MODELS

Abstract High grade gliomas (HGG) are among the most aggressive brain tumors affecting both adults and children. Adult HGG (aHGG) account for almost 25% of all brain tumors in adults, with glioblastoma (GBM) being the predominant subtype. Pediatric HGG (pHGG), though less common, accounts for 3-15% of primary brain tumors in children and exhibits distinct genetic profiles compared to aHGG. Standard treatment for HGG in both adults and pediatric patients includes maximal surgical resection followed by temozolomide (TMZ)-based chemotherapy and radiation therapy. Our group previously reported that euphol, a natural compound derived from the sap of Euphorbiaceae family plants, exerts cytotoxicity effects on glioma cells. In this study, we investigated the therapeutic potential of euphol in primary cell cultures and xenograft models derived from six Brazilian HGG patients, including three adults and three pediatrics. In vitro, euphol exposure significantly reduced cell viability reduction, clonogenic capacity, and migration, while enhancing apoptosis in all six primary cultures. Additionally, euphol sensitized glioma cells to TMZ, resulting in a synergistic cytotoxic effect. In vivo, euphol reduced tumor growth in both GBM and pHGG models, and prolonged the survival of mice in the GBM orthotopic experiment. These findings highlight the promising therapeutic potential of euphol for treating high-grade gliomas in both adult and pediatric populations.

BIOM-23. DEUTERIUM METABOLIC IMAGING OF RESPONSE TO PRECISION THERAPY IN BRAF-V600E MUTANT GLIOMAS

Abstract Oncogenic BRAF-V600E mutations are frequently observed in low- and high-grade gliomas in adults and children. BRAF transduces signals from receptor tyrosine kinases to downstream effectors such as MEK1/2 and ERK, which regulate both metabolism and proliferation. The combination of the BRAF-V600E inhibitor dabrafenib and the MEK1/2 inhibitor trametinib (Dab/Tra) improves patient survival. However, there is considerable variation in the durability of response, underscoring the need for early biomarkers of treatment response. Magnetic resonance imaging (MRI), which is the gold standard for patient management, does not reliably assess response to therapy. Since the BRAF/MEK pathway regulates metabolism, the goal of this study was to determine whether Dab/Tra induces alterations in glucose metabolism that can be leveraged for non-invasive imaging. Using gene expression profiling, in vivo metabolomics, and stable isotope tracing, we show that Dab/Tra downregulates glucose metabolism to lactate in human and murine BRAF-V600E mutant models (AM38, 2341). In vivo infusion with [U-13C]-glucose in mice bearing intracranial AM38 tumors confirmed that Dab/Tra downregulates glucose metabolism to lactate in the tumor in vivo. Mechanistically, Dab/Tra destabilizes hypoxia inducible factor-1a and downregulates glycolytic genes, including SLC2A1, HK2, PFKFB3, and LDHA. Deuterium metabolic imaging (DMI) is a novel, clinical stage method of tracing glucose metabolism in vivo. Our studies show that lactate production from [6,6-2H]-glucose is reduced in AM38 and 2341 cells treated with Dab/Tra. Importantly, lactate production is reduced within 48 h of treatment with Dab/Tra in mice bearing intracranial AM38 tumors at the clinical magnetic field strength of 3T. Furthermore, this drop in 2H-lactate production is observed in the absence of MRI-detectable volumetric alterations and is predictive of extended survival. Collectively, our studies mechanistically link BRAF/MEK inhibition with downregulation of glycolysis and identify [6,6’-2H]-glucose as a novel contrast agent for imaging early response to therapy. Clinical translation of our studies will enable precision imaging of response to therapy for patients with BRAF-mutant gliomas.

CSIG-09. BEYOND SINGLE AGENTS: EXPLORING THE POTENTIAL OF ABEMACICLIB IN COMBINATION WITH PANOBINOSTAT FOR IMPROVED GLIOMA TREATMENT

Abstract BACKGROUND Glioblastoma is the most common primary central nervous system tumour with a median survival of less than 15 months. Addressing the underlying redundant, and converging signaling pathways necessitates the utilization of small molecule inhibitors capable of simultaneous targeting and inhibition. In glioma, the aberrant CDK4/6-Rb pathway dysregulation resulting in disruption of cell cycle checkpoint progression can lead to uncontrolled cell division, a hallmark of cancer. The neuro-pharmacokinetics of abemaciclib, a Cyclin-dependent kinase inhibitor, is being currently investigated in phase 1 clinical trials by National Cancer Institue, [NCT05413304]. The importance of panobinostat as a Histone deacetylase inhibitor and potentiating the effects of various small molecular inhibitors in published literature is paramount. This study is based on investigating ways to overcome resistance by exploring the synergistic cytotoxic effects of abemaciclib in combination with panobinostat in glioma. METHODS We investigated the antiproliferative effects of abemaciclib and panobinostat on glioma cells using an MTS cell proliferation assay. Inhibitor combination analysis was done using, SYNERGYFINDER via zip-model. Flow cytometry with Annexin V staining further assessed cell death and apoptosis induced. RESULTS The antiproliferative effects of abemaciclib, alone and in combination with panobinostat, in pediatric lines (KNS 42, SJG2), and adult human glioblastoma line, SF188 exhibited lower IC50 as compared to adult high grade glioma lines (LN 18, LNZ 308). Synergy analysis revealed a strong cytotoxic effect in KNS 42 and SF 188 cells treated with the combination. Flow cytometric analysis indicated that the combination therapy induced significant cell death only in a subset of cell lines- KNS 42 and SF 188, suggesting underlying genetic heterogeneity influences treatment response, warranting further mechanistic studies. CONCLUSION Combination therapies using abemaciclib and panobinostat, targeting CDK4/6 and histone deacetylation pathways, show promise against aggressive and treatment-resistant gliomas. Further investigation into these combination approaches is crucial to understand resistant mechanisms, optimize efficacy, and establish their clinical efficacy for improving glioma patient outcomes.

CNSC-68. SEX DIFFERENCES IN GLYCINE BIOSYNTHESIS DRIVE RESPONSES TO COMBINED NUTRIENT DEPRIVATION AND PHARMACOLOGICAL INHIBITION IN PEDIATRIC HGG

Abstract In children and adults, high-grade gliomas (HGGs) are the most common and deadly primary brain malignancies. Generally, male HGGs occur at higher incidence and demonstrate more rapid proliferation, resulting in shorter overall male survival. Obscurity of molecular mechanisms driving this phenomenon prevents implementation of clinically effective treatments. Recently, a positive correlation between HGG cellular proliferation and metabolic reprogramming toward glycine biosynthesis was identified. By analyzing pediatric and adult HGG patient data, we discovered significantly worse outcomes unique to pediatric males bearing upregulation of serine and glycine biosynthesis transcripts. Previously, we have identified differential flux of glucose into serine and glycine biosynthesis drives sex differences in lung cancer. Therefore, we sought to confirm and target this paradigm in our NF1-/- DNp53 model of HGG. By performing metabolic tracing with [13C]-labeled glucose in male and female cells, we identified higher enrichment of [13C]-labeled serine and glycine in male cells relative to female cells. Through Western blotting, we identify male-specific upregulation of serine and glycine biosynthetic pathway enzymes in transformed cells, supporting our labelling results. Next, we sought to determine if inhibition of de-novo serine and glycine biosynthesis was similarly sex-biased. Utilizing serine-and-glycine-deprived media conditions, we identified a male-biased decrease in proliferation following pharmacological inhibition of de-novo serine and glycine biosynthesis. More precisely, in the absence of exogenous glycine, we discovered that inhibition of de-novo synthesis of glycine from serine drove male-specific decreases in proliferation. Additionally, we identified that transformed female cell robustness against inhibition of glycine biosynthesis is driven by the uptake of exogenous nucleotide precursors. These data confirm that sex differences in de-novo glycine biosynthesis drive sex differences in HGG cellular proliferation. As well, our work suggests that dietary restriction of serine and glycine, in-combination with pharmacological inhibition of de-novo glycine biosynthesis, represents a novel treatment paradigm.

RADT-34. RE-IRRADIATION REGIMENS FOR RECURRENT GLIOMA: SURVIVAL AND TOXICITY

Abstract Re-irradiation is a common treatment option for recurrent high-grade glioma (HGG), though the optimal dose-fractionation regimen remains unclear. This report presents single-center data from an ongoing multicenter, retrospective study in the Netherlands. We included adult HGG patients treated with re-irradiation. Dose-fractionation regimens were categorized in 3 groups: conventionally fractionated radiotherapy (CFRT, <3Gy/fraction), hypofractionated radiotherapy (HFRT, 3-5 Gy/fraction) and stereotactic radiotherapy (SRT, ≥5Gy/fraction). We compared baseline characteristics, overall survival, and toxicity including incidence of radionecrosis between groups to identify the optimal dose-fractionation regimen. Of 112 patients, 33 underwent CFRT, 60 HFRT and 19 SRT. 21 patients had a good prognostic Niyazi score, 70 intermediate and 6 poor, with more poor scores in the SRT group. SRT patients had smaller median GTVs compared to HFRT and CFRT (1.9, 20.5, 32.8 respectively, p=0.003). Radiation groups also differed in primary histology (less grade 4 in CFRT, p=0.009), but not in age and KPS. Overall survival (OS) was worse for HFRT (median OS 9 months (95%-CI 6.5-11.5)) compared to CFRT (12 months (8.9-15.2, p=0.039)) and SRT (12 months (9.2-14.8, p = 0.012)), but did not differ between CFRT and SRT (p=0.437). In Cox regression, Karnofsky performance score <80 (hazard ratio (HR): 1.874, p=0.006) and large GTV (HR: 1.011, p=0.003) were independently associated with poor survival, while the fractionation schedule was not. Multivariable logistic regression on toxicity analysis indicated an increased risk of radionecrosis in the CFRT and HFRT groups compared to the SRT group (OR 5.861, p=0.011), even after adjusting for GTV and age. In conclusion, re-irradiation schemes in HGG are univariably, but not independently, associated with overall survival; this relationship seems to be confounded by differences in GTV and possibly by KPS. Radionecrosis was more common in HFRT and CFRT than in SRT. Extension and/or validation of findings will be performed in a multicenter cohort.

PATH-10. UTILIZATION OF TUMOR-DERIVED EXTRACELLULAR VESICLES FOR PATIENT STRATIFICATION AND BIOMARKER DISCOVERY

Abstract Liquid biopsy is poised to play an increasingly important role in clinical decision making by enabling earlier cancer detection, diagnosis, patient stratification, and treatment monitoring. Most approaches rely on detection of cell-free circulating tumor DNA or circulating tumor cells in the peripheral blood of cancer patients. However, there are several limitations to these approaches, including miniscule abundance, unfavorable signal to noise ratios, and limited insight into mechanisms driving disease. Extracellular vesicles (EVs) are an alternative liquid biopsy analyte comprising lipid membrane encapsulated particles carrying diverse protein, nucleic acid, and metabolite cargos. Blood plasma of cancer patients contains EVs derived directly from tumor tissue that serve as rich sources of insight into tumor biology and disease pathology. We have developed a clinically applicable, multi-omic EV subpopulation interrogation pipeline that robustly profiles tumor-derived EVs in biofluids. We have demonstrated the ability of the platform to enrich cancer markers and detect activation of pathways driving oncogenesis across several different cancers, including brain cancer. There is a particularly compelling need for liquid biopsy-based solutions in neuro-oncology. We have applied our EV-omic (EVO) pipeline in combination with machine learning to distinguish adult high-grade gliomas from benign brain tumor and healthy patients, using blood-based EV proteomic and transcriptomic signatures. Marker profiles found to be most important for patient stratification combine markers known to be relevant in tumor tissue along with novel features. Furthermore, IDH status and MGMT methylation metadata derived from matched patient tissue for select cases was used to generate unique blood-based profiles for glioma subtypes. Lastly, we show preliminary longitudinal data demonstrating the utility of EVs to track tumor changes post-surgical resection and post-treatment. This work demonstrates that EV-omics can add significant value in the neuro-oncology space.

M6A RNA METHYLATION AS A THERAPEUTIC TARGET IN HIGH GRADE GLIOMA

Abstract AIMS High grade glioma (HGG) is a devastating brain cancer that has poor prognostic outcomes. Very recently, the field of epitranscriptome has emerged as a novel druggable target for multiple diseases, including cancers. In the present study, we sought to investigate the functional importance of N6-methyladenosine (m6A) RNA methylation in the pathogenesis and drug resistance of paediatric and adult high grade glioma. METHOD To identify the expression of key m6A effectors, RT-qPCR and immunofluorescence were undertaken in patient derived HGG cell lines, primary low passage HGG cells and human tissues. The expression of these effectors was modified using siRNA-mediated knockdown and small molecules to identify their effects on key transcription factors. The consequences of modification on the ability of the cells to form neurospheres and invade was also assessed. Developing chemotherapy-resistant cell lines is undertaking to assess the effect of m6A RNA levels on the ability of HGG cells to adapt to environmental changes. Measuring the level of m6A-modified transcripts were achieved by developing LC-MS/MS and MeRIP (methylated RNA immunoprecipitation) qPCR techniques. RESULTS We found that key m6A effectors such as methyltransferase like 3 (METTL3), Wilms tumor 1-associating protein (WTAP) and fat mass and obesity-associated (FTO) are expressed at significantly higher level in paediatric and adult HGG models than in control at both gene and protein levels. Furthermore, these effectors regulate the expression of key transcription factors in self-renewal, cell cycle regulation and tumorigenesis. siRNA-mediated depletion of m6A effectors and inhibition of METTL3 using small molecules such as STM2457 and STM3006 reduce the capacity of cells to form neurospheres and invade as well as improving the sensitivity of HGG cells to chemotherapeutic agents. CONCLUSION Our findings suggest that m6A effectors are potential pro-oncogenic factors that, if druggable, will represent an advanced avenue in HGG therapy.

A Review of Therapeutic Agents Given by Convection-Enhanced Delivery for Adult Glioblastoma.

Glioblastoma remains a devastating disease with a bleak prognosis despite continued research and numerous clinical trials. Convection-enhanced delivery offers researchers and clinicians a platform to bypass the blood-brain barrier and administer drugs directly to the brain parenchyma. While not without significant technological challenges, convection-enhanced delivery theoretically allows for a wide range of therapeutic agents to be delivered to the tumoral space while preventing systemic toxicities. This article provides a comprehensive review of the antitumor agents studied in clinical trials of convection-enhanced delivery to treat adult high-grade gliomas. Agents are grouped by classes, and preclinical evidence for these agents is summarized, as is a brief description of their mechanism of action. The strengths and weaknesses of each clinical trial are also outlined. By doing so, the difficulty of untangling the efficacy of a drug from the technological challenges of convection-enhanced delivery is highlighted. Finally, this article provides a focused review of some therapeutics that might stand to benefit from future clinical trials for glioblastoma using convection-enhanced delivery.

LGG-21. IMMUNE MICROENVIRONMENT PROFILING OF BRAF-FUSION PILOCYTIC ASTROCYTOMA: DIRECTIONAL PRIORITIZATION OF IMMUNOTHERAPEUTIC TARGETS

Abstract BACKGROUND The immune microenvironment of pediatric gliomas is relatively understudied despite being a leading cause of childhood mortality. Pilocytic astrocytomas (PA) are the most common pediatric glioma and surgical resection is often curative. However, PAs are not always amenable to surgery and can have significant long-term morbidity and mortality. The ten-year progression-free survival for PA patients with significant residual tumor is less than 50% and other non-surgical treatment options are frequently necessary. METHODS To identify PA patients that may be responsive to immune checkpoint inhibitors and to guide prioritization of available immunotherapeutic treatments, orthogonal immune profiling strategies were used to identify patients that may benefit from the next generation of immune therapeutics. Because the KIAA1549-BRAF fusion is expressed in 70% of PA, we prospectively collected patients to comprehensively characterize the unique immune biology of these tumors using nanostring profiling, scRNASeq, and SeqIF™ multiplex staining. RESULTS The tumor microenvironment of BRAF-fusion PA was notable for antigen presentation and the interaction of CD11c+ cells with T cells through Lck+ immunological synapses. PA CD11c+CD206+ dendritic cells localized to vessel walls and were positive for TIM3 expression, an immune checkpoint marker. A unique highly activated microglia subcluster was identified that morphologically resembled T cells expressing TNF and TIM3. Our results are consistent with others that suggest potential benefit in targeting tumors with elevated MAPK activity. Finally, the expression of other immune checkpoints such as Lag-3, PD-1, and TIGIT are minimally co-expressed, suggesting that T cells are not in a state of exhaustion, as seen in adult high-grade gliomas. CONCLUSIONS Analysis of BRAF-fusion PA identified a unique highly activated P2RY12+ microglia population dispersed throughout the tumor microenvironment, active antigen presentation between a CD11c+ antigen presenting cells and T cells, and a unique therapeutic opportunity for targeting TIM3.

LGG-60. DISTRIBUTION AND CLINICAL SIGNIFICANCE OF FGFR ALTERATIONS IN PEDIATRIC AND AYA GLIOMAS

Abstract Fibroblast growth factor receptor (FGFR) alterations are prevalent in human cancers. In a large Canadian population-based cohort, encompassing over 1,300 pediatric and Adolescent and young adult (AYA) gliomas, FGFR mutations occurred in 10% of pediatric low-grade gliomas (LGG) and 20% of IDH-WT AYA LGGs. Here we assembled a large multi-institutional cohort including more than 300 mutated gliomas, aged 6 months to 87 years, 53% of which were LGG. High-grade gliomas were more common with increasing age; over 90% of pediatric cases were LGGs, compared to 30% in the AYA group. Fusions, predominantly seen in the pediatric group (70% of LGGs), contrast with FGFR3-TACC3 fusions frequent found in adult high-grade gliomas. Interestingly, FGFR mutations sometimes existed as sole drivers or co-occurred with other alterations (~30%), it is unclear how this alters tumor behavior, although gain of additional alterations could be implied in malignant transformation and poor prognosis. Despite higher incidence of high-grade gliomas in AYAs, their progression-free survival was significantly better than that of pediatric LGGs (p=0.007), largely due to the prevalence of hemispheric tumors amenable to gross total resection. Approximately 30% of our LGG cohort underwent adjuvant therapy; with available data for 28 patients, objective responses were noted in 2/12 to chemotherapy, 2/9 to MEK inhibitors, and 3/7 to FGFR inhibitors, respectively. With the increasing promise of precision targeted therapy, molecular profiling and assessment for FGFR alterations is essential. Although encouraging, further studies are needed to assess the benefit of FGFR inhibition in these patients.

HGG-20. CANCER PREDISPOSITION SYNDROMES IN PEDIATRIC PATIENTS WITH HIGH-GRADE GLIOMAS

Abstract The association between pediatric high-grade gliomas (HGG) and cancer predisposition syndromes (CPS) remains inadequately elucidated in the existing literature, while next-generation sequencing (NGS) is increasingly utilized for diagnostic support. In this retrospective analysis, we evaluated a cohort of 95 consecutive pediatric patients with HGG reclassified according to the latest 2021 WHO classification, diagnosed and treated at the Bambino Gesù Children’s Hospital between 2011 and 2023. All patients underwent genetic germline testing with NGS technology to detect the presence of germline variants predisposing to cancer and were included in this study. Diagnosis of pHGG H3-IDH wild-type was performed in 23 patients (24.2%), diffuse midline glioma in 46 patients (48.4%), astrocytoma IDH-mutant in 7 patients (7.4%), anaplastic pleomorphic xanthoastrocytoma in 4 patients (4.2%), adult type HGG in 4 patients (4.2%), neuroepithelial tumor PATZ1 fusion-positive in 3 patients (3.2%), diffuse hemispheric glioma H3 G34-mutant in 2 patients (2.1%), infant-type hemisheric glioma in 2 patients (2.1%), other rare histologies in 4 patients (4.2%). Oncological family history was investigated up to the third generation for all patients and was positive in 43/95 (45.3%) cases. We identified a total of 65 variants in 95 patients, distributed as follows: 48 variants of uncertain significance (73.8%), 10 likely pathogenic (15.4%), and 7 pathogenic variants (10.8%). Notably, our findings reveal that pathogenic/likely pathogenic variants were detected in about 17% of the entire study population, higher than the 10% incidence reported in the existing literature. The high rate of mutations in CPS associated genes described in our work, leads to consider performing NGS even in the absence of clinical or anamnestic criteria suggestive of it. However, ethical and social issues are to be considered when we propose and investigate patients for CPS. Moreover, further research are needed to determine the role of variants of uncertain significance.

HGG-53. MULTI-DIMENSIONAL INTEGRATIVE PROFILING IDENTIFIES BCL2L1 METHYLATION AS A PREDICTIVE BIOMARKER FOR MCL-1 ACTIVITY IN PEDIATRIC HIGH-GRADE GLIOMAS

Abstract BACKGROUND Pediatric high-grade gliomas (pHGGs) pose a significant challenge as the most aggressive central nervous system tumors in children. The lack of effective treatment and poor survival rates emphasize the critical need for innovative therapies to improve the prognosis of pediatric patients with pHGG. METHODS We executed CRISPR-cas9 knockout (KO) screenings in 65 pediatric and 10 adult high-grade glioma (HGG) cell lines to explore unique functional dependencies associated with pHGGs. Drug assays were carried out to assess the targetability of a gene dependency of interest in pHGG cell lines. Subsequently, Random Forest machine learning algorithm was employed on ‘omics’ datasets to identify biomarkers indicative of drug response. Finally, biomarkers were confirmed through sequencing-based methods across various pediatric cancers. RESULTS CRISPR-cas9 KO screens revealed 8 crucial genes essential for pHGG growth, namely MCL-1, ATIC, DHFR, EED, HDAC2, PARP1, PDK1, PIK3CA and TYMS. Among these, Myeloid Cell Leukemia (MCL-1) was further characterized as it emerged as the top differential genetic dependency in pHGGs. Consistent with this, MCL1 inhibitors exhibited potent anti-cancer activity on 43% of pHGG cell lines. Multi-feature prediction analysis identified 140 features correlated to response. Strikingly, a previously undescribed methylation site within the BCL2L1 locus, cg00300298, ranked in the top 5% of features. Tissue analysis revealed a wide range of other pediatric brain cancers that harbor the BCL2L1 cg00300298 methylation mark as compared to non-malignant brain tissue. Lastly, we validated the utility of BCL2L1 methylation as a predictive biomarker of MCL1 inhibitor sensitivity across a large panel of pediatric brain cancer cell lines. CONCLUSION Using an integrated genomic approach, we identify MCL1 as a distinct therapeutic target in BCL2L1-methylated pediatric brain cancers. This offers a rational approach for stratifying patients who may benefit from MCL1 inhibitors.

Abstract 3955: A proteogenomic study of high-grade glioma among adolescents and young adults

Abstract To unravel the molecular mechanisms underlying high-grade glioma (HGG) in adolescent and young adult (AYA) patients, we conducted a comprehensive proteogenomic analysis for 34 AYA (age 15-40) and 59 pediatric (age 0-15) HGG cases. Our approach involved whole genome sequencing, methylation profiling, RNA sequencing, and a suite of mass spectrometry-based proteomic experiments, including global proteomic, phosphoproteomic, and glycoproteomic profiling. The proteomics study successfully identified and quantified approximately 11,000 proteins, 33,000 phosphosites, and 3000 glycopeptides with a 50% missing filtering threshold. To identify the unique characteristics of AYA HGG in contrast to both pediatric and adult HGG, we further integrated a proteogenomic dataset of 99 adult GBM tumors previously published by CPTAC and collaborators (PMID: 33577785). Our study unveiled a collection of mutations, copy number variations, epigenetic modifications and gene fusions that exhibited different frequencies across tumors from pediatric, AYA, and adult patients. Moreover, the influence of these genetic variations on RNA/protein activities also varied across different age groups. Clustering analysis using age-dependent molecular profiles revealed striking differences in RNA/protein/phosphosite activities between patients aged 15-26 and 26-40. Additionally, significantly better overall survival (OS) was observed in the 26-40 age group compared to all other age groups, highlighting distinct biological characteristics within the AYA category that differentiate adolescents from young adults.By leveraging proteogenomic datasets from normal brain tissues (PMID: 30518843), we identified genes, proteins, and pathways with differential age-dependent molecular profiles between tumor and normal brain tissues. Notably, this analysis highlighted significant alterations in proteins from the oxidative phosphorylation, tricarboxylic acid (TCA) cycle, and myelin sheath pathways in tumors compared to normal tissues, some of which were found to be sex-specific.To search for prognostic markers, we introduced a novel approach called Trans-Population Survival Analysis through Interpolation of Age-Dependent Tumor Molecular Profiles. Applying this method on the kinase activity scores derived from the phosphoproteomic data, we identified 150 kinases whose activities were significantly associated with OS among AYA patients. Additionally, employing a causal network analysis tool, we pinpointed six kinases causally linked to OS, suggesting their potential as treatment targets. This study not only characterizes the molecular landscape of AYA HGG but also explores the disease trajectory across the lifespan. Our findings shed light on the intricate interplay of various factors influencing glioma etiology and patient outcomes, paving the way for a deeper understanding of HGG in the AYA population. Citation Format: Nicole Tignor, Mateusz P. Koptyra, Shrabanti Chowdhury, Weiping Ma, Jo Lynne Rokita, Marina Gritsenko, Xiaoyu Song, Giacomo B. Marino, Eden Z. Deng, Francesca Petralia, Azra Krek, Dmitry Rykunov, Felipe da Veiga Leprevost, Noshad Hosseini, Komal S. Rathi, Yingwei Hu, Simona Migliozzi, Tomer Yaron, Weijia Fu, Bo Zhang, Yuankun Zhu, Miguel A. Brown, Jeffrey R. Whiteaker, Clinical Proteomics Tumor Analysis Consortium (CPTAC), Children’s Brain Tumor Network (CBTN), Mehdi Mesri, Ana I. Robles, Karin Rodland, Lewis C. Cantley, Antonio Iavarone, Kenneth Aldape, Marcin Cieślik, Alexey I. Nesvizhskii, Joseph E. Ippolito, Joshua B. Rubin, Amanda G. Paulovich, Hui Zhang, Avi Ma'ayan, Tao Liu, Phillip B. Storm, Adam C. Resnick, Brian R. Rood, Pei Wang. A proteogenomic study of high-grade glioma among adolescents and young adults [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3955.

Abstract 7656: Clinicogenomic anlaysis reveals a role for TP53 mutations in distant progression of high-grade glioma

Abstract Purpose: High-grade glioma (HGG), the most common form of primary brain tumor, is highly lethal and treatment options remain limited. Despite advances in genomic technologies, there are few molecular biomarkers to guide precision medicine for HGG. Here, we aimed to identify the clinicogenomic features associated with HGG prognosis and recurrence patterns. Methods: Our single-institution retrospective analysis included 220 patients initially diagnosed with adult HGG (grade 3 or 4) who underwent next-generation sequencing targeting 82 brain tumor-relevant genes. The patients were categorized according to the 2021 WHO classification and their clinical status, survival, genomic profile, and recurrence patterns were analyzed. Results: At a median follow-up of 23 months (ranges, 2-59 months), 180 patients (82%) showed either progression or recurrence. A total of 15% of patients were reclassified under the 2021 WHO classification, revealing a clear separation of progression-free survival (PFS) and overall survival (OS) curves between grades 3 and 4 gliomas. We found that TP53 mutations were significantly associated with the occurrence of distant progression, especially in grade 4 gliomas. Additionally, TP53 mutations were more common in patients with higher Ki67 index and subependymal/leptomeningeal seeding, indicating an increased risk of distant progression in TP53-mutated grade 4 glioma patients. Following multivariate Cox regression analysis, TP53 mutations were independent predictors of OS (hazard ratio [HR]=1.47, P=0.039) and distant PFS (HR=1.71, P=0.005). Conclusion: Considering the elevated risk of distant progression in grade 4 gliomas with TP53 mutations, our results underscore the necessity for additional research into the most effective treatment approaches for these patients. Keywords: high-grade glioma, TP53, pattern of failure, distant progression, next-generation sequencing Citation Format: Byung-Hee Kang, Seungbok Lee, Joo Ho Lee. Clinicogenomic anlaysis reveals a role for TP53 mutations in distant progression of high-grade glioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7656.

Abstract 5109: Novel acylfulvene LP184 shows single agent and combinatorial efficacy with PARP inhibitors in atypical teratoid rhabdoid tumors

Abstract Atypical Teratoid Rhabdoid Tumor (AT/RT) is an aggressive form of pediatric brain cancer that spreads quickly and leads to survival rates of less than 40%. Current treatments are insufficient at reducing this poor prognosis. A hallmark feature of ATRT is a SMARCB1 mutation. Illudins are a class of cytotoxic compounds with activity against pediatric solid tumors, including AT/RT. LP-184 is a novel synthetic illudin with improved brain penetration and activity against adult high-grade glioma orthotopic xenografts. We tested LP-184 against a battery of AT/RT cell lines including BT37, CHLA06, CHLA05, and CHLA266. LP-184 decreases viability at nanomolar concentrations with IC50s ranging from 9.91nM - 23.92nM. LP-184 decreased proliferation as measured by immunofluorescence and confirmed by western blots (BT37 p=0.0001, CHLA06 =0.0001, CHLA05=0.033). LP-184 also induced apoptosis as demonstrated in immunofluorescent images and western blots (BT37 p=0.0001, CHLA06 =0.0001, CHLA05=0.0015, CHLA266 p=0.002). Furthermore, LP-184 shows strong synergy with the PARP inhibitor Rucaparib, suggesting that inhibition of DNA repair potentiates LP-184 activity. LP-184 reduces viable cell count by as much as 50% and combination with Rucaparib further decreases viability by 75% (BT37=0.0001, CHLA06=0.0002, CHLA05=0.0077). The dual therapy also demonstrates cytostatic and cytotoxic effects as confirmed by immunofluorescence and western blots (BT37 BrdU = 0.0004, BT37 CC3 = 0.0002, CHLA06 BrdU = 0.0033, CHLA06 CC3 = 0.0117 compared to control). Further studies in vivo are being conducted to test single agent and combination therapies of LP-184 and Rucaparib in ATRT, as our data indicates that the two could provide a compelling treatment option for patients with this poor prognosis brain tumor. Citation Format: Abigail Tindall, Hyuk J. Kwon, Istabraq Musa, Tyler Findlay, Su Chan Lee, Charles Eberhart, Eric Raabe. Novel acylfulvene LP184 shows single agent and combinatorial efficacy with PARP inhibitors in atypical teratoid rhabdoid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5109.

Consensus guidelines for the management of adult high-grade gliomas for low and middle-income countries.

High-grade glioma (HGG), a formidable and often incurable disease, presents an even greater challenge in low- and middle-income countries (LMICs) where resources and medical expertise are scarce. This scarcity not only exacerbates the suffering of patients but also contributes to poorer clinical outcomes. Particularly in LMICs, the underrepresentation of the population in clinical trials and the additional hurdles posed by financial constraints underscore an urgent need for contextspecific management strategies. In response, we have rigorously evaluated recent guidelines from leading medical societies, adapting them to suit the specific needs and limitations of the local context in Pakistan. This effort, undertaken in collaboration with local physicians, aims to provide a comprehensive, standardised approach to diagnose, treat, and follow-up with HGG patients. By focussing on the best available clinical evidence and judicious use of limited resources, we strive to improve patient care and outcomes in these challenging settings.

Theranostic Uses of the Heme Pathway in Neuro-Oncology: Protoporphyrin IX (PpIX) and Its Journey from Photodynamic Therapy (PDT) through Photodynamic Diagnosis (PDD) to Sonodynamic Therapy (SDT).

ALA PDT, first approved as a topical therapy to treat precancerous skin lesions in 1999, targets the heme pathway selectively in cancers. When provided with excess ALA, the fluorescent photosensitizer PpIX accumulates primarily in cancer tissue, and ALA PDD is used to identify bladder and brain cancers as a visual aid for surgical resection. ALA PDT has shown promising anecdotal clinical results in recurrent glioblastoma multiforme. ALA SDT represents a noninvasive way to activate ALA PDT and has the potential to achieve clinical success in the treatment of both intracranial and extracranial cancers. This review describes the creation and evolution of ALA PDT, from the treatment of skin cancers to PDD and PDT of malignant brain tumors and, most recently, into a noninvasive form of PDT, ALA SDT. Current clinical trials of ALA SDT for recurrent glioblastoma and high-grade gliomas in adults, and the first pediatric ALA SDT clinical trial for a lethal brainstem cancer, diffuse intrinsic pontine glioma (DIPG), are also described.

Chimeric Antigen Receptor T Cell and Chimeric Antigen Receptor NK Cell Therapy in Pediatric and Adult High-Grade Glioma—Recent Advances

High-grade gliomas (HGG) account for approximately 10% of central nervous system (CNS) tumors in children and 25% of CNS tumors in adults. Despite their rare occurrence, HGG are a significant clinical problem. The standard therapeutic procedure in both pediatric and adult patients with HGG is the surgical resection of the tumor combined with chemotherapy and radiotherapy. Despite intensive treatment, the 5-year overall survival in pediatric patients is below 20–30%. This rate is even lower for the most common HGG in adults (glioblastoma), at less than 5%. It is, therefore, essential to search for new therapeutic methods that can extend the survival rate. One of the therapeutic options is the use of immune cells (T lymphocytes/natural killer (NK) cells) expressing a chimeric antigen receptor (CAR). The objective of the following review is to present the latest results of preclinical and clinical studies evaluating the efficacy of CAR-T and CAR-NK cells in HGG therapy.

Advancements in Glioma Care: Focus on Emerging Neurosurgical Techniques.

Despite significant advances in understanding the molecular pathways of glioma, translating this knowledge into effective long-term solutions remains a challenge. Indeed, gliomas pose a significant challenge to neurosurgical oncology because of their diverse histopathological features, genetic heterogeneity, and clinical manifestations. Relevant sections: This study focuses on glioma complexity by reviewing recent advances in their management, also considering new classification systems and emerging neurosurgical techniques. To bridge the gap between new neurosurgical approaches and standards of care, the importance of molecular diagnosis and the use of techniques such as laser interstitial thermal therapy (LITT) and focused ultrasound (FUS) are emphasized, exploring how the integration of molecular knowledge with emerging neurosurgical approaches can personalize and improve the treatment of gliomas. The choice between LITT and FUS should be tailored to each case, considering factors such as tumor characteristics and patient health. LITT is favored for larger, complex tumors, while FUS is standard for smaller, deep-seated ones. Both techniques are equally effective for small and superficial tumors. Our study provides clear guidance for treating pediatric low-grade gliomas and highlights the crucial roles of LITT and FUS in managing high-grade gliomas in adults. This research sets the stage for improved patient care and future developments in the field of neurosurgery.

Neuropsychological functioning during chemotherapy with temozolomide in high-grade glioma patients: a retrospective single centre study.

starting from a lack of precise and coherent data in literature, aim of this work is to retrospectively study the influence of chemotherapy with Temozolomide (TMZ) on a wide series of neuropsychological functions in a population of adult high-grade glioma patients. an extensive neuropsychological battery was administered pre-operatively (T0) and after 6 (T1) and 12 months (T2) from surgery. After full recovery from surgery, TMZ was delivered concomitant to radiotherapy and, subsequently, adjuvantly for 5-day cycles per month. Parametric and non-parametric analyses were conducted to verify the influence of several aspects of chemotherapy on the adjusted scores of each cognitive test at the two post-operative follow-ups. Sixty-one patients were included at T0; patients with a lower adjuvant TMZ dosage reported a better performance at the visual attention test at T1, and at the deductive reasoning test at T2. Undergoing more than 8 cycles of adjuvant therapy was slightly associated with a better performance at the long-term verbal memory tasks at T2. No other associations were found with the other cognitive tests and autonomy scales administered. TMZ proved to be a secure treatment with no negative side effects on cognition and on level of daily autonomy, even at the highest dosage used. This is a positive finding which enables clinicians to reassure patients about the absence of significant negative effects of TMZ on their daily life functioning. In this view, eventual cognitive changes during treatment might not be attributed to chemotherapy but to other events such as tumour relapse.