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 (6Suppl): Abstract nr 3955.