BIOS-07. GRADUAL METABOLIC ALTERATIONS RESTRUCTURE THE SPATIAL ARCHITECTURE AND IMMUNITY IN GLIOBLASTOMA

Abstract The organized layered structure of the human neocortex contrasts sharply with the chaotic architecture of malignant CNS tumors. The heterogenous nature of glioblastoma (GBM) poses significant challenges to research and treatment, given that effective strategies require consistent biological patterns. Here, we leverage recent advances in spatial biology, integrating spatially resolved transcriptomics and metabolomics to identify drivers of GBM-specific architectural evolution. We performed spatial metabolomics (MALDI) and transcriptomics (Visium n=43 and MERFISH n=25) on glioblastoma patients, with computational analysis conducted using the SPATA2 R package. Our findings reveal that most spatial recurrent patterns in glioblastoma emerge in a gradient-like organization, particularly influenced by proximity to areas of necrosis and hypoxia. Samples without hypoxic regions demonstrated less spatial organization. Metabolomic and transcriptomic profiling indicated enhanced responses to hypoxia, reduced cell proliferation, and elevated expression indicative of the S phase in cell division near necrotic regions. The vicinity to hypoxic areas was associated with increased extracellular matrix remodeling and epithelial-to-mesenchymal transition, suggesting that the invasive capabilities of GBM cells originate from these hypoxic niches. By further integrating spatially resolved TCR-sequencing, we identified that hypoxic gradients drive defined T cell responses with a higher likelihood of T cell dysfunction within a distance of 235 µm (sd: 132 µm) to hypoxia. This suggests that the presence of necrosis, hypoxia, and hypoxia-associated metabolites could serve as potential predictive markers for T-cell behavior and exhaustion in glioblastoma. Our study offers an in-depth analysis of the influence of two prevalent niches in glioblastoma: necrosis and hypoxia. We reveal that the complex architecture of glioblastoma is not solely dictated by genetic randomness and stochastic occurrences but is significantly influenced by spatial proximity to key factors like necrosis and hypoxia. This insight contributes to an evolving model that seeks to unravel the intricate biology underpinning this formidable disease.