Abstract 2705: Spatial profiling of tumor microenvironment uncovers potential novel therapeutic approach in pediatric neuroblastoma

Abstract Background: Neuroblastoma (NB) is a tumor of the sympathetic nervous system and is the most common extracranial solid malignancy in children. Patients with high-risk NB have much poorer outcomes compared with patients with low- and intermediate-risk neuroblastoma. These striking differences in clinical outcomes led us to investigate how the tumor microenvironment (TME) differs between high-risk and low-risk NB patients. We examined the cancerous and non-cancerous cells, along with other components, in the TME to determine their potential to either promote or suppress tumor growth, and to determine their association with a specific tissue spatial organization. Methods: In this study, we profiled 27 pediatric NB patients (n = 14 high-risk and 13 low-risk samples) using GeoMx DSP Whole Transcriptome Atlas (WTA) (Nanostring Technologies) and Phenocycler Fusion (Akoya Biosciences). We analyzed a total of 67 regions of interest (ROIs) using spatial transcriptomics, guided by fluorescent markers (CD45, Synaptophysin, CD56, and DAPI). ROIs were segmented into tumor regions (CD56+Synaptophysin+CD45-) and TME regions (CD45+CD56-). We conducted spatial proteomics to phenotype cells, map their locations, and assess functional states by profiling 53 markers. This 53-plex protein panel enabled us to identify various cell types within the NB TME, covering relevant lineages (tumor, lymphoid, myeloid, and stromal), subtypes (e.g., CD4 T cells, CD8 T cells, B cells, macrophages and neutrophils), and functional states (e.g., Ki67 and PD-1). Spatially resolved signatures in the NB identified characteristics of cellular neighborhoods that are linked to NB patients’ survival outcomes. Results: Within the tumor regions, we identified an upregulation of the glutathione metabolism pathways that are involved in the suppression of ferroptosis in high-risk NB tumors, which could be targeted with GPX4 inhibitors. We also discovered that NB with macrophage-rich and stroma-secluded immune cell neighborhoods had worse outcomes. Stroma-secluded immune cells were more frequent in high-risk NB, which may contribute to the resistance mechanisms to immunotherapy and overall survival of patients with high-risk NB. Conclusion: Our study highlights the need to combine the genomic profile of NB TME with spatially defined cellular neighborhoods to better understand tumor aggressiveness. Considering the upregulation of ferroptosis suppressive pathways and the macrophage-rich neighborhood in high-risk NB, our findings suggest that inducing ferroptosis with GPX4 inhibitors might be a promising therapy for high-risk NB. Overall, our study revealed key genes and pathways in high-risk NB and provides a new therapeutic avenue for patients with high-risk NB. This hypothesis is currently being investigated in our lab using animal models. Citation Format: Cui Tu, Chin Wee Tan, James Monkman, Ana Clara Almeida, Gabrielle Antonio-Carreon, Natacha Omer, Giaan Hull, Kimberly Chung, Ahmed Mehdi, Antonietta Salerno, Orazio Vittorio, Aaron Mayer, Cleber Machado de Souza, Fernanda de Almeida Brehm Pinhati, Selene Elifio-Esposito, Wayne Nicholls, Lucia de Noronha, Arutha Kulasinghe, Fernando Souza-Fonseca-Guimaraes. Spatial profiling of tumor microenvironment uncovers potential novel therapeutic approach in pediatric neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2705.