Abstract 3995: Investigating the role of sphingosine kinase 2 and p53 in bioprinted head and neck cancer 3D models

Abstract Head and neck squamous cell carcinoma (HNSCC) presents a high incidence of recurrences and metastasis. Alterations in sphingolipids metabolism caused by deregulation of sphingosine kinase 2 (SK2) is related to tumor progression. Additionally, the interaction between SK2 and p53 has been found to promote aggressive behavior in HNSCC (Milan et al, 2024). However, SK2 deregulation in HNSCC and SK2/p53 crosstalk remains to be fully investigated. Our goal is to explore the interaction between sphingosine kinase 2 and p53 in HNSCC cell lines and patient organoids. We leverage 3D HNSCC models generated by bioprinting HNSCC cell lines expressing different p53 and SK2 levels with extracellular matrix components in high throughput-compatible mini-ring format (Phan et al, 2019; Tebon et al, 2023; Al Shihabi et al, 2024). We then investigated metabolic activity, organoids size, and quantified both SK2 and p53 protein levels. Given that p53 misfolding and aggregation has been reported as contributing to tumor progression in several cancers, we have determined its folding status by multiplexed immunofluorescence using conformation-specific antibodies in the presence or absence of SK2 activity and p53 aggregation inhibitors. Combined inhibition of SK2 activity by Opaganib and p53 aggregation by ReACp53 (Soragni et al, 2016) decreased organoid size, ATP levels, and p53 aggregation. Single agent and combinatorial treatment with ReACp53 and Opaganib also resulted in elevated γH2AX levels. Our studies highlight a complex interplay between SK2 and p53 in HNSCC, resulting in more aggressive disease. Combinatorial targeting of these proteins could offer a potential therapeutic strategy for HNSCC. Funding: CAPES, CNPQ and FAPESP Grant n.2023/15046-8 Citation Format: Thaís Moré Milan, Luda Lin, Sara Sartini, Alberto Mendoza Valderrey, Alice Soragni, Andréia Machado Leopoldino. Investigating the role of sphingosine kinase 2 and p53 in bioprinted head and neck cancer 3D models [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 3995.