Abstract 1830: A chemoradiation platform for evaluating multimodal therapy effects on tumor viability and invasion ex vivo

Treatment of advanced head and neck squamous cell carcinoma (HNSCC) involves radiotherapy combined with chemotherapy, targeted therapy or immunotherapy. We have developed a high-throughput organoid-based drug screening platform to assess the combined effects of radiotherapy and chemotherapy or targeted therapies on HNSCC viability and invasion. To validate the platform, we used HNSCC cell lines establishing bioprinted 3D models in mini-ring format (Phan et al, 2019; Tebon et al, 2023; Al Shihabi et al 2024; Nguyen et al, 2024). Cells are exposed to X-ray radiation in combination with various small molecules and biologics. We quantified viability via ATP-release assays and extracellular matrix (ECM) invasion using a machine-learning-based brightfield image analysis pipeline (Al Shihabi et al, 2022). Proof-of-concept experiments with HPV-negative HNSCC lines (HN30 and HN31, established from primary and metastatic disease from the same patient) and HPV-positive HNSCC cells (SCC154) revealed that treatment with cetuximab and ibrutinib enhances radiosensitivity in HN31 cells. The PI3K inhibitor copanlisib radio-sensitized both HN30 and HN31, while alpelisib sensitized SCC154 cells. Additionally, copanlisib, afatinib, and ibrutinib were shown to limit ECM invasion of HN31, while the AKT inhibitor ipatasertib and the mTOR-targeting rapamycin promote invasion of HN30 cells, as observed in previous studies (Brolih et al., 2018). Our pilot experiments using bioprinted patient-derived HNSCC organoids confirmed the feasibility of performing sensitivity screening by integrating bioprinting, conventional viability assays, and advanced image analysis techniques. Our goal is to establish a personalized therapeutic pipeline for patients with advanced HNSCC, maximizing responses to radiotherapy and targeted agents to improve outcomes, and avoiding modulators that may promote tumor invasion. Citation Format: Luda Lin, Krishna K. Bommakanti, Bowen Wang, Yazeed Alhiyari, Christian Wooten, Andreanne Sannajust, Lauran K. Evans, Peyton Tebon, Maie A. St. John, Alice Soragni. A chemoradiation platform for evaluating multimodal therapy effects on tumor viability and invasion ex vivo [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 1830.