Head and Neck Cancer HuBiogel-embedded Microtumor Assay System for Therapeutic Efficacy Testing of Patient Tumor Specimens

Head and neck (HN) cancer recurrence is common, and selecting effective salvage systemic therapy remains difficult, particularly for oral cavity cancers. Developing a rapid, robust and predictive therapeutic testing system could support clinical decision-making and improve patient outcomes. We developed a Patient Therapy Evaluation System (PTES) that employs a three-dimensional (3D) fully human microtumor drug testing assay using tissue specimens collected during surgery of HN cancers. Remnant fresh tumor tissue from patients is dissociated into single-cell suspension that is embedded using a novel HuBiogel-cell encapsulation technology (3D microtumors). This high-throughput assay platform allows morphologic, functional, and molecular evaluations in parallel by real-time imaging, cell proliferation, and biomarker protocols. Microtumor viability, growth profiles, and drug screening data are captured at multiple time points up to 14 days. Our initial cohort included 57 patient specimens (53 squamous cell carcinomas, 1 verrucous carcinoma, 1 osteosarcoma, 1 ameloblastoma, and 1 non-cancerous lichenoid mucositis). HuBiogel-embedded tumor cells formed numerous multicellular colonies exhibiting distinct organization and growth patterns in 14-day microtumor cultures. Interestingly, epithelial, stromal and stem-cell like populations were preserved in HN microtumor models based on marker expression. Treatment with single (cisplatin, 5FU, docetaxel) drugs and their combinations resulted in tumor inhibitory responses (IC50) evaluated by CellTiter-Glo assay, and residual surviving cells were also recorded by Calcein-AM staining of 3D Microtumors. While patient-derived HN microtumors were produced with high success rates, factors associated with lower microtumor yield included smaller tumor specimens and low viability after dissociation. In conclusion, our new all human microtumor assay models replicating phenotypic, functional, and molecular properties ex vivo provide a potential theranostic tool for rapidly predicting drug sensitivity and improving treatment strategy for HN cancer patients. Citation Format: Christopher D. Willey, Yedeh P. Ying, Anthony B. Morlandt, Hope M. Amm, Patricia H. Hicks, Joshua C. Anderson, Andee M. Beierle, Carissa M. Thomas, Jason M. Warram, Jingsong Chen, Jeffrey A. Thomas, Katie Banko, Raj K. Singh. Head and neck cancer HuBiogel-embedded microtumor assay system for therapeutic efficacy testing of patient tumor specimens. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4554.