Abstract 336: Organotypic co-cultures as a novel 3D model for head and neck squamous cell carcinoma

Abstract

Abstract Background. Head and neck squamous cell carcinomas (HNSCC) are histologically and molecularly heterogeneous tumors and frequently develop resistance mechanisms against treatment. Reliable patient-derived 3D tumor models are urgently needed to further study the complex pathogenesis of these tumors and how to overcome treatment failure. Methods. We developed a 3D organotypic co-culture (OTC) model for HNSCCs that maintains the architecture and cell composition of the patients' tumor. A dermal equivalent, composed of healthy, human-derived fibroblasts embedded into viscose fibers, grows in an insert for approximately 10 days in culture and serves as a scaffold for the patient sample. After outgrowth of fibroblast within the dermal equivalent, we cultivated vital HNSCC tumor explants from 13 patients (non-HPV driven, n=7; HPV-driven HNSCC, n=6) by carefully placing them on top of the scaffold. Fractionated irradiation (IR) was applied to 5 samples. To evaluate tumor proliferation and areas of apoptosis, we performed immunohistochemistry and immunofluorescence with antibodies against ki-67, cleaved caspase-3, pan-cytokeratin (PanCK), p16INK4a, and vimentin. Results. All 3D OTC models of non-HPV driven samples encompassed proliferative cancer cells during cultivation for up to 21 days. Proliferation indices of primary and 3D-OTC models were comparable and consistent over time. Overall, tumor explants displayed heterogeneous growth and invasion patterns. Radioresistant and clonally expanding tumor cells were enriched in 3D-OTC models after fractionated IR. HPV DNA was detectable in both primary and OTC (day 14) of HPV-driven tumors; However, p16INK4a expression levels were varying. Conclusion. Our 3D-dimensional organotypic co-culture model for HNSCC supports cancer cell survival and proliferation in their original microenvironment. The model enables investigation of invasive cancer growth as well as clonal expansion of resistant cancer cells upon treatment. In the future, the introduced model might serve as a platform to perform sensitivity testing upon treatment to predict the patients' individual response to therapy. Citation Format: Julia C. Thierauf, Luca Engelmann, Natalia Koerich Laureano, Hans-Jürgen Stark, Elena-Sophie Prigge, Dominik Horn, Kolja Freier, Niels Grabe, Philippe Federspil, Peter K. Plinkert, Magnus von Knebel Doeberitz, Jochen Hess, Annette Affolter. Organotypic co-cultures as a novel 3D model for head and neck squamous cell carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 336.