Abstract 1682: Bridging gaps in treatment resistance 2D models with the incorporation of 3D models

Introduction: 3D cellular models have become of increasing interest in anti-cancer drug discovery as a bridge between clinical models and traditional in vitro methods. An important component of this research is the comparison of drug-to-cell interactions and morphological characteristics between cells in mono-layer culture and the cells in 3D spheroids. Materials and Methods:The ResCu system is a novel long term, physiologically relevant culture system that avoids the need for passaging. It propagates tumoroids in a microenvironment that resembleshuman tissue. Cells with KRAS G12C mutation were cultured in the ResCu system for three months, during which they were constantly exposed to G12C inhibitors (G12Ci) for the evolution of resistant cell populations. Cells were also cultured in traditional 2D cultures and exposed to G12Ci. Transcriptomics was performed to determine resistant networks and identify different resistant subclones in each group. Results: We applied the ResCu system to model clinical resistance. We captured 95% of clinically identified on-target and pathway bypass resistance changes, and in the 2D system, only a fraction of mechanisms were discovered. Additionally, we noticed certain cell populations could tolerate higher doses of the G12Ci after resistance evolution in ResCu compared to 2D. A few had similar responses suggesting that the origin of the cell line plays a role in the microenvironment's impact on cellular response. Conclusion: By comparatively analyzing resistance evolution data for KRAS G12Ci in traditional 2D and ResCu, we were able to collect physiologically relevant data that can more confidently be applied to clinical studies than mono-layer cell culture data alone. Citation Format: Manasa Gadde, Elizabeth Schwabe, Kshithija Mulam, Lindsay Hill, Christopher Bulow. Bridging gaps in treatment resistance 2D models with the incorporation of 3D models [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 1682.