Abstract A206: 2D cell culture can approximate 3D behavior: Applications for screening individual agents and drug combinations.

Abstract

Abstract Developed and serving over the last 30 years as an indispensible screening tool, 2D in vitro screening has been criticized for poor predictive powers in clinical settings. New tools are under development, e.g. 3D spheroids or “hanging-drops," to overcome these limitations. However, new tools have other restrictions. For example, costs and application for multiple cell lines: model 2D cell lines may not grow as spheroids. We developed a set of analytical and computational models to approximate cell growth upon drug treatment. We could show that for a common 2D cell culture the effect of drug treatment, and therefore interpretation of the results, depends on several factors: seeding cell density, treatment time, cell doubling time, and compound mode of action. To address such limitations we further developed a modified 2D culture. In contrast to a common experimental set-up of low cell density to allow exponential cell growth and short 48-96 hours treatment times, we allowed cells to grow to higher ∼80% confluence densities. Treatment was monitored not as an end-point assay, but in a kinetic mode (every 96 hours) over a period of 4 weeks. We treated 82 cell lines using a set of standard anticancer agents, including 5-FU, paclitaxel, sunitinib, etoposide, lapatinib and eroltinib. Interestingly, some cell lines showing significant responses in classical 2D models, appear to be non-responsive to the drug in dense 2D (D2D) models. This was very obvious for some targeted agents, e.g. EGFRi, probably due to down-regulation of the drug targets in cell lines growing as D2D. In addition, we have applied the same principle to drug combination studies in all 82 cell lines. These results indicate that D2D cell models can approximate cell growth observed in 3D cell cultures by enhancing cell-cell interactions. D2D screening can be performed in hundreds of cell lines (at least 82 different cancer cell lines, as shown here). In contrast to 3D models and end-point detection, D2D also records the drug response kinetics, and can be easily applied for drug combinations. This is especially relevant for slow acting agents, e.g. cytostatic agents. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A206. Citation Format: Igor Ivanov, Danial Taherzadeh, Maximilian Nunziante. 2D cell culture can approximate 3D behavior: Applications for screening individual agents and drug combinations. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A206.