Abstract 4247: Comparison of two-dimensional verses three-dimensional breast cancer models in drug discovery

Abstract

Abstract Two-dimensional (2D) monolayer cancer cell culture is generally used in most drug discovery screening programmes to identify novel anti-cancer compounds. However, three-dimensional (3D) cell culture more closely represents the in vivo tumor environment thus providing a more accurate measure of compound activity. Development of an automated, reproducible and miniaturised 3D culture model for drug discovery in breast cancer would be highly advantageous. Thus we have developed and optimised a miniaturised in vitro 3D culture model in which breast cancer cells interact with reconstituted basement membrane from MatrigelTM. To determine the effectiveness of our 3D breast cancer model for use in future drug discovery, chemotherapeutic drugs commonly used in breast cancer therapy were tested and differences in drug activity were compared to 2D cell culture models. Once validated, this 3D culture model will be used to evaluate and further characterise novel compounds. The results presented describe the development and reproducibility of our 3D culture model and its 2D culture model counterpart. This includes the linear relationship between fluorescence intensity and cell number for measurement of metabolic activity as an indicator of cell viability when using the indicator dye Resazurin; determination of an adequate signal window and the reproducible average mean sizes of spheroids present under assay conditions. We report that there is significantly more drug resistance in our 3D cell culture model compared to our 2D culture model. This is particularly evident in the presence of taxanes and anthracyclines. Results from this study also show that the degree of drug resistance in 3D is breast cancer cell line dependent for each of the chemotherapeutic drugs studied and not necessarily correlated to the profile observed in 2D. Image based analysis demonstrated a distinct correlation of 3D cell culture morphology to drug dose, where disassociation of spheroids indicates drug effectiveness and intact spheroids indicates ineffectiveness of drug activity. Further research is underway to determine the mechanism for the drug resistance in 3D culture, which may be important in providing information on resistance mechanisms and potential drug targets. Miniaturisation of 3D culture for breast cancer cell lines allows a higher throughput of novel compound testing in a more cost effective, biologically relevant model. Our work highlights the importance of using 3D cell culture in the early stages of drug discovery in evaluating compound activity. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4247. doi:1538-7445.AM2012-4247