Abstract 4966: Influence of the microenvironment on drug sensitivity in breast cancer using a three-dimensional cell culture model.

Abstract

Abstract Three-dimensional (3D) cell culture is an important research tool and an invaluable alternative to two-dimensional (2D) cell culture as it is more suitable to represent in vivo conditions. The tumor microenvironment influences cellular activity and using 3D cell culture allows these interactions to be studied in vitro. We have evaluated the efficacy of a novel 3D cell culture model for breast cancer and determined cellular responses caused by drug activity. We have recently developed and optimized a miniaturized 3D breast cancer culture model. Our model uses reconstituted basement membrane from Growth Factor Reduced Matrigel™ as a scaffold and is suitable for semi-automated early stage drug discovery. The newly developed 3D culture model has been extensively characterized for reproducibility and the activity of known anti-breast cancer therapies. Notably, anthracyclines and taxanes showed significantly altered drug sensitivity in 3D when compared to monolayer cell cultures of breast cancer cell lines. To determine the mechanisms underlying the altered sensitivity in 3D cell culture, we sought to identify the differences between untreated and drug treated spheroids, as well as the differences between 2D and 3D cell culture responses to anthracyclines and taxanes. We evaluated proliferation, penetration, cellular architecture and signaling of major cellular pathways in our 3D model. We will discuss the proliferation rate comparing 2D and 3D cell culture models and drug penetration (exemplified by doxorubicin) in 3D cell culture. The effect of anthracyclines and taxanes on the 3D cellular architecture, without the influence of extracellular matrix proteins in the microenvironment, will also be presented. In addition, we have characterized the signaling pathways in 2D and 3D cell culture commonly associated with enhanced drug resistance and other relevant proteins including those associated with apoptosis. Deconstructing the cellular processes in 3D breast cancer cell culture in response to breast cancer therapies has the potential to elucidate drug resistance mechanisms. The results obtained from this research illustrate the characteristics and mechanisms of both monolayer and 3D cell culture with respect to anthracycline and taxane drug activity. These results demonstrate the benefits of 3D cell culture in early stage novel compound evaluation for breast cancer. Citation Format: Carrie J. Lovitt, Vicky M. Avery. Influence of the microenvironment on drug sensitivity in breast cancer using a three-dimensional cell culture model. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4966. doi:10.1158/1538-7445.AM2013-4966