Abstract 2022: Importance of ECM and media permeation in 3D modeling of breast cancer

Background: Three dimensional (3D) culture is a more physiologically relevant method to model cell behavior in vitro than two dimensional culture. 3D modeling of cancer is of particular importance in drug development where predicting in vivo effectiveness is challenging. Not only is the 3D structure important for proper modeling of cancer but the response from the surrounding microenvironment, including the extracellular matrix (ECM) and fibroblasts, is also necessary to accurately predict drug response. A major hindrance to 3D culture is loss of cell viability due to nutrient limitation. Herein, we demonstrate the ability of our novel bioreactor system to prolong viability of 3D cultures and the importance of ECM composition in breast cancer modeling. Methods: To gain further understanding of the effect of different ECM on the 3D arrangement of breast cancer cells and breast fibroblasts, three different variations of ECM were tested: 1) 100% basement membrane (BM, reduced growth factor Matrigel) diluted to 9-12 μg/ml, 2) an equal volume of BM and Collagen I (50% BM + 50% Collagen I), and 3) 10% BM in Collagen I. MDA-MB-231 (231) breast cancer cells were grown in each ECM in monoculture or co-culture with breast fibroblasts (ratio of 2:1) for 3 or 7 days. The formation of cell aggregates, as seen in most infiltrating carcinomas of the breast, was assessed by image analysis. To improve viability, 250 μM channels penetrated the 3D co-cultures (consisting of 231 cells and fibroblasts (2:1) mixed into 10% BM/Collagen I) in our perfusion bioreactor system. Proliferation, measured by Ki-67 immunostaining, was compared over time in solid co-cultures and perfused and non-perfused co-cultures after 3 or 7 days. Results: In 3D monocultures, significantly greater cell aggregation was seen with 100% BM compared to 50% and 10% BM at both 3 and 7 days (p Citation Format: Kayla F. Goliwas, Lauren E. Marshall, Kun Yuan, Joel Berry, Andra R. Frost. Importance of ECM and media permeation in 3D modeling of breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2022. doi:10.1158/1538-7445.AM2014-2022