Abstract C64: Polystyrene scaffolds: A novel tool for in vitro three-dimensional cancer models

Abstract

Abstract It is well known that three-dimensional (3D) cultures can more accurately represent physiological cell responses, and that two-dimensional (2D) in vitro cell culture systems fall short in predicting tumor cell behavior in vivo. Major shortcomings of 2D cell culture systems include altered cell morphologies, reduced aggression, and an inaccurate representation of the dynamic 3D cellular environment experienced by cells in vivo. These 2D cell culture obstacles become even more deleterious to research when performing drug screenings or studying disease pathogenesis. Hence, cancer research demands a more biologically relevant in vitro model system that can improve drug discovery success rates to combat rising rates of cancer and other diseases. Moreover, an accurate and reproducible in vitro model will accelerate the drug discovery process and significantly reduce development costs. To this end, we have engineered a novel transparent 3D polystyrene (PS) scaffold to meet the emerging demand. We hypothesize that these 3D PS scaffolds are a superior 3D in vitro model for tumor pathogenesis research and drug discovery and development. To test our hypothesis we cultured and observe the growth of two cancer cell lines, human epithelial MCF-7 cells and HepG2 hepatocarcinoma cells, on both 2D PS-tissue culture plates (TCP) and 3D PS scaffolds (3D Insert™-PS). Observation by an inverted light microscope indicated that MCF-7 and HepG2 cells cultured on the 3D PS scaffolds formed cell aggregates along scaffold fibers and within pores, whereas cells cultured on the 2D PS-TCPs adopted a phenotype characteristically seen in cells growing in flat monolayers. Proliferation time-course assays performed with MCF-7 and HepG2 cells demonstrated that growth rates and metabolic activities of cells cultured on 3D scaffolds were significantly enhanced at numerous time points when compared with cells cultured on 2D TCPs, as determined by Alamar blue and MTT assays. These data suggest that 3D Insert™-PS scaffolds provide an improved in vitro culture environment. The susceptibility of both 2D and 3D cultured MCF-7 and HepG2 cells to anticancer drugs was assessed by tamoxifen (TAM) [10-6 M and 10-5 M] and methotrexate (MTX) [25 µM and 100 µM] treatments, respectively. The cellular cytotoxic response to TAM and MTX was measured by MTT and LDH assays and was found to be significantly lower in MCF-7 and HepG2 cultured on 3D scaffolds compared with cells cultured in 2D TCPs. Taken together, these data indicate that cancer cells cultured on 3D Insert™-PS scaffolds are more robust and resistant to anticancer drug treatments than cells cultured on traditional 2D TCPs. Furthermore, 3D Insert™-PS scaffolds do not have the same limitations encountered with traditional 2D cell culture. In conclusion, using 3D Insert™-PS scaffolds as in vitro 3D tumor models will provide a superior 3D cell culture environment for cancer research and the evaluation of new anticancer drugs. Citation Information: Cancer Res 2009;69(23 Suppl):C64.