3D cell culture models are currently of great interest to the bioscience community. This is most notable in the cancer biology area, where a growing body of evidence suggests that more relevant and translational observations can be made by testing compounds in a physiological relevant 3D model compared to a 2D model. In this study, we take a kinetic, live-cell imaging approach to measure the growth or shrinkage of non-adherent tumor spheroids using Ultra Low Attachment (ULA) 96-well and 384-well microtiter plates (Corning®). These round-bottomed, hydrogel coated plates facilitate the formation of spheroids by promoting self-adherence as opposed to adherence to the plate surface. In a single cell type, monoculture model, A549 lung epithelial carcinoma cells developed into single spheroid structures in each well of 96 and 384-well plates within 48-96 hours in culture. In both plate types, the resulting spheroid size, ranging from 330 µm - 600 µm, was proportional to the number of cells (1K - 5K cells per well). Post formation, spheroids remained untreated or were subjected to three test agents, staurosporine, oxaliplatin or cycloheximide. The increase or decrease in spheroid size was monitored over 3 - 10 days using the IncuCyte™ ZOOM Live Content Imaging system. Using the red fluorescent channel, spheroid growth was analyzed using fluorescent area and intensity metrics. Whereas staurosporine and oxaliplatin significantly decreased spheroid size at high concentrations, cycloheximide treatment resulted in a cytostatic response, effectively inhibiting spheroid growth in a concentration dependent manner, while not reducing total spheroid area at any tested concentration. Interestingly, in side-by-side comparisons of kinetic 2D and 3D assays, we observed a significant, 10-fold (one log) shift in the pharmacology of cycloheximide. In a 3D co-culture breast cancer model, this study also illustrates the effect of Lapatinib on SK-BR-3 cells grown in the presence of mammary derived stromal cells (fibroblasts). Together, this study describes a kinetic, live-cell approach to measuring spheroid size over time, illustrates a differential response of cycloheximide in a 3D system compared to identically treated cells grown in a 2D monolayer, and details a complex co-culture method for elucidating the effect of Lapatinib in a physiologically relevant 3D model of breast cancer.
Citation Format: Kalpana Patel, Belinda O'Clair, Tim O'Callaghan, Daniel M. Appledorn, Derek Trezise. A 3D culture model for screening of cancer therapeutics. [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 4295. doi:10.1158/1538-7445.AM2014-4295