Spatial control of oxygen delivery to 3D cultures alters cancer cell growth and gene expression

Commonly used monolayer cell cultures lack the capacity to provide a physiologically relevant environment for cell culture in terms of cell-cell architecture, extracellular matrix composition, and spatiotemporal delivery of key growth factors and small molecules, such as oxygen. Here, we describe a three-dimensional (3D) approach to cell culture in vitro, utilizing a bioreactor system designed to control oxygenation of 3D cancer cell cultures, in order to better mimic tumor microenvironments observed in vivo. We found transcriptomic differences in breast and ovarian cancer cell cultures grown in traditional monolayer cultures as compared to cultures grown in a Matrigel three-dimensional matrix. We also investigated the transcriptomes of 3D cultures grown in 21% O2, 3% O2, and a gradient of 3% O2 to 0% O2 using our bioreactor system. By controlling oxygen delivery, we observed differences in cell growth morphology and transcriptome regulation under the three conditions. Overall design: Examination of the effects of oxygenation gradients on 3D cancer cell cultures grown in a bioreactor. 3D cell cultures grown in 3% oxygen, 21% oxygen, and gradient oxygen are examined and compared to cells grown in 2D 21% oxygen. MCF-7 and OVCAR-8 cell lines are investigated.