Abstract
Three-dimensional (3D) in vitro spheroid/organoid culture increasingly appears to better mimic physiological states than standard 2D systems. The biological consequence of 3D spheroids, however, differs for different cell types: for pluripotent embryonic stem cells (ESCs), differentiation and loss of stemness occur, while the converse is true for somatic and cancer cells. Despite such diverse consequences, there are likely conserved mechanisms governing 3D spheroid formation across cell types that are unknown but could be efficiently targeted for translational application. To elucidate such processes, we performed transcriptome analysis with functional validation on 2D- and 3D-cultured mouse ESCs, mesenchymal stromal/stem cells (MSCs), and cancer cells. At both the transcriptomic and functional levels, 3D spheroid formation resulted in commitment towards known cell-specific functional outcomes. Surprisingly in all cell types, downregulation of the cholesterol synthesis pathway was found during 3D spheroid formation, with modulation concomitantly affecting 3D spheroid formation and cell-specific consequences; similar results were seen with human cell types. Furthermore, improved antioxidant capacity after 3D spheroid formation across cell types was further enhanced with modulation of the pathway. These findings demonstrate the profound cell-specific consequences and the translational value of understanding conserved mechanisms across diverse cell types after 3D spheroid formation.