Mixed cell-type spheroids endorse the generation and maintenance of heme-TAMs in an experimental tumor microenvironment

To more accurately mimic the tumor microenvironment, we established a three-dimensional culture of MC38 cancer cells mixed with heme-treated BMDMs in microwell plates. This resulted in tumor spheroids with uniformly interspersed macrophages. We profiled the transcriptome of macrophages within these spheroids using scRNA-seq 24 hours after spheroid formation. To test the robustness of the heme effects in this model, we conducted a multiplexed experiment evaluating heme alone and in combination with the classical M1-polarization stimuli INFγ and LPS. We profiled the transcriptome of macrophages within BMDM + MC38-GFP spheroids using scRNA-seq 24 hours after spheroid formation. To test the robustness of the heme effects in this model, we conducted a multiplexed experiment evaluating heme alone and in combination with the classical M1-polarization stimuli INFγ and LPS.