Figure 2.

Conventional 2D cell culture does not enable the study of vascular–parenchymal interactions. (top) Human umbilical vein endothelial cells (HUVEC) (labeled with orange CellTracker) were cultured for 24 h with the breast cancer cell line MDA-MB-231 (labeled with green Calcein) in 2D culture. Breast cancer cells grew on top of HUVEC, resulting in endothelial cell death. (bottom) In contrast, when HUVEC (labeled with red CellTracker) were cultured in 3D tubes in Matrigel, and MDA-MB-231 3D spheroids (labeled for nuclei with Hoescht (blue) and integrin α6 (green), also formed in Matrigel) were pipetted onto the endothelial tubes, both cell types remained viable for up to 96 h and breast cancer cells migrated out of the spheroid and along the endothelial tubes within 48 h. Scale bar = 100 μm.