Incorporation of MDA-MB-231 does not depend on subendothelial substrate stiffness.

<p>(A) Cumulative fraction of MDA-MB-231 cells incorporated into endothelial cells on a fibronectin-coated 0.87 kPa or 280 kPa polyacrylamide gel, or glass (50 GPa). Data points represent mean ± SEM for at least 3 independent experiments (N>20 cells for each experiment). (B) Final fraction of MDA-MB-231 cells incorporated into the (untreated) endothelium as a function of subendothelial substrate stiffness. Bars represent mean, while error bars represent SEM of at least 3 independent experiments. P>0.05 between these values indicates there is no statistical difference (n.s.). (C) Time for MDA-MB-231 cells to complete incorporation is independent of the mechanical properties of the substrate below the endothelial cells. Endothelial cells on fibronectin-coated glass coverslips (50 GPa) or polyacrylamide gels (0.87 kPa or 280 kPa) were left untreated (no TNF) or treated with TNF-α (TNF). No statistical difference in incorporation time was measured as a function of subendothelial substrate stiffness or endothelial cell treatment (P>0.05).