Figure 7.

Schematic of the effect of substrate stiffness on WM35 and A375 cells. WM35 cells exhibit dependence on substrate modulus by forming stiffness-dependent focal adhesions (green dots) and increase f-actin stress fiber formation (red lines). We hypothesize that for the WM35 cells, increased signaling from focal adhesion formation, perhaps an indication of stronger cell-matrix interactions, can increase survival signaling to inhibit apoptosis induced by PLX4032. In comparison, A375 cells show little dependence on the underlying matrix elasticity, always forming similarly sized matrix interactions. The lack of large focal adhesions, however, does not increase levels of apoptosis. Instead, A375 cells may have very different intracellular signaling that compensates for the lack of stiffness dependence for survival.