Figure 6. Cortactin promotes growth in a “solid” 3D Matrigel culture environment.

To test the role of cortactin in a space-constrained environment, SCC61 and FaDu cortactin-manipulated cell lines were cultured for 16 days fully embedded in 90% Matrigel. Duplicate wells were used for each cell line and the experiment was performed twice. Cells were imaged every two days. For each, eight randomly chosen 10× fields were imaged and the diameter of the “in-focus” structures were measured using Metamorph software. A. Representative images from Day 12. Scale bar = 100 μm. B. Combined data from two independent experiments for SCC61 and FaDu cells. Note that cortactin expression (both increased and decreased) correlates with the size of colonies growing in this “solid” embedded Matrigel environment. By contrast, cortactin levels do not affect the size of cells grown in a “fluid” Matrigel environment (Supp Fig 2), suggesting that the key factor may be the ability of cortactin to remodel ECM in the solid environment. Data are represented as mean ± SEM. Asterisks indicate p<0.05 compared with scrambled oligo control.