Figure 5.

Inter-invadopodia spacing influences the size of invasion tracks. (A) Representative images of 1 μM Y-27632-treated MDA-MB-231 cancer cells cultured on 0.5 and 5.0% fluorescent gelatin. Scale bar represents 20 μm. Insets show colocalization of F-actin puncta and degraded areas. Scale bar represents 2.5 μm. (B) Quantitative analysis of inter-invadopodia spacing of Y-27632-treated MDA-MB-231 cancer cells cultured on 0.5 and 5.0% fluorescent gelatin. Only invadopodia spaced less than 5 μm apart were considered for quantification of inter-invadopodia spacing. Statistical significance was performed using one-way ANOVA ($n=2$, 18–25 cells per condition; ^∗∗∗p < 0.001). Error bars show mean ± SE. (C) Multi-invadopodia simulations were performed where growth of two parallel invadopodia placed at a distance of d = 1, 2, and 3 μm was simulated. (D) Representative images showing size/shape of the degraded zones underneath the invadopodia at the end of the simulations for d = 1, 2, and 3 μm and for ξ = 20 and 100%. (E) Pore size was calculated as the area of the largest degraded region perpendicular to the direction of invadopodia penetration. Error bars are ± standard deviation. (F and G) ECM degradation and pore size for d = 1, 2, and 3 μm at varying ECM densities. Error bars are ± standard deviation. To see this figure in color, go online.