Fig. 7.

Guidance and stiffness sensing on competing cell–ECM and cell–cell interactions. a–d 3D reconstructions of MDA-MB-468 cells spreading on the collagen (vertical, red) versus E-cadherin (horizontal, green) orthogonal elastic grids. a MDA-MB-468 breast carcinoma cell sensing and protruding along competing collagen and E-cadherin cues on soft (2.3 kPa) and stiff (50 kPa) substrates under control conditions and in the presence of blebbistatin, where the dendritic protrusion phenotype emerges in response to both collagen and E-cadherin. Note that cells on soft substrates do not respond to E-cadherin cues. b–d Breast carcinoma cell response to collagen and E-cadherin cues on soft and stiff substrates in response to b microtubule disruption (nocodazole), c Arp2/3 inhibition, or d FAK inhibition, with ±blebbistatin treatment for each condition. Following microtubule disruption, cells are no longer biased along collagen on soft substrates but instead respond to both collagen and E-cadherin ligands on both soft and stiff substrates. Inhibition of Arp2/3 complex does not substantially impact contractile cells but ablates low-traction-dependent dendritic protrusions along both collagen and E-cadherin while inhibition of FAK disrupts the guidance sensing response in contractile cells but is dispensable for Arp2/3-dependent dendritic protrusion. e Morpho-mechanical analysis of cells on soft and stiff substrates for each experimental condition. Note, we define cells with R > 10 µm as polygonal and cells with R < 10 µm as dendritic, consistent with the lower limit for R/d as ~0.71. The corresponding n values are shown in Supplementary Figure 10a. Scale bars—15 µm. Number of replicates (independent experiments) for all measurements N = 5. Data in e are mean ± s.d.; ns: no significant difference between groups; *p < 0.05, **p < 0.001 (ANOVA). See also Supplementary Figure 10a for the raw data of population-wide distribution of individual R and d measurements