Figure 3.

Mechanical load enhances the adhesion of cancer cells to endothelial cells and collagen I under shear stress. (A) Diagram of the experimental design. The cells were first treated with mechanical load in a high throughput system and then adhesion measured in a high throughput flow device. (B) MDA-MB-231 breast cancer cells were mechanically strained at maximal strain from 0 to 17.5% at a frequency of 0.1 and 1 Hz for 24 h. Initial adhesion of strained cells under 0.5 dynes/cm² shear stress to a TNF-α treated endothelial monolayer was measured relative to the static group. *p < 0.05 compared to the static group (n = 8). (C) Relative adhesion of the cells treated with mechanical load after detachment shear stress up to 20 dynes/cm². (D) Adhesion of cells to endothelial cells and isolated ECM molecules including laminin (LM), vitronectin (VN), collagen I (COL I), collagen II (COL 2) and fibronectin (FN). *p < 0.05 versus control group with the same adhesion substrate. (E) Adhesion of cells to endothelial cells and ECM after detachment with shear stresses up 20 dynes/cm² (n = 8). *p < 0.05 versus control group with the same adhesion substrate. (F) Initial adhesion of cells to endothelial cells in the presence of integrin inhibitors. Adhesion is to endothelial cells treated with TNF-α unless otherwise noted. (G) Relative adhesion of cells after detachment up to 20 dynes/cm² (n = 8). Adhesion is to endothelial cells treated with TNF-α unless otherwise noted. *p < 0.05 versus the HUVEC group. ^†p < 0.05 versus the TNF-α treated HUVEC group. ^‡p < 0.05 versus the TNF-a treated HUVEC with 5% strain group.