Figure 3.

PDAC cell traction forces increase with substrate stiffness, but not with metastatic potential. (A) Representative linear regression of the total forces (nN) vs. spreading area (μm²) of SUIT-2.028. All the linear regression models of the other cell lines are found in Supplemental Figure S1. In all the measurements, the regression coefficient was R² > 0.45. (B) Representative confocal microscopy images of the traction forces of the BxPC-3 cells (green) growing on fibronectin-coated pillars (red). White arrows indicate cellular traction forces on the pillars. (C) Boxplots of the PDAC cell traction forces expressed as mean force per pillar (nN) (25th and 75th percentiles marked, line at median). Statistical significance was calculated using the softest condition (11 kPa) as the reference group. (D) Mean force per pillar (nN) of the PDAC cell lines of different phenotypes. The results from other stiffness values (11, 29, and 142 kPa) are shown in Supplemental Figure S3 and pillar‘s background forces are shown in Supplemental Figure S2. Each dot of plots in (A,C,D) represents the result from one cell. (C,D) Statistical significance was set at p < 0.05 and is indicated by ****, p < 0.0001.