IR cells present increased invasive ability in a 3D collagen gel.

<p>(A) Quantification of invasion speed in P and IR cells presented as mean values ± S.D, ***p<0.001. (B) Diagrams representing the invasion trajectories of 4 representative cells from P and IR cells in 3D collagen gel-sand covered for 6 h. Cell origins were set as (0,0), and the scale unit is µm. (C) Confocal images of representative MFP488 phalloidin-stained P and IR spheroids in collagen gel at 0 h or 24 h. Scale bar, 200 µm. (D) Quantification of the area of spheroids by ImageJ software. (E) The aspect ratio of spheroids was calculated from perimeter²/[4π(area)]. Results are presented as mean values ± S.D (***p<0.001) from 3 independent experiments in triplicate.