Figure 5.
Confinement suppresses the roles of contraction and integrins in migration. A) Representative trajectory for cells treated with vehicle control, 50 μM blebbistatin, and 2.5 μg/ml CT04 (grid origin denotes starting point). Ten trajectories are plotted for each condition (grid units: μm). B) Representative time-lapse images depicting migration through 3-μm channels (red arrows indicate cell front). C) Plot of instantaneous velocity for each condition. D) Treatment with a β1-integrin blocking antibody abolished migration outside the channels (bottom panel and bottom of top panel, arrowheads), but had no effect on migration through 3-μm channels (top panel). E) Average net displacement of cells with or without anti-β1 in planar regions and 3-μm channels. Values are means ± se. F) Pa03C pancreatic tumor cells were treated with siRNA targeting myosin IIA or a scramble control, as indicated by the Western blot depicting an immunoblot for myosin IIA. Migration velocities for both wild-type and siRNA-transfected cells are shown. G) Inhibiting integrins in Pa03C cells does not inhibit migration in confinement. Treatment with an anti-β1 integrin function-blocking antibody abolished cell movement outside the channels but had no effect on the net displacement through 3-μm channels. Three independent trials were performed. **P < 0.001, ***P < 0.0001; Student's t test.