Migration assays

The bottom chambers of Transwell filter chambers (8 μm pores; Corning, Tewksbury, MA, USA) were coated with 40 μg/ml of FN or 100 μg/ml of GST-IIICS (prepared as described).¹⁰⁰ Cells (5 × 10⁵) were placed in the upper chamber and incubated for 16 h at 37 °C. Cells on the bottom of the filter were fixed and stained with 0.1% crystal violet, and five random fields were imaged and counted. For live imaging, cells were plated in FN-coated 48-well plates in plating medium and allowed to attach and spread for 2.5 h. Attached cells were observed at 37 ^oC on a Nikon Eclipse TE2000U equipped with environmental chamber using a PlanApo 20X objective (0.75 numerical aperture) and a Photometrics CoolSnap ES camera. Cells were tracked with Metamorph and images were collected at 10-min intervals over 3 h.