Transwell Migration and Invasion Assays

The in vitro cell migration assay was performed using transwell chambers (8 μm pore size; Costar), and transwell invasion assay was conducted using the transwell chambers (8 μm pore size; Costar) and Matrigel (BD Biosciences, San Jose, CA, United States), according to the manufacturer’s instructions. For migration and invasion assays, media containing 20% FBS in the lower chamber served as a chemoattractant. After 24 or 48 h, the nonmigrating or noninvasive cells were removed from the upper face of the filters using cotton swabs. The migrated and invaded cells located on the lower side of the chamber were fixed with 4% paraformaldehyde and stained using crystal violet, air dried, photographed and counted. The number of migratory and invasive cells were counted in 5 randomly selected visual fields from the central and peripheral portions of the filter.