Transwell assay

Transwell assay was carried out in PC‐3 or DU145 cells from different groups using a 24‐well Transwell chamber with 8‐µm pore size (Costar; Corning, Inc., Corning, NY, USA) without coated Matrigel (BD Biosciences) for cell migration or with coated Matrigel for cell invasion. In brief, 3 × 10⁵ cells were transferred to the top chamber, and the chemoattractant (the medium containing 10% FBS) was added to the lower chamber. Following 24‐h incubation, 4% paraformaldehyde was used for fixation of those cells that migrated into the lower chamber; then, the cells were stained by 0.1% crystal violet; and finally, the cell counting was performed on a microscope (Olympus Corporation, Tokyo, Japan).