PA28γ silencing decreased the migration and invasion of OSCC cells. (a) Cell migration was decreased by silencing PA28γ in OSCC cell lines (CAL-27, HSC-3), as shown by transwell migration assay, 24 h. Cells that migrated to the bottom of the chamber were counted in five fields under 20 × magnification. The scale bar represents 50 μm. Error bars mean ± SD (*P < 0.05). (b) Cell invasion was decreased by silencing PA28γ in OSCC cell lines, as shown by invasion assay, 30 h (right panels, scale bars represent 50 μm). Cells that invaded to the bottom of the chamber were counted in five fields under 20 × magnification. Error bars mean ± SD (*P < 0.05).