2.9. Transwell assay

For Transwell migration and invasion assays, 2 × 10⁵ transfected cells were seeded into the upper chamber of Transwell filters precoated with or without Matrigel. A total of 500 μl serum-free medium was added to the upper chamber, and 200 μl of medium containing 10% FBS was added to the lower chamber. After incubation for 24 h, the migrated or invaded cells on the lower membrane surface were fixed in paraformaldehyde for 15 min and then stained with a 0.1% crystal violet solution for 15 min. Cell migration or invasion through the membrane was evaluated under an inverted microscope.