2.10. Matrigel Invasion Assay

Precoated Matrigel was used to conduct a Transwell invasion assay using invasion chambers (BD Biocoat, Bedford, MA, USA). Cells (5 × 10⁴) were added to the inserts, whereas both medium and drug were added to the receiver plate. The inserts containing cells were retained onto the receiver plate and incubated at 37 °C in a humidified chamber for 48 h. After incubation, cells that invaded the apical surface of the inserts were fixed with crystal violet, whereas those that stayed attached to the upper surface of the insert were removed using a cotton swab. The invaded cells were observed using a microscope and counted.