24-well transwell plates with 8 μm pore (Corning, NY, USA) were hired to detect the migratory and invasive ability of A549 and H1299 cells. For migration assay, 1 × 105 cells in 100 μL DMEM containing 0.2% FBS and 600 μL CMs were placed into the upper and lower chamber, respectively. After the cells stained with 0.1% crystal violet for 15 min, the photos were taken by microscope (Olympus, Japan).
For invasion assay, 500 µL serum-free medium was added to both the upper and lower chambers, and incubated in 37°C for 2 h to rehydrate the Matrigel matrix layer (BD, USA). 1 × 105 cells in 100 μL DMEM containing 0.2% FBS and 600 μL CMs containing 10% FBS were placed into the upper and lower chamber, respectively. The cells fixed by 4% paraformaldehyde for 30 min, then stained with 0.1% crystal violet for 30 min, the photos were taken by microscope (Olympus, Japan).
For invasion assay, 500 µL serum-free medium was added to both the upper and lower chambers, and incubated in 37°C for 2 h to rehydrate the Matrigel matrix layer (BD, USA). 1 × 105 cells in 100 μL DMEM containing 0.2% FBS and 600 μL CMs containing 10% FBS were placed into the upper and lower chamber, respectively. The cells fixed by 4% paraformaldehyde for 30 min, then stained with 0.1% crystal violet for 30 min, the photos were taken by microscope (Olympus, Japan).