Cell migration and invasion assay

Cell invasion assay was evaluated using Transwell inserts (Corning Costar) with matrigel-coated membrane matrix (8 µm pore sizes). The HCT-116 and HCT-8 cells were treated with miR-141 mimics, 5-FU, or combination of miR-141 with 5-FU and then seeded in the upper chamber in the 24-well plate. The medium with FBS was added to the lower chamber. Serum-free medium was added in the lower chamber. The cells were cultured in the incubator at 37°C with 5% CO₂ for 24 h and then removed with a cotton swab. After being fixed, stained, washed, and air dried, invading cells were counted under a microscope.

Wound-healing assay was conducted to evaluate the migration ability of colon cells. After treated by compounds, colon cells were cultured in a six-well plate at a density of 10⁵ cells each well. At last, the cell monolayer was scratched with a 10-µl pipette tip. Images of the colon cancer cells with different treatment were taken using a microscope every 24 h. The cell-healing rate was calculated.