Cell migration and invasion assay

The cell migratory and invasion capacity was determined using transwell chambers (BD Biosciences, San Jose, CA, USA). Briefly, HCT-8 and SW480 cells were transfected with si-CAPS or si-NC. For the migration assays, cells (1×10⁵/well) were suspended in 100 µL serum-free medium and then added to the upper chamber of the inserts. For the invasion assays, cells were added into the upper chamber of the insert precoated with Matrigel (BD Biosciences). DMEM (Thermo Fisher Scientific) containing 10% fetal bovine serum (500 µL) was added to the lower chamber as the chemotactic factor. After culturing for 48 hours, non-migrated or non-invaded cells on the upper surface were gently removed with a cotton swab, and cells that migrated or invaded to the lower side of the department were fixed and dyed with 0.1% crystal violet. The numbers of migrated or invaded cells were calculated by counting five different views under the microscope. The experiment was performed in triplicate and repeated for three times.