Transwell assay

Cell migration was assayed by Boyden chamber assay with 24 well transwell permeable supports with 8 μm pores (Corning Coaster, Lowell, MA, USA). 200 μL of serum-free medium containing 0.1M cells for the migration assay were added to the filter. The bottom chamber was prepared with 750ul complete cell culture medium in which the FBS as a chemoattractant. After incubated for indicated time, the non-invasive cells were cleaned by scrubbing with a cotton swab. The cells that adhered to the outside of the membrane were fixed and dyed with crystal violet solution. The stained cells were dissolved in extraction buffer and solutions were transferred to a 96-well culture plates for colorimetric reading at OD 560 nm. The OD values reflected the cell ability of migration or invasion.¹⁰

List of the primers used.