A total of 3×105 cells were seeded in six-well plates and incubated overnight. After treatment with 100 ng/ml of rhL1CAM or 100 nM of siL1CAM for 24 h, cells were incubated with 5% CO2 at 37°C for 24, 48 and 72 h. Viable cells were stained with 0.4% trypan blue solution (Gibco; Thermo Fisher Scientific, Inc.) at RT for 5 min and counted using a hemocytometer at each time-point.