The proliferative capacity of the transfected cell was assessed using the bromodeoxyuridine (Brdu) incorporation assay kits (Millipore, Billerica, MA, USA). Briefly, cells (1×104 (link)) were seeded in each well of a 96-well plate after 48 hours of transfection. 10 µL of Brdu was subsequently added to each well. After 5 hours incubation, cells were fixed by FixDenat for 30 minutes. Cells were then incubated with anti-Brdu antibody in incubation buffer from Roche for 1 hour at 37°C. Cell nuclei were stained with 1 µM SYTOX Green (S7020, Life Technologies) at room temperature for 15 minutes. In each treatment, cells were washed with PBS at least three times.