EdU incorporation

The transfected cells were incubated at 37 °C for two hours with DMEM containing EdU (50 μm, RiboBio, Guangzhou, China), After that, the cells were fixed with 4% formaldehyde for 20 minutes and then added glycine for 5 minutes. After 10 minutes, it was treated at room temperature with 0.5% Triton X-100. The cells were washed with PBS for three times, and then each well was treated with a 200 μL 1 X Apollo reaction cocktail for 10 minutes. Subsequently, each well was stained with 100 μL of DAPI (5 μg/mL) for 10 minutes and imaged using a fluorescent microscope (MOTIC, Hongkong, China).