Coimmunoprecipitation (Co-IP)
The cells were washed three times with PBS and subsequently lysed on ice in lysis buffer (Beyotime, Beijing, China). Next, the lysates were centrifuged at 12,000 × g for 15 min. Subsequently, the cell lysates were incubated with specific antibodies for 1 h, followed by a 30-minute incubation with Dynabeads Protein G beads at 4°C. The beads were then washed three times with cold lysis buffer. Following the washes, the beads were boiled in 10 µL of 5× loading buffer (Beyotime, Shanghai, China) for 5 min before being analyzed by western blot using antibodies against DNMT1, G9a, E2F1, Flag, Myc, and GST.