Western‐blot detection of CDK1, cycle B and caspase‐3 expression in cell lines

Extraction of total protein: The culture medium was discarded and the cells rinsed with PBS. The cell lines were then lysed at a ratio of 150–250 μL of lysis solution per well in a six‐well plate, and transfered to an EP tube. They were placed on ice for 30 minutes and then shaken for 15 seconds every five minutes before being centrifuged at 12000 rpm/minute for 10 minutes at 4°C, and the supernatant taken as total cell protein.

Western‐blot procedures: The protein solution was added into the same volume of buffer and boiled at 100°C for 10 minutes, then frozen on ice. The separation gel was prepared, the sample added and electrophoresis performed at 80–100 V. The membrane was then transferred on ice at 90 V for 90 minutes, sealed with 5% skimmed milk powder for two hours and the sealing solution was diluted with primary antibody at 4°C overnight. The membrane was washed with PBTS, a secondary antibody added and incubated for two hours. The membrane was then washed again and exposed with an imaging system. The images were analyzed by image processing Software Image Laboratory and plotted using Graph Pad Prism 8.0.