Total protein was extracted from A172 cells using RIPA lysis buffer (Beyotime Institute of Biotechnology). Total protein concentration was quantified with a BCA assay kit (Beyotime Institute of Biotechnology) and equal amount of proteins (20 µg per lane) was separated using 10% SDS-PAGE and subsequently transferred onto PVDF membranes (MilliporeSigma) which were blocked with 5% non-fat milk for 2 h at room temperature. The membranes were incubated with primary antibodies targeting KIF18A (1:2,000; cat. no. ab72417; Abcam), CDK1 (1:10,000; cat. no. ab133327; Abcam), cyclin B (1:50,000; cat. no. ab32053; Abcam), MMP9 (1:1,000; cat. no. ab76003; Abcam), MMP2 (1:1,000; cat. no. ab92536; Abcam), PPP1CA (1:20,000; cat. no. ab52619; Abcam), or GAPDH (1:1,000; cat. no. ab9485; Abcam) overnight at 4˚C. Following the rinse with PBS for three times, membranes were incubated with HRP-conjugated secondary antibodies (cat. no. ab6759; 1:5,000; Abcam) for 1.5 h. The protein bands were visualized using ECL detection reagent (MilliporeSigma) and analysed with ImageJ software 1.8.0 (National Institutes of Health). GAPDH was used as internal reference.