CDCA8 is key gene high expressed and correlated to chemoresistance in ovarian cancer. (A) Public data sets were used to identify genes associated with chemoresistance of ovarian cancer. (B-H) Oncomine and GEPIA databases showed the mRNA expression of CDCA8 and TOP2A in serous ovarian carcinoma and normal controls. (I-N) The mRNA expression level of CDCA8 and TOP2A in cisplatin resistance A2780, SKOV3 and TGROV1 cells. (O and P) The mRNA level of CDCA8 and TOP2A in pan cancer. (Q and R) Pathway analysis showed the signal pathways participated in by co-expression genes of CDCA8 and TOP2A. (S and T) The mRNA and protein levels of CDCA8 in HGSOC and FT tissues. (U) Representative IHC staining of CDCA8 in HGSOC and FT tissues (200 ×), Scale bar: 50 µm. (Data are mean ± SEM, #P > 0.05, *P < 0.05, **P < 0.01, ***P < 0.001, n = 3).