To observe the effect of the histone deacetylase inhibitor PCI-24781 on the apoptosis and cell cycle of epithelial ovarian cancer SKOV-3 cells, and to explore its mechanisms of action.

After SKOV-3 cells were treated with PCI-24781 at different concentrations (0, 0.25, 0.5, 0.75, and 1.0 μmol/L) for 48 hours, apoptosis was detected by BD FACSCalibur flow cytometry, the changes in cell cycle distribution were analyzed, the changes of intracellular reactive oxygen species (ROS) were detected by using DCFH-DA probe. Western blot was used to assay the expression of β-catenin, Wnt-5a, Caspase-8, ROR2, Cyclin D1, and CDK4.

After treatment with different concentrations of PCI-24781, the apoptosis rate of SKOV-3 cells was increased (P＜0.001), the intracellular ROS level showed an upward trend (P＜0.001), and oxidative stress increased, PCI-24781 exerted these effects in a dose-dependent manner; The expression levels of β-catenin and Wnt-5a decreased, the expression level of Caspase-8 increased, and the expression of ROR2 had no obvious change. SKOV-3 cell cycle was blocked in G1/G0 phase, the percentages of cells in S phase and G2/M phase were reduced (P＜0.05), and the expression levels of cell cycle-related proteins Cyclin D1 and CDK4 were decreased.

PCI-24781 induces apoptosis of SKOV-3 cells by activating Caspase-8 and promoting ROS generation, arrests the cells in the G1/G0 phase to inhibit their proliferation, and exerts a dual inhibitory effect on the canonical and non-canonical Wnt signaling pathways.