Pin1 inhibitor juglone induces apoptosis in human cervical cancer SiHa cells

AIM: To explore the effect of peptidyl-prolyl cis/trans isomerase (Pin1) inhibitor juglone on apoptosis of human cervical cancer SiHa cells. METHODS: Cultured SiHa cells were incubated with juglone at concentrations of 10, 20, 50, 80 and 100 μmol/L for 24 h. The SiHa cell activity was detected by methyl thiazolyl tetrazolium (MTT) assay. The cell apoptosis was analyzed by flow cytometry with Hoechst 33258 staining. The protein levels of cleaved caspase-3,8,9 and PTEN was determined by Western blotting. RESULTS: In different doses of juglone groups, the SiHa cell growth was greatly inhibited (P<0.05) in a dose-dependent manner as compared with control group. The IC₅₀ of juglone was 20.4 μmol/L. After treatment with juglone at concentration of 20 μmol/L for 12 h, the apoptosis of SiHa cells was induced, and the typical morphological changes of cell apoptosis such as karyopyknotic pyknic hyperfluorescence bolus, nuclear fragmentation and apoptotic body were observed by Hoechst 33258 staining. The early apoptotic rate was increased significantly as compared with the control. The protein levels of cleaved caspase-3, 8, 9 and PTEN were also increased significantly as compared with control group. CONCLUSION: Juglone significantly inhibits the cell activity and induces the apoptosis of SiHa cells in vitro by inhibiting the caspase pathway and increasing the expression of anti-oncogene.