A Study On The Relationship Between Skp2, P27 Protein And Ovarian Neoplasm

Objective:(1) To investigate the correlation between the expression of S-phase kinase-interacting protein-2(Skp2),P27 protein and clinical pathological features of epithelial ovarian carcinoma by detecting their expression in epithelial ovarian neoplasm.(2) To study the effect of 1,25(OH)₂D₃ and DDP on growth in human ovarian cancer cell line HO8910 and to explore its mechanism by detecting the distribution of cell cycle and expression of Skp2 and P27 protein.Methods:(1) The expression of Skp2 and P27 protein were detected by immunohistochemistry technique in 35 cases serous adenocarcinoma,10 cases borderline serous adenoma,20 cases serous adenoma and 10 cases normal ovarian tissue.(2) HO8910 human ovarian cancer cell line were cultured and treaed with different concentrations of 1,25(OH)₂D₃ and/or DDP in vtro.Cell proliferation was evaluated by MTT assay.(3) The FCM(Flow Cytometry) was used to measure and analyse the effect of 1,25(OH)₂D₃ and DDP on cell cycle.(4) Immunocytochemistry technique was used to detect the expression of Skp2 and P27 protein in HO8910 cell line treated with 1,25(OH)₂D₃ and DDP.Results:(1)Skp2 expression was negative in ovarian borderline serous adenoma,serous adenoma and normal ovarian tissue.In contrast,Skp2 expression was detected in 48.5%serous adenocarcinoma.Positive Skp2 expression was significantly higher in grade 3(61.5%),stageâ…¢/â…£(66.7%) than in grade 1/2(11.1%),stageâ… /â…¡(21.4%)(P＜0.05).A significantly higher rate of Skp2 expression was observed in those with lymph node metastasis(85%) than those without lymph node metastasis(20%)(P＜0.01).P27 protein expression was significantly lower in serous adenocarcinoma than in serous adenoma and normal ovarian tissue(P＜0.01).In ovarian serous adenocarcinoma,P27 protein expression was inversely correlated with Skp2 (P＜0.05).There was no significant difference either Skp2 or P27 protein expression in those with different ages.(2) 1,25(OH)₂D₃ inhibited the growth of HO8910 cells at concentrations of 160×10^-9mol/L or more(P＜0.05).There was positive interaction between 1,25(OH)₂D₃ and DDP.Combination of 1,25(OH)₂D₃ and DDP enhanced the inhibitory effect on cell proliferation.(3) Compared to control group,1,25(OH)₂D₃ and DDP induced G₀/G₁ arrest of HO8910 cells(P＜0.01),decreased cell rate of S and G₂/M and PI(P＜0.01).(4)1,25(OH)₂D₃ and DDP decreased expression of Skp2 and increased P27 protein(P＜0.01).Conclusion:(1) Skp2 expression in ovarian serous adenocarcinoma increased and was positively correlated with clinical stage and histological grades of the tumors.In contrast,P27 protein expression in ovarian serous adenocarcinoma decreased and was inversely correlated with Skp2.Both of them may be correlated with the development and progression of ovarian serous adenocarcinoma.(2) Both 1,25(OH)₂D₃ and DDP can inhibit proliferation of HO8910 cells.1,25(OH)₂D₃ can enhance the inhibitory effect of DDP on HO8910 cells proliferation.(3) 1,25(OH)₂D₃ and DDP can down-regulate Skp2 expression,up-regulae P27 protein expression and induced G₀/G₁ arrest of HO8910 cells.