High Expression Of RBBP6 Promotes Cell Proliferation And Inhibits Apoptosis In Epithelial Ovarian Cancer

OBJECTIVE: To verify the expression of Retinoblastoma binding protein 6(RBBP6)in epithelial ovarian cancer(EOC)tissues and cell lines,to analyze its correlation with clinicopathology,and try to verify the effects of RBBP6 on cell proliferation,migration,apoptosis and cell cycle of epithelial ovarian cancer,reveal the role of RBBP6 in the development of epithelial ovarian cancer,and explore the specific molecular mechanism of RBBP6 regulation of ovarian cancer cell proliferation and apoptosis in epithelial ovarian cancer.METHODS: Immunohistochemistry was used to detect the expression of RBBP6 protein in epithelial ovarian cancer tissues.Western blot was used to detect the expression of RBBP6 in human epithelial ovarian cancer cell lines including Caov3,Hey,Skov3,HO8910 and A2780.RBBP6-specific siRNA was used to down-regulate the expression of RBBP6 in ovarian cancer cells.The changes of cell migration ability before and after RBBP6 intervention were observed by using scratch test and Transwell cell migration experiment.The effect of RBBP6 expression on cell proliferation was observed by cck-8 assay and clone formation assay.Flow cytometry was used to analyze the effects of RBBP6 on cell cycle and apoptosis.We evaluated the relationship between the core molecule p-JNK of JNK signaling pathway and the expression of downstream target proteins c-Jun,P53 and RBBP6 in HO8910 cells pretreated with RBBP6 siRNA.To further analyze whether JNK signaling is involved in the mechanism by which RBBP6 regulates proliferation and apoptosis of epithelial ovarian cancer cells,we treated the cells with the JNK pathway inhibitor SP600125.RESULTS:(1)The expression of RBBP6 in epithelial ovarian cancer tissues was significantly higher than that in ovarian borderline tumors and normal ovarian epithelial tissues.(2)The expression of RBBP6 was positively correlated with FIGO stage and lymph node metastasis(p<0.01),but not correlated with the age,pathological type,degree of differentiation,CA125,HE4 and CA199 levels.(3)RBBP6 was expressed in the five epithelial ovarian cancer cell lines Caov3,Hey,Skov3,HO8910 and A2780,and the expression was higher in Skov3 and HO8910.(4)Down-regulation of RBBP6 expression can decrease the ability of proliferation and clonality of ovarian cancer cells in vitro.(5)Down-regulation of RBBP6 expression can decrease the migration ability of ovarian cancer cells in vitro.(6)Down-regulation of RBBP6 expression can stagnate the cell cycle of ovarian cancer cells in G1 / S phase,and cell cycle-associated proteins CyclinD1,CyclinE1,CDK2,CDK4 were down-regulated.(7)Down-regulation of RBBP6 expression can promote the apoptosis of ovarian cancer cells,pro-apoptotic proteins Bax,caspase-3 and cleaved PARP were up-regulated,and anti-apoptotic proteins BCL-xL and BCL-2 were down-regulated.(8)RBBP6 regulates proliferation and apoptosis of epithelial ovarian cancer cells via JNK signaling pathway.CONCLUSIONS:RBBP6 is highly expressed in epithelial ovarian cancer tissues and cell lines and is associated with progression of epithelial ovarian cancer.Increased expression of RBBP6 can promote the proliferation and migration of ovarian cancer cells.Down-regulation of RBBP6 expression can stagnate ovarian cancer cell cycle in G1 /S phase and promote apoptosis of ovarian cancer cells.RBBP6 may regulate proliferation and apoptosis of epithelial ovarian cancer cells through JNK signaling pathway...