Effect Of RCC2 On DDP-resistance Of Ovarian Cancer Cells

BackgroundEpithelial ovarian cancer is nowadays one of the most common malignant tumors in women.Whose main characteristics are late detected,easy recurrence,and poor prognosis.The current clinical treatment of late epithelial ovarian cancer is tumor cytoreductive surgery supplemented with Cisplatin based chemotherapy,of which cisplatin is a first-line chemotherapy drug for epithelial ovarian cancer,more than 80%of patients are sensitive to DDP initially,but acquired resistance in most patients eventually leads to relapse and death.The mechanism of the drug is unclear.RCC2 is an important component of the chromosome passenger complex.,some studies have confirmed that RCC2 may be related to the drug sensitivity of tumor cells.This subject aims to find out the relationship between cisplatin resistance and RCC2,then provide new ideas for the study of resistance mechanisms of epithelial ovarian cancer,and provide a new target for effectively preventing and reversing chemotherapy resistance of epithelial ovarian cancer cells.Methods1.Detection of RCC2 expression in epithelial ovarian cancer cell lines(Skov3,A2780)and drug-resistant epithelial ovarian cancer cell lines(Skov3/DDP,A2780/DDP)by fluorescence quantitative PCR and Western Blotting,and analyze the difference between two groups.2.Epithelial ovarian cancer sensitive cells and epithelial ovarian cancer resistant cell lines were divided into five groups for experimental comparison:blank group,RCC2 overexpression/silence group,negative control group,DDP group,RCC2 In the/si RCC2+DDP group.CCK8,transwell,and flow cytometry were used to detect the cell proliferation,invasion,and apoptotic capacity of each group,and Western Blotting was used to detect the RalA/RalBP1 protein expression level of each group.Results1.RCC2 is differentially expressed in sensitive cells and resistant cell lines of epithelial ovarian cancer.The expression of RCC2 in resistant ovarian cancer cell lines A2780/DDP and SKOV3/DDP is higher than that of sensitive ovarian cancer cell lines A2780,SKOV3.2.RCC2 can promote the proliferation and invasion of ovarian cancer cell lines,inhibit its apoptosis capacity and DDP sensitivity,which may be regulated by the RalA/RalBPl pathway.The results of CCK-8 showed that RCC2 overexpression significantly promoted cell proliferation and reduced DDP-induced cell growth inhibition in A2780 and SK-OV-3 cells.In contrast,knockout of RCC2 significantly inhibited the cell proliferation of A2780/DDP and SKOV-3/DDP cells and promoted DDP-induced cell growth inhibition.Transwell results showed that the migration capacity of A2780 and SKOV-3 cells could be overexpressed by RCC2.In contrast,knockdown of RCC2 alone may significantly inhibit the migration capacity of A2780/DDP and SKOV-3/DDP cells.The combination of RCC2 knockout and DDP may maximally inhibit cell migration in A2780/DDP and SKOV-3/DDP cells.Flow cytometry results showed that RCC2 overexpression can significantly reduce the apoptosis of A2780 and SKOV-3 cells treated with or without DDP.The knockdown of RCC2 significantly accelerated the apoptosis of A2780/DDP and SKOV-3/DDP cells.The combination of RCC2 knockdown and DDP may lead to maximal apoptosis in A2780/DDP and SKOV-3/DDP cells.Western Blotting results showed that RalA expression was significantly increased in RCC2 overexpressing A2780,SKOV-3,A2780+DDP,and SKOV-3+DDP cell lines,while in RCC2 knockout A2780/DDP,SKOV-3/DDP,A2780/DDP+DDP,SKOV-3/DDP+DDP were significantly reduced.ConclusionThe expression level of RCC2 in ovarian cancer resistant cell lines is higher than that of sensitive cell lines,and it promotes the proliferation and invasion of ovarian cancer cell lines,inhibits its apoptosis ability and sensitivity to cisplatin,up-regulates the protein expression level of RalA/RalBPl,which suggests that it may promote the occurrence of cisplatin resistance in ovarian cancer by regulating the RalA/RalBP1 pathway.