Long non-coding RNA CPS1-IT1 is a positive prognostic factor and inhibits epithelial ovarian cancer tumorigenesis.

OBJECTIVE: The aim of the present study was to explore the prognostic value of long non-coding RNA CPS1-IT1 (CPS1-IT1) expression in epithelial ovarian cancer (EOC) patients and identify the effect of CPS1-IT1 on cell proliferation and apoptosis of EOC cells.

PATIENTS AND METHODS: Expression levels of CPS1-IT1 in tissues and cells were detected by the Real-time quantitative RT-PCR assay. The χ2-test was used to analyze the relationship between CPS1-IT1 expression and the clinicopathological characteristics. Survival analysis was performed using the Kaplan-Meier method and Cox's proportional hazards model. The capacity for cellular proliferation was measured with cell counting Kit-8. Cell apoptosis assays were performed using flow cytometry. Western blot was used to detect the expression levels of cell apoptosis-related proteins.

RESULTS: We observed that CPS1-IT1 was significantly downregulated in EOC cell lines and tissue samples. The expression of CPS1-IT1 was significantly associated with FIGO stage and lymph node metastases. In addition, EOC patients in the low tissue CPS1-IT1 expression group had significantly shorter 5-year overall survival time than those in the high tissue CPS1-IT1 expression group. Furthermore, univariate and multivariable Cox regression analysis identified low CPS1-IT1 expression in EOC tissues as an independent poor prognostic marker of overall survival. It was also found that over-expression of CPS1-IT1 markedly promoted proliferation of EOC cells. Further studies revealed that over-expression of CPS1-IT1 induced cell apoptosis by through regulating apoptosis-related proteins.

CONCLUSIONS: CPS1-IT1 may be a functional tumor suppressor in EOC. It may also serve as an independent prognostic factor for patients with EOC.