CircRNA UBAP2 promotes the progression of ovarian cancer by sponging microRNA-144.

ABSTRACT

OBJECTIVE: This study aims to elucidate the regulatory effect of circular RNA UBAP2 (circUBAP2) on the progression of ovarian cancer (OC). PATIENTS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to detect the expressions of circUBAP2, microRNA-144 and CHD2 in OC tissues and adjacent normal tissues. The correlation between the expression levels of circUBAP2 and microRNA-144 with pathological parameters of OC patients was analyzed. Subcellular distribution of circUBAP2 was detected by chromatin fractionation assay. After overexpression of circUBAP2 in OC cells, changes in proliferative and migratory abilities were evaluated by Cell Counting Kit-8 (CCK-8) and transwell assay, respectively. In addition, the Dual-Luciferase reporter gene assay was used to verify the binding of circUBAP2 and microRNA-144, and the binding of CHD2 to microRNA-144. RESULTS: QRT-PCR results showed that circUBAP2 was highly expressed in OC tissues, and its expression was negatively correlated with TMN stage and five-year survival of OC patients. CircUBAP2 was mainly distributed in the cytoplasm. Overexpression of circUBAP2 significantly promoted the proliferative and migratory abilities of OC cells. The Dual-Luciferase reporter gene assay demonstrated that circUBAP2 could bind to microRNA-144. Meanwhile, circUBAP2 negatively regulated microRNA-144 expression in OC cells. Besides, the promotive effects of circUBAP2 on the proliferation and migration of OC cells were reversed by microRNA-144 overexpression. MicroRNA-144 was lowly expressed in OC tissues, which was negatively correlated with TNM stage of OC patients. The Dual-Luciferase reporter gene assay confirmed the binding condition between CHD2 and microRNA-144. CHD2 expression was negatively regulated by microRNA-144 in OC cells. Moreover, CHD2 could bind to microRNA-144 and partially inhibited its activity, thereby promoting the proliferative and migratory abilities of OC cells. CONCLUSIONS: CircUBAP2 promotes the progression of ovarian cancer by adsorbing microRNA-144.