Circular RNA CDR1as Alleviates Cisplatin-Based Chemoresistance by Suppressing MiR-1299 in Ovarian Cancer

Cisplatin (CDDP) chemoresistance seriously affects the prognosis and survival of patients with ovarian cancer (OC). Previous research has shown that circular RNA CDR1as is biologically associated with a large number of cancers. However, the molecular mechanism underlying the role of CDR1as in CDDP chemoresistance in OC remains unclear. Here, we investigated the mechanism of CDR1as in CDDP-resistant OC. First, we employed bioinformatics analysis and quantitative real-time PCR (qRT-PCR) to determine the expression of CDR1as and related RNAs in CDDP-sensitive and -resistant OC tissues and cells. Then, functional experiments were used to determine cell proliferation, invasion, migration, and apoptosis in CDDP chemoresistance and parent OC cells in vitro. The effect of CDR1as in CDDP chemoresistance OC progression was tested in nude mice in vivo. Moreover, dual-luciferase assays and RNA immunoprecipitation (RIP) were performed to confirm the interactions of CDR1as and related RNAs. Finally, we used Western blotting to determine protein expression levels. Our findings interpret the underlying mechanisms of the CDR1as/miR-1299/PPP1R12B axis and shed light on the clinical applications for CDDP-chemoresistant OC.