Interplay of microRNAs and circRNAs in Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) with its high death incidence rate is generally detected at advanced stages. During its progression, EOC often develops peritoneal metastasis aggravating the outcomes of EOC patients. Studies on non-coding RNAs (ncRNAs), such as microRNAs (miRNAs) and circular RNAs (circRNAs), have analyzed the impact of miRNAs and circRNAs, along with their interaction among each other, on cancer cells. MiRNAs can act as oncogenes or tumor suppressors modulating post-transcriptional gene expression. There is accumulating evidence that circRNAs apply their stable, covalently closed, continuous circular structures to competitively inhibit miRNA function, and so act as competing endogenous RNAs (ceRNAs). This interplay between both ncRNAs participates in the malignity of a variety of cancer types, including EOC. In the current review, I describe the characteristics of miRNAs and circRNAs, and discuss their interplay with each other in the development, progression, and drug resistance of EOC. Sponging of miRNAs by circRNAs may be used as a biomarker and therapeutic target in EOC.