New insights into the role of circular RNAs in ovarian cancer

Ovarian cancer (OC) is one of the most aggressive tumors in women and has a poor prognosis and the highest mortality rate. Circular RNAs (circRNAs) are a type of endogenous non-coding RNAs that have recently attracted interest in cancer research. Increasing evidence has demonstrated that circRNAs play an oncogenic or sup-pressive role in tumorigenesis and progression, and show tissue-or developmental-stage-specific expression. Due to high stability, conservation, abundance, and specificity, circRNAs are considered promising biomarkers for the diagnosis and prognosis of cancer. Herein, we have summarized the expression profiles of circRNAs in OC tissues, serums, and cell lines. Moreover, we discuss how circRNAs participate in the regulation of multiple biological processes in OC, including cell proliferation, apoptosis, migration, invasion, autophagy, epithelial-to-mesenchymal transition, glucose metabolism, angiogenesis, immune response, and chemotherapy resistance, by sponging microRNAs and interacting with proteins.