Circular RNAs as Targets for Developing Anticancer Therapeutics.

Circular RNA (CircRNA) is a single-stranded RNA arising from back splicing. CircRNAs interact with mRNA, miRNA, and proteins. These interactions regulate various life processes, including transcription, translation, cancer progression, anticancer drug resistance, and metabolism. Due to a lack of cap and poly(A) tails, circRNAs show exceptional stability and resistance to RNase degradation. CircRNAs exhibit dysregulated expression patterns in various cancers and influence cancer progression. Stability and regulatory roles in cancer progression make circRNAs reliable biomarkers and targets for the development of anticancer therapeutics. The dysregulated expression of circRNAs is associated with resistance to anticancer drugs. Enhanced glycolysis by circRNAs leads to resistance to anticancer drugs. CircRNAs have been known to regulate the response to chemotherapy drugs and immune checkpoint inhibitors. Exogenous circRNAs can encode antigens that can induce both innate and adaptive immunity. CircRNA vaccines on lipid nanoparticles have been shown to enhance the sensitivity of cancer patients to immune checkpoint inhibitors. In this review, we summarize the roles and mechanisms of circRNAs in anticancer drug resistance and glycolysis. This review discusses clinical applications of circRNA vaccines to overcome anticancer drug resistance and enhance the efficacy of immune checkpoint inhibitors. The advantages and disadvantages of circRNA vaccines are also discussed. Overall, this review stresses the potential value of circRNAs as new therapeutic targets and diagnostic/prognostic biomarkers for cancer.