Circular RNAs in esophageal squamous cell carcinoma: What do we know so far?

Esophageal squamous cell carcinoma (ESCC) is a highly lethal malignancy, with limited early diagnostic tools and effective therapeutic targets. Circular RNAs (circRNAs) are a class of stable non-coding RNAs that have emerged as crucial regulators in the process of ESCC tumorigenesis, highlighting their great application potential in ESCC diagnosis and treatment. This review provides a comprehensive overview of current advances and prospects of circRNAs in ESCC. We provide an overview of the biogenesis mechanism of circRNAs and summarize their expression and biological functions in ESCC. Among them, we specifically emphasize the mechanism by which circRNAs regulate ESCC through interaction with proteins and the role of circRNAs in regulating the tumor microenvironment. The review also systematically summarizes the existing circRNA research databases and the use of high-throughput techniques to study dysregulated circRNA expressions. In addition, we discuss the translational potential of emerging technologies, including advanced circRNA detection tools, targeted delivery systems, and circRNA-based vaccines, which are expected to open up new avenues for ESCC diagnosis and treatment. circRNAs are central regulators of ESCC tumor progression, and they have the dual potential as biomarkers and therapeutic targets. The latest developments in emerging technologies for circRNA-based treatment have shown encouraging results, but the transformation of circRNA-based strategies into clinical practice is still limited by small sample sizes, lack of multicenter verification, and inconsistent detection methods. Future research should continue to carry out mechanism verification, multi-omics integration, and prospective clinical trials to promote its transformation into ESCC therapies.