环状RNA作为肿瘤标志物及其在肿瘤放疗中应用的研究进展

放疗是肿瘤综合治疗的重要手段之一，但放疗抵抗是影响肿瘤患者放疗疗效及预后的一大难题。由于肿瘤细胞放疗抵抗的机制十分复杂，所以至今还未找到特别有效的调控放疗敏感性的开关分子。环状RNA（circRNA）是一类通过反式剪接使得 3' 末端与 5' 末端共价结合的闭合circRNA分子，具有丰度高、结构稳定和特异性强等特征。circRNA参与肿瘤的发生、发展、侵袭和转移等过程，可以作为新型肿瘤分子标志物和潜在的治疗靶点。此外，circRNA在受照后的肿瘤细胞中存在差异性表达，并可作为微小RNA（miRNA）的海绵，调控与肿瘤放疗抵抗相关的miRNA及其下游信号通路，使其有望成为攻克肿瘤放疗抵抗的突破口。笔者综述了circRNA作为新型肿瘤标志物及其在肿瘤放疗中应用的研究进展。

Progress in the research on circRNAs as tumor markers and their applications in radiotherapy

Radiotherapy is one of the important means of combined therapy for treating tumors. However, radioresistance is a serious issue that affects the curative effect and prognosis of radiotherapy for tumor patients. Given the complex mechanism of radioresistance in tumor cells, the specific switch molecules that can regulate radiosensitivity are not yet discovered. Circular RNA (circRNA) is a kind of closed circular RNA molecules that covalently bind the 3'-end and 5'-end by trans-splicing with high abundance, stable structure, and strong specificity. CircRNA is involved in tumorigenesis, development, invasion, and metastasis and can be used as a novel tumor molecular marker and potential therapeutic target. In addition, circRNA is differentially expressed in irradiated tumor cells and can serve as a sponge to regulate microRNA and its downstream signaling pathways that are related to tumor radioresistance. Therefore, the research on circRNA might be a promising breakthrough toward overcoming tumor radioresistance. In this study, we reviewed the progress in the research on circRNAs as novel tumor markers, as well as the research prospects regarding the application of radiotherapy.