Circular RNAs (circRNAs), resulting from the non-canonical splicing of linear pre-mRNAs, have permanently altered our perspectives toward cancer recently, especially in carcinogenesis and cancer progression. However, the roles of circRNAs in esophageal squamous cell carcinoma (ESCC) remain largely unknown. In the current study, circRNAs expression profiles are screened in ESCC, using plasma samples from 10 ESCC patients, including different TNM stages and 5 normal controls. Characteristics of circRNAs including length, types, and the possibility of binding to proteins are analyzed. Candidate tumor-related circRNAs are then quantitated in ESCC tissues, plasmas and cell lines. ESCC tissues can secret circRNAs into plasma and patients with high plasma circ-SLC7A5 are associated with high TNM stage, tending to have shorter overall survival than those with high levels. In addition, the biological characteristics of circ-SLC7A5 including location, miRNAs binding, m⁶A modification were analyzed. Our study reveals a novel prognosis biomarker of circ-SLC7A5, providing a preliminary landscape of circRNA expression for detection of ESCC.

线性pre-mRNA的非经典剪接产生的环状RNA（circRNA）最近永久改变了我们对癌症的看法，尤其是在致癌和癌症进展方面。但是，circRNA在食管鳞状细胞癌（ESCC）中的作用仍然未知。在当前的研究中，使用来自10位ESCC患者的血浆样品（包括不同的TNM分期和5位正常对照）在ESCC中筛选circRNA的表达谱。分析了circRNA的特征，包括长度，类型和与蛋白质结合的可能性。然后在ESCC组织，血浆和细胞系中定量与候选肿瘤相关的circRNA。食管鳞癌组织可以将circRNA分泌到血浆中，血浆circ-SLC7A5高的患者与TNM分期高有关，往往比高水平者的总生存期短。此外，circ-SLC7A5的生物学特性包括位置，miRNA结合，m⁶分析了一个修改。我们的研究揭示了circ-SLC7A5的新型预后生物标志物，为circRNA表达的初步检测提供了ESCC的检测方法。