摘要目的 探讨环状 RNA-MYC-overlap.2(circ-MYC-overlap.2)/微小 RNA-19a-3p(miR-19a-3p)在胃癌的表达及其临床意义.方法 采用RT-PCR检测56例胃癌组织及其癌旁正常组织以及56例胃癌患者和50例健康人群血清中circ-MYC-overlap.2、miR-19a-3p的表达,并分析circ-MYC-overlap.2表达与胃癌患者临床特征的相关性.采用Kaplan-Meier生存曲线分析胃癌患者血清中circ-MYC-overlap.2表达与术后5年生存期的关系.观察人胃癌细胞株SGC-7901中信号传导与转录激活因子3(STAT3)信号通路对circ-MYC-overlap.2表达的调控作用.结果 与癌旁正常组织相比,胃癌组织中circ-MYC-overlap.2表达上调,miR-19a-3p表达下调(P＜0.01);胃癌组织中circ-MYC-overlap.2与miR-19a-3p表达呈负相关(r=-0.503,P＜0.01).与健康人群相比,胃癌患者血清中circ-MYC-overlap.2表达上调,miR-19a-3p表达下调(P＜0.01);胃癌患者血清中circ-MYC-overlap.2 与 miR-19a-3p表达呈负相关(r=-0.658,P＜0.01).TNM分期Ⅲ和Ⅳ期、伴有淋巴结或远处转移患者的胃癌组织和血清中circ-MYC-overlap.2表达分别高于TNM分期Ⅰ和Ⅱ期、未转移患者(P＜0.05).circ-MYC-overlap.2低表达患者5年生存率高于circ-MYC-overlap.2高表达患者(P＜0.01).在 SGC-7901 细胞中,IL-6 可上调 circ-MYC-overlap.2 表达(P＜0.01),而加入STAT3抑制剂硝呋齐特后circ-MYC-overlap.2表达下调(P＜0.01).结论 circ-MYC-overlap.2可作为判断胃癌患者临床分级、转移及预后的潜在标志物.circ-MYC-overlap.2可能通过吸附效应下调miR-19a-3p的作用.