Jia Youjuan, Liu Meijuan, Wang Shuxia
Department of Gynecology, Weifang People's Hospital, 151 Guangwen Street, Kuiwen District, Weifang, 261041 Shandong China.
Department of Ultrasound, Yantai Yuhuangding Hospital, Yantai, 264000 Shandong China.
Cancer Cell Int. 2020 Aug 26;20:412. doi: 10.1186/s12935-020-01437-y. eCollection 2020.
Endometrial cancer (EC) is a common malignancy of the female reproductive system. Circular RNAs (circRNAs) were demonstrated to exert critical roles in cancers, including EC. This study aimed to investigate the effects of hsa_circRNA_0001776 (circ_0001776) on EC.
Real-time quantitative PCR (RT-qPCR) was used to measure circ_0001776, microRNA-182 (miR-182) and leucine-rich repeats and immunoglobulin-like domains 2 (LRIG2) expression. The diagnostic and prognostic values of circ_0001776 were identified by receiver operating characteristic (ROC) curve analysis and survival analysis, respectively. RNase R digestion was used to characterize circ_0001776, and the localization of circ_0001776 was evaluated by cell fractionation assay. Then, cell counting kit-8 (CCK-8), colony formation, and flow cytometry analysis were used to detect cell proliferation and apoptosis, respectively. The real-time glycolytic rate (ECAR) and lactate production were measured by extracellular flux analysis and a lactate assay kit, respectively. Bioinformatics analysis and dual-luciferase reporter assay were used to determine the interaction among circ_0001776, miR-182 and LRIG2. The protein expression of LRIG2 was determined by western blot. Moreover, circ_0001776 overexpression vector was used to upregulate circ_0001776 expression in an animal tumor model.
Circ_0001776 and LRIG2 were downregulated, while miR-182 was upregulated in EC tissues and cells. Low expression of circ_0001776 was correlated with the 5-year survival rate of EC patients. Upregulated circ_0001776 markedly attenuated cell proliferation and glycolysis, and enhanced cell apoptosis. Besides, circ_0001776 sponged miR-182 to regulate LRIG2 expression. Circ_0001776 could suppress EC progression by miR-182/LRIG2 axis. Furthermore, we also found that circ_0001776 significantly inhibited tumor growth in vivo.
Our results confirmed that circ_0001776 inhibited EC tumorigenesis and progression via miR-182/LRIG2 axis, providing a potential therapeutic target for EC.
子宫内膜癌（EC）是女性生殖系统常见的恶性肿瘤。环状RNA（circRNAs）已被证明在包括EC在内的多种癌症中发挥关键作用。本研究旨在探讨hsa_circRNA_0001776（circ_0001776）对EC的影响。
采用实时定量PCR（RT-qPCR）检测circ_0001776、微小RNA-182（miR-182）和富含亮氨酸重复序列和免疫球蛋白样结构域2（LRIG2）的表达。分别通过受试者工作特征（ROC）曲线分析和生存分析确定circ_0001776的诊断和预后价值。用核糖核酸酶R消化法对circ_0001776进行特征鉴定，并通过细胞分级分离试验评估circ_0001776的定位。然后，分别用细胞计数试剂盒-8（CCK-8）、集落形成和流式细胞术分析检测细胞增殖和凋亡。分别通过细胞外通量分析和乳酸检测试剂盒测定实时糖酵解率（ECAR）和乳酸生成量。采用生物信息学分析和双荧光素酶报告基因检测法确定circ_0001776、miR-182和LRIG2之间的相互作用。通过蛋白质免疫印迹法测定LRIG2的蛋白表达。此外，在动物肿瘤模型中使用circ_0001776过表达载体上调circ_0001776的表达。
在EC组织和细胞中，circ_0001776和LRIG2表达下调，而miR-182表达上调。circ_0001776低表达与EC患者的5年生存率相关。上调circ_0001776可显著减弱细胞增殖和糖酵解，并增强细胞凋亡。此外，circ_0001776通过吸附miR-182来调节LRIG2表达。circ_0001776可通过miR-182/LRIG2轴抑制EC进展。此外，我们还发现circ_0001776在体内可显著抑制肿瘤生长。
我们的结果证实，circ_0001776通过miR-182/LRIG2轴抑制EC的发生和进展，为EC提供了一个潜在的治疗靶点。
