Gao Shan, Lou Weiyang
General Surgery, Cancer Center, Department of Colorectal Surgery, Zhejiang Provincial People's Hospital (Affiliated People's Hospital), Hangzhou Medical College Hangzhou 310014, Zhejiang, China.
Department of Breast Surgery, The First Affiliated Hospital, College of Medicine, Zhejiang University Hangzhou 310003, Zhejiang, China.
Am J Cancer Res. 2024 Dec 15;14(12):5665-5679. doi: 10.62347/EFEO7205. eCollection 2024.
Esophageal squamous cell carcinoma (ESCC), the most predominant subtype of esophageal cancer, is notorious for its high lymph node metastatic potential and poor prognosis. Growing evidence has demonstrated crucial function of circRNAs in human malignancies. However, the knowledge of circRNAs in lymph node metastasis of ESCC is still inadequate. In this study, a series of bioinformatic analyses and experimental validation were performed. By performing differential expression analysis and selection for GEO dataset GSE150476, a total of 8 circRNAs associated with lymph node metastasis of ESCC were identified. Expression analysis confirmed their low expression in ESCC tissues (relative to normal tissues) or metastatic sites (relative to primary sites). By combination of binding miRNAs from CSCD and starBase databases, six potential miRNAs (miR-532-5p, miR-2681-5p, miR-670-5p, miR-1252-5p, miR-382-3p and miR-542-3p) were predicted and a circRNA-miRNA regulatory network was constructed. Next, 695 target genes were predicted to bind to the 6 miRNAs. After conducting protein-protein interaction (PPI) network analysis, hub gene identification and expression analysis, a hub gene PIK3R1 was identified as the most potential downstream target gene of hsa_circ_0087104/miR-542-3p in ESCC. Hsa_circ_0087104 and PIK3R1 were decreased while miR-542-3p was increased in ESCC cells compared with normal esophageal epithelial cell line. Luciferase reporter and MS2-RIP assays confirmed the direct bind of miR-542-3p to hsa_circ_0087104 or PIK3R1. Hsa_circ_0087104 increased PIK3R1 expression but ectopic expression of miR-542-3p reversed hsa_circ_0087104-mediated PIK3R1 overexpression in ESCC. Overexpression of hsa_circ_0087104 suppressed migration and invasion of ESCC cells and this suppressive effect could be weakened by upregulation of miR-542-3p. Collectively, the current findings elucidated a potential hsa_circ_0087104/miR-542-3p/PIK3R1 axis that might be involved in suppression of lymph node metastasis of ESCC.
食管鳞状细胞癌（ESCC）是食管癌最主要的亚型，因其高淋巴结转移潜能和不良预后而声名狼藉。越来越多的证据表明circRNA在人类恶性肿瘤中发挥着关键作用。然而，关于circRNA在ESCC淋巴结转移中的知识仍不充分。在本研究中，进行了一系列生物信息学分析和实验验证。通过对GEO数据集GSE150476进行差异表达分析和筛选，共鉴定出8个与ESCC淋巴结转移相关的circRNA。表达分析证实它们在ESCC组织（相对于正常组织）或转移部位（相对于原发部位）中低表达。通过结合CSCD和starBase数据库中的结合miRNA，预测了6个潜在的miRNA（miR-532-5p、miR-2681-5p、miR-670-5p、miR-1252-5p、miR-382-3p和miR-542-3p），并构建了circRNA-miRNA调控网络。接下来，预测了695个与这6个miRNA结合的靶基因。在进行蛋白质-蛋白质相互作用（PPI）网络分析、枢纽基因鉴定和表达分析后，枢纽基因PIK3R1被鉴定为ESCC中hsa_circ_0087104/miR-542-3p最具潜力的下游靶基因。与正常食管上皮细胞系相比，ESCC细胞中hsa_circ_0087104和PIK3R1表达降低，而miR-542-3p表达升高。荧光素酶报告基因和MS2-RIP实验证实了miR-542-3p与hsa_circ_0087104或PIK3R1的直接结合。hsa_circ_0087104增加了PIK3R1的表达，但miR-542-3p的异位表达逆转了hsa_circ_0087104介导的ESCC中PIK3R1的过表达。hsa_circ_0087104的过表达抑制了ESCC细胞的迁移和侵袭，而miR-542-3p的上调可削弱这种抑制作用。总的来说，目前的研究结果阐明了一个潜在的hsa_circ_0087104/miR-542-3p/PIK3R1轴，可能参与抑制ESCC的淋巴结转移。
