Long non-coding RNA NCK1-AS1 functions as a ceRNA to regulate cell viability and invasion in esophageal squamous cell carcinoma via microRNA-133b/ENPEP axis

This study is designed to explore the role of long non-coding RNAs (lncRNAs) NCK1-AS1 in proliferative and invasive activities of esophageal squamous cell carcinoma (ESCC) cells by binding to microRNA-133b (miR-133b) to regulate ENPEP. Differentially expressed lncRNAs, miRs, genes and their targeting relationships were screened on ESCC-related gene expression datasets GSE17351 and GSE6188. The targeting relationships among NCK1-AS1, miR-133b, and ENPEP were verified using functional assays. Loss- and gain- of function assays were carried out to examine the roles of NCK1-AS1, miR-133b, and ENPEP in ESCC cell proliferative, invasive, migrative and apoptotic abilities as well as tumorigenesis in vivo. Elevated NCK1-AS1 and ENPEP but reduced miR-133b expression were found in ESCC. NCK1-AS1 knockdown or miR-133b overexpression inhibited the malignant properties of ESCC cells as well as tumorigenesis in vivo. NCK1-AS1 regulated the ENPEP expression by competitively binding to miR-133b. ENPEP overexpression reversed inhibition of NCK1-AS1 knockdown on the function of ESCC cells. This study provides evidence that silencing NCK1-AS1 inhibits expression of ENPEP by sponging miR-133b, thereby suppressing ESCC.

本研究旨在探究长非编码RNA（lncRNA）NCK1-AS1在食管鳞状细胞癌（ESCC）细胞的增殖和侵袭活性中的作用，该作用通过结合miR-133b（microRNA-133b）来调节ENPEP。通过对与ESCC相关的基因表达数据集GSE17351和GSE6188中差异表达的lncRNA、miRNA、基因及其靶向关系进行筛选，验证了NCK1-AS1、miR-133b和ENPEP之间的靶向关系。利用功能实验对NCK1-AS1、miR-133b和ENPEP在ESCC细胞的增殖、侵袭、迁移、凋亡能力以及体内肿瘤发生中的作用进行了功能缺失和功能获得实验。研究发现，在ESCC中NCK1-AS1和ENPEP的表达升高，而miR-133b的表达降低。NCK1-AS1敲低或miR-133b过表达可抑制ESCC细胞的恶性特性和体内肿瘤的发生。NCK1-AS1通过竞争性结合miR-133b来调节ENPEP的表达。ENPEP过表达可逆转NCK1-AS1敲低对ESCC细胞功能的抑制。本研究提供了证据表明，通过吸收miR-133b，沉默NCK1-AS1可抑制ENPEP的表达，从而抑制ESCC。