Tianyu Lu1, Rui Wang2, Hongfei Cai3, Youbin Cui4. 1. Department of Thoracic Surgery, the First Hospital of Jilin University, Changchun, Jilin 130021, China. Electronic address: 1705133520@qq.com. 2. Department of Thoracic Surgery, the First Hospital of Jilin University, Changchun, Jilin 130021, China. Electronic address: 280988838@qq.com. 3. Department of Thoracic Surgery, the First Hospital of Jilin University, Changchun, Jilin 130021, China. Electronic address: chfee@163.com. 4. Department of Thoracic Surgery, the First Hospital of Jilin University, Changchun, Jilin 130021, China. Electronic address: cuiyb@jlu.edu.cn.
Abstract
BACKGROUND: Emerging evidences have proven the important roles of lncRNAs in tumorigenesis and cancer biology. However, the function of lncRNA DLEU2 in the progression of esophageal cancer (EC) has not been elaborated. In the present study, we aimed to investigate the effects of lncRNA DLEU2 on the progression of EC and the underlying mechanism. METHODS: In this study, lncRNA DLEU2 was silenced by siRNA interference in EC cell lines Eca-109 and KYSE-150, and its expression was up-regulated in TE-1 cells by transfection with pcDNA3.1-DLEU2, and its biological functions were examined. Then, bioinformatics analysis and dual-luciferase reporter assay were used to identify the binding miRNA of lncRNA DLEU2 and the target gene of miRNA. In addition, loss-of-function assays were performed to detect the biological functions of the target gene. At last, the rescue assays were used to investigate the relationship among lncRNA DLEU2, miRNA and target gene. RESULTS: With the help of GEPIA analysis, we observed that lncRNA DLEU2 was up-regulated in EC tissues and associated with poor prognosis. Loss-of-function assay showed that silencing lncRNA DLEU2 inhibited the proliferation, migration and invasion of EC cells, and induced apoptosis by regulating the Bcl-2/Bax axis and Caspase cascade. Overexpression of lncRNA DLEU2 increased the proliferation, migration and invasion abilities of TE-1 cells, as well as decreased cell apoptosis. Bioinformatics analysis and dual-luciferase reporter assay verified that miR-30e-5p could directly bind with lncRNA DLEU2, and E2F7 was a direct target for miR-30e-5p in EC cells. Moreover, our data revealed that silencing E2F7 decreased the proliferation, migration and invasion abilities of EC cells, and induced apoptosis. Furthermore, the rescue assays demonstrated that the effects of lncRNA DLEU2 on the proliferation, migration and invasion of EC cells were reversed by miR-30e-5p inhibitor or up-regulation of E2F7. CONCLUSIONS: Our findings revealed the pro-oncogenic role of lncRNA DLEU2 and E2F7 in the progression of EC, suggesting that lncRNA DLEU2 exerts ceRNA functions in EC through regulating miR-30e-5p/E2F7 axis.
BACKGROUND: Emerging evidences have proven the important roles of lncRNAs in tumorigenesis and cancer biology. However, the function of lncRNA DLEU2 in the progression of esophageal cancer (EC) has not been elaborated. In the present study, we aimed to investigate the effects of lncRNA DLEU2 on the progression of EC and the underlying mechanism. METHODS: In this study, lncRNA DLEU2 was silenced by siRNA interference in EC cell lines Eca-109 and KYSE-150, and its expression was up-regulated in TE-1 cells by transfection with pcDNA3.1-DLEU2, and its biological functions were examined. Then, bioinformatics analysis and dual-luciferase reporter assay were used to identify the binding miRNA of lncRNA DLEU2 and the target gene of miRNA. In addition, loss-of-function assays were performed to detect the biological functions of the target gene. At last, the rescue assays were used to investigate the relationship among lncRNA DLEU2, miRNA and target gene. RESULTS: With the help of GEPIA analysis, we observed that lncRNA DLEU2 was up-regulated in EC tissues and associated with poor prognosis. Loss-of-function assay showed that silencing lncRNA DLEU2 inhibited the proliferation, migration and invasion of EC cells, and induced apoptosis by regulating the Bcl-2/Bax axis and Caspase cascade. Overexpression of lncRNA DLEU2 increased the proliferation, migration and invasion abilities of TE-1 cells, as well as decreased cell apoptosis. Bioinformatics analysis and dual-luciferase reporter assay verified that miR-30e-5p could directly bind with lncRNA DLEU2, and E2F7 was a direct target for miR-30e-5p in EC cells. Moreover, our data revealed that silencing E2F7 decreased the proliferation, migration and invasion abilities of EC cells, and induced apoptosis. Furthermore, the rescue assays demonstrated that the effects of lncRNA DLEU2 on the proliferation, migration and invasion of EC cells were reversed by miR-30e-5p inhibitor or up-regulation of E2F7. CONCLUSIONS: Our findings revealed the pro-oncogenic role of lncRNA DLEU2 and E2F7 in the progression of EC, suggesting that lncRNA DLEU2 exerts ceRNA functions in EC through regulating miR-30e-5p/E2F7 axis.