Background Emerging evidence demonstrates that lncRNAs play pivotal roles in tumor energy metabolism; however, the detailed mechanisms of lncRNAs in the regulation of tumor glycolysis remain largely unknown. Methods The expression of SLC2A1-AS1 was investigated by TCGA, GEO dataset and qRT-PCR. The binding of GLI3 to SLC2A1-AS1 promoter was detected by Luciferase Reporter Assay System and Ago2-RIP assay. FISH was performed to determine the localization of SLC2A1-AS1 in ESCC cells. Double Luciferase Report assay was used to investigate the interaction of miR-378a-3p with SLC2A1-AS1 and Glut1. Gain-of-function and Loss-of-function assay were performed to dissect the function of SLC2A1-AS1/miR-378a-3p/Glut1 axis in ESCC progression in vitro and in vivo. Results We identified a novel lncRNA SLC2A1-AS1 in ESCC. SLC2A1-AS1 was frequently overexpressed in ESCC tissues and cells, and its overexpression was associated with TNM stage, lymph node metastasis and poor prognosis of ESCC patients. Importantly, GLI3 and SLC2A1-AS1 formed a regulatory feedback loop in ESCC cells. SLC2A1-AS1 promoted cell growth in vitro and in vivo, migration and invasion, and suppressed apoptosis, leading to EMT progression and increased glycolysis in ESCC cells. SLC2A1-AS1 functioned as ceRNA for sponging miR-378a-3p, resulting in Glut1 overexpression in ESCC cells. MiR-378a-3p inhibited cell proliferation and invasion as well as induced apoptosis, resulting in reduced glycolysis, which was partly reversed by SLC2A1-AS1 or Glut1 overexpression in ESCC cells. Conclusion SLC2A1-AS1 plays important roles in ESCC development and progression by regulating glycolysis, and SLC2A1-AS1/miR-378a-3p/Glut1 regulatory axis may be a novel therapeutic target in terms of metabolic remodeling of ESCC patients.

Increasing evidence has demonstrated that long non-coding RNAs serve pivotal roles in tumor development, progression, metastasis and metabolism. However, to the best of our knowledge, the roles and molecular mechanisms of long intergenic nonprotein-coding RNA 00514 (LINC00514) in esophageal squamous cell carcinoma (ESCC) remain unknown. The present study found that LINC00514 and sphingosine kinase 1 (SPHK1) were both upregulated in ESCC tissues and cells, and their high expression levels were closely associated with Tumor-Node-Metastasis stage, lymph node metastasis and poor prognosis of patients with ESCC. Functionally, knockdown of LINC00514 inhibited cell proliferation and invasion, and led to the downregulation of lipogenesis-related proteins, including SPHK1, fatty acid synthase, acetyl-coenzyme (Co)A carboxylase α and stearoyl-CoA desaturase 1, whereas LINC00514 overexpression promoted cell proliferation and invasion in ESCC KYSE150 and KYSE30 cells, and upregulated expression of lipogenesis-related proteins. Mechanistically, LINC00514 functioned as a competing endogenous RNA by sponging microRNA (miR)-378a-5p, resulting in the upregulation of SPHK1, which was accompanied by the activation of lipogenesis-related pathways, to promote ESCC cell proliferation and invasion. Taken together, these findings suggest that LINC00514 may participate in ESCC lipogenesis, and targeting the LINC00514/miR-378a-5p/SPHK1 signaling axis may be a novel and promising therapeutic strategy for management of patients with ESCC.

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Background: Esophageal squamous cell carcinoma (ESCC) is a fatal disease with poor prognosis. The predominant reason for ESCC-related death is metastasis caused by tumor cell invasion. Human MENA protein is a member of Ena/Vasp family, which plays a critical role during tumor cell invasion. However, the biological effect of MENA in ESCC cell lines remains unclear Methods: In this study, fluorescent quantitative real-time PCR (qRT-PCR) were conducted to detect the mRNA expression of MENA in tumor and para-cancer tissue, CCK-8 assay and clone formation assay were conducted to evaluate cell proliferation activity, Transwell assay and wound-healing assay were conducted to detect the changes of cell invasion and migration capacity, siRNA and MENA expression vector were constructed to explore biological function of MENA in ESCC cell lines. Western blot analysis were conducted to detect the expressions of MENA , molecular markers of epithelial-mesenchymal transition (EMT), Akt, p-Akt, MMP-2 and MMP-9 respectively in ESCC cell line. Results: The qRT-PCR experiment results showed that MENA expression in ESCC tissue of 35 patients was relatively higher than that in tissue adjacent to cancer. CCK-8 assay suggested that tumor cell proliferation capacity was suppressed followed by the knockdown of MENA expression in Mena high ESCC cell TE13 and was potentiated by the overexpression of MENA in Mena low ESCC cell TE1. Transwell assay and wound healing assay demonstrated that interfering in MENA could inhibit TE13 cells invasion and migration capacity by affecting the expressions of Matrix metalloproteinase-2(MMP-2) and Matrix metalloproteinase-9 (MMP-9), in contrast, overexpression of MENA in Mena low ESCC cell TE1 could promote invasion and migration by up-regulated expression of MMP-2 and MMP-9. Western blot analysis indicated that interfering of MENA expression could affect EMT-related molecular markers (E-cadherin, N-cadherin, Snail, Slug), Akt and p-Akt Conclusions: Our study reveal that MENA could promote the ESCC cell invasion and migration by upregulate MMP-2, MMP-9 expression and Akt activation. Meanwhile, interfering of MENA expression could affect EMT in ESCC cells. This indicated that MENA may be a potential molecular therapeutic target for ESCC metastasis