Multiple studies have unveiled that long non-coding RNAs (lncRNAs) play a pivotal role in tumour progression and metastasis. However, the biological role of lncRNA ZEB1-AS1 in oesophageal squamous cell carcinoma (ESCC) remains under investigation, and thus, the current study was to investigate the functions of ZEB1-AS1 in proliferation and invasion of ESCC. Here, we discovered that ZEB1-AS1 and ZEB1 were markedly up-regulated in ESCC tissues and cells relative to their corresponding normal control. ZEB1-AS1 and ZEB1 overexpressions were both related to TNM staging and lymph node metastasis as well as poor prognosis in ESCC. The hypomethylation of ZEB1-AS1 promoter triggered ZEB1-AS1 overexpression in ESCC tissues and cells. In addition, ZEB1-AS1 knockdown mediated by siRNA markedly suppressed the proliferation and invasion in vitro in EC9706 and TE1 cells, which was similar with ZEB1 siRNA treatment, coupled with EMT alterations including the up-regulation of E-cadherin level as well as the down-regulation of N-cadherin and vimentin levels. Notably, ZEB1-AS1 depletion dramatically down-regulated ZEB1 expression in EC9706 and TE1 cells, and ZEB1 overexpression obviously reversed the inhibitory effects of proliferation and invasion triggered by ZEB1-AS1 siRNA. ZEB1-AS1 shRNA evidently inhibited tumour growth and weight, whereas ZEB1 elevation partly recovered the tumour growth in ESCC EC9706 and TE1 xenografted nude mice. In conclusion, ZEB1-AS1 overexpression is tightly involved in the development and progression of ESCC, and it exerts the antitumour efficacy by regulating ZEB1 level in ESCC.
Keywords: Epithelial-mesenchymal transition; ZEB1; ZEB1-AS1; long non-coding RNA; oesophageal squamous cell carcinoma.
© 2019 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.