The lncRNA ZEB2-AS1 is upregulated in gastric cancer and affects cell proliferation and invasion via miR-143-5p/HIF-1[alpha] axis

Background: Growing evidence has implicated the important role of the long non-coding RNAs (lncRNAs) in gastric cancer progression. In this study, we examined the expression of lncRNA zinc finger E-box-binding homeobox 2 antisense RNA 1 (ZEB2-AS1) in gastric cancer tissues and elucidated the molecular mechanisms underlying ZEB2-AS1-mediated gastric cancer progression. Methods: Quantitative real-time PCR measured the gene expression level; CCK-8, colony formation and cell invasion assays determined gastric cancer cell proliferation, growth and invasion, respectively; the xenograft nude mice model was used to determine in vivo tumor growth; Bioinformatics analysis and luciferase reporter assay determined the downstream targets of ZEB2-AS1 and miR-143-5p. The expression of ZEB2-AS1 was upregulated in gastric cancer cell lines. Results: Knockdown of ZEB2-AS1 suppressed gastric cancer cell proliferation, growth and invasion, and also suppressed in vivo tumor growth in the nude mice. Overexpression of ZEB2AS1 potentiated gastric cancer cell proliferation, growth and invasion. Bioinformatics analysis and luciferase reporter assay showed that miR-143-5p was a direct target of ZEB2-AS1 and was negatively regulated by ZEB2-AS1. Furthermore, hypoxia-inducible factor-1[alpha] (HIF-1[alpha]) was found to be a target of miR-143-5p and was negatively regulated by miR-143-5p. The rescue in vitro assays showed that the effects of ZEB2-AS1 overexpression on gastric cancer cell proliferation, growth and invasion was mediated via miR-143-5p/HIF-1[alpha]. ZEB2-AS1 and HIF-1[alpha] was upregulated in gastric cancer tissues, while miR-143-5p was down-regulated; and ZEB2-AS1 expression level was inversely correlated with miR-143-5p expression level, and positively correlated with HIF-1[alpha] mRNA expression level; while miR-143-5p expression level was inversely correlated with HIF-1[alpha] expression level. High ZEB2-AS1 expression level was correlated with poor differentiation, lymph node metastasis and distant metastasis. Conclusion: Collectively, our results indicated that ZEB2-AS1 was up-regulated in gastric cancer tissues and cells and promoted cell proliferation and metastasis through miR-143-5p/ HIF-1[alpha] pathway, which may provide a promising target for treatment of gastric cancer. Keywords: gastric cancer, ZEB2-AS1, miR-143-5p, HIF-1[alpha], cell proliferation, metastasis