Regulation of IncRNA ZNF667-AS1 in Proliferation and Invasion of Esophageal Squamous Cell Carcinoma Cells via Mediating ceRNA Network.

Esophageal squamous cell carcinoma (ESCC), classified as a primary histological subtype of esophageal cancer (EC), dominates approximately 90% of the newly diagnosed EC. Long non-coding RNAs (lncRNAs) are frequently related to the course of ESCC. The current study aimed to investigate whether lncRNA zinc finger protein 667-antisense RNA 1 (ZNF667-AS1) modulates the proliferation and invasion of ESCC cells. ESCC tissues and cell lines, para-carcinoma tissues, and human esophageal epithelial cells (HEEpiCs) were collected. lncRNA ZNF667-AS1 expression in the above tissues and cells was detected. The effect of lncRNA ZNF667-AS1 on proliferation and invasion of Eca109 cells was detected using cell counting kit-8, colony formation, and Transwell assays. lncRNA ZNF667-AS1 subcellular localization was determined via the nuclear/cytosol fractionation assay. The binding relationships between miR-18b-5p and lncRNA ZNF667-AS1 and RAS p21 protein activator 1 (RASA1) were verified using dual-luciferase reporter gene experiment and RNA immunoprecipitation experiment. The expressions of miR-18b-5p and RASA1 in the tissues and cells were identified. The roles of miR-18b-5p overexpression or silencing RASA1 in proliferation and invasion of ESCC cells were examined through rescue experiments. lncRNA ZNF667-AS1 was underexpressed in ESCC tissues and cells, and lncRNA ZNF667-AS1 overexpression hampered ESCC cell proliferation and invasiveness. miR-18b-5p targeted RASA1 while lncRNA ZNF667-AS1 promoted RASA1 transcription via binding to miR-18b-5p. Over-expression miR-18b-5p or silencing RASA1 reversed the inhibitory effects of lncRNA ZNF667-AS1 overexpression on ESCC cell proliferation and invasion. lncRNA ZNF667-AS1 overexpression accelerated RASA1 transcription by competitively binding to miR-18b-5p, thus suppressing ESCC cell proliferation and invasion.