MicroRNA-199b Targets the Regulation of ZEB1 Expression to Inhibit Cell Proliferation, Migration and Invasion in Non‑small Cell Lung Cancer.

Lung cancer is one of the leading causes of cancer-associated mortality worldwide. Previous evidence suggested that microRNAs (miRs) exhibit important regulatory roles in tumorigenesis and tumor development, including in non‑small cell lung cancer (NSCLC). The present study investigated the expression of miR‑199b in NSCLC tissues and cell lines, in addition to the biological roles of miR‑199b in the carcinogenesis and progression of NSCLC. The results of the present study demonstrated that miR‑199b expression was decreased in NSCLC tissues and cell lines compared with matched adjacent healthy tissues and a healthy human bronchial epithelial cell line, respectively. An MTT assay demonstrated that the viability of NSCLC cells was decreased by miR‑199b. The migratory and invasive abilities of NSCLC cells were suppressed by miR‑199b overexpression. In addition, zinc finger E‑box‑binding homeobox 1 (ZEB1) was identified to be a novel direct downstream and functional target for miR‑199b in NSCLC, using bioinformatics analysis, luciferase reporter assay, the reverse transcription‑quantitative polymerase chain reaction and western blotting. ZEB1 underexpression mimicked the roles of miR‑199b overexpression in NSCLC cells. In conclusion, the present study demonstrated that miR‑199b was downregulated in NSCLC and acted as a tumor suppressor by targeting ZEB1.