LncRNA WT1-AS/miR-494-3p Regulates Cell Proliferation, Apoptosis, Migration and Invasion via PTEN/PI3K/AKT Signaling Pathway in Non-Small Cell Lung Cancer

BACKGROUND: Non-small cell lung cancer (NSCLC) is one of the most common malignancies with the highest morbidity and mortality worldwide. Long non-coding RNAs (lncRNAs) are recently recognized as noteworthy regulators of different tumors, counting NSCLC. However, the biological functions and regulatory mechanism of lncRNA WT1-AS in NSCLC progression still stay uninvestigated. METHODS: WT1-AS and miR-494-3p levels in NSCLC cell lines were detected by real-time quantitative polymerase chain reaction (RT-qPCR). In the current study, the regulatory effects of WT1-AS/miR-494-3p axis on cellular behaviors of NSCLC cell lines (A549 and NCI-H1975) were evaluated by a variety of methods. Cell counting kit-8 (CCK-8) and EDU assays were adopted to assess NSCLC cell proliferation. Tunnel staining and flow cytometry assay were applied to determine cell apoptosis and cell cycle distribution. Besides, cell migration and invasion abilities were analyzed by performing wound healing and transwell assays. Meanwhile, the levels of key proteins related to NSCLC cell apoptosis and PTEN/PI3K/AKT pathway were examined using Western blot assay. In addition, luciferase reporter assays were used to determine the interaction between WT1-AS and miR-494-3p or miR-494-3p and PTEN. RESULTS: Visibly downregulated WT1-AS in NSCLC cell lines was obtained from Broad Institute Cancer Cell Line Encyclopedia (CCLE) database and further verified by performing RT-qPCR. Besides, miR-494-3p was the downstream target gene of WT1-AS and obviously upregulated miR-494-3p in NSCLC cell lines was confirmed. WT1-AS overexpression suppressed cell proliferation, migration and invasion abilities while enhanced cell apoptosis of A549 and NCI-H1975 cells. Furthermore, upregulation of miR-494-3p distinctly reversed these inhibitory effects of WT1-AS overexpression on the tumorigenesis and progression of NSCLC. In addition, WT1-AS promoted PTEN expression and thereby inhibited activation of PI3K/AKT pathway by sponging miR-494-3p. CONCLUSION: To conclude, lncRNA WT1-AS impeded cell proliferation, migration, invasion but accelerated cell apoptosis via negatively regulating miR-494-3p to mediate PTEN/PI3K/AKT pathway in NSCLC.