LncRNA MAGI2-AS3 acts as a tumor suppressor that attenuates non-small cell lung cancer progression by targeting the miR-629-5p/TXNIP axis

BACKGROUND: Lung cancer is a malignant tumor that seriously threatens the health of human beings. Long non-coding RNAs (lncRNAs) are thought to play important roles in the pathophysiology of lung cancer. In this study, we identified a new lncRNA, MAGI2-AS3 in non-small cell lung cancer (NSCLC) tissues by conducting an integrated bioinformatics analysis. Mechanistic studies were also performed to explore the biological functions of MAGI2-AS3 in NSCLC progression. METHODS: A bioinformatics analysis was conducted to determine the prognostic role of MAGI2-AS3. CCK-8, EdU assay, colony formation and Transwell were performed to determine the effects of MAGI2-AS3 on the progression of NSCLC cells. A nude mice model was used to evaluate the effects of MAGI2-AS2 on the in vivo tumor growth of NSCLC. Luciferase reporter and RNA pull-down assays were used to evaluate interactions between MAGI2-AS3 and its downstream targets. RESULTS: MAGI2-AS3 was found to be downregulated in NSCLC tissues. The gain-of-function in vitro studies showed that the overexpression of MAGI2-AS3 suppressed NSCLC cell proliferation and invasion. Conversely, the knockdown of MAGI2-AS3 had the opposite effects. The bioinformatics analysis and luciferase report assay revealed that MAGI2-AS3 functioned as competing endogenous RNA to suppress microRNA (miR)-629-5p expression, while miR-629-5p suppressed thioredoxin-interacting protein (TXNIP) expression by targeting its 3' untranslated region. The rescue experiment results showed that MAGI2-AS3 knockdown enhanced NSCLC cell progression (increasing cell proliferation and invasion, but reducing cell apoptosis), which was counteracted by miR-629-5p inhibition or TXNIP overexpression. CONCLUSIONS: The study revealed that MAGI2-AS3 was downregulated in NSCLC tissues and cells, and MAGI2-AS3 suppressed NSCLC cell progression. Further, the mechanistic results showed that MAGI2-AS3 exerted a tumor-suppressive effect in NSCLC by targeting the miR-629-5p/TXNIP axis.