LncRNA MNX1-AS1 contributes to lung adenocarcinoma progression by targeting the miR-34a/SIRT1 axis.

LncRNA MNX1-AS1 is known to be involved in progression of several tumor types. However, few studies have investigated the molecular mechanism of MNX1-AS1 in lung adenocarcinoma (LAC). To explore the function of MNX1-AS1 in the pathogenesis of LAC, qRT-PCR was performed to show MNX1-AS1 expression. MNX1-AS1 expression in LAC cells was suppressed by siRNA to detect the biologic behavior. The relationships among miR-34a, MNX1-AS1 and SIRT1 were confirmed by pull-down and dual-luciferase reporter assay. Whether MNX1-AS1 was involved in LAC by targeting miR-34a/SIRT1 axis was verified. MNX1-AS1 was up-regulated in LAC, and over-expression of MNX1-AS1 was significantly associated with lymph node metastasis and poor prognosis. In A549 and H1299 cells, cell proliferation, migration, and invasion were suppressed, the cell cycle was regulated, as well as apoptosis was increased after silencing MNX1-AS1. Mechanistically, MNX1-AS1 served as a ceRNA of miR-34a to down-regulate miR-34a expression. SIRT1 is targeted by miR-34a and its expression is regulated by MNX1-AS1 and miR-34a. Up-regulation of SIRT1 salvaged the effect of silencing MNX1-AS1 on A549 and H1299 cells, to some extent. These results showed that MNX1-AS1 contributes to LAC progression by targeting the miR-34a/SIRT1 axis.