Knockdown of the lncRNA MALAT1 alleviates lipopolysaccharide­induced A549 cell injury by targeting the miR­17­5p/FOXA1 axis.

Long­noncoding RNAs (lncRNAs) are crucial for the pathophysiology of acute lung injury (ALI). Metastasis­associated lung adenocarcinoma transcript 1 (MALAT1) suppresses inflammatory responses via microRNA (miR)­146a in lipopolysaccharide (LPS)­induced ALI. However, the molecular mechanisms underlying the MALAT1­mediated regulation of cell proliferation and apoptosis in LPS­induced ALI remain unclear. In the present study, it was found that LPS treatment upregulated MALAT1 expression and suppressed the proliferation of A549 cells. MALAT1 knockdown significantly promoted the proliferation and G1/S phase transition and inhibited apoptosis in LPS­treated A549 cells. In addition, miR­17­5p was a direct target of MALAT1. miR­17­5p expression was downregulated and FOXA1 expression was upregulated in LPS­treated A549 cells. Further, MALAT1 knockdown promoted miR­17­5p expression and inhibited FOXA1 expression, whereas the combined suppression of MALAT1 and miR­17­5p induced FOXA1 expression. Moreover, miR­17­5p knockdown reversed the effects of MALAT1 suppression on LPS­induced A549 cell proliferation. These results indicated that MALAT1 serves as a competing endogenous lncRNA that, by sequestering miR­17­5p, stimulates FOXA1 expression and mediates LPS­induced A549 cell injury. In conclusion, the present study demonstrated that MALAT1 knockdown alleviates LPS­induced A549 cell injury by targeting the miR­17­5p/FOXA1 axis.