miR-145 Attenuates Migration and Invasion of Non-small Cell Lung Cancer A549 Cells by Targeting AP4

Objective To investigate the effect of miR-145 on the migration and invasion of non-small cell lung cancer (NSCLC) cells and possible mechanism.

Methods The expression of miR-145 and activating enhancer binding protein 4 (AP4) mRNA in NSCLC tissues were detected by qRT-PCR. After the transfection with miR-145 mimic or AP4 siRNA, the migration and invasion of A549 cells were examined by wound healing and Transwell assay, respectively; The mRNA and protein expressions of AP4 were detected by qRT-PCR and Western blot, respectively. The relationship between AP4 mRNA and miR-145 was detected by double luciferase reporter gene method.

Results Compared with adjacent normal tissues, the level of miR-145 was significantly decreased in NSCLC tissues (P < 0.05), however, the mRNA and protein levels of AP4 were significantly increased (P < 0.05). Compared with control group, the level of miR-145 was significantly increased (P < 0.05), the mRNA and protein levels of AP4 were significantly decreased (P < 0.05), and cells migration and invasion were significantly decreased (P < 0.05) in A549 cells after the transfection with miR-145 mimic. Moreover, AP4 was a direct target of miR-145. After the transfection with AP4 siRNA, the migration and invasion of A549 cells were significantly decreased (P < 0.05).

Conclusion miR-145 upregulation could efficiently attenuate the migration and invasion of A549 cells via inhibiting target gene AP4 expression.