Abstract:Objective: To investigate the expression of miRNA-103a-3p (miR-103a-3p) in lung cancer tissues and its effect on proliferation, migration and invasion of lung cancer A549 cells. Methods: 52 tissues of lung cancer patients were collected from Nantong tumor hospital. The expressions of miR-103a-3p were compared between lung cancer tissues and the para-carcinoma tissues by real-time PCR. miR-103a-3p mimic, mimic NC, miR-103a-3p inhibitor and inhibitor NC were transfected into lung cancer 549 cells by Lipofecta mineTM 3000 and the transfection efficiency was detected by QRT-PCR. The cell proliferation was evaluated by CCK8 assay. The cell apoptosis was detected by flow cytometry assay. The cell migration and invasion abilities were detected by wound healing assay and transwell assay. Results: The expressions of miR-103a-3p in lung cancer tissues were less than those in para-carcinoma tissues (p＜0.01). The expressions of miR-103a-3p in miR-103a-3p mimic group were higher than in mimic NC group, and the proliferation, migration and invasion abilities of A549 cells were decreased. While the expressions of miR-103a-3p in miR-103a-3p inhibitor group were less than inhibitor NC group, and the proliferation, migration and invasion abilities of A549 cells were increased. But the cell apoptosis had no significant difference in four groups. Conclusion: miR-103a-3p is down-regulated in lung cancer tissues. The proliferation, migration and invasion abilities of lung cancer A549 cells were inhibited after the transfection of miR-103a-3p.