Abstract:Abstract: Objective To investigate the role of microRNA-22 (miR-222) in the proliferation, migration and invasion of human lung adenocarcinoma cells. Methods Firstly, miR-222 and negative control were transfected into lung adenocarcinoma cells, and the CCK-8 assay, Transwell migration and Matrigel invasion assays were performed to detect the effect of miR-222 on cell proliferation, migration and invasion respectively. Then the luciferase reporter assay, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were performed to validate the putative target of miR-222. Subsequently, loss-of-function assay was applied to determine the target involved in the regulation of proliferation, migration and invasion of lung adenocarcinoma cells. Results The results of CCK-8 assay, Transwell migration and Matrigel invasion assays indicated that miR-222 could promote the proliferation, migration and invasion of lung adenocarcinoma cells. The luciferase reporter assay, qRT-PCR and Western blot showed that miR-222 directly targeted the 3'UTR of ETS1. And overexpression of ETS1 significantly inhibited the miR-222-induced proliferation, migration and invasion of lung adenocarcinoma cells. Conclusions miR-222 facilitates proliferation, migration and invasion of lung adeno-carcinoma cells by repressing ETS1.