Objective:To characterize microRNA-206 (miR-206) in the development of bronchopulmonary dysplasia (BPD).Design/Methods:We assessed the expression of miR-206 in BPD mouse lung tissues and blood samples of BPD patients by quantitative real-time PCR. Then, the role of miR-206 in regulating cell biology were examined by XTT assay, flow cytometry, transwell invasion assay, wound healing assay and adhesion assay in vitro. Furthermore, luciferase reporter assay, real-time PCR, western blot and Immunofluorescence staining were performed to figure out the target gene of miR-206.Results:A reduction in expression of miR-206 was observed in BPD mice compared with controls and in BPD patients compared with controls. miR-206 overexpression significantly induced cell apoptosis, reduced cell proliferation, migration and adhesion abilities, whereas the inhibition of miR-206 expression had the opposite effect. Fibronectin 1 (FN1) is a direct target of miR-206, and fn 1 can be transcriptionally and translationally regulated by miR-206. Down-regulation of miR-206 modulates biological functions of the cells, at least in part, by increasing the level of fn 1. Furthermore, fn 1 expression levels were increased in the BPD mice and BPD patients.Conclusions:The expression of miR-206 and its target gene, fn 1, may contribute to the progression of BPD. © 2013 Zhang et al.