The non-small cell lung cancer (NSCLC) is among the lethal malignancies with high metastasis and recurrence. The microRNAs are classified into noncoding RNAs and dictate various biological processes. However, few reports have focused on miR-520f in NSCLC. In current work, we showed that miR-520f behaved like a tumor suppressor and effectively inhibited NSCLC development. We found decreased miR-520f expression in NSCLC specimens and cell lines. Meanwhile, overexpression of miR-520f could inhibit

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... NSCLC proliferation, migration and invasion. Bioinformatics screening identified transmembrane4-L-six-family-1 (TM4SF1) as a putative target of miR-520f and transfection with miR-520f can significantly downregulate TM4SF1 expression at both mRNA and protein levels. The miR-520f can further decrease VEGF expression via TM4SF1 and fulfill its role in epithelial-mesenchymal transition. We also found that TM4SF1 was upregulated in NSCLC samples. A significantly negative correlation between miR-520f and TM4SF1 has also been identified. Immunohistochemistry also showed enhanced TM4SF1 and VEGF staining in NSCLC tissues compared with normal specimens. These data suggest a tumor suppressive role of miR-520f and may provide novel insight into lung cancer oncogenesis.