The current study is to evaluate the functional role of microRNA-505 (miR-505) in human non-small cell lung cancer (NSCLC).

Quantitative RT-PCR was performed to examine miR-505 expression in tumors of NSCLC patients and NSCLC cell lines. Lentiviruses of miR-505 mimics and miR-505 inhibitor were used to upregulate or downregulate miR-505 in NSCLC cell lines, A549 and H810 cells. Their effects on NSCLC in vitro growth, migration and in vivo growth were evaluated by proliferation, migration and tumorigenicity assays, respectively. Dual luciferase assay and qRT-PCR were used to evaluate whether Frizzled-4 gene (FZD4) was targeted by miR-505 in NSCLC. FZD4 was then overexpressed in NSCLC cells to evaluate its impact on miR-505-induced tumor regulation.

MiR-505 was lowly expressed in both NSCLC tumors and cell lines. MiR-505 upregulation inhibited NSCLC in vitro growth, migration and in vivo growth, whereas miR-505 downregulation had no effect. FZD4 was verified to be targeted by miR-505 in NSCLC. Overexpressing FZD4 reversed the tumor suppression induced by miR-505 upregulation in A549 and H810 cells.

MiR-505 is a tumor inhibitor in NSCLC. Its regulation is inversely associated with FZD4 in NSCLC.