MicroRNA­4500 suppresses tumor progression in non­small cell lung cancer by regulating STAT3.

ABSTRACT

Research has revealed that microRNA (miR)­4500 is downregulated in non­small cell lung cancer (NSCLC), and miR­4500 suppresses tumor growth by targeting lin­28 homolog B and NRAS proto­oncogene, GTPase. In the present study, it was reported that signal transducer and activator of transcription 3 (STAT3) may function as a novel target gene for miR­4500 in NSCLC. The experiments conducted in the present study confirmed that the miR­4500 expression was decreased in NSCLC tissues and cells compared with adjacent normal tissues and a normal lung cell line. miR­4500 suppressed the cell proliferation, migration, invasion and promoted apoptosis of the human NSCLC cell lines A549 and H1975. Expression of STAT3 was negatively correlated with miR­4500 expression in vivo. A luciferase reporter assay suggested that miR­4500 directly targeted the 3' untranslated region of STAT3. The tumor inhibition effect of small interfering RNA STAT3 in A549 and H1975 lines may be partially impaired by a miR­4500 inhibitor. The results of the present study suggests that miR­4500 may be a tumor suppressor and a potential therapeutic target in NSCLC.