MicroRNA-320 was downregulated in non-small cell lung cancer and inhibited cell proliferation, migration and invasion by targeting fatty acid synthase

The expression and functions of microRNA (miR)-320 have been previously investigated in various types of cancer. However, to the best of our knowledge, no previous studies have investigated miR-320 in human lung cancer. The current study determined the expression, biological functions and molecular mechanisms of miR-320 in human lung cancer. The expression level of miR-320 in human non-small cell lung cancer (NSCLC) and normal adjacent tissue samples (NATs), NSCLC cell lines and non-tumorigenic bronchial epithelial cells was measured by reverse transcription-quantitative polymerase chain reaction. Following transfection with miR-320 mimics, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, cell migration and cell invasion assays, western blot analysis and luciferase assay were performed in human NSCLC cell lines. The results demonstrated that miR-320 was significantly downregulated in NSCLC tissue samples and cell lines compared with NATs and a control cell line, respectively. Statistical analysis demonstrated that expression of miR-320 was significantly associated with the TNM classification and metastasis. It was also observed that miR-320 inhibited cell growth, migration and invasion in NSCLC cells. Additionally, the present study provided evidence that miR-320 may directly target fatty acid synthase. These results suggest that miR-320 may serve as a therapeutic biomarker of NSCLC in the future.