Upregulation of miR-20a in human breast cancer. (a) miR-20a expression in normal breast tissues (n=83) and breast cancer tissues (n=694) in TCGA data set, P<0.001 was calculated using nonparametric Mann–Whitney test. (b) miR-20a expression is higher in triple-negative breast cancer tissues (n=82) than the other subtypes (n=391) in TCGA data set, P<0.001. (c) Gene set enrichment analysis (GESA) comparing the miR-20a lower group (red) against the miR-20a higher expression group (blue) of breast cancer cohorts in TCGA data set, lower expression of miR-20a correlates with autophagy and lysosome pathways. (d) GFP-LC3 puncta formation assay in MDA-MB-231 cells overexpressing NC or miR-20a. The samples were cultured in complete medium (Ctrl) or EBSS solution to induce nutrient starvation for 4 h. Scale bar, 10 μm. GFP-LC3 dots per cell was shown as means±s.d. (**P<0.01). (e) MDA-MB-231 and MCF7 cells transfected with NC or miR-20a were cultured in normal medium or EBSS solution for 4 h. Relative levels of LC3-II versus GAPDH were analyzed by immunoblotting and Image J software.