Fig. 2

Ectopic expression of miR-33a inhibits the malignant behaviors in TNBC cells. a The expression of miR-33a in TNBC cell lines and normal breast epithelial cells was measured by qRT-PCR assay. ***P < 0.001 compared with MCF10A. b The expression of miR-33a in TNBC cell lines was elevated after transfection with miR-33a mimics. c, d MDA-MB-231 and BT-549 cells were transfected with NC or miR-33a mimics for 24 h and cell proliferation was determined by EdU cell proliferation kit. EdU positive cells and images were captured. e, f The effect of miR-33a on cell proliferation rate was detected by CCK-8 assay. g Increased miR-33a reduced colony formation capacities in TNBC. h–l TNBC cells were transfected with NC or miR-33a mimics for 48 h and then cell cycle analyses were performed by a flow cytometer. j, k miR-33a mimics decreased the number of migrated j, k and invasive (l) cells. Magnification, ×200. Data are shown as mean ± SEM (n = 3). *P < 0.05, **P < 0.01 and ***P < 0.001 compared with cells transfected with NC mimics groups