Objective · To investigate the effect of miR-27a down-regulation on proliferation, migration and invasion in triple-negative breast cancer (TNBC) cell line MDA-MB-453. Methods · Sixty-eight pairs of breast cancer tissues and para-carcinoma tissues the TNBC cancer patients were harvested for the study. The differential of miR-27a in the collected tissues, MDA-MB-453 cell line and normal breast epithetial cell line MCF-10A were detectedquantitative real-time PCR (qPCR). The relationship between miR-27a and the clinical characteristics of TNBC patients was analyzed. miR-27a inhibitor was transfected into MDA-MB-453 cell line. CCK-8 assay and Transwell chamber test were used to detect the difference in proliferation, migration and invasion of MDA-MB-453 cells between miR-27a inhibitor group and negative control group (NC group). The levels of F-box and WD repeat domain-containing 7 (FBW7) and Egl nine homolog 2 (EGLN2) protein were examinedWestern blotting. Results · The of miR-27a in TNBC tissues was significantly higher than that in para-carcinoma tissues (PPPPPPPConclusion · The of miR-27a in TNBC tissues and TNBC cell line increases. Down-regulation of miR-27a can inhibit the proliferation, migration and invasion of MDA-MB-453 cells, which may be through increasing FBW7 and decreasing EGLN2 .