Objective To investigate the relationship of glycoprotein serglycin (SRGN) expression with invasion and metastasis of breast cancer cells,and the role of microRNA in the regulation of SRGN expression.Methods Real-time quantitative polymer ase chain reaction (PCR) and Western blot were used to detect the differences in SRGN expression between higher metastasis Michigan cancer foundation-7 (MCF-7)/5-Fu breast cancer cell lines and weaker metastasis MCF-7 cell line.The siRNA interference experiment and in vitro Transwell experiment were used to detect effect of SRGN on the ability of invasion and metastasis of breast cancer cells.Bioinformatics software was used to predict miRNAs targeting SRGN,and integrated microRNA differentially expressed chip data between breast cancer cell MCF-7 versus MCF-7/5-Fu.The miRNA quantitative PCR was used to determine the differences of candi date miRNA expression.After transfection of microRNA minics,Western blot was used to test candidate microRNA target SRGN.Transwell experiment was used to test the effects of candidate microRNAs on tumor cell invasion and metastasis.Results SRGN was increased significantly in MCF-7/5-Fu cells,and the invasion and metastasis of tumor cells were inhibited when SRGN was interfered.In addition,miR181 b/c expressed in MCF-7/5-Fu cells was reduced significantly,negatively correlated with SRGN expression,and targeted SRGN expression.It inhibited invasion and metastasis of tumor cells.Conclusions MicroRNA181b/c inhibits metastasis of breast cancer by targeting SRGN.