This study aimed to analyze the expression, clinical significance of
epithelial membrane protein 1 (EMP1) in
breast carcinoma and the
biological effect in its cell line by EMP1 overexpression. Immunohistochemistry and western blot were used to analyze EMP1
protein expression in 67 cases of
breast cancer and 35 cases of normal tissues to study the relationship between EMP1 expression and clinical factors. Quantitative real-time RT-PCR and western blot were used to detect the
mRNA level and
protein of EMP1. MTT assay, migration and invasion assays were also conducted as to the influence of the upregulated expression of EMP1 that might be found on MCF-7 cell
biological effect. The relative amount of EMP1
protein in
breast cancer tissue was found to be significantly lower than in normal tissues (P < 0.05). The level of EMP1
protein expression was correlated with T stages,
lymph node metastasis, clinic stage, and histological grade (P < 0.05). Meanwhile, loss of EMP1 expression correlated significantly with poor overall survival time by Kaplan-Meier analysis (P < 0.05). The result shown that MCF-7 cell transfected EMP1 had a lower survival fraction, higher cell apoptosis, significant decrease in migration and invasion, higher
caspase-9, and lower VEGFC
protein expression compared with MCF-7 cell untransfected EMP1 (P < 0.05). EMP1 expression decreased in
breast cancer and correlated significantly with
lymph node metastasis, clinic stage, histological grade, and poor overall survival, T stages, suggesting that EMP1 may play important roles as a negative regulator to
breast cancer MCF-7 cell by regulating the expression of
caspase 9 and VEGFC
protein.