Cytoplasmic polyadenylation element binding protein 4 (CPEB4) is a member of CPEB family which is overexpressed in variety of cancers. However, the biological role and regulatory mechanism of CPEB4 in cancers remain unknown. Here, we first investigate the role of CPEB4 in breast cancer progression and metastasis. The expression of CPEB4 is elevated in breast cancer tissues compared with adjacent normal tissues. Furthermore, high expression levels of CPEB4 is associated with tumor metastasis in breast cancer patients. Ectopic expression of CPEB4 dramatically promotes EMT, migration and invasion of breast cancer cells, while silencing CPEB4 expression significantly reduces these events. Mechanically, overexpression of CPEB4 upregulates Vimentin expression and silencing Vimentin expression blocks CPEB4-induced migration and invasion of breast cancer cells. These results implicate the potential role of CPEB4 and Vimentin in breast cancer metastasis, which is further confirmed by the finding that there is a physical interaction between the two proteins. Altogether, our results provide a novel insight into CPEB4 in regulating breast cancer progression and metastasis. (C) 2017 Elsevier Inc. All rights reserved.