Downregulation of transcription factor Oct4 induces an epithelial-to-mesenchymal transition via enhancement of Ca2+ influx in breast cancer cells

► We examine the role of Oct4 in metastasis in cultured MCF-7 cells. ► The down regulation of Oct4 induces EMT and increases the capability of migration and invasion in MCF-7 cells. ► TGF-β1 inhibits Oct4 expression in both time- and dose-dependent manners. ► The EMT induced by TGF-β1 or down regulation of Oct4 could be abrogated by inhibitor of SOCE. ► The down regulation of STIM1 (one of the major components of the CRAC channel) alleviates the EMT induce by Oct4 silencing down.