Increased vimentin mRNA expression in MCF-7 breast cancer cell line after repeated endoxifen-treatment

Background: epithelial mesenchymal transition (emt) plays a significant role in the development of cancer cell resistance to drugs. vimentin, a type iii intermediate filament protein, is a marker of emt. vimentin's overexpression in cancer correlates well with increased tumor growth, change in cell shape and poor prognosis. endoxifen is an active metabolite of tamoxifen and has become a new potent agent in the treatment of breast cancer. this is a study that aimed to investigate the effect of endoxifen exposure with or without estradiol on cell viability, cell morphology and emt progression through the analysis of vimentin mrna expression after 4-week treatment. methods: endoxifen, 100 nm or 1,000 nm, with or without beta-estradiol were given repeatedly to mcf-7 cells. cells treated with dimethyl sulfoxide (dmso) 0.001% were used as control. after 2- and 4-week exposure, the cells were counted, analyzed for mrna vimentin expression, and observed for morphological changes. results: compared to control, there were significant decreases in vimentin mrna expressions in endoxifen and endoxifen+β-estradiol treated cells after 2-weeks, which then significantly increased after 4-week compared with the 2-week exposure. we found no change in morphology of mcf-7 cells. conclusion: repeated exposure of endoxifen might induce emt progression through increased expression of vimentin in mcf-7 breast cancer cell line.