Transcriptional effects of metal ions on the bovine oxytocin and the thymidine kinase-ERE promoter through the estrogen receptor a in MDA-MB 231 breast cancer cell line

Background: some of metal ions as environmental pollutants show estrogenic activity. this xenostrogenic compounds can be caused carcinogenicity in organs. the mechanism of carcinogenicity of metal ions is not clarified. objectives: in this study, we investigated the transcriptional effects of variety of metal ions on the bovine oxytocin and the thymidine kinase-ere promoter by estrogen receptor a in mda-mb 231 breast cancer cell line. methods: cells were plated into flask (75cm2) at 1.3 density or into 12- well plates (nunc) at a density of 100000 cells per well and were transfected with a total of 3 µg of plasmid dna using calcium phosphate coprecipitation. oestrogen and some metal ions were used for stimulation of transfected cells. results: our results showed that copper and cadmium ions activating specifically the oxytocin promoter, and cobalt and possibly, mercury ions activating specifically the ere-controlled promoter and the majority of the ions did not affect transcriptional activation significantly. conclusions: the study revealed that some metal ions show estrogenic activity by classical or non-classical mechanisms as well as some metal ions exhibit estrogenic activity by undetermined mechanisms in transfected mda-mb 231 cell line.