In a new study published online on May 1, 2015 in the peer-reviewed journal Environmental Health Perspectives, scientists from Stanford University, U.S., show that bisphenol A (BPA, CAS 80-05-7) exposure at environmentally relevant doses has an adverse effect on mammary cells. Pfeifer and colleagues evaluated the effects of low concentrations of BPA (nanomolar doses) on DNA damage, the expression of oncogenic cell-cycle regulatory proteins, and on the proliferation in noncancerous and cancerous breast cells. The authors found that low-dose BPA upregulates c-Myc oncogene, which induces DNA damage and proliferation in estrogen receptor-α negative, benign mammary cells. As the authors stress, silencing c-Myc diminished these BPA-induced cellular events. This finding suggests that c-Myc is essential for regulating effects of BPA on DNA damage and proliferation in mammary cells. Overall, the findings of this study provide significant evidence of adverse effects of low-dose BPA on mammary cells, the authors say. The ultimate goal is to extrapolate these in vitro findings to human health, however, it is premature to do so, according to the authors. In vivo studies investigating the effect of low-dose BPA on mammary gland carcinogenesis and cancer development are first needed to validate the results.
Pfeifer, D. et al. (2015). “Effects of low-dose bisphenol A on DNA damage and proliferation of breast cells: The role of c-Myc.” Environmental Health Perspectives (published online May 1, 2015, open access).