Bisphenol A Reduces the Effectiveness of Chemotherapeutics

Elizabeth W. LaPensee, Ph.D. and Nira Ben-Jonathan, Ph.D.,
University of Cincinnati
NIEHS Grants T32ES007250 and R01ES012212

Recent research results suggest that the environmental estrogen, bisphenol A (BPA), in addition to its potential carcinogenic and reproductive health effects, reduces the effectiveness of three common chemotherapeutic agents used to treat breast cancer.

BPA is structurally similar to diethylstilbesterol (DES) and its carcinogenic potential is of strong concern to scientists and regulators. Similar to DES, BPA has estrogenic activity, and exposure in young rodents leads to increased rates of hormonally related cancers as the animals age. Since estrogen has been shown to antagonize some anticancer drugs, the research team wanted to test BPA for its potential to reduce the effectiveness of these anticancer agents.

The findings were clear. At nanomolar concentrations of BPA, levels routinely found in humans, estrogen receptor-positive and –negative breast cancer cells lines were protected from the chemotherapeutic effects of doxorubicin, cisplatin, and vinblastine. The researchers speculate that the protective effect could be the result of increased expression of antiapoptotic proteins caused by BPA. This study highlights a previously unrecognized effect of BPA in carcinogenicity and therefore adds strong support to the growing knowledge of the adverse effects of BPA on human health. It also suggests that BPA exposure may be a factor in choosing therapeutic regimens in patients undergoing treatment for hormonally-related cancers.

Citation: Lapensee EW, Tuttle TR, Fox SR, Ben-Jonathan N. Bisphenol A at low nanomolar doses confers chemoresistance in estrogen receptor-alpha-positive and –negative breast cancer cells. Environ Health Perspect. 2009 Feb; 117(2):175-80.