The Effect of PFOA on ERα+ and ERα- Human Breast Cancer Cell Lines

Abstract

Perfluorooctanoic acid (PFOA) is a man-made chemical that belongs to a large group of fluorotelomers. PFOA is used to manufacture both industrial and consumer products and individuals can be exposed to PFOA through ingesting PFOA-contaminated water or food. While the long-term effects of perfluorooctanoic acid are largely unknown, there is increased evidence suggesting it to be an endocrine disruptor. Studies have shown that PFOA binds to and activates the peroxisomeproliferator-activated receptor α (PPARα), which can regulate the expression of other genes and receptors such as the other PPAR isoforms as well as estrogen receptor α (ERα). Previous experiments in our lab demonstrated that PFOA treatment of MCF-7 breast cancer cells (an ERα positive cell line) decreased ERα mRNA and protein levels, and decreased cell viability by ~20% within 48h of treatment. However, these cells were treated in the absence of fetal bovine serum (FBS), a cell culture additive that contains important growth factors. When we repeated these experiments without serum withdrawal, we initially noted a tendency towards increased proliferation in MCF-7 cells treated with 50µM and 100µM PFOA at both 24h and 48h compared to control. To further examine the role of ERα in PFOA-induced proliferation, we carried out additional experiments in another ERα positive cell line, T47-D, as well as an ERα negative cell line, MDA-MB-231. All three cell lines showed a tendency for increased viability. These data suggest that the PFOA-induced increase in cell viability in these cell lines is not dependent on ERα expression. In addition, the opposing effects of PFOA on proliferation in MCF-7 cells in the presence and absence of FBS demonstrates the importance of accurately and completely reporting cell culture and treatment conditions.