2,3,7,8 –tetrachlorodibenzo-p-dioxin (known as dioxin or TCDD) is a chemical
pollutant that can be found in drinking water, soil, dust, and air. TCDD has a
biological half-life of 7-10 years in humans. It is unethical to study the effects of TCDD on humans and the use of an animal model may not always relevant to humans. A reasonable alternative is to use 3-dimensional human cell culture. The
human breast epithelial cell line MCF10A represents normal breast tissue and can
be grown in 3D culture. In contrast to traditional 2D culture, MCF10A cells form
secondary structures, called acini, when grown in 3D culture. Studying acini offers
a unique advantage because these structures more accurately portray tissue growth and development in vivo. TCDD binds to the aryl hydrocarbon receptor (AhR) and can induce cytochrome P450s and growth factors. In these
experiments MCF10A cells were grown in 2D or 3D culture and were exposed to TCDD or left untreated. AhR mediated gene expression of two cytochrome P450s, CYP1A1 and CYP1B1, were measured.