Birgit Puschner, DVM, PhD – Department of Molecular Biosciences

One-shot analysis to determine the concentrations of environmental toxins in low-volume breast milk samples from California women

The contribution of the pesticide DDT and its metabolite DDE to breast cancer risk is controversial, where a recent report by the World Health Organization noted the importance of early-life exposure to DDT remains unresolved. We recently demonstrated that prenatal DDT exposure is associated with nearly four-fold higher incidence of breast cancer among adult daughters born at the Oakland Kaiser Permanente hospital in the 1960s.

In parallel we exposed mice to DDT while they were in the womb and found they also had nearly four-fold higher mammary tumors. Based on our preliminary research, we suggest that a daughter’s prenatal DDT exposure increases breast cancer risk through altered metabolism that increases tumor growth. The best system to rigorously evaluate this mechanistic hypothesis is cell culture but dosing standard mammary cell lines with DDT would not model prenatal DDT exposure or endocrine carcinogenesis.

We seek to establish a plausible mechanism of our striking human and mouse observations by evaluating tumor cells of mice exposed to DDT prenatally. We will characterize the growth and metabolism of these cells and whole mouse tumors.