105P - Long-Term Effects of Early Pregnancy On the Gene Expression and Properties of Mammary Epithelial Cell Subpopulations in Mice

Abstract

The breast cancer protective effect of an early pregnancy is well established in humans and rodents, but the underlying mechanism is unclear. Since breast cancers are thought to originate from specific cell subpopulations of mammary epithelia, we studied the effect of early parity on the gene expression and properties of specific luminal and basal mammary cells in mice. Thereby, mammary epithelial cell subpopulations were isolated by flow cytometry from parous and age-matched nulliparous mice and investigated using unbiased genomics and bioinformatics, as well as in vitro colony formation and in vivo mammary gland reconstitution assays.