Identification of mammary epithelial cells subject to chronic oxidative stress in mammary epithelium of young women and teenagers living in USA: implication for breast carcinogenesis.

Current knowledge of changes in the mammary epithelium relevant to breast carcinogenesis is limited to when histological changes are already present because of a lack of biomarkers needed to identify where such molecular changes might be ongoing earlier during the decades-long latent stages of breast carcinogenesis. Breast reduction tissues from young women and teenagers, representative of the USA's high breast cancer incidence population, were studied using immunocytochemistry and a targeted PCR array in order to learn whether a marker of chronic oxidative stress [protein adducts of 4-hydroxy-2-nonenal (4HNE)] can identify where molecular changes relevant to carcinogenesis might be taking place prior to any histological changes. 4HNE-immunopositive (4HNE+) mammary epithelial cell-clusters were identified in breast tissue sections from most women and from many teenagers (ages 14–30 y) and, in tissues from women ages 17–27 y with many vs. few 4HNE+ cells, the expression of 30 of 84 oxidative stress associa...