Development of a liquid chromatography electrospray ionization tandem mass spectrometry method for analysis of stable 4-hydroxyequilenin-DNA adducts in human breast cancer cells.

ABSTRACT: Estrogen-DNA adducts are potential biomarkers for assessing cancer risk and progression in estrogen-dependent cancer. 4-Hydroxyequilenin (4-OHEN), the major catechol metabolite of equine estrogens present in hormone replacement therapy formulations, autoxidizes to a reactive o-quinone that subsequently causes DNA damage. The formation of stable stereoisomeric cyclic 4-OHEN-DNA adducts has been reported in vitro and in vivo, but their removal by DNA repair processes in cells has not been determined. Such studies have been hampered by low yields of cyclic adducts and poor reproducibility when treating cells in culture with 4-OHEN. These problems are attributed in part to the instability of 4-OHEN in aerobic, aqueous media. We show herein that low yields and reproducibility can be overcome by

SUBMITTER: Wang Z 

PROVIDER: S-EPMC2714912 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature