title: C2- and C4-position 17beta-estradiol metabolites and their relation to breast cancer.
abstract: C2- and C4-position 17beta-estradiol metabolites play an important role in breast carcinogenesis. 2-Hydroxyestradiol and 4-hydroxyestradiol are implicated in tumorigenesis via two pathways. These pathways entail increased cell proliferation and the formation of reactive oxygen species that trigger an increase in the likelihood of deoxyribonucleic acid mutations. 2-Methoxyestradiol, a 17beta-estradiol metabolite, however, causes induction of apoptosis in transformed and tumor cells; thus exhibiting an antiproliferative effect on tumor growth. The 4-hydroxyestradiol:2-methoxyestradiol and 2-hydroxyestradiol:2-methoxyestradiol ratios therefore ought to be taken into account as possible indicators of carcinogenesis.
authors.affiliation: Department of Physiology, University of Pretoria, P.O. Box 2034, Pretoria 0001, South Africa. annie.joubert@up.ac.za
authors.forename: Annie
authors.initials: A
authors.lastname: Joubert
authors.forename: Hermia
authors.initials: H
authors.lastname: Van Zyl
authors.forename: Johannes
authors.initials: J
authors.lastname: Laurens
authors.forename: Mona-Liza
authors.initials: ML
authors.lastname: Lottering
mesh_terms: D000077584:2-Methoxyestradiol; D000818:Animals; D001943:Breast Neoplasms / Q000378:metabolism*; D049109:Cell Proliferation; D004958:Estradiol / Q000031:analogs & derivatives* / Q000378:metabolism*; D002393:Estrogens, Catechol; D006801:Humans
chemical_list: D002393:Estrogens, Catechol; D004958:Estradiol; D000077584:2-Methoxyestradiol; C001390:2-hydroxyestradiol; C014036:4-hydroxyestradiol