title: Gene expression profiling identifies lobe-specific and common disruptions of multiple gene networks in testosterone-supported, 17beta-estradiol- or diethylstilbestrol-induced prostate dysplasia in Noble rats.
abstract: The xenoestrogen diethylstilbestrol (DES) is commonly believed to mimic the action of the natural estrogen 17beta-estradiol (E2). To determine if these two estrogens exert similar actions in prostate carcinogenesis, we elevated circulating levels of estrogen in Noble (NBL) rats with E(2/DES-filled implants, while maintaining physiological levels of testosterone (T) in the animals with T-filled implants. The two estrogens induced dysplasia in a lobe-specific manner, with E2 targeting only the lateral prostate (LP) and DES impacting only the ventral prostate (VP). Gene expression profiling identified distinct and common E2-disrupted versus DES-disrupted gene networks in each lobe. More importantly, hierarchical clustering analyses revealed that T + E2 treatment primarily affected the gene expression pattern in the LP, whereas T + DES treatment primarily affected the gene expression profile in the VP. Gene ontology analyses and pathway mapping suggest that the two hormone treatments disrupt unique and/or common cellular processes, including cell development, proliferation, motility, apoptosis, and estrogen signaling, which may be linked to dysplasia development in the rat prostate. These findings suggest that the effects of xenoestrogens and natural estrogens on the rat prostate are more divergent than previously suspected and that these differences may explain the lobe-specific carcinogenic actions of the hormones.
authors.affiliation: Division of Environmental Genetics and Molecular Toxicology, Department of Environmental Health, University of Cincinnati Medical Center, Cincinnati, OH 45267 USA.
authors.forename: Neville N C
authors.initials: NN
authors.lastname: Tam
authors.forename: Carol Ying-Ying
authors.initials: CY
authors.lastname: Szeto
authors.forename: Maureen A
authors.initials: MA
authors.lastname: Sartor
authors.forename: Mario
authors.initials: M
authors.lastname: Medvedovic
authors.forename: Shuk-Mei
authors.initials: SM
authors.lastname: Ho
mesh_terms: D000818:Animals; D004054:Diethylstilbestrol / Q000494:pharmacology*; D004958:Estradiol / Q000494:pharmacology*; D020869:Gene Expression Profiling; D053263:Gene Regulatory Networks / Q000187:drug effects*; D008297:Male; D011467:Prostate / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D011470:Prostatic Hyperplasia / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology; D051381:Rats; D011919:Rats, Inbred Strains; D013739:Testosterone / Q000494:pharmacology*
chemical_list: D013739:Testosterone; D004958:Estradiol; D004054:Diethylstilbestrol