PARENT SESSION
SLIDE SESSION 15: UTERUS & OVIDUCT
Chairs: Ron Magness, Frank Bartol, Gonzalo Rivera (Trainee)
Univ Ottawa-Morisset 218
1:30 PM-3:30 PM

NEONATAL DIETHYLSTILBESTROL-INDUCED DISRUPTION OF PROTEIN EXPRESSION IN THE HAMSTER UTERUS: EARLY vs. LATE EFFECTS.

Hendry, William¹, Hariri, Houssam¹, ¹

ABSTRACT- In the hamster, neonatal treatment with the potent endocrine disruptor agent, diethylstilbestrol (DES), directly and permanently alters the developing uterus (early initiating event) such that it thereafter responds abnormally to estrogen stimulation (later promoting event) in terms of both cell proliferation (endometrial adenocarcinoma) and cell removal (apoptosis). As part of a campaign to define the mechanism(s) of both the early and later stages of the phenomenon, immunoblotting was used to screen for neonatally DES-induced alterations in gene expression at the protein level. We analyzed uterine extract samples from early prepubertal animals (day 5 of life) and from estrogen-stimulated adult animals (ovariectomized and implanted with an estradiol-releasing pellet on day 21 of life) that had been injected on the day of birth with 50 l of corn oil either alone (control) or containing 100 g of DES. As expected, neonatal DES exposure induced stage-specific alterations in the level of various structural and regulatory proteins. Particularly striking were the effects on the progesterone receptor protein. It underwent precocious induction in the early prepubertal uterus but then became undetectable in the estrogen-stimulated adult uterus from neonatally DES-treated animals. To expand the screening effort, we recently tested a new proteomics service (BD PowerBlot™) using total protein extracts of estrogen-stimulated adult uteri from control vs. neonatally DES-treated animals. That survey effort, in which duplicate analyses were performed using hundreds of monoclonal antibodies, detected more than 20 protein signals that varied more than 2-fold (both positive and negative) between the two samples. These results give some insight into the extent to which the established endocrine disruptor DES affects proteomics in the hamster uterus. They also provide guidance for the choice of immunoreagents that could be used to study/screen the cell and tissue-specific consequences of exposure to DES and other putative endocrine disruptor agents. (Supported by USPHS grants ES10232, HD37835 and by the Flossie E. West Memorial Foundation)

KEY WORDS: uterus, endocrine disruption, diethylstilbestrol, proteomics