Synthesis and estrogen receptor affinity of a 4-hydroxytamoxifen-labeled ligand for diagnostic imaging.

A 10-step synthesis of a novel 4-hydroxytamoxifen-DTPA ligand (HOTam-DTPA) is reported. Tamoxifen and its primary metabolite 4-hydroxytamoxifen are common estrogen receptor ligands. Consequently, tamoxifen has found utility as the targeting component of various diagnostic agents for selective imaging of estrogen receptor-rich tissue, specifically breast cancer.

Detection of xenoestrogens in serum after immunoprecipitation of endogenous steroidal estrogens.

In this article we report a simple and efficient method for detecting nonsteroidal estrogens in a biologic sample. This method uses polyclonal antibodies to estradiol (E2) to immunoprecipitate these major biologically active steroidal estrogens, leaving behind the nonsteroidal estrogens, which are then detected in a cell-based transcriptional activation bioassay for estrogen receptor agonist. The immunoprecipitation method efficiently removed 99% of radiolabeled E2 and estrone (E1) from human serum.

Analysis of the antiestrogenic activity of 2,3,7,8-tetrachlorodibenzo-p-dioxin in human ovarian carcinoma BG-1 cells.

We have used human ovarian carcinoma BG-1 cells to determine which steps in the pathway of estrogen signaling are disrupted by the aryl hydrocarbon receptor (AhR) ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). We report that inhibition of estrogen signaling occurs between 7 and 18 h after TCDD treatment and that this effect is not caused by a decrease in estradiol concentration. TCDD decreased estrogen receptor (ER) levels in cells grown in standard medium; however, in estrogen-stripped medium, ER (but not AhR) levels were dramatically reduced (approximately 7-fold) but were not decreased further by TCDD.

Analysis of the aryl hydrocarbon receptor (AhR) signal transduction pathway.

Analysis of the Ah Receptor Signal Transduction Pathway (Michael S. Denison, Jane M. Rohers, S.