Expression of a dominant negative estrogen receptor alpha variant in transgenic mice accelerates uterine cancer induced by the potent estrogen diethylstilbestrol.

ERΔ3 transgenic mice expressing a dominant negative estrogen receptor α (ERα) variant lacking the second zinc finger in the DNA binding domain were developed to examine its potential to inhibit estrogen action in vivo. To investigate if ERΔ3 expression influences uterine carcinogenesis, ERΔ3 transgenic mice were exposed to diethylstilbestrol (DES) on post-natal days 1-5. Neonatal DES treatment induced uterine adenocarcinomas in 81% of 8-month-old ERΔ3 mice compared to 49% of wild-type females (p<0.