Estrogen-responsive genes encoding egg yolk proteins vitellogenin and apolipoprotein II in chicken are differentially regulated by selective estrogen receptor modulators.

In a hen, large quantities of the egg yolk proteins, apolipoprotein II (apo-II) and vitellogenin (VG), are expressed in the liver and transported to the oviduct during egg production. Estrogenic stimulation of the hepatic expression of apo-II and VG is due to both transcriptional increase and mRNA stabilization. The nucleolytic degradation of apo-II messenger RNA (mRNA) is prevented by estrogen-regulated mRNA-stabilizing factor (E-RmRNASF).

Inhibition of estrogenic stimulation of gene expression by genistein.

Two principle soy-derived isoflavones, genistein and daidzein, are believed to play a key role in inhibiting tumor growth. The molecular basis of the anti-tumor activity of these two isoflavones has not been fully established. To determine the mechanism of action of the above phytochemicals on estrogen-responsive genes, we tested the effect of the same on the expression of Estrogen-Regulated mRNA Stabilizing Factor (E-RmRNASF).

The upstream stem-loop domain of the 3' untranslated region of apolipoprotein II mRNA binds the estrogen-regulated mRNA stabilizing factor.

Apolipoprotein II (apoII), a component of the very low density lipoprotein (VLDL) particle, is a yolk protein expressed in the liver in response to estrogen. Its expression is modulated by estrogen-mediated stimulation of transcription as well as stabilization of its mRNA. This stabilization is due to the estrogen-regulated mRNA stabilizing factor (E-RmRNASF) [Cell.

The action of dietary phytochemicals quercetin, catechin, resveratrol and naringenin on estrogen-mediated gene expression.

Hepatic expression of apolipoprotein (apo) II is in part modulated by estrogen-mediated stabilization of its mRNA. This stabilization is due to the estrogen-regulated mRNA stabilizing factor (E-RmRNASF) expressed in the liver in response to estrogen (Ratnasabapathy, 1995, Cell. Mol.