Estrogens are thought to regulate female reproductive functions by altering gene transcription in target organs primarily via the nuclear estrogen receptor-alpha (ER-alpha). By using ER-alpha "knock-out" (ERKO) mice, we demonstrate herein that a catecholestrogen, 4-hydroxyestradiol-17beta (4-OH-E2), and an environmental estrogen, chlordecone (kepone), up-regulate the uterine expression of an es...

Lifetime exposure to estrogens is a major risk factor in breast cancer, but the mechanism for this action is not fully defined. To better determine this mechanism, the activation domain of estrogen receptor (ER) alpha was used in yeast two-hybrid screenings. These screenings resulted in the identification of a novel antiproliferative protein, estrogen down-regulated gene 1 (EDG1), of which the ...

The estrogen receptor (ER) signaling cascade is a vulnerable target of exposure to environmental xenoestrogens, like nonylphenol (NP), which are causally associated with impaired health status. However, the impact of xenoestrogens on the individual receptor isotypes (alpha, beta a, and beta b) is not well understood. The goal of these studies was to determine the impact of NP on largemouth bass...

Immunoglobulin heavy chain binding protein (BiP, GRP 78) coprecipitates with soluble and membrane-associated variants of the T-cell antigen receptor alpha chain (TCR-alpha) which are stably retained within the ER. Chelation of Ca2+ during solubilization of cells leads to the dissociation of BiP from the TCR-alpha variants, which is dependent upon the availability of Mg2+ and hydrolyzable ATP; t...

The role of the a form of estrogen receptor (ER alpha) gene expression in the regulation of testosterone-dependent male reproductive behaviors was investigated using ER knockout mice (ERKO), which are specifically deficient in functional ER alpha, but not ER beta, gene expression. Previous studies in gonadally intact ERKO mice revealed that male aggressive behavior was greatly reduced by the la...

The expression of carbonic anhydrase XII (CA12), a gene that encodes a zinc metalloenzyme responsible for acidification of the microenvironment of cancer cells, is highly correlated with estrogen receptor alpha (ER alpha) in human breast tumors. Here, we show that CA12 is robustly regulated by estrogen via ER alpha in breast cancer cells, and that this regulation involves a distal estrogen-resp...

We have shown previously in the developing cerebral cortex that estrogen elicits the rapid and sustained activation of multiple signaling proteins within the mitogen-activated protein (MAP) kinase cascade, including B-Raf and extracellular signal-regulated kinase (ERK). Using estrogen receptor (ER)-alpha gene-disrupted (ERKO) mice, we addressed the role of ER-alpha in mediating this action of e...

Estrogen receptor (ER) and/or progesterone receptor (PR) expression has been associated with more favorable breast cancer prognosis. Results on the differential association of diet with ER and/or PR positive and negative tumors have been inconclusive. In a large case-control study conducted in Athens, Greece, we investigated whether diet is associated with the expression of ER-alpha or PR in ma...

Oxidative stress and endoplasmic reticulum (ER) stress have been implicated in cardiovascular diseases although the interplay between the two is not clear. This study was designed to examine the influence of oxidative stress through glutathione depletion on myocardial ER stress and contractile function in the absence or presence of the heavy metal scavenger antioxidant metallothionein (MT). FVB...

objective: breast cancer is the most common cancer in iranian women. breast tumors are classified based on the estrogen receptor alpha (erα) expression status into er negative and er positive tumors. er negative tumors tend to have worse prognosis and less likely to respond to endocrine therapy. aberrant methylation of gene promoter is one of the mechanisms for gene silencing in breast tumors. ...