Product Feature - Estrogen Receptors

Estrogen controls many cellular processes including growth, differentiation and function of the reproductive system. Estrogen is also responsible for the growth and maintenance of the skeleton and the normal functioning of the cardiovascular and nervous system.

Estrogen exerts most of its actions via estrogen receptors (ER) that are ligand-activated transcription factors. Today two estrogen receptors are known, ERα and ERβ, which are highly homologous in the DNA and ligand binding domains, but divergence exists in the tranactivational domain. Hence ERα and ERβ interact with the same DNA response element and show a similar ligand binding profile.

Key estrogen receptor compounds now available from Tocris include:

Selective ERβ antagonist
2662 l PHTPP
Displays 36-fold selectivity over ERα. Exhibits full antagonism at ERβ in a cotransfection assay in human endometrial cancer cells (HEC-1), with minimal effects on ERα.

Selective estrogen receptor modulator
2676 l Y 134
Displays selectivity for ERα over ERβ (K_i values are 0.09 and 11.31 nM respectively). Acts as an agonist in the bone and antagonist in reproductive tissue. Suppresses estrogen-stimulated proliferation of ER-positive human breast cancer MCF-7 and T47D cells.

Potent estrogen receptor silent antagonist
2183 l ZK 164015
Inhibits 17β-estradiol stimulation of luciferase activity (IC₅₀ = 0.025 μM) and potently inhibits the growth of estrogen-sensitive human MCF-7 breast cancer cells in vitro (IC₅₀ ~ 1 nM).

View all Estrogen Receptor Related Products.

Estrogen and Cancer

There is considerable evidence that links estrogen to the formation of breast cancer. The molecular mechanism behind estrogen's cancer causing effects is not clear. Two possible mechanisms have been proposed:

• Estrogen stimulates proliferation of breast epithelial cells
• Certain metabolites of estrogen can bind DNA and cause mutations

It is generally believed that many breast tumours depend, at least initially, on the stimulatory effects of estrogen (hormone-dependent). However many tumours eventually develop to an estrogen-independent state. Antiestrogens are currently the drug of choice in treatment of hormone-dependent breast cancer.

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More Estrogen Receptor Compounds

Estrogen Receptors and their Targets

Heldring et al review estrogen receptor signalling (more)