Role Of ERα Research Articles

The oestrogen receptors (ERα and ERβ) and their role in breast cancer: a review

One of the main prognostic markers measured in breast tumours is oestrogen receptor (ER) status. With the discovery of ERβ, it has been necessary to re-evaluate ER signalling and the role of ER in breast cancer. Preliminary reports on ERβ signalling suggest it might induce opposite effects to those of ERα. To further understand the biology of breast cancer, the role each ER plays in disease progression must be established. This review summarizes the current understanding of ERβ and discusses some of the published work on the role of ERα and ERβ in breast cancer.

Perimembrane Localization of the Estrogen Receptor α Protein in Neuronal Processes of Cultured Hippocampal Neurons

There is clear evidence of rapid, nongenomic responses to estrogen in a variety of neuronal model systems. To address the question of whether some of these rapid estrogen signals might be transduced by the classical estrogen receptor (ER) α or a closely related protein in nontransformed neurons, we undertook the present study using isolated fetal rat hippocampal neurons. Several antibodies developed to detect ERα were tested in this system and showed positive membrane staining in nonpermeabilized neurons. MC-20, an affinity purified anti-ERα, rabbit polyclonal IgG antibody which does not recognize ERβ was selected to carry out the majority of the experiments. When permeabilized, the hippocampal neurons exhibited low levels of nuclear staining for ERα, but abundant labeling for ERα throughout the entire cell including the neurites. In addition to traditional immunocytochemistry controls, incubation of neurons for 24 h in the presence of 10 µM antisense oligonucleotide directed against the translation start site of ERα reduced ERα immunoreactivity throughout the neurons providing further evidence that the immunostaining was specific for ERα. Confocal and conventional microscopy demonstrated that the antigen was predominately extranuclear and localization of ERα in the neurites suggests that the receptor is in close proximity to the plasma membrane. This localization is consistent with a role for ERα as a transducer of rapid, nongenomic estrogen responses in hippocampal neurons.