Estrogen receptors in membrane lipid rafts and signal transduction in breast cancer

A retinoic acid receptor RARα pool present in membrane lipid rafts forms complexes with G protein αQ to activate p38MAPK

“…The fact that RARa colocalizes with flotillin-2 in lipid rafts is a novelty in the field. It is also in line with the new concept in which most of the classical so-called nuclear steroid and non-steroid receptors (ER, GR, PR, AR, VDR) can be found in specialized plasma membrane structures such as caveolae and lipid rafts (Huhtakangas et al, 2004;Marquez et al, 2006;Pedram et al, 2007;Luoma et al, 2008;Matthews et al, 2008).…”

17β-Estradiol and tamoxifen stimulate rapid and transient ERK activation in MCF-7 cells via distinct signaling mechanisms

“…Previous work suggests that cells must express ERs in order for ERK to be activated in response to E2 stimulation. 9,11,21 Additionally, it has been shown that EGFR activation is needed for ERK activation in response to E2 stimulation. 2,12 Lastly, it has been suggested that ER and HER-2 might interact, leading to ERK activation.…”

“…[18][19][20] This can be partially explained by differences in the expression levels of ER, EGFR, and the HER-2 receptor. [21][22][23][24] Furthermore, it has been suggested that multiple mechanisms exist by which estrogen stimulation can lead to ERK activation. 15,25 This underscores the need for a study using an appropriate cell type and consistent experimental conditions to elucidate the mechanisms by which E2 and tamoxifen induce ERK phosphorylation.…”

Lipid Rafts as Master Regulators of Breast Cancer Cell Function

“…This implies that lipid rafts play a key role in transduction of this oncogenic signal. Another protein known to localise in lipid rafts with HER2, in addition to EGFR, is the estrogen receptor (ER) (Marquez et al, 2006). Estrogen signalling is linked to lipid rafts, where ER co-localises with ErbB receptors to modulate growth events (Marquez et al, 2006).…”

“…Another protein known to localise in lipid rafts with HER2, in addition to EGFR, is the estrogen receptor (ER) (Marquez et al, 2006). Estrogen signalling is linked to lipid rafts, where ER co-localises with ErbB receptors to modulate growth events (Marquez et al, 2006). Both these receptors may be activated by membrane-bound ER (Razandi et al, 2003), resulting in MAP kinase-dependent ER phosphorylation (Pietras, 2003).…”