Tamoxifen overcomes the trastuzumab-resistance of SK-BR-3 tumorspheres by targeting crosstalk between cytoplasmic estrogen receptor α and the EGFR/HER2 signaling pathway

2021 ◽  
pp. 114635
Author(s):  
Yun-Suk Kwon ◽  
Kyung-Soo Nam ◽  
Soyoung Kim
Keyword(s):  
Estrogen Receptor ◽  
Signaling Pathway ◽  
Estrogen Receptor Α ◽  
Trastuzumab Resistance ◽  
Her2 Signaling

scholarly journals GPR30 Activation by 17β-Estradiol Promotes p62 Phosphorylation and Increases Estrogen Receptor α Protein Expression by Inducing Its Release from a Complex Formed with KEAP1

2021 ◽  
Vol 11 (9) ◽  
pp. 906
Author(s):  
Chia-Lung Tsai ◽  
Chiao-Yun Lin ◽  
Angel Chao ◽  
Yun-Shien Lee ◽  
Ren-Chin Wu ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Protein Expression ◽  
Signaling Pathway ◽  
Critical Role ◽  
Adaptor Protein ◽  
Estrogen Receptor Α ◽  
Mtor Signaling ◽  
Mtor Signaling Pathway ◽  
17Β Estradiol ◽  
Esr1 Expression

Estrogens can elicit rapid cellular responses via the G-protein-coupled receptor 30 (GPR30), followed by estrogen receptor α (ERα/ESR1)-mediated genomic effects. Here, we investigated whether rapid estrogen signaling via GRP30 may affect ESR1 expression, and we examined the underlying molecular mechanisms. The exposure of human endometrial cancer cells to 17β-estradiol promoted p62 phosphorylation and increased ESR1 protein expression. However, both a GPR30 antagonist and GPR30 silencing abrogated this phenomenon. GPR30 activation by 17β-estradiol elicited the SRC/EGFR/PI3K/Akt/mTOR signaling pathway. Intriguingly, unphosphorylated p62 and ESR1 were found to form an intracellular complex with the substrate adaptor protein KEAP1. Upon phosphorylation, p62 promoted ESR1 release from the complex, to increase its protein expression. Given the critical role played by p62 in autophagy, we also examined how this process affected ESR1 expression. The activation of autophagy by everolimus decreased ESR1 by promoting p62 degradation, whereas autophagy inhibition with chloroquine increased ESR1 expression. The treatment of female C57BL/6 mice with the autophagy inhibitor hydroxychloroquine—which promotes p62 expression—increased both phosphorylated p62 and ESR1 expression in uterine epithelial cells. Collectively, our results indicate that 17β-estradiol-mediated GPR30 activation elicits the SRC/EGFR/PI3K/Akt/mTOR signaling pathway and promotes p62 phosphorylation. In turn, phosphorylated p62 increased ESR1 expression by inducing its release from complexes that included KEAP1. Our findings may lead to novel pharmacological strategies aimed at decreasing ESR1 expression in estrogen-sensitive cells.

scholarly journals Mechanistic Differences in the Activation of Estrogen Receptor-α (ERα)- and ERβ-dependent Gene Expression by cAMP Signaling Pathway(s)

2003 ◽  
Vol 278 (15) ◽  
pp. 12834-12845 ◽  
Author(s):  
Kevin M. Coleman ◽  
Martin Dutertre ◽  
Abeer El-Gharbawy ◽  
Brian G. Rowan ◽  
Nancy L. Weigel ◽  
...  
Keyword(s):  
Gene Expression ◽  
Estrogen Receptor ◽  
Signaling Pathway ◽  
Estrogen Receptor Α ◽  
Camp Signaling ◽  
Camp Signaling Pathway
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