scholarly journals Notch-1 activates estrogen receptor-α-dependent transcription via IKKα in breast cancer cells

Oncogene ◽  
2009 ◽  
Vol 29 (2) ◽  
pp. 201-213 ◽  
Author(s):  
L Hao ◽  
P Rizzo ◽  
C Osipo ◽  
A Pannuti ◽  
D Wyatt ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Estrogen Receptor Α ◽  
Notch 1

Calcineurin regulates the stability and activity of estrogen receptor α

2021 ◽  
Vol 118 (44) ◽  
pp. e2114258118
Author(s):  
Takahiro Masaki ◽  
Makoto Habara ◽  
Yuki Sato ◽  
Takahiro Goshima ◽  
Keisuke Maeda ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Breast Cancer Cells ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Estrogen Receptor Α ◽  
The Stability ◽  
Positive Breast Cancer

Estrogen receptor α (ER-α) mediates estrogen-dependent cancer progression and is expressed in most breast cancer cells. However, the molecular mechanisms underlying the regulation of the cellular abundance and activity of ER-α remain unclear. We here show that the protein phosphatase calcineurin regulates both ER-α stability and activity in human breast cancer cells. Calcineurin depletion or inhibition down-regulated the abundance of ER-α by promoting its polyubiquitination and degradation. Calcineurin inhibition also promoted the binding of ER-α to the E3 ubiquitin ligase E6AP, and calcineurin mediated the dephosphorylation of ER-α at Ser294 in vitro. Moreover, the ER-α (S294A) mutant was more stable and activated the expression of ER-α target genes to a greater extent compared with the wild-type protein, whereas the extents of its interaction with E6AP and polyubiquitination were attenuated. These results suggest that the phosphorylation of ER-α at Ser294 promotes its binding to E6AP and consequent degradation. Calcineurin was also found to be required for the phosphorylation of ER-α at Ser118 by mechanistic target of rapamycin complex 1 and the consequent activation of ER-α in response to β-estradiol treatment. Our study thus indicates that calcineurin controls both the stability and activity of ER-α by regulating its phosphorylation at Ser294 and Ser118. Finally, the expression of the calcineurin A–α gene (PPP3CA) was associated with poor prognosis in ER-α–positive breast cancer patients treated with tamoxifen or other endocrine therapeutic agents. Calcineurin is thus a promising target for the development of therapies for ER-α–positive breast cancer.

BRCA1 and Estrogen Receptor α Expression Regulation in Breast Cancer Cells

2019 ◽  
Vol 53 (3) ◽  
pp. 442-451
Author(s):  
A. M. Scherbakov ◽  
E. A. Shestakova ◽  
K. E. Galeeva ◽  
T. A. Bogush
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Estrogen Receptor Α ◽  
Expression Regulation
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