scholarly journals Heat Shock Factor 1 (HSF1) cooperates with estrogen receptor α (ERα) in the regulation of estrogen action in breast cancer cells

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Natalia Vydra ◽  
Patryk Janus ◽  
Paweł Kuś ◽  
Tomasz Stokowy ◽  
Katarzyna Mrowiec ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Heat Shock ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Estrogen Receptor Α ◽  
Heat Shock Factor ◽  
Heat Shock Factor 1 ◽  
Er Positive ◽  
Positive Breast Cancer

Heat shock factor 1 (HSF1), a key regulator of transcriptional responses to proteotoxic stress, was linked to estrogen (E2) signaling through estrogen receptor α (ERα). We found that an HSF1 deficiency may decrease ERα level, attenuate the mitogenic action of E2, counteract E2-stimulated cell scattering, and reduce adhesion to collagens and cell motility in ER-positive breast cancer cells. The stimulatory effect of E2 on the transcriptome is largely weaker in HSF1-deficient cells, in part due to the higher basal expression of E2-dependent genes, which correlates with the enhanced binding of unliganded ERα to chromatin in such cells. HSF1 and ERα can cooperate directly in E2-stimulated regulation of transcription, and HSF1 potentiates the action of ERα through a mechanism involving chromatin reorganization. Furthermore, HSF1 deficiency may increase the sensitivity to hormonal therapy (4-hydroxytamoxifen) or CDK4/6 inhibitors (palbociclib). Analyses of data from the TCGA database indicate that HSF1 increases the transcriptome disparity in ER-positive breast cancer and can enhance the genomic action of ERα. Moreover, only in ER-positive cancers, an elevated HSF1 level is associated with metastatic disease.

scholarly journals Heat shock factor 1 confers resistance to lapatinib in ERBB2-positive breast cancer cells

2018 ◽  
Vol 9 (6) ◽  
Author(s):  
Alisha Yallowitz ◽  
Amr Ghaleb ◽  
Lucas Garcia ◽  
Evguenia M. Alexandrova ◽  
Natalia Marchenko
Keyword(s):  
Breast Cancer ◽  
Heat Shock ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Heat Shock Factor ◽  
Heat Shock Factor 1 ◽  
Positive Breast Cancer

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.

scholarly journals Smad4 Inhibits Tumor Growth by Inducing Apoptosis in Estrogen Receptor-α-positive Breast Cancer Cells

2005 ◽  
Vol 280 (29) ◽  
pp. 27022-27028 ◽  
Author(s):  
Qingnan Li ◽  
Liyu Wu ◽  
Denise K. Oelschlager ◽  
Mei Wan ◽  
Cecil R. Stockard ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Tumor Growth ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Estrogen Receptor Α ◽  
Positive Breast Cancer

Poly(ADP-ribose) Polymerase-1 Regulates Estrogen-Dependent Gene Expression in Estrogen Receptor α-Positive Breast Cancer Cells

2021 ◽  
pp. molcanres.0103.2021
Author(s):  
Shrikanth S. Gadad ◽  
Cristel V Camacho ◽  
Venkat Malladi ◽  
Charles R Hutti ◽  
Anusha Nagari ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Estrogen Receptor Α ◽  
Positive Breast Cancer

scholarly journals The mechanisms involved in the resistance of estrogen receptor-positive breast cancer cells to palbociclib are multiple and change over time

2021 ◽  
Author(s):  
Mayu Ono ◽  
Takaaki Oba ◽  
Tomohiro Shibata ◽  
Ken-ichi Ito
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Copy Number ◽  
Breast Cancer Cells ◽  
Copy Number Alterations ◽  
Altered Expression ◽  
Er Positive ◽  
Positive Breast Cancer

Abstract Purpose Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors are widely used for the treatment of advanced estrogen receptor (ER)-positive breast cancer. To develop a treatment strategy for cancers resistant to CDK4/6 inhibitors, here, we established palbociclib-resistant sublines and analyzed their resistance mechanisms. Methods Palbociclib-resistant sublines were established from T47D and MCF7 cells. Sensitivity to other drugs was assessed via the WST assay. Altered expression/phosphorylation of proteins related to signal transduction and cell cycle regulation was examined using western blotting. Copy number alterations and mutations in the retinoblastoma (RB1) gene were also analyzed. Results Although an increase in CDK6 and decrease in retinoblastoma protein (Rb) expression/phosphorylation were commonly observed in the resistant sublines, changes in other cell cycle-related proteins were heterogeneous. Upon extended exposure to palbociclib, the expression/phosphorylation of these proteins became altered, and the long-term removal of palbociclib did not restore the Rb expression/phosphorylation patterns. Consistently a copy number decrease, as well as RB1 mutations were detected. Moreover, although the resistant sublines exhibited cross-resistance to abemaciclib, their response to dinaciclib was the same as that of wild-type cells. Of note, the cell line exhibiting increased mTOR phosphorylation also showed a higher sensitivity to everolimus. However, the sensitivity to chemotherapeutic agents was unchanged in palbociclib-resistant sublines. Conclusion ER-positive breast cancer cells use multiple molecular mechanisms to survive in the presence of palbociclib, suggesting that targeting activated proteins may be an effective strategy to overcome resistance. Additionally, palbociclib monotherapy induces mutations and copy number alterations in the RB1 gene.

scholarly journals Aberrant expression of SETD1A promotes survival and migration of estrogen receptor α-positive breast cancer cells

2018 ◽  
Vol 143 (11) ◽  
pp. 2871-2883 ◽  
Author(s):  
Ming Li Jin ◽  
Young Woong Kim ◽  
Hong Lan Jin ◽  
Hoin Kang ◽  
Eun Kyung Lee ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Estrogen Receptor Α ◽  
Aberrant Expression ◽  
And Migration ◽  
Positive Breast Cancer

scholarly journals Loss of HAS2 Confers Acquired Antiestrogen Resistance By Upregulating Ezrin Expression In ER-Positive Breast Cancer

2022 ◽  
Author(s):  
Xiaodan Sun ◽  
Fen Tang ◽  
Yiwen Liu ◽  
Yiqing He ◽  
Yan Du ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Mapk Signaling ◽  
Erk Signaling ◽  
Signaling Cascade ◽  
Ezrin Expression ◽  
Er Positive ◽  
Positive Breast Cancer

Abstract Background: Resistance to endocrine therapy is a major challenge for estrogen receptor-positive (ER+) breast cancer patients, but the underlying mechanisms remain unclear. Methods: Loss of hyaluronan synthase 2 (Has2) in adaptive resistant cells to tamoxifen and fulvestrant was observed by immunblotting assay. CRISPR/Cas9 technology was used to knock out Has2 in MCF7 cells to verify the effect of Has2 on the expression of ER and Ezrin and Akt and MAPK/ERK signaling routes. We utilized an Ezrin small-interfering RNA and Ezrin inhibitor to inhibit Ezrin expression for evaluating Has2 and ERα expression and the Akt/MAPK signaling cascade upon tamoxifen or fulvestrant treatment.Results: In this work, we showed that a Has2-loss state was acquired from adaptive resistance to tamoxifen and fulvestrant in luminal BrCas. Notably, the adapted loss of Has2 induced acquired resistance to antiestrogens in estrogen receptor (ER)-positive breast cancer cells through up-regulating the expression of Ezrin. Furthermore, we found that the loss of Has2 promoted while the consequent increase of Ezrin inhibited ERα expression/activity through the Akt and MAPK/ERK signaling routes, indicating an opposite effect on ERα expression during the development of antiestrogens-resistance. Inhibition of Ezrin reversed Has2 and ERα expression and the Akt/MAPK signaling cascade upon tamoxifen or fulvestrant, suggesting a Has2-Ezrin-ER negative-feedback loop in governing cellular sensitivity to tamoxifen or fulvestrant in luminal-like breast cancer cells. Finally, Knockdown or inhibition of Ezrin restored sensitivity to antiestrogens, implying that Ezrin could be a potential therapeutic target to tackle endocrine resistance. Conclusions: Taken together, our findings provide a direct relationship between ERα and Has2 implicated in resistance to endocrine therapy and a new insight into how ERα-signaling is regulated upon antiestrogens treatment, suggesting a novel therapeutic target for ER-positive breast cancer.

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