scholarly journals Amphiregulin retains ERα expression in acquired aromatase inhibitor resistant breast cancer cells

2020 ◽  
Vol 27 (12) ◽  
pp. 671-683
Author(s):  
Yuanzhong Wang ◽  
Yen-Dun Tony Tzeng ◽  
Gregory Chang ◽  
Xiaoqiang Wang ◽  
Shiuan Chen

Acquired resistance to aromatase inhibitors (AIs) is a significant clinical issue in endocrine therapy for estrogen receptor (ER) positive breast cancer which accounts for the majority of breast cancer. Despite estrogen production being suppressed, ERα signaling remains active and plays a key role in most AI-resistant breast tumors. Here, we found that amphiregulin (AREG), an ERα transcriptional target and EGF receptor (EGFR) ligand, is crucial for maintaining ERα expression and signaling in acquired AI-resistant breast cancer cells. AREG was deregulated and critical for cell viability in ER+ AI-resistant breast cancer cells, and ectopic expression of AREG in hormone responsive breast cancer cells promoted endocrine resistance. RNA-sequencing and reverse phase protein array analyses revealed that AREG maintains ERα expression and signaling by activation of PI3K/Akt/mTOR signaling and upregulation of forkhead box M1 (FOXM1) and serum- and glucocorticoid-inducible kinase 3 (SGK3) expression. Our study uncovers a previously unappreciated role of AREG in maintaining ERα expression and signaling, and establishes the AREG-ERα crosstalk as a driver of acquired AI resistance in breast cancer.

2020 ◽  
Author(s):  
Ting Zhuang ◽  
Huijie Yang ◽  
Wuchen Zhao ◽  
Xin Li ◽  
Zhiguo Niu ◽  
...  

Abstract Background Breast cancer is the most common women malignancy worldwide, while estrogen receptor alpha positive type accounts for two third of all breast cancers. Although ER alpha positive breast cancer could be effectively controlled by endocrine therapy, more than half of the cases could develop endocrine resistance, making it an important clinical issue in breast cancer treatment. Thus, decoding the detailed mechanism, which controls ER alpha signaling activation and ER alpha protein stability, is of great importance for the improvement of breast cancer therapy. Methods ZNF213 and ER alpha protein expression level were measured by western blot, while ER alpha target genes were determined by QPCR. WST-1 assay was used to measure cell proliferation. RNA sequence was performed by Ingenuity pathway analysis. The ER alpha signaling activities were measured with luciferase assay, QPCR and western blotting. Protein stability assay and ubiquitin assay were used to determine ER alpha protein degradation and ubiquitination. The immuno-precipation was utilized to determine ER alpha and ZNF213 interaction. The ubiquitin-based immuno-precipitation assay was sued to detect specific ubiquitination manner on ER alpha. The prognostic data of ZNF213 was derived from public available database. Results Here, we identified ZNF213 as a novel zinc finger protein, which modulates ER alpha protein. ZNF213 expression correlates with poor outcome in endocrine treated patients. ZNF213 depletion inhibits ER alpha signaling and proliferation in breast cancer cells. Further mechanistic studies show that ZNF213 is located in cytosol and nuclear, which modulates ER alpha stability via inhibiting ER alpha K48-linked ubiquitination. Conclusions Our study reveals an interesting post-translational mechanism between ER alpha and ZNF213 in breast cancer. Targeting ZNF213 could be an appealing strategy for ER alpha positive breast cancer.


2020 ◽  
Author(s):  
Huijie Yang ◽  
Xulei Lv ◽  
Xin Li ◽  
Lanzhi Mao ◽  
Zhiguo Niu ◽  
...  

Abstract Background Breast cancer is the most common women malignancy worldwide, while estrogen receptor alpha positive type accounts for two third of all breast cancers. Although ER alpha positive breast cancer could be effectively controlled by endocrine therapy, more than half of the cases could develop endocrine resistance, making it an important clinical issue in breast cancer treatment. Thus, decoding the detailed mechanism, which controls ER alpha signaling activation and ER alpha protein stability, is of great importance for the improvement of breast cancer therapy. Methods CCK8 and Edu assay was used to measure cell proliferation. RNA sequence was performed by Ingenuity pathway analysis. The ER alpha signaling activities were measured with luciferase assay, QPCR and western blotting. Protein stability assay and ubiquitin assay were used to determine ER alpha protein degradation and ubiquitination. The immuno-precipitation was utilized to determine ER alpha and ZNF213 interaction. The ubiquitin-based immuno-precipitation assay was sued to detect specific ubiquitination manner on ER alpha. Results we identified ZNF213 as a novel zinc finger protein, which modulated ER alpha protein. ZNF213 expression correlated with poor outcome in endocrine treated patients. ZNF213 depletion inhibited ER alpha signaling and proliferation in breast cancer cells. Further mechanistic studies showed ZNF213 located in cytosol and nuclear, which modulated ER alpha stability via inhibiting ER alpha K48-linked ubiquitination. Conclusions Our study reveals an interesting post-translational mechanism between ER alpha and ZNF213 in breast cancer. Targeting ZNF213 could be an appealing strategy for ER alpha positive breast cancer.


Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1132
Author(s):  
Javier A. Menendez ◽  
Adriana Papadimitropoulou ◽  
Travis Vander Steen ◽  
Elisabet Cuyàs ◽  
Bharvi P. Oza-Gajera ◽  
...  

The identification of clinically important molecular mechanisms driving endocrine resistance is a priority in estrogen receptor-positive (ER+) breast cancer. Although both genomic and non-genomic cross-talk between the ER and growth factor receptors such as human epidermal growth factor receptor 2 (HER2) has frequently been associated with both experimental and clinical endocrine therapy resistance, combined targeting of ER and HER2 has failed to improve overall survival in endocrine non-responsive disease. Herein, we questioned the role of fatty acid synthase (FASN), a lipogenic enzyme linked to HER2-driven breast cancer aggressiveness, in the development and maintenance of hormone-independent growth and resistance to anti-estrogens in ER/HER2-positive (ER+/HER2+) breast cancer. The stimulatory effects of estradiol on FASN gene promoter activity and protein expression were blunted by anti-estrogens in endocrine-responsive breast cancer cells. Conversely, an AKT/MAPK-related constitutive hyperactivation of FASN gene promoter activity was unaltered in response to estradiol in non-endocrine responsive ER+/HER2+ breast cancer cells, and could be further enhanced by tamoxifen. Pharmacological blockade with structurally and mechanistically unrelated FASN inhibitors fully impeded the strong stimulatory activity of tamoxifen on the soft-agar colony forming capacity—an in vitro metric of tumorigenicity—of ER+/HER2+ breast cancer cells. In vivo treatment with a FASN inhibitor completely prevented the agonistic tumor-promoting activity of tamoxifen and fully restored its estrogen antagonist properties against ER/HER2-positive xenograft tumors in mice. Functional cancer proteomic data from The Cancer Proteome Atlas (TCPA) revealed that the ER+/HER2+ subtype was the highest FASN protein expressor compared to basal-like, HER2-enriched, and ER+/HER2-negative breast cancer groups. FASN is a biological determinant of HER2-driven endocrine resistance in ER+ breast cancer. Next-generation, clinical-grade FASN inhibitors may be therapeutically relevant to countering resistance to tamoxifen in FASN-overexpressing ER+/HER2+ breast carcinomas.


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Lingling Wang ◽  
Jiashen Sun ◽  
Yueyuan Yin ◽  
Yanan Sun ◽  
Jinyi Ma ◽  
...  

AbstractTo support cellular homeostasis and mitigate chemotherapeutic stress, cancer cells must gain a series of adaptive intracellular processes. Here we identify that NUPR1, a tamoxifen (Tam)-induced transcriptional coregulator, is necessary for the maintenance of Tam resistance through physical interaction with ESR1 in breast cancers. Mechanistically, NUPR1 binds to the promoter regions of several genes involved in autophagy process and drug resistance such as BECN1, GREB1, RAB31, PGR, CYP1B1, and regulates their transcription. In Tam-resistant ESR1 breast cancer cells, NUPR1 depletion results in premature senescence in vitro and tumor suppression in vivo. Moreover, enforced-autophagic flux augments cytoplasmic vacuolization in NUPR1-depleted Tam resistant cells, which facilitates the transition from autophagic survival to premature senescence. Collectively, these findings suggest a critical role for NUPR1 as a transcriptional coregulator in enabling endocrine persistence of breast cancers, thus providing a vulnerable diagnostic and/or therapeutic target for endocrine resistance.


2019 ◽  
Vol 11 (12) ◽  
pp. 1042-1055 ◽  
Author(s):  
Weiwei Shi ◽  
Dongmei Wang ◽  
Xinwang Yuan ◽  
Yi Liu ◽  
Xiaojie Guo ◽  
...  

Abstract Glucocorticoid receptor (GR) is involved in the transcriptional regulation of genes that are important for various biological functions, including tumor growth and metastatic progression. However, the cellular and biological effects of GR remain poorly understood. Here, we investigated the role of GR and its underlying mechanism in mediating breast cancer cell survival and metastasis. We observed that the GR levels were increased in drug-resistant breast cancer cells and in metastatic breast cancer samples. GR promoted tumor cell invasion and lung metastasis in vivo. The GR expression levels were negatively correlated with the survival rates of breast cancer patients. Both ectopic expression and knockdown of GR revealed that GR is a strong inducer of epithelial-to-mesenchymal transition (EMT), which is consistent with its effects on cell survival and metastasis. GR suppressed the expression of insulin receptor substrate 1 (IRS-1) by acting as an IRS-1 transcriptional repressor. In addition, GR has an opposite effect on the expression levels of IRS-2, indicating that GR is able to differentially regulate the IRS-1 and IRS-2 expression. The cellular and biological effects elicited by GR were consistent with the reduced levels of IRS-1 observed in cancer cells, and GR-mediated IRS-1 suppression activated the ERK2 MAP kinase pathway, which is required for GR-mediated EMT. Taken together, our results indicate that GR–IRS-1 signaling axis plays an essential role in regulating the survival, invasion, and metastasis of breast cancer cells.


2020 ◽  
Vol 31 ◽  
pp. S13
Author(s):  
A.M. Scherbakov ◽  
Y. Shchegolev ◽  
D. Sorokin ◽  
M. Krasil’nikov

2017 ◽  
Vol 65 (6) ◽  
pp. 1122-1135.e5 ◽  
Author(s):  
Joshua D. Stender ◽  
Jerome C. Nwachukwu ◽  
Irida Kastrati ◽  
Yohan Kim ◽  
Tobias Strid ◽  
...  

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