scholarly journals TRIM8 Inhibits Breast Cancer Proliferation by Regulating Estrogen Signaling

2020 ◽  
Author(s):  
Zelin Tian ◽  
Jianing Tang ◽  
Xing Liao ◽  
Qian Yang ◽  
Yumin Wu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Target Genes ◽  
Estrogen Signaling ◽  
Endocrine Treatment ◽  
Interaction Domain ◽  
Expression Levels ◽  
Protein Ubiquitination ◽  
Er Positive

Abstract Background: Breast cancer (BC) ranks first in female malignancies wordwide, 70% of which are estrogen receptor alpha (ERα) positive. Endocrine treatment, such as tamoxifen, is primary adjuvant therapy for patients with ER-positive BC, while some of them can develop acquired resistance during long-time treatment. Thus, further research on estrogen signaling is of significance to improve the prognosis of BC patients. Methods: In this study, we report that the E3 ubiquitin ligase TRIM8 acts as a novel regulator of ERα signaling. TRIM8 and ERα target genes expression levels were measured by RT-PCR, while protein expression levels were measured by western blot. CCK8 assay, clone formation, and EDU assay were used to measure cells proliferation. Wound healing assay was used to measure cells migration. Protein stability assay and protein ubiquitination analysis were used to detect ERα protein degradation. Co-immunoprecipitation assay was used to detect the interaction domain between TRIM8 and ERα. Results: TRIM8 is downregulated in BC and is associated with poor prognosis. The protein level of TRIM8 is negatively correlated with ERα. RNA-seq result revealed that estrogen signaling maybe a potential target of TRIM8. Knockdown of TRIM8 can significantly enhance BC cell proliferation and migration in vitro and in vivo. And this effect can be reversed by ERα depletion. Further mechanistic studies have shown that TRIM8 interacts with AF1 domain of ERα via its RING domain in the cytoplasm, and affects poly-ubiquitination of ERα protein. Conclusion: Our study reveals an interesting post-translational mechanism between ERα and TRIM8 in ER-positive BC, TRIM8 may be a potential therapeutic target for BC treatment.

In vitro evaluation of estrogenic, antiestrogenic and antitumor effects of amentoflavone

2021 ◽  
pp. 096032712199945
Author(s):  
AT Aliyev ◽  
S Ozcan-Sezer ◽  
A Akdemir ◽  
H Gurer-Orhan
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Antitumor Effects ◽  
Antiestrogenic Activity ◽  
Er Positive ◽  
In Vivo Effects ◽  
Mcf 7

Apigenin, a flavonoid, is reported to act as an estrogen receptor (ER) agonist and inhibit aromatase enzyme. However, amentoflavone, a biflavonoid bearing two apigenin molecules, has not been evaluated for its endocrine modulatory effects. Besides, it is highly consumed by young people to build muscles, enhance mood and lose weight. In the present study, apigenin was used as a reference molecule and ER mediated as well as ER-independent estrogenic/antiestrogenic activity of amentoflavone was investigated. Antitumor activity of amentoflavone was also investigated in both ER positive (MCF-7 BUS) and triple-negative (MDA-MB-231) breast cancer cells and its cytotoxicity was evaluated in human breast epithelial cells (MCF-10A). Our data confirmed ER agonist, aromatase inhibitory and cytotoxic effects of apigenin in breast cancer cells, where no ER mediated estrogenic effect and physiologically irrelevant, slight, aromatase inhibition was found for amentoflavone. Although selective cytotoxicity of amentoflavone was found in MCF-7 BUS cells, it does not seem to be an alternative to the present cytotoxic drugs. Therefore, neither an adverse effect, mediated by an estrogenic/antiestrogenic effect of amentoflavone nor a therapeutical benefit would be expected from amentoflavone. Further studies could be performed to investigate its in vivo effects.

scholarly journals Overexpression of BQ323636.1 Modulated AR/IL-8/CXCR1 Axis to Confer Tamoxifen Resistance in ER-Positive Breast Cancer

Life ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 93
Author(s):  
Ho Tsoi ◽  
Ling Shi ◽  
Man-Hong Leung ◽  
Ellen P. S. Man ◽  
Zi-Qing So ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Tamoxifen Resistance ◽  
In Silico Analysis ◽  
Luciferase Reporter ◽  
Androgen Response Element ◽  
Er Positive

NCOR2 is a co-repressor for estrogen receptor (ER) and androgen receptor (AR). Our group previously identified a novel splice variant of NCOR2, BQ323636.1 (BQ), that mediates tamoxifen resistance via interference of NCOR2 repression on ER. Luciferase reporter assay showed BQ overexpression could enhance the transcriptional activity of androgen response element (ARE). We proposed that BQ employs both AR and ER to confer tamoxifen resistance. Through in silico analysis, we identified interleukin-8 (IL-8) as the sole ERE and ARE containing gene responsiveness to ER and AR activation. We confirmed that BQ overexpression enhanced the expression of IL-8 in ER+ve breast cancer cells, and AR inhibition reduced IL-8 expression in the BQ overexpressing cell lines, suggesting that AR was involved in the modulation of IL-8 expression by BQ. Moreover, we demonstrated that IL-8 could activate both AKT and ERK1/2 via CXCR1 to confer tamoxifen resistance. Targeting CXCR1/2 by a small inhibitor repertaxin reversed tamoxifen resistance of BQ overexpressing breast cancer cells in vitro and in vivo. In conclusion, BQ overexpression in ER+ve breast cancer can enhance IL-8 mediated signaling to modulate tamoxifen resistance. Targeting IL-8 signaling is a promising approach to overcome tamoxifen resistance in ER+ve breast cancer.

scholarly journals HOXA5 Expression Is Elevated in Breast Cancer and Is Transcriptionally Regulated by Estradiol

2020 ◽  
Vol 11 ◽  
Author(s):  
Imran Hussain ◽  
Paromita Deb ◽  
Avisankar Chini ◽  
Monira Obaid ◽  
Arunoday Bhan ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Female Rats ◽  
Er Positive ◽  
Gene Regulatory ◽  
Cancer Tissues ◽  
Positive Breast Cancer

HOXA5 is a homeobox-containing gene associated with the development of the lung, gastrointestinal tract, and vertebrae. Here, we investigate potential roles and the gene regulatory mechanism in HOXA5 in breast cancer cells. Our studies demonstrate that HOXA5 expression is elevated in breast cancer tissues and in estrogen receptor (ER)-positive breast cancer cells. HOXA5 expression is critical for breast cancer cell viability. Biochemical studies show that estradiol (E2) regulates HOXA5 gene expression in cultured breast cancer cells in vitro. HOXA5 expression is also upregulated in vivo in the mammary tissues of ovariectomized female rats. E2-induced HOXA5 expression is coordinated by ERs. Knockdown of either ERα or ERβ downregulated E2-induced HOXA5 expression. Additionally, ER co-regulators, including CBP/p300 (histone acetylases) and MLL-histone methylases (MLL2, MLL3), histone acetylation-, and H3K4 trimethylation levels are enriched at the HOXA5 promoter in present E2. In summary, our studies demonstrate that HOXA5 is overexpressed in breast cancer and is transcriptionally regulated via estradiol in breast cancer cells.

scholarly journals Cubitus interruptus Requires DrosophilaCREB-Binding Protein To Activate wingless Expression in theDrosophila Embryo

2000 ◽  
Vol 20 (5) ◽  
pp. 1616-1625 ◽  
Author(s):  
Yang Chen ◽  
R. H. Goodman ◽  
Sarah M. Smolik
Keyword(s):  
Transcriptional Activation ◽  
Target Genes ◽  
Binding Protein ◽  
Point Mutations ◽  
Creb Binding Protein ◽  
Wild Type ◽  
Interaction Domain ◽  
Cubitus Interruptus

ABSTRACT CREB-binding protein (CBP) serves as a transcriptional coactivator in multiple signal transduction pathways. The Drosophilahomologue of CBP, dCBP, interacts with the transcription factors Cubitus interruptus (CI), MAD, and Dorsal (DL) and functions as a coactivator in several signaling pathways during Drosophiladevelopment, including the hedgehog (hh),decapentaplegic (dpp), and Tollpathways. Although dCBP is required for the expression of thehh target genes, wingless (wg) andpatched (ptc) in vivo, and potentiatesci-mediated transcriptional activation in vitro, it is not known that ci absolutely requires dCBP for its activity. We used a yeast genetic screen to identify several ci point mutations that disrupt CI-dCBP interactions. These mutant proteins are unable to transactivate a reporter gene regulated by cibinding sites and have a lower dCBP-stimulated activity than wild-type CI. When expressed exogenously in embryos, the CI point mutants cannot activate endogenous wg expression. Furthermore, a CI mutant protein that lacks the entire dCBP interaction domain functions as a negative competitor for wild-type CI activity, and the expression of dCBP antisense RNAs can suppress CI transactivation in Kc cells. Taken together, our data suggest that dCBP function is necessary forci-mediated transactivation of wg duringDrosophila embryogenesis.

Identification of estrogenically synthesized LRP16 as an ERα coactivator and its role in ERα-positive breast cancer

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 10676-10676
Author(s):  
W. Han ◽  
Y. Zhao ◽  
Z. Wu ◽  
Y. Mu ◽  
L. Yu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Northern Blot ◽  
Breast Cancer Cells ◽  
Tumor Diameter ◽  
Er Positive ◽  
Mcf 7 ◽  
Positive Breast Cancer

10676 Background: Aberrant ERα activity is linked to genesis and malignant progression of breast cancer through direct target gene activation or repression. A complex network of coregulatory proteins is largely believed to determine the transcriptional activity of ERα. LRP16 was identified previously to be an estrogen (E2) responsive gene, but its function involving in conferring estrogen signalling pathway is not clear. Methods: Endogenous LRP16 expression in MCF-7 cells was stably suppressed by retrovirus-mediated small interference RNA (siRNA). The effects of LRP16 expression on E2-stimulated growth and invasive ability of MCF-7 cells were determined in vitro and in vivo assays. The effects of LRP16 expression on ERα transactivation were determined by luciferase assays. The interaction of LRP16 and ERα was examined by GST pull-down and coimmunopricipitation (CoIP) assays. Northern blot and Western blot were used to detect the mRNA and protein levels of ER target genes in LRP16-inhibited MCF-7 cells. The LRP16 expression levels in primary breast cancer were detected by Northern blot. Results: Fristly, LRP16 expression was characterized to be dependent on estrogen activities. Then, LRP16 was identified to be an estrogen-independent ERα cofactor in ER-positive breast cancer cells and demonstrate that LRP16 is an essential coactivator to ERα-mediated transactivation in an estrogen-dependent manner. Suppression of LRP16 expression in ER-positive breast cancer cells specifically inhibits the transcription of ER upregulated genes, results in the increase of E-cadherin expression through ER mediation. In vitro and in vivo data demonstrate that suppression of LRP16 inhibits the ability of estrogen-stimulated proliferation and invasiveness of ER-positive breast cancer cells. The pathological and clinical characteristics of human breast cancer includining ER/PR-positiveness, tumor diameter and the involvement of axillary lymphoid nodes were tightly linked with the LRP16 gene expression level. Conclusions: These results establish a mechanistic link between estrogen receptor status, its coactivator LRP16, and progression of ER-positive breast cancers, and may provide a novel antiestrogenic target for the therapy of ER positive breast cancer. No significant financial relationships to disclose.

scholarly journals Endoxifen and fulvestrant regulate estrogen-receptor α and related DEADbox proteins

2020 ◽  
Vol 9 (12) ◽  
pp. 1156-1167
Author(s):  
Jasmin Asberger ◽  
Thalia Erbes ◽  
Markus Jaeger ◽  
Gerta Rücker ◽  
Claudia Nöthling ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Endocrine Therapy ◽  
Hormone Receptor ◽  
Target Genes ◽  
Endocrine Treatment ◽  
Proliferation Markers ◽  
Expression Levels ◽  
Hormone Receptor Positive ◽  
Mcf 7

Breast cancer (BC) represents the most common type of cancer in females worldwide. Endocrine therapy evolved as one of the main concepts in treatment of hormone-receptor positive BC. Current research focuses on the elucidation of tumour resistance mechanisms against endocrine therapy. In a translational in vitro approach, potential regulatory effects of clinically implemented BC anti-oestrogens on ERα, its coactivators DDX5, DDX17 and other DEADbox proteins as well as on the proliferation markers cyclin D1 and Ki67 were investigated on both the RNA and protein level. BC in vitro models for hormone-receptor positive (MCF-7, T-47D) and hormone-receptor negative cells (BT-20) were subjected to endocrine therapy. Anti-oestrogen-dependent expression regulation of target genes on the transcriptional and translational level was quantified and statistically assessed. Endocrine therapy decreases the expression levels of Ki67, cyclin D1 and ERα in hormone-receptor positive cells. In the hormone-receptor negative cells, the three parameters remained stable after endocrine therapy. Endoxifen triggers a downregulation of DDX5 and DDX23 in MCF-7 cells. Fulvestrant treatment downregulates the expression levels of all investigated DEADbox proteins in MCF-7 cells. In T-47D cells, endoxifen and fulvestrant lead to a decrease of all target gene expression levels. Interestingly, endocrine therapy affects DEADbox RNA expression levels in BT-20 cells, too. However, this result could only be confirmed for DDX1, immunocytologically. The investigated DEADbox proteins appear to correlate with the oestrogen-dependent tumourigenesis in hormone-receptor positive BC and show expression alterations after endocrine treatment.

scholarly journals Estrogen deprivation triggers an immunosuppressive phenotype in breast cancer cells

2019 ◽  
Author(s):  
Daniela Hühn ◽  
Pablo Martí-Rodrigo ◽  
Silvana Mouron ◽  
Catherine S. Hansel ◽  
Kirsten Tschapalda ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Breast Cancers ◽  
Breast Cancer Patients ◽  
Mcf7 Cells ◽  
Estrogen Deprivation ◽  
Er Positive

ABSTRACTEstrogen receptor (ER)-positive breast tumors are routinely treated with estrogen-depriving therapies. Despite their effectiveness, patients often progress into a more aggressive form of the disease. Through a chemical screen oriented to identify chemicals capable of inducing the expression of the immune-checkpoint ligand PD-L1, we found antiestrogens as hits. Subsequent validations confirmed that estrogen deprivation or ERα depletion induces PD-L1 expression in ER-positive breast cancer cells, both in vitro and in vivo. Likewise, PD-L1 expression is increased in metastasis arising from breast cancer patients receiving adjuvant hormonal therapy for their local disease. Transcriptome analyses indicate that estrogen deprivation triggers a broad immunosuppressive program, not restricted to PD-L1. Accordingly, estrogen deprived MCF7 cells are resistant to T-cell mediated cell killing, in a manner that can be reverted by estradiol. Our study reveals that while antiestrogen therapies effectively limit tumor growth in ER-positive breast cancers, they also trigger a transcriptional program that favors immune evasion.

scholarly journals A network pharmacology-based approach to explore potential targets of Caesalpinia pulcherima: an updated prototype in drug discovery

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nikhil S. Sakle ◽  
Shweta A. More ◽  
Santosh N. Mokale
Keyword(s):  
Breast Cancer ◽  
Target Genes ◽  
Docking Study ◽  
Network Pharmacology ◽  
Egfr Expression ◽  
Target Network ◽  
Anti Fungal ◽  
Compound Target

Abstract Caesalpinia pulcherima (CP) is a traditional herb used for the treatment of asthma, bronchitis, cancer, anti-bacterial, anti-fungal and as abortifacient. In the present study, bioactive components and potential targets in the treatment of breast cancer validated through in silico, in vitro and in vivo approach. The results for the analysis were as among 29 components, only four components were found active for further study which proved the use of CP as a multi-target herb for betterment of clinical uses. The results found by PPI states that our network has significant interactions which include the ESR-1, ESR-2, ESRRA, MET, VEGF, FGF, PI3K, PDK-1, MAPK, PLK-1, NEK-2, and GRK. Compound-target network involves 4 active compound and 150 target genes which elucidate the mechanisms of drug action in breast cancer treatment. Furthermore, on the basis of the above results the important proteins were fetched for the docking study which helps in predicting the possible interaction between components and targets. The results of the western blotting showed that CP regulates ER and EGFR expression in MCF-7 cell. In addition to this animal experimentation showed that CP significantly improved immunohistological status in MNU induced carcinoma rats. Network pharmacology approach not only helps us to confirm the study of the chosen target but also gave an idea of compound-target network as well as pathways associated to the CP for treating the complex metabolic condition as breast cancer and they importance for experimental verification.

scholarly journals In vivo NCL targeting affects breast cancer aggressiveness through miRNA regulation

2013 ◽  
Vol 210 (5) ◽  
pp. 951-968 ◽  
Author(s):  
Flavia Pichiorri ◽  
Dario Palmieri ◽  
Luciana De Luca ◽  
Jessica Consiglio ◽  
Jia You ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Target Genes ◽  
Human Cancer ◽  
Mirna Regulation ◽  
Altered Expression ◽  
Specific Subset ◽  
Cancer Aggressiveness

Numerous studies have described the altered expression and the causal role of microRNAs (miRNAs) in human cancer. However, to date, efforts to modulate miRNA levels for therapeutic purposes have been challenging to implement. Here we find that nucleolin (NCL), a major nucleolar protein, posttranscriptionally regulates the expression of a specific subset of miRNAs, including miR-21, miR-221, miR-222, and miR-103, that are causally involved in breast cancer initiation, progression, and drug resistance. We also show that NCL is commonly overexpressed in human breast tumors and that its expression correlates with that of NCL-dependent miRNAs. Finally, inhibition of NCL using guanosine-rich aptamers reduces the levels of NCL-dependent miRNAs and their target genes, thus reducing breast cancer cell aggressiveness both in vitro and in vivo. These findings illuminate a path to novel therapeutic approaches based on NCL-targeting aptamers for the modulation of miRNA expression in the treatment of breast cancer.

scholarly journals GABRQ is Overexpressed and Correlated with Tumor Progression in Breast Cancer

2021 ◽  
Author(s):  
Ran Mei ◽  
Xichun Cui ◽  
Lili Zheng ◽  
Li Jingyi
Keyword(s):  
Breast Cancer ◽  
Molecular Mechanisms ◽  
Tumor Development ◽  
Bioinformatic Analysis ◽  
Gamma Aminobutyric Acid ◽  
Nude Mouse Model ◽  
Expression Levels ◽  
The Public

Abstract Background: Breast cancer (BRCA) is the most common type of women's cancer with a high incidence. The function of gamma-aminobutyric acid A receptor θ subunit (GABRQ) has been studied in other cancers. The results demonstrated that the expression levels of GABRQ were closely associated with tumor prognosis. However, the functions and mechanisms of GABRQ in BRCA remain unclear.Materials and methods: We used the public genome datasets and a tissue microarray (TMA) cohort to analyze the GABRQ expression levels. We performed Immunohistochemistry (IHC) and Western blot to determine GABRQ expression in BRCA cell lines and tissues. Cell proliferation was assessed by EDU assay and colony formation assay. Transwell assay was carried out to investigate the cell invasion ability in vitro and Xenograft nude mouse model was constructed to test the function of GABRQ on tumor growth in vivo. Moreover, we utilized bioinformatic analysis to identify the potential molecular mechanisms mediated by GABRQ modification in BRCA.Results: GABRQ was markedly up-regulated in BRCA tissues, and the expression levels of GABRQ were closely associated with BRCA prognosis. Functional analysis elucidated that knockdown of GABRQ could suppress BRCA cell growth and invasion in vitro, and inhibit tumor development in vivo. Moreover, we found that GABRQ overexpression activated the EMT signaling pathway.Conclusions: These results demonstrated that the function of GABRQ in BRCA progression provided potential prognostic predictors for BRCA patients.

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