scholarly journals A functional drug re-purposing screening identifies carfilzomib as a drug preventing 17β-estradiol: ERα signaling and cell proliferation in breast cancer cells

2017 ◽  
Author(s):  
Claudia Busonero ◽  
Stefano Leone ◽  
Cinzia Klemm ◽  
Filippo Acconcia
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Cell Model ◽  
Acquired Resistance ◽  
Estrogen Receptor Α ◽  
Attractive Alternative ◽  
Novel Drugs ◽  
A Cell ◽  
17Β Estradiol ◽  
Cell Model System

AbstractMost cases of breast cancer (BC) are estrogen receptor α-positive (ERα+) at diagnosis. The presence of ERα drives the therapeutic approach for this disease, which often consists of endocrine therapy (ET). 4OH-Tamoxifen and faslodex (i.e., fulvestrant - ICI182,780) are two ETs that render tumor cells insensitive to 17β-estradiol (E2)-dependent proliferative stimuli and prevent BC progression. However, ET has limitations and serious failures in different tissues and organs. Thus, there is an urgent need to identify novel drugs to fight BC in the clinic. Re-positioning of old drugs for new clinical purposes is an attractive alternative for drug discovery. For this analysis, we focused on the modulation of intracellular ERα levels in BC cells as target for the screening of about 900 Food and Drug Administration (FDA) approved compounds that would hinder E2:ERα signaling and inhibit BC cell proliferation. We found that carfilzomib induces ERα degradation and prevents E2 signaling and cell proliferation in two ERα+ BC cell lines. Remarkably, the analysis of carfilzomib effects on a cell model system with an acquired resistance to 4OH-tamoxifen revealed that this drug has an antiproliferative effect superior to faslodex in BC cells. Therefore, our results identify carfilzomib as a drug preventing E2:ERα signaling and cell proliferation in BC cells and suggest its possible re-position for the treatment of ERα+ BC as well as for those diseases that have acquired resistance to 4OH-tamoxifen.

scholarly journals Unexpected Impact of a Hepatitis C Virus Inhibitor on 17β-Estradiol Signaling in Breast Cancer

2020 ◽  
Vol 21 (10) ◽  
pp. 3418 ◽  
Author(s):  
Stefania Bartoloni ◽  
Stefano Leone ◽  
Filippo Acconcia
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Drug Repurposing ◽  
Estrogen Receptor Α ◽  
Physiological Processes ◽  
17Β Estradiol ◽  
Approved Drugs ◽  
First Time

17β-Estradiol (E2) controls diverse physiological processes, including cell proliferation, through its binding to estrogen receptor α (ERα). E2:ERα signaling depends on both the receptor subcellular localization (e.g., nucleus, plasma membrane) and intracellular ERα abundance. Indeed, the control of ERα levels is necessary for the effects of E2, and E2 itself induces ERα degradation and cell proliferation in parallel. Thus, the modulation of intracellular ERα levels is a critical parameter for E2-induced cell proliferation. Therefore, we used this parameter as a bait to identify compounds that influence ERα levels and E2-dependent proliferation in breast cancer (BC) cells from a library of Food and Drug Administration (FDA)-approved drugs. We found that telaprevir (Tel) reduces ERα levels and inhibits BC cell proliferation. Tel is an inhibitor of the hepatitis C virus (HCV) NS3/4A serine protease, but its effect on E2:ERα signaling has not been investigated. Here, for the first time, we analyzed the effects of Tel on intracellular ERα levels and E2:ERα signaling to cell proliferation in different ERα-expressing BC cell lines. Overall, our findings demonstrate that Tel reduces intracellular ERα levels, deregulates E2:ERα signaling and inhibits E2-induced proliferation in BC cells and suggest the potential drug repurposing of Tel for the treatment of BC.

scholarly journals Evaluation of a Luciferase-Based Reporter Assay as a Screen for Inhibitors of Estrogen-ERα-Induced Proliferation of Breast Cancer Cells

2012 ◽  
Vol 17 (7) ◽  
pp. 921-932 ◽  
Author(s):  
Neal Andruska ◽  
Chengjian Mao ◽  
Mathew Cherian ◽  
Chen Zhang ◽  
David J. Shapiro
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Cancer Cells ◽  
Cell Lines ◽  
Breast Cancer Cells ◽  
Estrogen Receptor Α ◽  
Luciferase Reporter ◽  
Cancer Proliferation ◽  
Estrogen Response ◽  
A Cell

Estrogens, acting through estrogen receptor α (ERα), stimulate breast cancer proliferation, making ERα an attractive drug target. Since 384-well format screens for inhibitors of proliferation can be challenging for some cells, inhibition of luciferase-based reporters is often used as a surrogate end point. To identify novel small-molecule inhibitors of 17β-estradiol (E2)–ERα-stimulated cell proliferation, we established a cell-based screen for inhibitors of E2-ERα induction of an estrogen response element (ERE)3–luciferase reporter. Seventy-five “hits” were evaluated in tiered follow-up assays to identify where hits failed to progress and evaluate their effectiveness as inhibitors of E2-ERα-induced proliferation of breast cancer cells. Only 8 of 75 hits from the luciferase screen inhibited estrogen-induced proliferation of ERα-positive MCF-7 and T47D cells but not control ERα-negative MDA-MB-231 cells. Although 12% of compounds inhibited E2-ERα-stimulated proliferation in only one of the ERα-positive cell lines, 40% of compounds were toxic and inhibited growth of all the cell lines, and ~37% exhibited little or no ability to inhibit E2-ERα-stimulated cell proliferation. Representative compounds were evaluated in more detail, and a lead ERα inhibitor was identified.

scholarly journals A New Anti-Estrogen Discovery Platform Identifies FDA-Approved Imidazole Anti-Fungal Drugs as Bioactive Compounds against ERα Expressing Breast Cancer Cells

2021 ◽  
Vol 22 (6) ◽  
pp. 2915
Author(s):  
Manuela Cipolletti ◽  
Stefania Bartoloni ◽  
Claudia Busonero ◽  
Martina Parente ◽  
Stefano Leone ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Bioactive Compounds ◽  
Estrogenic Activity ◽  
Estrogen Receptor Α ◽  
Breast Cancers ◽  
Cellular Models ◽  
Cancer Models ◽  
17Β Estradiol ◽  
Approved Drugs ◽  
Anti Fungal

17β-estradiol (E2) exerts its physiological effects through the estrogen receptor α (i.e., ERα). The E2:ERα signaling allows the regulation of cell proliferation. Indeed, E2 sustains the progression of ERα positive (ERα+) breast cancers (BCs). The presence of ERα at the BC diagnosis drives their therapeutic treatment with the endocrine therapy (ET), which restrains BC progression. Nonetheless, many patients develop metastatic BCs (MBC) for which a treatment is not available. Consequently, the actual challenge is to complement the drugs available to fight ERα+ primary and MBC. Here we exploited a novel anti-estrogen discovery platform to identify new Food and Drug Administration (FDA)-approved drugs inhibiting E2:ERα signaling to cell proliferation in cellular models of primary and MBC cells. We report that the anti-fungal drugs clotrimazole (Clo) and fenticonazole (Fenti) induce ERα degradation and prevent ERα transcriptional signaling and proliferation in cells modeling primary and metastatic BC. The anti-proliferative effects of Clo and Fenti occur also in 3D cancer models (i.e., tumor spheroids) and in a synergic manner with the CDK4/CDK6 inhibitors palbociclib and abemaciclib. Therefore, Clo and Fenti behave as “anti-estrogens”-like drugs. Remarkably, the present “anti-estrogen” discovery platform represents a valuable method to rapidly identify bioactive compounds with anti-estrogenic activity.

scholarly journals PARP7 and Mono-ADP-Ribosylation Negatively Regulate Estrogen Receptor α Signaling in Human Breast Cancer Cells

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 623
Author(s):  
Marit Rasmussen ◽  
Susanna Tan ◽  
Venkata S. Somisetty ◽  
David Hutin ◽  
Ninni Elise Olafsen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Protein Modification ◽  
Target Genes ◽  
Estrogen Receptor Α ◽  
Transactivation Domain ◽  
Adp Ribosylation ◽  
Protein Levels ◽  
17Β Estradiol ◽  
Mcf 7

ADP-ribosylation is a post-translational protein modification catalyzed by a family of proteins known as poly-ADP-ribose polymerases. PARP7 (TIPARP; ARTD14) is a mono-ADP-ribosyltransferase involved in several cellular processes, including responses to hypoxia, innate immunity and regulation of nuclear receptors. Since previous studies suggested that PARP7 was regulated by 17β-estradiol, we investigated whether PARP7 regulates estrogen receptor α signaling. We confirmed the 17β-estradiol-dependent increases of PARP7 mRNA and protein levels in MCF-7 cells, and observed recruitment of estrogen receptor α to the promoter of PARP7. Overexpression of PARP7 decreased ligand-dependent estrogen receptor α signaling, while treatment of PARP7 knockout MCF-7 cells with 17β-estradiol resulted in increased expression of and recruitment to estrogen receptor α target genes, in addition to increased proliferation. Co-immunoprecipitation assays revealed that PARP7 mono-ADP-ribosylated estrogen receptor α, and mass spectrometry mapped the modified peptides to the receptor’s ligand-independent transactivation domain. Co-immunoprecipitation with truncated estrogen receptor α variants identified that the hinge region of the receptor is required for PARP7-dependent mono-ADP-ribosylation. These results imply that PARP7-mediated mono-ADP-ribosylation may play an important role in estrogen receptor positive breast cancer.

Activation of ClC-3 chloride channel by 17β-estradiol relies on the estrogen receptor α expression in breast cancer

2017 ◽  
Vol 233 (2) ◽  
pp. 1071-1081 ◽  
Author(s):  
Haifeng Yang ◽  
Lianshun Ma ◽  
Yawei Wang ◽  
Wanhong Zuo ◽  
Bingxue Li ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Chloride Channel ◽  
Estrogen Receptor Α ◽  
17Β Estradiol

scholarly journals Cell Context-Dependent Differences in the Induction of E2F-1 Gene Expression by 17β-Estradiol in MCF-7 and ZR-75 Cells

Endocrinology ◽  
2003 ◽  
Vol 144 (5) ◽  
pp. 1675-1685 ◽  
Author(s):  
Sharon Ngwenya ◽  
Stephen Safe
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Chimeric Protein ◽  
Gene Promoter ◽  
Estrogen Receptor Α ◽  
Breast Cancer Cell Lines ◽  
Er Positive ◽  
17Β Estradiol ◽  
Positive Breast Cancer Cell ◽  
Mcf 7

17β-Estradiol (E2) induces E2F-1 gene expression in ZR-75 and MCF-7 human breast cancer cells. Analysis of the E2F-1 gene promoter in MCF-7 cells previously showed that hormone-induced transactivation required interactions between estrogen receptor α (ERα)/Sp1 bound to upstream GC-rich sites and NFYA bound to downstream CCAAT sites within the −169 to −54 region of the promoter. This same region of the E2F-1 promoter was also E2 responsive in ERα-positive ZR-75 cells; however, further analysis of the promoter showed that cooperative ERα/Sp1/NFY interactions were not necessary for hormone-induced transactivation in ZR-75 cells. The upstream GC-rich motifs (−169 to −111) are activated independently by ERα/Sp1 in ZR-75 but not MCF-7 cells, and a construct (pE2F-1jm1) containing the −122 to −54 downstream CCAAT site that bound NFYA was also E2 responsive. E2 also induced reporter gene activity in ZR-75 cells transfected with an expression plasmid for a chimeric protein containing the DNA-binding domain of the yeast GAL4 protein fused to NFYA (pM-NFYA) and a construct containing five tandem GAL4 response elements. Subsequent studies showed that hormonal activation of pE2F-1jm1 and pM-NFYA are dependent on nongenomic pathways in which E2 activates cAMP/protein kinase A. Hormone-dependent regulation of E2F-1 gene expression in ZR-75 and MCF-7 involves the same cis elements and interacting transcription factors but different mechanisms, demonstrating the importance of cell context on transactivation pathways, even among ER-positive breast cancer cell lines.

scholarly journals Palmitoylation-dependent Estrogen Receptor α Membrane Localization: Regulation by 17β-Estradiol

2005 ◽  
Vol 16 (1) ◽  
pp. 231-237 ◽  
Author(s):  
Filippo Acconcia ◽  
Paolo Ascenzi ◽  
Alessio Bocedi ◽  
Enzo Spisni ◽  
Vittorio Tomasi ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Estrogen Receptor ◽  
Plasma Membrane ◽  
Estrogen Receptor Α ◽  
Membrane Localization ◽  
Target Cells ◽  
Dependent Manner ◽  
Caveolin 1 ◽  
17Β Estradiol

A fraction of the nuclear estrogen receptor α (ERα) is localized to the plasma membrane region of 17β-estradiol (E2) target cells. We previously reported that ERα is a palmitoylated protein. To gain insight into the molecular mechanism of ERα residence at the plasma membrane, we tested both the role of palmitoylation and the impact of E2 stimulation on ERα membrane localization. The cancer cell lines expressing transfected or endogenous human ERα (HeLa and HepG2, respectively) or the ERα nonpalmitoylable Cys447Ala mutant transfected in HeLa cells were used as experimental models. We found that palmitoylation of ERα enacts ERα association with the plasma membrane, interaction with the membrane protein caveolin-1, and nongenomic activities, including activation of signaling pathways and cell proliferation (i.e., ERK and AKT activation, cyclin D1 promoter activity, DNA synthesis). Moreover, E2 reduces both ERα palmitoylation and its interaction with caveolin-1, in a time- and dose-dependent manner. These data point to the physiological role of ERα palmitoylation in the receptor localization to the cell membrane and in the regulation of the E2-induced cell proliferation.

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