17β-Estradiol suppresses MHC class I chain-related B gene expression via an intact GC box

2013 ◽  
Vol 91 (2) ◽  
pp. 102-108 ◽  
Author(s):  
Niramai Sroijak ◽  
Mathurose Ponglikitmongkol
Keyword(s):  
Surface Protein ◽  
Promoter Sequence ◽  
Estrogen Receptor Α ◽  
Inhibitory Effect ◽  
Class I ◽  
Mobility Shift ◽  
Nkg2d Ligands ◽  
Protein Levels ◽  
17Β Estradiol ◽  
Gc Box

Major histocompatibility complex class I chain-related B (MICB) is a membrane-bound glycoprotein involved in both innate and adaptive immunity through its interaction with NKG2D receptors present on γδ T, αβ CD8+ T, and natural killer cells. Factors known to upregulate MICB expression include heat shock, viral or bacterial infection, and tumorigenesis, and here, we explored the effect of 17β-estradiol (E2) on MICB regulation. Physiological concentrations of E2 were found to suppress MICB mRNA and surface protein levels and this effect was antagonized by the antiestrogen ICI 182780. The inhibitory effect of E2 was also observed for other NKG2D ligands, MICA and ULBPs. Evaluation of promoter fragments from the common MICB*00502 allele revealed that inhibition of transcription by E2 required the GC box at −87. The electrophoretic mobility shift assay and supershift analysis established the presence of SP1, SP3, or estrogen receptor α recognition sites within the MICB promoter sequence and interaction of these factors in situ was confirmed by chromatin immunoprecipitation. We conclude that E2 upon forming a complex with its cognate receptor suppresses MICB expression through binding with SP1/SP3 sites within the MICB promoter GC box. These results suggest that the partial benefit of 17β-estradiol on autoimmune diseases may be mediated by reducing the immune NKG2D ligands like MICB.

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.

scholarly journals Transrepression of the estrogen receptor promoter by calcitriol in human breast cancer cells via two negative vitamin D response elements

2013 ◽  
Vol 20 (4) ◽  
pp. 565-577 ◽  
Author(s):  
Srilatha Swami ◽  
Aruna V Krishnan ◽  
Lihong Peng ◽  
Johan Lundqvist ◽  
David Feldman
Keyword(s):  
Breast Cancer ◽  
Vitamin D ◽  
Estrogen Receptor ◽  
Promoter Sequence ◽  
Estrogen Receptor Α ◽  
Mobility Shift ◽  
Response Elements ◽  
Dihydroxyvitamin D ◽  
Mobility Shift Assay ◽  
Estrogen Receptor Promoter

Calcitriol (1,25-dihydroxyvitamin D3), the hormonally active metabolite of vitamin D, exerts its anti-proliferative activity in breast cancer (BCa) cells by multiple mechanisms including the downregulation of the expression of estrogen receptor α (ER). We analyzed an ∼3.5 kb ER promoter sequence and demonstrated the presence of two potential negative vitamin D response elements (nVDREs), a newly identified putative nVDRE upstream at −2488 to −2473 bp (distal nVDRE) and a previously published sequence (proximal nVDRE) at −94 to −70 bp proximal to the P1 start site. Transactivation analysis using ER promoter deletion constructs and heterologous promoter–reporter constructs revealed that both nVDREs functioned to mediate calcitriol transrepression. In the electrophoretic mobility shift assay, the vitamin D receptor (VDR) showed strong binding to both nVDREs in the presence of calcitriol, and the chromatin immunoprecipitation assay demonstrated the recruitment of the VDR to the distal nVDRE site. Mutations in the 5′ hexameric DNA sequence of the distal nVDRE resulted in the loss of calcitriol-mediated transrepression and the inhibition of protein–DNA complex formation, demonstrating the importance of these nucleotides in VDR DNA binding and transrepression. A putative nuclear factor-Y (NFY) binding site, identified within the distal nVDRE, led to the findings that NFY bound to the distal nVDRE site interfered with the binding of the VDR at the site and reduced calcitriol-mediated transrepression. In conclusion, the ER promoter region contains two negative VDREs that act in concert to bind to the VDR and both nVDREs are required for the maximal inhibition of ER expression by calcitriol. The suppression of ER expression and estrogen-mediated signaling by calcitriol in BCa cells suggests that vitamin D may be useful in the treatment of ER+ BCa.

scholarly journals Trafficking of Kv1.4 potassium channels: interdependence of a pore region determinant and a cytoplasmic C-terminal VXXSL determinant in regulating cell-surface trafficking

2003 ◽  
Vol 375 (3) ◽  
pp. 761-768 ◽  
Author(s):  
Jing ZHU ◽  
Itaru WATANABE ◽  
Barbara GOMEZ ◽  
William B. THORNHILL
Keyword(s):  
Cell Surface ◽  
Cell Function ◽  
Cell Signalling ◽  
Surface Protein ◽  
Surface Expression ◽  
Inhibitory Effect ◽  
Cell Surface Expression ◽  
Pore Region ◽  
Expression Levels ◽  
Protein Levels

Kv1.4 and Kv1.1 potassium channel homomers have been shown to exhibit different intracellular trafficking programmes and cell-surface expression levels in cell lines: a determinant in the pore region of Kv1.4 and Kv1.1 [Zhu, Watanabe, Gomez and Thornhill (2001) J. Biol. Chem. 276, 39419–39427] and a cytoplasmic C-terminal VXXSL determinant on Kv1.4 [Li, Takimoto and Levitan (2000) J. Biol. Chem. 275, 11597–11602] have been described, which affected trafficking and cell-surface expression levels. In the present study, we examined whether trafficking pore determinants influenced any cytoplasmic C-terminal trafficking determinant. We found that removal of VXXSL from a Kv1.4 chimaera that contained the pore of Kv1.1 did not affect cell-surface trafficking. Therefore removal of the C-terminal VXXSL of Kv1.4 inhibited protein surface levels only in the presence of the Kv1.4 pore. In contrast, truncating the cytoplasmic C-terminus of Kv1.1 or truncating a Kv1.1 chimaera with the pore of Kv1.4, had little effect on surface protein levels. Furthermore, the subregion of the Kv1.4 pore trafficking determinant that was required for the inhibitory effect of VXXSL removal was mapped to a threonine residue in the deep pore region. Therefore the Kv1.4 pore determinant affected the trafficking and cell-surface levels directed by the C-terminal VXXSL determinant. Different Kv1 trafficking programmes would affect cell-surface expression levels either positively or negatively and also cell signalling. Cells may use differential trafficking programmes of membrane proteins as a post-translational mechanism to regulate surface protein levels and cell function.

scholarly journals Transcriptional Activation of E2F1 Gene Expression by 17β-Estradiol in MCF-7 Cells Is Regulated by NF-Y-Sp1/Estrogen Receptor Interactions

1999 ◽  
Vol 13 (8) ◽  
pp. 1373-1387 ◽  
Author(s):  
Weili Wang ◽  
Lian Dong ◽  
Brad Saville ◽  
Stephen Safe
Keyword(s):  
Gene Expression ◽  
Estrogen Receptor ◽  
Dna Binding ◽  
Transcriptional Activation ◽  
Gene Promoter ◽  
Proximal Region ◽  
Mobility Shift ◽  
Protein Levels ◽  
17Β Estradiol ◽  
Mcf 7

Abstract 17β-Estradiol (E2) stimulated proliferation and DNA synthesis in MCF-7 human breast cancer cells, and this was accompanied by induction of E2F1 mRNA and protein levels. Analysis of the E2F1 gene promoter showed that the −146 to− 54 region was required for E2-responsiveness in transient transfection assays, and subsequent deletion/mutation analysis showed that a single upstream GC-rich and two downstream CCAAT-binding sites were required for transactivation by E2. Gel mobility shift assays with multiple oligonucleotides and protein antibodies (for supershifts) showed that the −146 to −54 region of the E2F1 gene promoter bound Sp1 and NF-Y proteins in MCF-7 cells. The estrogen receptor (ER) protein enhanced Sp1 interactions with upstream GC-rich sites, and interactions of ER, Sp1, and ER/Sp1 with downstream DNA bound-NF-Y was investigated by kinetic analysis for protein-DNA binding (on- and off-rates), coimmunoprecipitation, and pulldown assays using wild-type and truncated glutathione S-transferase (GST)-Sp1 chimeric proteins. The results showed that Sp1 protein enhanced the Bmax of NF-Y-DNA binding by more than 5-fold (on-rate); in addition, the Sp1-enhanced NF-Y-DNA complex was further stabilized by coincubation with ER and the rate of dissociation (t1/2) was decreased by approximately 50%. Sp1 antibodies immunoprecipitated [35S]NF-YA after coincubation with unlabeled Sp1 protein. Thus, transcriptional activation of E2F1 gene expression in MCF-7 cells by E2 is regulated by multiprotein ER/Sp1-NF-Y interactions at GC-rich and two CCAAT elements in the proximal region of the E2F1 gene promoter. This represents a unique trans-acting protein complex in which ligand-dependent transactivation by the ER is independent of direct ER interactions with promoter elements.

scholarly journals CK2 Pro-Survival Role in Prostate Cancer Is Mediated via Maintenance and Promotion of Androgen Receptor and NFκB p65 Expression

2019 ◽  
Vol 12 (2) ◽  
pp. 89
Author(s):  
Janeen H. Trembley ◽  
Betsy T. Kren ◽  
Md. J. Abedin ◽  
Daniel P. Shaughnessy ◽  
Yingming Li ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Inhibitory Effect ◽  
Strongly Correlated ◽  
Protein Levels ◽  
Small Molecule Inhibition ◽  
Prostate Cells ◽  
Cell Death Response ◽  
Stress Signals ◽  
Castrate Resistant

The prosurvival protein kinase CK2, androgen receptor (AR), and nuclear factor kappa B (NFκB) interact in the function of prostate cells, and there is evidence of crosstalk between these signals in the pathobiology of prostate cancer (PCa). As CK2 is elevated in PCa, and AR and NFκB are involved in the development and progression of prostate cancer, we investigated their interaction in benign and malignant prostate cells in the presence of altered CK2 expression. Our results show that elevation of CK2 levels caused increased levels of AR and NFκB p65 in prostate cells of different phenotypes. Analysis of TCGA PCa data indicated that AR and CK2α RNA expression are strongly correlated. Small molecule inhibition or molecular down-regulation of CK2 caused reduction in AR mRNA expression and protein levels in PCa cells and in orthotopic xenograft tumors by various pathways. Among these, regulation of AR protein stability plays a unifying role in CK2 maintenance of AR protein levels. Our results show induction of various endoplasmic reticulum stress signals after CK2 inhibition, which may play a role in the PCa cell death response. Of note, CK2 inhibition caused loss of cell viability in both parental and enzalutamide-resistant castrate-resistant PCa cells. The present work elucidates the specific link of CK2 to the pathogenesis of PCa in association with AR and NFκB expression; further, the observation that inhibition of CK2 can exert a growth inhibitory effect on therapy-resistant PCa cells emphasizes the potential utility of CK2 inhibition in patients who are on enzalutamide treatment for advanced cancer.

scholarly journals Regulation of Swarming Motility and flhDCSm Expression by RssAB Signaling in Serratia marcescens

2008 ◽  
Vol 190 (7) ◽  
pp. 2496-2504 ◽  
Author(s):  
Po-Chi Soo ◽  
Yu-Tze Horng ◽  
Jun-Rong Wei ◽  
Jwu-Ching Shu ◽  
Chia-Chen Lu ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Binding Site ◽  
Promoter Region ◽  
Transcriptional Start Site ◽  
Direct Interaction ◽  
Underlying Mechanism ◽  
Inhibitory Effect ◽  
Start Codon ◽  
Mobility Shift

ABSTRACT Serratia marcescens cells swarm at 30°C but not at 37°C, and the underlying mechanism is not characterized. Our previous studies had shown that a temperature upshift from 30 to 37°C reduced the expression levels of flhDCSm and hagSm in S. marcescens CH-1. Mutation in rssA or rssB, cognate genes that comprise a two-component system, also resulted in precocious swarming phenotypes at 37°C. To further characterize the underlying mechanism, in the present study, we report that expression of flhDCSm and synthesis of flagella are significantly increased in the rssA mutant strain at 37°C. Primer extension analysis for determination of the transcriptional start site(s) of flhDCSm revealed two transcriptional start sites, P1 and P2, in S. marcescens CH-1. Characterization of the phosphorylated RssB (RssB∼P) binding site by an electrophoretic mobility shift assay showed direct interaction of RssB∼P, but not unphosphorylated RssB [RssB(D51E)], with the P2 promoter region. A DNase I footprinting assay using a capillary electrophoresis approach further determined that the RssB∼P binding site is located between base pair positions −341 and −364 from the translation start codon ATG in the flhDCSm promoter region. The binding site overlaps with the P2 “−35” promoter region. A modified chromatin immunoprecipitation assay was subsequently performed to confirm that RssB∼P binds to the flhDCSm promoter region in vivo. In conclusion, our results indicated that activated RssA-RssB signaling directly inhibits flhDCSm promoter activity at 37°C. This inhibitory effect was comparatively alleviated at 30°C. This finding might explain, at least in part, the phenomenon of inhibition of S. marcescens swarming at 37°C.

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 Let-7a-5p regulates the inflammatory response in chronic rhinosinusitis with nasal polyps

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jianwei Zhang ◽  
Lei Han ◽  
Feng Chen
Keyword(s):  
Inflammatory Response ◽  
Chronic Rhinosinusitis ◽  
Nasal Polyps ◽  
Mapk Pathway ◽  
Inhibitory Effect ◽  
Luciferase Reporter ◽  
Western Blot Assay ◽  
Protein Levels ◽  
Tnf Α

Abstract Background Let-7a-5p is demonstrated to be a tumor inhibitor in nasopharyngeal carcinoma. However, the role of let-7a-5p in chronic rhinosinusitis with nasal polyps (CRSwNP) has not been reported. This study is designed to determine the pattern of expression and role of let-7a-5p in CRSwNP. Methods The expression level of let-7a-5p, TNF-α, IL-1β, and IL-6 in CRSwNP tissues and cells were detected by RT-qPCR. Western blot assay was carried out to measure the protein expression of the Ras-MAPK pathway. Dual luciferase reporter assay and RNA pull-down assay were used to explore the relationship between let-7a-5p and IL-6. Results Let-7a-5p was significantly downregulated in CRSwNP tissues and cells. Moreover, the mRNA expression of TNF-α, IL-1β and IL-6 was increased in CRSwNP tissues, while let-7a-5p mimic inhibited the expression of TNF-α, IL-1β and IL-6. Besides that, let-7a-5p was negatively correlated with TNF-α, IL-1β and IL-6 in CRSwNP tissues. In our study, IL-6 was found to be a target gene of let-7a-5p. Additionally, let-7-5p mimic obviously reduced the protein levels of Ras, p-Raf1, p-MEK1 and p-ERK1/2, while IL-6 overexpression destroyed the inhibitory effect of let-7a-5p on the Ras-MAPK pathway in CRSwNP. Conclusion We demonstrated that let-7a-5p/IL-6 interaction regulated the inflammatory response through the Ras-MAPK pathway in CRSwNP.

scholarly journals TBP and SNAP50 transcription factors bind specifically to the Pr77 promoter sequence from trypanosomatid non-LTR retrotransposons

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Francisco Macías ◽  
Raquel Afonso-Lehmann ◽  
Patricia E. Carreira ◽  
M. Carmen Thomas
Keyword(s):  
Transcription Factors ◽  
Protein Interactions ◽  
Dna Sequences ◽  
Direct Interaction ◽  
Promoter Sequence ◽  
Nuclear Proteins ◽  
Hill Coefficient ◽  
Small Nuclear Rna ◽  
Mobile Dna ◽  
Mobility Shift

Abstract Background Trypanosomatid genomes are colonized by active and inactive mobile DNA elements, such as LINE, SINE-like, SIDER and DIRE retrotransposons. These elements all share a 77-nucleotide-long sequence at their 5′ ends, known as Pr77, which activates transcription, thereby generating abundant unspliced and translatable transcripts. However, transcription factors that mediates this process have still not been reported. Methods TATA-binding protein (TBP) and small nuclear RNA-activating protein 50 kDa (SNAP50) recombinant proteins and specific antibodies raised against them were generated. Protein capture assay, electrophoretic mobility-shift assays (EMSA) and EMSA competition assays carried out using these proteins and nuclear proteins of the parasite together to specific DNA sequences used as probes allowed detecting direct interaction of these transcription factors to Pr77 sequence. Results This study identified TBP and SNAP50 as part of the DNA-protein complex formed by the Pr77 promoter sequence and nuclear proteins of Trypanosoma cruzi. TBP establishes direct and specific contact with the Pr77 sequence, where the DPE and DPE downstream regions are docking sites with preferential binding. TBP binds cooperatively (Hill coefficient = 1.67) to Pr77 and to both strands of the Pr77 sequence, while the conformation of this highly structured sequence is not involved in TBP binding. Direct binding of SNAP50 to the Pr77 sequence is weak and may be mediated by protein–protein interactions through other trypanosomatid nuclear proteins. Conclusions Identification of the transcription factors that mediate Pr77 transcription may help to elucidate how these retrotransposons are mobilized within the trypanosomatid genomes and their roles in gene regulation processes in this human parasite. Graphic abstract

FOXD3 inhibits cell proliferation, migration, and invasion in nasopharyngeal carcinoma through regulation of the PI3K–Akt pathway

2020 ◽  
Vol 98 (6) ◽  
pp. 653-660 ◽  
Author(s):  
Xiaoxing Xie ◽  
Gaoyun Xiong ◽  
Wenjun Chen ◽  
Hongdan Fu ◽  
Mingqian Li ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Nasopharyngeal Carcinoma ◽  
Cell Apoptosis ◽  
Inhibitory Effect ◽  
Akt Pathway ◽  
Migration And Invasion ◽  
Inhibitory Effects ◽  
Protein Levels ◽  
Flow Cytometric ◽  
Phosphoinositide 3 Kinase

FOXD3 has been found previously to positively regulate miR-26b, a tumor inhibitor of nasopharyngeal carcinoma (NPC). However, FOXD3’s precise function and associated mechanism of action in NPC have not yet been investigated. In this study, the expression of FOXD3 mRNA and protein was evaluated using RT-qPCR, western blotting, and immunohistochemistry. Protein levels involved in the phosphoinositide 3-kinase – protein kinase B (PI3K–Akt) pathway were assessed by western blot, and cell proliferation was determined by MTT and colony forming assays. Additionally, cell apoptosis was assessed by flow cytometric assay. Finally, the migration and invasion capabilities of the NPC cells were determined using wound healing and Transwell assays. We found that FOXD3 levels were relatively low in NPC tissue and cells, while an increase caused the inhibition of the PI3K–Akt pathway. Functional experiments found that overexpression of FOXD3 suppressed cell proliferation, migration, and invasion and enhanced cell apoptosis in NPC C6661 cells. IGF-1, an activator of the PI3K–Akt pathway, reversed the inhibitory effect of FOXD3. Furthermore, we found upregulation of the PI3K–Akt pathway and upregulation of the inhibitory effects of FOXD3 on C6661 cellular activities. In conclusion, FOXD3 negatively affected the PI3K–Akt pathway to restrain the processes involved in C6661 cell pathology. These findings further exposed the function and downstream axis of FOXD3 in NPC and displayed a promising new target for NPC therapy.

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