A cell-permeable stapled peptide inhibitor of the estrogen receptor/coactivator interaction
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ABSTRACT:
PROVIDER: PRJNA423076 | ENA |
REPOSITORIES: ENA
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Project description:We and others have proposed that coactivator binding inhibitors, which block the interaction of estrogen receptor and steroid receptor coactivators, may represent a potential class of new breast cancer therapeutics. The development of coactivator binding inhibitors has been limited, however, because many of the current molecules which are active in in vitro and biochemical assays are not active in cell-based assays. Our goal in this work was to prepare a coactivator binding inhibitor active in cellular models of breast cancer. To accomplish this, we used molecular dynamics simulations to convert a high-affinity stapled peptide with poor cell permeability into R4K1, a cell-penetrating stapled peptide. R4K1 displays high binding affinity for estrogen receptor ɑ, inhibits the formation of estrogen receptor/coactivator complexes, and distributes throughout the cell with a high percentage of nuclear localization. R4K1 represses native gene transcription mediated by estrogen receptor ɑ and inhibits proliferation of estradiol-stimulated MCF-7 cells. Using RNA-Seq, we demonstrate that almost all of the effects of R4K1 on global gene transcription are estrogen receptor-associated. This chemical probe provides a significant proof-of-concept for preparing cell-permeable stapled peptide inhibitors of the estrogen receptor/coactivator interaction.
2018-01-09 | GSE108308 | GEO
Project description:Our previous studies demonstrated that specific inhibition of the BIG3-PHB2 complex, which is indispensable for estrogen (E2)-signaling activation, using ERAP, a dominant-negative peptide inhibitor, leads to the suppression of E2-dependent breast cancer cell growth in vitro and in vivo. However, duration of its effect is very short for clinical use. Here, we developed the chemically modified ERAP using stapling methods (stERAP; stapled ERAP) to improve duration of their antitumor effects. Tumor bearing mice treated with every 4 and 7 days with stERAP (1 mg/kg body weight) treatment effectively prevented the BIG3-PHB2 interaction, thereby releasing PHB2 to directly bind to both nuclear- and cytoplasmic ERalpha. This event led to the complete suppression of the E2-signalling pathways and ERalpha-positive breast cancer cell growth both in vitro and in vivo, but did not suppress the growth of normal mammary epithelial cells. Our findings suggest that the chemically modified stERAP may be a promising anti-tumor drug to suppress the growth of luminal-type breast cancer in clinical use.
2017-06-09 | GSE87378 | GEO
Project description: Not available
| S-EPMC6057476 | biostudies-literature
Project description:Estrogen improves insulin sensitivity and increases energy expenditure, contributing to sexual dimorphism regarding type 2 diabetes mellitus (T2DM) susceptibility. Estrogen receptor α (ERα) plays a crucial role in mediating estrogen action on glucose and energy homeostasis. However, the underlying mechanisms remain incompletely understood. Here, we found a ligand-independent effect of ERα on the regulation of glucose homeostasis and identified an ERα-derived peptide as a potential insulin sensitizer. Deficiency of ERα but not ERβ in the liver impaired glucose homeostasis in male, female, and ovariectomized (OVX) female mice. Mechanistic studies revealed that ERα promoted hepatic insulin sensitivity by suppressing ubiquitination-induced IRS1 degradation. The ERα 1-280 domain mediated the ligand-independent effect of ERα on insulin sensitivity. Furthermore, we designed a peptide based on ERα 1-280 domain and found that ERα-derived peptide interacted with IRS1, increased IRS1 stability through suppressing its ubiquitination, and enhanced insulin sensitivity. Importantly, administration of ERα-derived peptide into obese mice significantly increased insulin sensitivity, attenuated glucose intolerance, and improved serum lipid profiles. These findings pave the way for the therapeutic intervention of T2DM by targeting the ligand-independent effect of ERα and indicate that ERα-derived peptide is a potential insulin sensitizer for the treatment of T2DM.
2024-04-05 | GSE262841 | GEO
Project description:The Ras-family small GTPase RAB25 is involved in numerous aspects of endosomal protein trafficking and cell polarity. Recent evidence has established a role for RAB25, as well as related RAB-family and effector proteins, in oncogenic signaling, highlighting the need for chemical probes targeting this class of proteins. Here we report the development of all-hydrocarbon stabilized peptides targeting RAB25 derived from the RAB-binding FIP-family of proteins. Relative to unmodified FIP peptides, optimized stapled peptides show markedly increased structural stability, binding affinity, cell permeability and inhibition of RAB25:FIP complex formation. RAB25 expression has been shown to promote both pro- and anti-oncogenic phenotypes in specific cellular contexts. Stapled peptide RFP14 treatment of breast and ovarian cancer cell lines, in which RAB25 is pro-oncogenic, inhibited migration and proliferation in a RAB25-dependent manner. In contrast, treatment of a triple-negative breast cancer cell line in which RAB25 is tumor suppressive augmented proliferation and migration. Gene expression (RNA Seq) profiling identified significantly altered transcripts in response to RAB25 expression in ovarian cancer cells, and treatment with the optimized stapled peptide RFP14 reversed this expression profile. These data validate first-in-class chemical probes targeting RAB-family proteins and support the role of RAB25 in regulating context-specific oncogenic phenotypes.
2017-07-18 | GSE101528 | GEO
Project description:Nuclear Role for Human Argonaute-1 as an Estrogen-dependent Transcription Coactivator
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Project description:DNA-binding transcription factors (TFs) have been challenging to target with molecular probes. Many TFs function in part through interaction with Mediator; we sought to block p53 function by disrupting the p53-Mediator interaction. Through rational design and activity-based screening, we characterized a stapled peptide, with functional mimics of both p53 activation domains, that selectively disrupted p53- and Mediator-dependent transcription in vitro. This “bivalent peptide” also suppressed p53 transcriptional response in human cancer cells. Our strategy circumvents the TF and instead targets the TF-Mediator interface, with desired transcriptional outcomes. Different TFs target Mediator through different subunits, suggesting this strategy could be generalizable.
2022-04-05 | GSE193418 | GEO
Project description:DNA-binding transcription factors (TFs) have been challenging to target with molecular probes. Many TFs function in part through interaction with Mediator; we sought to block p53 function by disrupting the p53-Mediator interaction. Through rational design and activity-based screening, we characterized a stapled peptide, with functional mimics of both p53 activation domains, that selectively disrupted p53- and Mediator-dependent transcription in vitro. This “bivalent peptide” also suppressed p53 transcriptional response in human cancer cells. Our strategy circumvents the TF and instead targets the TF-Mediator interface, with desired transcriptional outcomes. Different TFs target Mediator through different subunits, suggesting this strategy could be generalizable.
2020-08-01 | GSE135870 | GEO
Project description:Excessive Toll-like receptor (TLR) and NF-kB activation during infection causes the overactivation of inflammatory pathways seen in sepsis. Thrombin-derived C-terminal peptides (TCPs) target both bacteria and the resulting TLR-mediated inflammatory response during infection. The present study describes the design and development of a novel multifunctional stapled peptide mimicking the actions of such immunomodulatory TCPs, providing a new drug class based on nature’s own anti-infective strategies. Using a combination of structure-based design, nuclear magnetic resonance spectroscopy (NMR), biophysics, mass spectrometry, microbiology, cellular, and in vivo studies, we describe the development of a structurally locked active stapled form of the endogenous peptide HVFRLKKWIQKVIDQFGE, denoted sHVF18. The stapled peptide shows a higher affinity to CD14 than the linear peptide, retains a partly helical and stabilized structure, and is protease resistant. In vivo, it shows efficacy in experimental models of endotoxin shock in mice and pigs and increases survival in mouse models of polymicrobial sepsis.
2024-01-01 | GSE217695 | GEO
Project description:Background: Clinical trial and epidemiological data support that the cardiovascular effects of estrogen are complex, including a mixture of both potentially beneficial and harmful effects. In animal models, estrogen protects females from vascular injury and inhibits atherosclerosis. These effects are mediated by estrogen receptors (ERs), which when bound to estrogen can bind to DNA to directly regulate transcription. ERs can also activate several cellular kinases by inducing a M-bM-^@M-^\rapidM-bM-^@M-^] non-nuclear signaling cascade. However, the biologic significance of this rapid signaling pathway has been unclear. Methods and Results: Here, we develop a novel transgenic mouse in which rapid signaling is blocked by over-expression of a peptide that prevents ERs from interacting with the scaffold protein, striatin (the Disrupting Peptide Mouse, DPM). Microarray analysis of ex vivo-treated mouse aortas demonstrates that rapid ER signaling plays an important role in E2-mediated gene regulatory responses. Disruption of ER-striatin interactions also eliminates the ability of E2 to stimulate cultured endothelial cell migration and to inhibit cultured vascular smooth muscle cell growth. The importance of these findings is underscored by in vivo experiments demonstrating loss of estrogen-mediated protection against vascular injury in the DPM mouse following carotid artery wire injury. Conclusions: Taken together, these results support that rapid, non-nuclear ER signaling contributes to the transcriptional regulatory functions of ER, and is essential for many of the vasoprotective effects of estrogen. These findings also identify the rapid ER signaling pathway as a potential target for the development of novel therapeutic agents. Transgenic disrupting peptide mice (DPM) express the Estrogen Receptor (ER) alpha amino acids 176-253 peptide under CMV promoter control. This peptide blocks interactions between ER and striatin, which inhibits rapid non-genomic signaling by ER to cellular kinases. Female WT and DPM mice (4 mice per sample) were overiectomized, and 1 week later aortas were harvested and treated + 10 nM beta-estradiol (E2) or + EtOH vehicle (Veh) for 4 hrs ex vivo. Total RNA was collected, reverse transcribed to cDNA and used to probe Affymetrix mouse 430.A 2.0 arrays.
2012-09-01 | E-GEOD-35558 | biostudies-arrayexpress