MCF-7 cells long-term treated with Fulv plus Abema acquired ESR1 Y537S mutation and exhibited defective RSR and DDR
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE314294 | GEO | 2026/01/05
REPOSITORIES: GEO
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Project description:Purpose: Breast cancers with ESR1 mutations are resistant to antiestrogen therapy. We aimed to investigate the association of ESR1 mutations with resistance to CDK4/6 inhibitors (CDK4/6i) using real-world data analysis and experimental validation. Patients and Methods: A total of 3,958 patients with estrogen receptor-positive (ER+) metastatic breast cancer with DNA sequencing data were analyzed. Breast tumor DNA and circulating tumor (ct) DNA were sequenced using the Tempus xT tumor assay and Tempus xF liquid biopsy, respectively. Patients were stratified into either treated with CDK4/6i (breast tumors: 1,070; ctDNA: 1,885) or CDK4/6i naïve (breast tumors: 750; ctDNA: 253). Engineered MCF7 cells carrying ESR1 Y537S or D538G knock-in mutations were used to study antitumor efficacy of the CDK4/6i, palbociclib in vitro and in vivo. Results: In both xF and xT assays, ESR1 mutations were the only somatic alterations significantly more frequent in those who received CDK4/6i than those who did not. Knock-in of ESR1 Y537S or ESR1 D538G in MCF7 cells resulted in upregulation of cell cycle-related gene signatures upon treatment with CDK4/6i ± antiestrogen compared to cells with non-mutant ESR1. MCF7 xenografts harboring ESR1 Y537S and D538G mutations established in nude mice were resistant to palbociclib. Conclusions: We report herein real-world and preclinical evidence that ESR1 mutations, particularly Y537S and D538G, can drive resistance to CDK4/6 inhibitors.
2024-11-12 | GSE281302 | GEO
Project description:Background: The constitutively active ESR1 Y537S mutation is associated with endocrine therapy resistance and progression of metastatic breast cancer through its effects on estrogen receptor (ERα) gene regulatory functions. However, the complex relationship between ERα and the progesterone receptor (PR), known as ERα/PR crosstalk, has yet to be characterized in the context of the ERα Y537S mutation. This study aimed to elucidate the effects of the ERα Y537S mutation on ERα/PR crosstalk and resultant transcriptional activity and to identify potential therapeutic sensitivities that may offer novel treatment options to patients with endocrine therapy-resistant breast cancer. Methods: Proximity-based interactions of ERα and PR were assessed via proximity ligation assay (PLA). Gene expression in MCF7 and T47D cells was assessed by RNA-seq analysis with comparison to publicly available patient tumor transcriptome data. Chromatin immunoprecipitation (ChIP)-qPCR and immunoblotting were used to assess ERα/PR-associated gene expression and protein expression, respectively. Data were analyzed by ordinary two-way ANOVA (α = 0.05) with Tukey’s multiple comparisons tests. Results: Physical interaction of ERα and PR was increased in the context of the ERα Y537S mutation, including in the nucleus where this interaction may translate to altered gene expression. As such, more than 30 genes were differentially expressed in both patient tumor and cell line data (MCF7 and/or T47D cells) in the context of the ERα Y537S mutation compared to ERα WT. Of these, IRS1 stood out as a gene of interest, and ERα and PR occupancy at chromatin binding sites along IRS1 were uniquely altered in the context of ERα Y537S. Furthermore, siRNA knockdown of IRS1 or treatment with the IRS1 inhibitor NT-157 indicated a significant anti-proliferative effect of IRS1 depletion or inhibition in ERα Y537S cell lines. Conclusions: Previous research has characterized gene regulatory changes associated with the ERα Y537S mutation from the viewpoint of ERα. Here, we identify consequential changes to both ERα and PR transcription factor activity, including at chromatin binding sites for the signaling adaptor protein IRS1. We identified a significant dependence of ERα Y537S-expressing cells on IRS1 for proliferation, implicating IRS1 as a potential therapeutic target for restoring treatment sensitivity to patients with breast cancers harboring ERα Y537S mutations.
2023-09-20 | GSE243454 | GEO
Project description:MCF-7 cells long-term treated with Fulv plus Abema acquired ESR1 Y537S mutation and exhibited defective RSR and DDR
| PRJNA1390673 | ENA
Project description:The ESR1 ligand binding domain activating mutations are the most prevalent genetic mechanism of acquired endocrine resistance in metastatic hormone receptor-positive breast cancer. These mutations confer endocrine resistance that remains estrogen receptor (ER) dependent. We hypothesized that in the presence of the ER mutations, continued ER blockade with endocrine therapies that target mutant ER is essential for tumor suppression even with chemotherapy treatment. Here, we conducted comprehensive pre-clinical in vitro and in vivo experiments testing the efficacy of adding fulvestrant to fluorouracil (5FU) and the 5FU pro-drug, capecitabine, in models of wild-type (WT) and mutant ER. Our findings revealed that while this combination had an additive effect in the presence of WT-ER, in the presence of the Y537S ER mutation there was synergy. Notably, these effects were not seen with the combination of 5FU and selective estrogen receptor modulators, such as tamoxifen, or in the absence of intact P53. Likewise, in a patient derived xenograft (PDX) harboring a Y537S ER mutation the addition of fulvestrant to capecitabine potentiated tumor suppression. Moreover, multiplex immunofluorescence revealed that this effect was due to decreased cell proliferation in all cells expressing ER and was not dependent on the degree of ER expression. Taken together, these results support the clinical investigation of the combination of ER antagonists with capecitabine in patients with metastatic hormone receptor-positive breast cancer who have experienced progression on endocrine therapy and targeted therapies, particularly in the presence of an ESR1 activating mutation.
2024-06-01 | GSE266932 | GEO
Project description:Three quarters of all breast cancer cases express the estrogen receptor (ER, ESR1 gene), which promotes tumor growth and constitutes a direct target for endocrine therapies. ESR1 mutations have been implicated in therapy resistance in metastatic breast cancers, in particular to aromatase inhibitors. ESR1 mutations promote constitutive ER activity and affect other signaling pathways, allowing cancer cells to proliferate by employing mechanisms within and outwith direct regulation by the ER. Although subjected to extensive genetic and transcriptomic analyses, understanding of protein alterations remains poorly investigated. Towards this, we employed an integrated mass spectrometry (MS) based proteomic approach to profile the protein and phosphoprotein differences in breast cancer cell lines expressing the frequent Y537N and Y537S ER mutations. Global proteome analysis revealed enrichment of mitotic and immune signaling pathways in ER mutant cells, while phosphoprotein analysis evidenced enriched activity of proliferation associated kinases, in particular CDKs and MTOR. Integration of protein expression and phosphorylation data revealed pathway-dependent discrepancies (motility vs proliferation) that were observed at varying degrees across mutant and wt ER cells. Additionally, protein expression and phosphorylation patterns, while under different regulation, still recapitulated the estrogen-independent phenotype of ER mutant cells.
2024-03-26 | PXD032404 | Pride
Project description:Three quarters of all breast cancer cases express the estrogen receptor (ER, ESR1 gene), which promotes tumor growth and constitutes a direct target for endocrine therapies. ESR1 mutations have been implicated in therapy resistance in metastatic breast cancers, in particular to aromatase inhibitors. ESR1 mutations promote constitutive ER activity and affect other signaling pathways, allowing cancer cells to proliferate by employing mechanisms within and outwith direct regulation by the ER. Although subjected to extensive genetic and transcriptomic analyses, understanding of protein alterations remains poorly investigated. Towards this, we employed an integrated mass spectrometry (MS) based proteomic approach to profile the protein and phosphoprotein differences in breast cancer cell lines expressing the frequent Y537N and Y537S ER mutations. Global proteome analysis revealed enrichment of mitotic and immune signaling pathways in ER mutant cells, while phosphoprotein analysis evidenced enriched activity of proliferation associated kinases, in particular CDKs and MTOR. Integration of protein expression and phosphorylation data revealed pathway-dependent discrepancies (motility vs proliferation) that were observed at varying degrees across mutant and wt ER cells. Additionally, protein expression and phosphorylation patterns, while under different regulation, still recapitulated the estrogen-independent phenotype of ER mutant cells.
2024-03-26 | PXD032285 | Pride
Project description:Three quarters of all breast cancer cases express the estrogen receptor (ER, ESR1 gene), which promotes tumor growth and constitutes a direct target for endocrine therapies. ESR1 mutations have been implicated in therapy resistance in metastatic breast cancers, in particular to aromatase inhibitors. ESR1 mutations promote constitutive ER activity and affect other signaling pathways, allowing cancer cells to proliferate by employing mechanisms within and outwith direct regulation by the ER. Although subjected to extensive genetic and transcriptomic analyses, understanding of protein alterations remains poorly investigated. Towards this, we employed an integrated mass spectrometry (MS) based proteomic approach to profile the protein and phosphoprotein differences in breast cancer cell lines expressing the frequent Y537N and Y537S ER mutations. Global proteome analysis revealed enrichment of mitotic and immune signaling pathways in ER mutant cells, while phosphoprotein analysis evidenced enriched activity of proliferation associated kinases, in particular CDKs and MTOR. Integration of protein expression and phosphorylation data revealed pathway-dependent discrepancies (motility vs proliferation) that were observed at varying degrees across mutant and wt ER cells. Additionally, protein expression and phosphorylation patterns, while under different regulation, still recapitulated the estrogen-independent phenotype of ER mutant cells.
2024-03-26 | PXD046446 | Pride
Project description:Three quarters of all breast cancer cases express the estrogen receptor (ER, ESR1 gene), which promotes tumor growth and constitutes a direct target for endocrine therapies. ESR1 mutations have been implicated in therapy resistance in metastatic breast cancers, in particular to aromatase inhibitors. ESR1 mutations promote constitutive ER activity and affect other signaling pathways, allowing cancer cells to proliferate by employing mechanisms within and outwith direct regulation by the ER. Although subjected to extensive genetic and transcriptomic analyses, understanding of protein alterations remains poorly investigated. Towards this, we employed an integrated mass spectrometry (MS) based proteomic approach to profile the protein and phosphoprotein differences in breast cancer cell lines expressing the frequent Y537N and Y537S ER mutations. Global proteome analysis revealed enrichment of mitotic and immune signaling pathways in ER mutant cells, while phosphoprotein analysis evidenced enriched activity of proliferation associated kinases, in particular CDKs and MTOR. Integration of protein expression and phosphorylation data revealed pathway-dependent discrepancies (motility vs proliferation) that were observed at varying degrees across mutant and wt ER cells. Additionally, protein expression and phosphorylation patterns, while under different regulation, still recapitulated the estrogen-independent phenotype of ER mutant cells.
2024-03-26 | PXD032369 | Pride
Project description:Estrogen receptor alpha (ER) is a critical driver of tumorigenesis and tumor progression in most breast cancers. Endocrine therapies targeting the ER are the cornerstone treatments in hormone receptor-positive breast cancer. Resistance to these therapies poses a significant clinical challenge and is due to diverse mechanisms. Some of these mechanisms, particularly through estrogen independent activity and the ESR1 mutations, remain dependent on the estrogen axis providing a rationale for the development of next-generation endocrine therapies. This study investigates the preclinical efficacy of imlunestrant, a next-generation oral selective estrogen receptor degrader, in ER-positive breast cancer pre-clinical models, including models harboring the Y537S ESR1 mutation, a prevalent and potent ER activating mutation. Imlunetsrant demonstrated pure antagonistic activity and effective degradation of both wild-type and mutant ER, significantly suppressing cell growth. In vivo, imlunestrant outperformed fulvestrant leading to tumor regression in a patient derived xenograft harboring the Y537S ESR1 mutation. Cyclic multiplexed immunofluorescence and transcriptomic analysis revealed enhanced cell cycle arrest and downregulation of estrogen-responsive genes with imlunestrant treatment. Additionally, a genome wide CRISPR knock-out screen identified several vulnerabilities that were either persistent or gained after imlunestrant treatment, which provides a rational for future studies of combination treatments with imlunestrant. In summary, these results highlight the on target and selective potent activity of imlunestrant, which can circumvent resistance engendered by the Y537S ESR1 mutation and support the clinical development of imlunestrant.
2025-04-18 | GSE295024 | GEO
Project description:Analysis of MCF7 cells transfected with ER mutants (S463P, Y537S and D538G) in phenol-red free, charcoal stripped FBS media and regular DMEM/F12 media. Results provide insight on the gene expression profiles induced by the various ER mutants. Total RNA extracted from transfected cells 48 hours after transfection 36 samples were analyzed, triplicates for each constructs (GFP vector control, WT, S463P, Y537S, D538G and S463P/D538G) for each type of media
2013-10-25 | E-GEOD-51448 | biostudies-arrayexpress