Megacomplex protects ESR1 from degradation by Fulvestrant in epithelial ovarian cancer
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ABSTRACT:
PROVIDER: PRJNA1111537 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR29024600_1.fastq.gz | Fastqsanger.gz | |||
| SRR29024600_2.fastq.gz | Fastqsanger.gz | |||
| SRR29024601_1.fastq.gz | Fastqsanger.gz | |||
| SRR29024601_2.fastq.gz | Fastqsanger.gz | |||
| SRR29024602_1.fastq.gz | Fastqsanger.gz |
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Project description:Ovarian cancer, a significant contributor to cancer-related mortality, often exhibits limited responsiveness to hormonal therapies targeting the estrogen receptor (ESR1). This study aimed to elucidate the mechanisms behind ESR1 resistance to the therapeutic drug Fulvestrant (ICI182780 or ICI). We identified a 1.3MDa Megacomplex comprising ESR1, FOXA1, and PITX1 using size exclusion chromatography. These factors showed colocalized binding at 6,775 genomic positions in the ovarian cancer cell line, PEO4, including important super-enhancers. Notably, compared to the cytoplasmic version, nuclear ESR1 was minimally degraded by ICI, suggesting a mechanism for drug resistance via the protective confines of the Megacomplex. Combining a small molecule inhibitor of active chromatin and super-enhancers, JQ1, with ICI significantly enhanced ESR1 degradation, especially within the Megacomplex. Molecular analysis showed that this combination disrupted the cyto-nuclear ESR1 shuttling responsible for tumor cell proliferation. Pathway enrichment analysis of RNAseq gene sets following Estradiol, ICI, or ICI plus JQ1 treatments paralleled pathway enrichment found from target genes of Megacomplex binding identified through ChIPseq. Mass-spec analysis revealed that proteins within the Megacomplex macromolecule also produced similar pathway enrichments after modulation by Estradiol or ICI. Each of these findings independently implicates Megacomplex in ESR1-driven ovarian cancer chromatin regulation. Moreover, this combined treatment strategy exhibited superior inhibition of cell proliferation and viability compared to ICI alone. Other cell lines, PEO1, OVCAR4, OVCAR8, and the normal ovarian cell line, T1074, substantiated the specificity of the response. By uncovering ESR1's resistance within the Megacomplex, the combined ICI plus JQ1 treatment elucidates a novel drug treatment vulnerability.
2025-05-15 | GSE267459 | GEO
Project description:The goal of the study was to understand whether mutations in ERa can promote resistance to various ERa antagonists of the SERD and SERM class. We found that ESR1 mutations can maintain higher ER pathway activity relative to control lines following short-term treatment with ERa antagonists raloxifene or fulvestrant.
2018-06-12 | GSE115564 | GEO
Project description:Estrogens have been shown to elicit anti-cancer effects against estrogen receptor alpha (ER)-positive breast cancer. We sought to determine the underlying mechanism of therapeutic response. Response to 17b-estradiol was assessed in ER+ breast cancer models with resistance to estrogen deprivation: WHIM16 patient-derived xenografts, C7-2-HI and C4-HI murine mammary adenocarcinomas, and long-term estrogen-deprived MCF-7 cells. As another means to reactivate ER, the anti-estrogen fulvestrant was withdrawn from fulvestrant-resistant MCF-7 cells. Transcriptional, growth, apoptosis, and molecular alterations in response to ER reactivation were measured. 17b-estradiol treatment and fulvestrant withdrawal induced transcriptional activation of ER, and cells adapted to estrogen deprivation or fulvestrant were hypersensitive to 17b-estradiol. ER transcriptional response was followed by an unfolded protein response and apoptosis. Such apoptosis was dependent upon the unfolded protein response, p53, and JNK signaling. Anti-cancer effects were most evident in models exhibiting genomic amplification of the gene encoding ER (ESR1), suggesting that engagement of ER at high levels is cytotoxic. These data indicate that long-term adaptation to estrogen deprivation or ER inhibition alters sensitivity to ER reactivation. In such adapted cells, 17b-estradiol treatment and anti-estrogen withdrawal hyperactivate ER, which drives an unfolded protein response activation and subsequent growth inhibition and apoptosis. 17b-estradiol treatment should be considered as an alternative therapy for anti-estrogen-resistant disease, particularly in patients with tumors harboring ESR1 amplification or overexpression. Furthermore, therapeutic strategies that enhance an unfolded protein response may enhance the therapeutic effects of ER reactivation.
2019-08-19 | GSE121379 | GEO
Project description:The estrogen receptor (ER) is a well-established target for the treatment of breast cancer, with the majority of patients presenting as ER-positive (ER+). Endocrine therapy is a mainstay of breast cancer treatment but the development of resistance mutations in response to aromatase inhibitors, poor pharmacokinetic properties of fulvestrant, agonist activity of tamoxifen, and limited benefit for elacestrant leave unmet needs for patients with or without resistance mutations in ESR1, the gene that encodes the ER protein. Here we describe OP-1250, a novel, orally bioavailable complete ER antagonist and selective ER degrader. OP-1250, like fulvestrant, has no agonist activity on the ER and completely blocks estrogen-induced transcriptional activity. In addition, OP-1250 demonstrates favorable biochemical binding affinity, ER degradation, and antiproliferative activity in ER+ breast cancer models that is comparable or superior to other agents of interest. OP-1250 has superior pharmacokinetic properties relative to fulvestrant, including oral bioavailability and brain penetrance, as well as superior performance in wild-type and ESR1-mutant breast cancer xenograft studies. OP-1250 combines well with cyclin-dependent kinase 4 and 6 inhibitors in xenograft studies of ER+ breast cancer models and effectively shrinks intracranially implanted tumors, resulting in prolonged animal survival. With demonstrated preclinical efficacy exceeding fulvestrant in wild-type models, elacestrant in ESR1-mutant models, and tamoxifen in intracranial xenografts, OP-1250 has the potential to benefit patients with ER+ breast cancer.
2023-09-01 | GSE241764 | GEO
Project description:Purpose: Resistance to endocrine therapy in estrogen receptor-positive (ER+) breast cancer remains a major clinical problem. Recently, the CDK4/6 inhibitor palbociclib combined with letrozole was approved for treatment of ER+ advanced breast cancer, and other CDK4/6 inhibitors are being investigated in combination with different endocrine treatments. However, the role of CDK4/6 in endocrine resistance and their potential as predictive biomarkers of endocrine treatment response remains undefined. Experimental Design: We investigated the specific role of increased CDK6 expression in fulvestrant-resistant cells by gene knockdown and treatment with palbociclib, and evaluated the effect in cell proliferation, apoptosis and kinase activity. Furthermore, we evaluated CDK6 expression in metastatic samples from breast cancer patients treated or not with fulvestrant. Results: We found increased expression of CDK6 in two fulvestrant-resistant cell models vs. sensitive cells. Reduction of CDK6 expression impaired fulvestrant-resistant cell growth and induced apoptosis by reducing p70 ribosomal S6 kinase 2 activity. Treatment with palbociclib re-sensitized fulvestrant-resistant cells to fulvestrant through alteration of retinoblastoma phosphorylation. High CDK6 levels in metastatic samples from breast cancer patients treated with fulvestrant (N=45) correlated significantly with shorter progression-free survival (PFS) (p=0.0006), while no association was observed in patients receiving other endocrine treatments (N=41, p=0.874). Conclusions: Our results indicate that upregulation of CDK6 may be an important mechanism in overcoming fulvestrant-mediated growth inhibition in breast cancer cells. Patients with advanced ER+ breast cancer exhibiting high CDK6 expression in the metastatic lesions show shorter PFS upon fulvestrant treatment and thus may benefit from the addition of CDK4/6 inhibitors in their therapeutic regimens.
2017-02-08 | GSE74391 | GEO
Project description:It has previously been shown that FOXL2 and ESR1 cooperate to repress the testis-determining gene Sox9 in murine granulosa cells, and suggested that FOXL2/ESR1 cooperation may be central to granulosa cell differentiation (Uhlenhaut et al., 2009). However, no study has so far compared the DNA-binding of FOXL2 and ESR1 at the genomic level or analyzed the impact of FOXL2 on ESR1 binding to its regulatory elements. Here, we have analyzed and compared the genomic locations recognized by ESR1 and FOXL2 in E2-treated primary murine granulosa cells. Input DNA, FOXL2 and ESR1 ChIP
2015-07-01 | E-GEOD-62545 | biostudies-arrayexpress
Project description:We carried out a comparative study of the orally bioavailable investigational SERD elacestrant, versus fulvestrant, in models of endocrine sensitive and resistant BC harbouring varying genetic backgrounds. Both drugs showed comparable effects on tumour growth of ER+ patient-derived xenograft models harbouring several ESR1 mutations and elacestrant showed activity after acquired resistance to fulvestrant. Treatment with either drug showed similar impact on ER-cistrome, ER- interactome and suppression of estrogen-regulated genes, confirming the anti-estrogenic activity of elacestrant.
2022-08-01 | GSE190384 | GEO
Project description:We carried out a comparative study of the orally bioavailable investigational SERD elacestrant, versus fulvestrant, in models of endocrine sensitive and resistant BC harbouring varying genetic backgrounds. Both drugs showed comparable effects on tumour growth of ER+ patient-derived xenograft models harbouring several ESR1 mutations and elacestrant showed activity after acquired resistance to fulvestrant. Treatment with either drug showed similar impact on ER-cistrome, ER- interactome and suppression of estrogen-regulated genes, confirming the anti-estrogenic activity of elacestrant.
2022-08-01 | GSE190385 | GEO
Project description:It has previously been shown that FOXL2 and ESR1 cooperate to repress the testis-determining gene Sox9 in murine granulosa cells, and suggested that FOXL2/ESR1 cooperation may be central to granulosa cell differentiation (Uhlenhaut et al., 2009). However, no study has so far compared the DNA-binding of FOXL2 and ESR1 at the genomic level or analyzed the impact of FOXL2 on ESR1 binding to its regulatory elements. Here, we have analyzed and compared the genomic locations recognized by ESR1 and FOXL2 in E2-treated primary murine granulosa cells.
2015-07-01 | GSE62545 | GEO
Project description:Fulvestrant withdrawal from fulvestrant-resistant MCF-7/FR cells
| PRJNA497213 | ENA