Tamoxifen Response at Single Cell Resolution in Estrogen Receptor Positive Primary Human Breast Tumors
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE245601 | GEO | 2023/10/19
REPOSITORIES: GEO
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Project description:MCM3 is one of several genes whose expression profile is markedly altered in tamoxifen-resistant breast cancer cell lines. We observed that increased MCM3 expression is associated with tamoxifen resistance. Knockdown of MCM3 resulted in increased susceptibility of tamoxifen-resistant breast cancer cell lines. Moreover, MCM3 expression is significantly associated with clinical outcome of endocrine treated receptor positive breast cancer. To understand the effect of MCM3 on the mechanism of endocrine resistance, we performed gene expression array on tamoxifen-resistant breast cancer cell lines. Here we show that MCM3 knockdown affects the expression of hundreds of genes. Resistance to endocrine therapy in estrogen receptor-positive (ER+) breast cancer is a major clinical problem with poorly understood mechanisms. There is an unmet need for prognostic and predictive biomarkers to allow appropriate therapeutic targeting. We evaluated the mechanism by which minichromosome maintenance protein 3 (MCM3) influences endocrine resistance and its predictive/prognostic potential in ER+ breast cancer. We discovered that ER+ breast cancer cells survive tamoxifen and letrozole treatments through upregulation of minichromosome maintenance proteins (MCMs), including MCM3, which are key molecules in cell cycle and DNA replication. Lowering MCM3 expression in endocrine-resistant cells restored drug sensitivity and altered phosphorylation of cell cycle regulators, including p53(Ser315,33), CHK1(Ser317) and cdc25b(Ser323), suggesting that the interaction of MCM3 with cell cycle proteins is an important mechanism of overcoming replicative stress and anti-proliferative effects of endocrine treatments. Evaluation of MCM3 levels in primary tumors from four independent cohorts of breast cancer patients receiving adjuvant tamoxifen mono-therapy or no adjuvant treatment, including the Stockholm tamoxifen (STO-3) trial, showed MCM3 to be an independent prognostic adding information beyond Ki67. In addition, MCM3 was shown to be a predictive marker of response to endocrine treatment. Our study reveals a coordinated signaling network centered around MCM3 that limits response to endocrine therapy in ER+ breast cancer and identifies MCM3 as a clinically useful prognostic and predictive biomarker that allows personalized treatment of ER+ breast cancer patients.
2020-11-17 | GSE148878 | GEO
Project description:One of the greatest advances in therapy of estrogen receptor positive breast cancer has been the development of endocrine therapy. More than two thirds of primary breast tumors express estrogen receptor alpha (ERα) and their growth is mainly dependent on estrogen receptor activity. Several therapeutic approaches have thus been designed to inhibit ER activity in breast tissue. Tamoxifen, a selective ER modulator, is one of the main treatment options for premenopausal women with advanced ER positive breast cancer, and has also become well established as adjuvant therapy in the early breast cancer setting (Davies et al., 2011; Group, 1998; Jaiyesimi et al., 1995). In contrast to tamoxifen, which in other tissues such as bone and endometrium, can exert partial agonistic activity (Braithwaite et al., 2003; Fisher et al., 1994; Pietras, 2006), the selective ER downregulator, fulvestrant, is a potent ER antagonist. Binding of fulvestrant to ER inhibits receptor dimerization and nuclear uptake, prevents estrogen-response element binding and accelerates ER degradation (Dauvois et al., 1993; Dowsett et al., 2005; Fawell et al., 1990; Wakeling et al., 1991). Fulvestrant is approved for treatment of postmenopausal women with advanced breast cancer who have relapsed or progressed on first-line endocrine therapy (Howell et al., 2002; Osborne et al., 2002; Robertson et al., 2003). Estrogen deprivation by treatment with aromatase inhibitors (such as letrozole, anastrozole or exemestane) which block synthesis of estrogens is another effective therapy option in postmenopausal women (Bonneterre et al., 2000; Cuzick et al., 2010; Dowsett et al., 2010; Mouridsen et al., 2001; Nabholtz et al., 2000). The large majority of patients with ER+ breast cancer experience an initial response to endocrine therapy, however, in many of these patients, the disease subsequently progresses and eventually anti-estrogen therapy ceases to have effect. Biomarkers predicting response to estrogen deprivation and new alternative treatments targeting the pathways supporting estrogen independent growth are therefore urgently needed (Patani and Martin, 2014; Patani et al., 2013). In order to understand how tumors respond to withdrawal of their main growth signal, a comparison of molecular features of tumor before and during endocrine therapy is necessary, and the fate of individual cancer cell sub-clones should be monitored. Since studies of cellular dynamics are very difficult to perform with clinical material, we made use of a patient derived, estrogen dependent, orthotopically growing luminal-like primary breast cancer xenograft model (PDX) (Bergamaschi et al., 2009; Huuse et al., 2012). This PDX model is a representative model for luminal breast cancers as the molecular characteristics, cellular heterogeneity and estrogen dependency of the primary tumor are retained over many passages. Functionally different subpopulations of cancer cells were previously defined by expression of the markers CD24 and SSEA-4 in this model (Skrbo et al., 2014), and it is therefore a suitable model for comparison of cellular and molecular effects of estrogen deprivation and ER-signaling inhibition. In this study, a quantitative MS-based proteomic analysis using SILAC and a label-free approach were performed, aiming to map changes in protein expression induced by endocrine therapy. Inhibition of ER-signaling seemed to induce CD24 and SSEA-4 expression on residual tumor cells. Proteomic analysis revealed overexpression of enzymes involved in TCA cycle, oxidative phosphorylation and fatty acid beta-oxidation following endocrine treatment when compared to untreated tumors. These results indicated possible reprogramming of cell metabolism and utilization of aerobic respiration, i.e. oxidative phosphorylation, in response to endocrine therapy.
2022-02-28 | PXD002352 | Pride
Project description:Expression of estrogen receptor (ESR1) determines whether a breast cancer patient receives endocrine therapy as part of their adjuvant care, but does not guarantee patient response. However, the molecular factors that define endocrine response in ESR1-positive breast cancer patients remain poorly understood. Here, we characterize the DNA methylome of endocrine sensitivity and demonstrate the potential impact of differential DNA methylation on endocrine response in breast cancer. We show that DNA hypermethylation occurs predominantly at estrogen-responsive enhancers and is associated with reduced ESR1 binding and decreased gene expression of key regulators of ESR1-activity; thus providing a novel mechanism by which endocrine response is abated in ESR1-positive breast cancers. Conversely, we delineate that ESR1-responsive enhancer hypomethylation is critical in transition from normal mammary epithelial cells to endocrine responsive ESR1-positive cancer. Cumulatively these novel insights highlight the potential of ESR1-responsive enhancer methylation to both predict ESR1-positive disease and stratify ESR1-positive breast cancer patients as responders to endocrine therapy. Methylation profiling with Illumina's HumanMethylation450K array was performed on ESR1-positive hormone sensitive MCF7 cells, and three different well characterised endocrine resistant MCF7-derived cell lines; tamoxifen-resistant (TAMR), fulvestrant-resistant (FASR) and estrogen deprivation resistant (MCF7X) cells. For each cell line two biological replicates were profiled bringing the number of samples to eight.
2015-07-01 | E-GEOD-69118 | biostudies-arrayexpress
Project description:Estrogen Receptor-a (ER) is the key feature in the majority of breast cancers and ER binding to the genome correlates with the Forkhead protein FOXA1 (HNF3a), but mechanistic insight is lacking. We now show that FOXA1 is the defining factor that governs differential ER-chromatin interactions. We show that almost all ER-chromatin interactions and gene expression changes are dependent on the presence of FOXA1 and that FOXA1 dictates genome-wide chromatin accessibility. Furthermore, we show that CTCF is an upstream negative regulator of FOXA1-chromatin interactions. In ER responsive breast cancer cells, the dependency on FOXA1 for tamoxifen-ER activity is absolute and in tamoxifen resistant cells, ER binding occurs independently of ligand, but in a FOXA1 dependent manner. Importantly, expression of FOXA1 in non-breast cancer cells is sufficient to alter ER binding and response to endocrine treatment. As such, FOXA1 is the primary determinant that regulates estrogen-ER activity and endocrine response in breast cancer cells and is sufficient to program ER functionality in non-breast cancer contexts. breast cancer MCF-7 cell lines were treaated in the presence of Estrogen, Estrogen plus Tamoxifen, Tamoxifen or a vehicle. MCF-7 cells were hormone-depleted for 3 d and treated with 100 nM estrogen or 1 microM Tamoxifen for 6 h. There were four biological replicates for each of the four different groups.
2010-11-17 | E-GEOD-25314 | biostudies-arrayexpress
Project description:Invasive lobular carcinoma (ILC) is a histological subtype of breast cancer that is frequently associated with favorable outcomes, as ~90% of ILC express the estrogen receptor (ER). However, recent retrospective analyses suggest that ILC patients receiving adjuvant endocrine therapy may not benefit from improved outcomes versus other breast cancer patients. Based on these observations, we characterized ER function and endocrine response in ILC models. The ER-positive ILC cell lines MDA MB 134VI (MM134) and SUM44PE were used to examine the ER-regulated transcriptome in vitro via gene expression microarray analyses and ER ChIP-Seq. In parallel, estrogen response was assessed in vivo in the patient-derived ILC xenograft HCI-013. Response to endocrine therapy was also examined in ILC cell lines. We identified 915 genes that were uniquely E2-regulated in ILC cell lines versus other breast cancer cell lines, and a subset of these genes were also regulated in vivo in HCI-013. We observed that MM134 were de novo tamoxifen resistant, and were induced to grow by 4-hydroxytamoxifen, as well as other anti-estrogens, as partial agonists. Growth was accompanied by agonist activity of tamoxifen on ER-mediated gene expression. Though tamoxifen induced cell growth, MM134 cells required FGFR1 signaling to maintain viability and were sensitive to combined endocrine therapy and FGFR1 inhibition. Our observation that ER drives a unique program of gene expression in ILC cells correlates with the ability of tamoxifen to induce growth in these cells. Targeting growth factors using FGFR1 inhibitors may block survival pathways required by ILC and reverse tamoxifen resistance.
2014-01-16 | GSE50694 | GEO
Project description:Invasive lobular carcinoma (ILC) is a histological subtype of breast cancer that is frequently associated with favorable outcomes, as ~90% of ILC express the estrogen receptor (ER). However, recent retrospective analyses suggest that ILC patients receiving adjuvant endocrine therapy may not benefit from improved outcomes versus other breast cancer patients. Based on these observations, we characterized ER function and endocrine response in ILC models. The ER-positive ILC cell lines MDA MB 134VI (MM134) and SUM44PE were used to examine the ER-regulated transcriptome in vitro via gene expression microarray analyses and ER ChIP-Seq. In parallel, estrogen response was assessed in vivo in the patient-derived ILC xenograft HCI-013. Response to endocrine therapy was also examined in ILC cell lines. We identified 915 genes that were uniquely E2-regulated in ILC cell lines versus other breast cancer cell lines, and a subset of these genes were also regulated in vivo in HCI-013. We observed that MM134 were de novo tamoxifen resistant, and were induced to grow by 4-hydroxytamoxifen, as well as other anti-estrogens, as partial agonists. Growth was accompanied by agonist activity of tamoxifen on ER-mediated gene expression. Though tamoxifen induced cell growth, MM134 cells required FGFR1 signaling to maintain viability and were sensitive to combined endocrine therapy and FGFR1 inhibition. Our observation that ER drives a unique program of gene expression in ILC cells correlates with the ability of tamoxifen to induce growth in these cells. Targeting growth factors using FGFR1 inhibitors may block survival pathways required by ILC and reverse tamoxifen resistance.
2014-01-16 | GSE50693 | GEO
Project description:Estrogen and estrogen receptor (ER) signaling play critical roles in the development of ER-positive breast cancer, and endocrine therapy is the frontline treatment for ER-positive breast cancer patients. However, the primary and acquired resistance to endocrine therapy including tamoxifen and fulvestrant remains as the major challenge in the clinic. Here, we identified an estrogen-induced lncRNA, LINC02568, through transcriptomic analysis, which is highly expressed in ER-positive breast cancer. LINC02568 is functional important in ER-positive breast cancer cell growth in vitro and tumorigenesis in vivo as well as endocrine therapy resistance. Mechanically, we demonstrated that LINC02568 regulates, in trans, estrogen/ERα-induced gene transcriptional activation by sponging miR-1233-5p to stabilize ESR1 mRNA in the cytoplasm. Meanwhile, LINC02568 contributes to tumor-specific pH homeostasis in breast cancer cells by regulating CA12 in cis in the nucleus. The dual functions of LINC02568 together contribute to breast cancer cell growth and tumorigenesis as well as endocrine therapy resistance. Antisense oligonucleotides (ASO) targeting LINC02568 significantly inhibits ER-positive breast cancer cell growth in vitro and tumorigenesis in vivo as well as resensitize tamoxifen-resistant cells to tamoxifen. Furthermore, combination treatment with ASO targeting LINC02568 and tamoxifen exhibits synergistic effect on tumor growth. Taken together, our findings revealed dual mechanisms of LINC02568 in regulating ERα signaling and pH homeostasis in ER-positive breast cancer, and indicated that targeting LINC02568 might represent a potential therapeutic avenue in clinic.
2023-09-13 | GSE217190 | GEO
Project description:We profile the binding of Steroid Receptor Co-activator (SRC1) in LY2 cells, a tamoxifen-resistant cell line, in the presence and absence of tamoxifen using ChIP-sequencing technology. The development of breast cancer resistance to endocrine therapy results from an increase in cellular plasticity leading to the development of a steroid-independent tumour. The p160 steroid coactivataor protein SRC-1, through interactions with developmental proteins and other non-steroidal transcription factors, drives this tumour adaptability. Here, using discovery studies, we identify ADAM22, a non-protease member of the ADAMs family, as a direct, ER-independent target of SRC-1. Molecular, cellular and in vivo studies confirmed SRC-1 as a regulator of ADAM22. At a functional level, a role for ADAM22 in cellular migration and differentiation was observed. In vivo data from a mouse xenograft model indicated that ADAM22 expression was higher in 4-OHT-treated endocrine-resistant tumours than in tumours derived from isogenic, sensitive cells. Furthermore, in breast cancer patients, ADAM22 expression is an independent predictor of poor disease free survival. SRC-1 can function as a molecular switch which converts a steroid-responsive tumour to a steroid-resistant tumour. The ER-independent SRC-1 target ADAM22 is a potential drug target and a companion predictive biomarker in the treatment of endocrine-resistant breast cancer. Examination of SRC-1 binding in LY2 cells in the presence or absence of tamoxifen treatment. 2 replicates each.
2011-11-01 | E-GEOD-28987 | biostudies-arrayexpress
Project description:Estrogen Receptor-a (ER) is the key feature in the majority of breast cancers and ER binding to the genome correlates with the Forkhead protein FOXA1 (HNF3a), but mechanistic insight is lacking. We now show that FOXA1 is the defining factor that governs differential ER-chromatin interactions. We show that almost all ER-chromatin interactions and gene expression changes are dependent on the presence of FOXA1 and that FOXA1 dictates genome-wide chromatin accessibility. Furthermore, we show that CTCF is an upstream negative regulator of FOXA1-chromatin interactions. In ER responsive breast cancer cells, the dependency on FOXA1 for tamoxifen-ER activity is absolute and in tamoxifen resistant cells, ER binding occurs independently of ligand, but in a FOXA1 dependent manner. Importantly, expression of FOXA1 in non-breast cancer cells is sufficient to alter ER binding and response to endocrine treatment. As such, FOXA1 is the primary determinant that regulates estrogen-ER activity and endocrine response in breast cancer cells and is sufficient to program ER functionality in non-breast cancer contexts.
2010-11-17 | GSE25315 | GEO
Project description:Estrogen Receptor-a (ER) is the key feature in the majority of breast cancers and ER binding to the genome correlates with the Forkhead protein FOXA1 (HNF3a), but mechanistic insight is lacking. We now show that FOXA1 is the defining factor that governs differential ER-chromatin interactions. We show that almost all ER-chromatin interactions and gene expression changes are dependent on the presence of FOXA1 and that FOXA1 dictates genome-wide chromatin accessibility. Furthermore, we show that CTCF is an upstream negative regulator of FOXA1-chromatin interactions. In ER responsive breast cancer cells, the dependency on FOXA1 for tamoxifen-ER activity is absolute and in tamoxifen resistant cells, ER binding occurs independently of ligand, but in a FOXA1 dependent manner. Importantly, expression of FOXA1 in non-breast cancer cells is sufficient to alter ER binding and response to endocrine treatment. As such, FOXA1 is the primary determinant that regulates estrogen-ER activity and endocrine response in breast cancer cells and is sufficient to program ER functionality in non-breast cancer contexts.
2010-11-17 | GSE25314 | GEO