A Preclinical Model for ERα-Positive Breast Cancer Points to the Epithelial Microenvironment as Determinant of Luminal Phenotype and Hormone Response [BT20 & HCC1806]
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE74608 | GEO | 2016/03/03
SECONDARY ACCESSION(S): PRJNA300954
REPOSITORIES: GEO
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Project description:A high percentage of potential oncology drugs fail in clinical trials, partly because preclinical models used to test them are inadequate. Breast cancer is the leading cause of cancer-related death among women worldwide but we lack appropriate in vivo models for the ER+ subtypes, which represent more than 75% of all cases. We address these issues by xenografting tumor cells to their site of origin, the milk ducts. All ER+ cell lines and patient-derived xenografts grow mimicking their clinical counterparts. Disease progresses with invasion and metastasis, which become amenable to study. The action of hormones, important in breast carcinogenesis, can now be studied in a relevant context. Importantly, these open opportunities for development and evaluation of therapies.
2016-03-03 | GSE68694 | GEO
Project description:A high percentage of potential oncology drugs fail in clinical trials, partly because preclinical models used to test them are inadequate. Breast cancer is the leading cause of cancer-related death among women worldwide but we lack appropriate in vivo models for the ER+ subtypes, which represent more than 75% of all cases. We address these issues by xenografting tumor cells to their site of origin, the milk ducts. All ER+ cell lines and patient-derived xenografts grow mimicking their clinical counterparts. Disease progresses with invasion and metastasis, which become amenable to study. The action of hormones, important in breast carcinogenesis, can now be studied in a relevant context. Importantly, these open opportunities for development and evaluation of therapies. Eight- to twelve-week-old female SCID Beige mice (Charles River) were injected with 5x10e5 BT20-GFP/luc2 cells (n=3) or 5x10e5 HCC1806-GFP/luc2 cells (n=3) either into the mammary fat pad or 2x10e5 BT20-GFP/luc2 cells (n=3) or 2x10e5 HCC1806-GFP/luc2 cells intraductally (n=3). Xenografted BT20 and HCC1806 basal breast cancer cells were sorted by FACS based on GFP expression; total RNA was extracted using Trizol Reagent (Invitrogen), purified with the miRNeasy Mini Kit (Qiagen), quantity and quality were assessed by NanoDrop®ND-1000 spectrophotometer and RNA 6000 NanoChips with the Agilent 2100 Bioanalyzer (Agilent, Palo Alto, USA). Only samples with RIN score >7.0 were included. For each sample, 300 ng of total RNA were amplified using the message amp II enhanced kit (AM1791, Ambion). 12.5 μg of biotin-labelled cRNA were chemically fragmented. Affymetrix GeneChip Human Genome U133A 2.0 Arrays (Affymetrix, Santa Clara, CA, USA) were hybridized with 11μg of fragmented target, at 45°C for 17 hours, washed and stained according to Affymetrix GeneChip® Expression Analysis Manual (Fluidics protocol FS450_0007). Arrays were scanned using the GeneChip® Scanner 3000 7G (Affymetrix) and raw data was extracted from the scanned images and analyzed with the Affymetrix Power Tools software package (Affymetrix). All statistical analyses were performed using R and Bioconductor packages (http://www.Bioconductor.org). Hybridization quality was assessed using the Expression Console software (Affymetrix). Normalized expression signals were calculated from Affymetrix CEL files using RMA. Differential hybridized features were identified using Bioconductor package â??limmaâ?? that implements linear models for microarray data (Smyth, 2004). P values were adjusted for multiple testing with Benjamini and Hochbergâ??s method to control false discovery rate (FDR) (Benjamini et al., 2001). Probe sets showing â?¥2-fold change and a FDR â?¤0.05 were considered significant.
2016-03-03 | E-GEOD-74608 | biostudies-arrayexpress
Project description:A high percentage of potential oncology drugs fail in clinical trials, partly because preclinical models used to test them are inadequate. Breast cancer is the leading cause of cancer-related death among women worldwide but we lack appropriate in vivo models for the ER+ subtypes, which represent more than 75% of all cases. We address these issues by xenografting tumor cells to their site of origin, the milk ducts. All ER+ cell lines and patient-derived xenografts grow mimicking their clinical counterparts. Disease progresses with invasion and metastasis, which become amenable to study. The action of hormones, important in breast carcinogenesis, can now be studied in a relevant context. Importantly, these open opportunities for development and evaluation of therapies. Eight- to twelve-week-old female SCID Beige mice (Charles River) were injected with 2x10e5 MCF7-DsRed/luc2 cells (n=3) either into the mammary fat pad or 5x10e4 MCF7-DsRed/luc2 cells intraductally (n=3). Xenografted MCF7 were FACS sorting based on DsRed expression; total RNA was extracted using Trizol Reagent (Invitrogen), purified with the miRNeasy Mini Kit (Qiagen), quantity and quality were assessed by NanoDrop®ND-1000 spectrophotometer and RNA 6000 NanoChips with the Agilent 2100 Bioanalyzer (Agilent, Palo Alto, USA). Only samples with RIN score >7.0 were included. For each sample, 300 ng of total RNA were amplified using the message amp II enhanced kit (AM1791, Ambion). 12.5 μg of biotin-labelled cRNA were chemically fragmented. Affymetrix GeneChip Human Genome U133A 2.0 Arrays (Affymetrix, Santa Clara, CA, USA) were hybridized with 11μg of fragmented target, at 45°C for 17 hours, washed and stained according to Affymetrix GeneChip® Expression Analysis Manual (Fluidics protocol FS450_0007). Arrays were scanned using the GeneChip Scanner 3000 7G (Affymetrix) and raw data was extracted from the scanned images and analyzed with the Affymetrix Power Tools software package (Affymetrix). All statistical analyses were performed using R and Bioconductor packages (http://www.Bioconductor.org). Hybridization quality was assessed using the Expression Console software (Affymetrix). Normalized expression signals were calculated from Affymetrix CEL files using RMA. Differential hybridized features were identified using Bioconductor package âlimmaâ that implements linear models for microarray data (Smyth, 2004). P values were adjusted for multiple testing with Benjamini and Hochbergâs method to control false discovery rate (FDR) (Benjamini et al., 2001). Probe sets showing â¥2-fold change and a FDR â¤0.05 were considered significant.
2016-03-03 | E-GEOD-68694 | biostudies-arrayexpress
Project description:A critical mechanism that has been proposed for transcription regulation by estrogen receptor α (ER) is the tethering of ER to DNA via other transcription factors, such as AP-1. However, genome-wide assessment of the overlap in chromatin binding repertoires of these two transcription factors has not been reported. Here, we show that the AP-1 transcription factor c-Jun interacts with ER and that c-Jun chromatin binding shows extensive overlap with ER binding at the global level. Further, we show that c-Jun overexpression reprograms ER chromatin binding and modulates ER-mediated gene regulation. Our data are consistent with a mechanism where estrogen/ER-dependent crosstalk with AP-1 at the transcriptional level is mediated through the tethering of ER to DNA bound AP-1. Additionally, in our system c-Jun overexpression causes reduced sensitivity to tamoxifen in ER+ breast cancer cells. Integrated cistrome, transcriptome, and clinical data reveal TGFBI as a candidate gene which may confer tamoxifen resistance by ER and AP-1 crosstalk. Further, we show that TGFBI expression is elevated in breast cancer compared to normal breast. Together, our data provide a novel genome-wide footprint of ER and AP-1 crosstalk and suggest AP-1 and TGFBI signaling as potential therapeutic targets in AP-1-overexpressing ER-positive breast tumors.
2018-03-02 | GSE102367 | GEO
Project description:Estrogen receptor positive breast cancer is the most prevalent form of breast cancer. Although a number of available drugs are highly effective at blocking estrogen mediated receptor activity, thousands of patients die every year from ER positive breast cancers because the disease progresses to a stage at which these drugs are no longer effective. Thus, it is crucial to establish a comprehensive understanding of the biology of the estrogen receptor (ER) in ER:positive breast cancers that progress despite hormone therapy, a gap in knowledge that remains a serious impediment to successful treatment of patients with ER positive breast cancer. A key question that must be answered is how the estrogen receptor retains the capacity to activate transcription in the absence or near absence of estrogen. We have found a partial answer to this question upon investigating the effect of amplification and overexpression of Wolf Hirschhorn Syndrome Candidate 1:Like 1 (WHSC1L1), a gene that is amplified in 15% of breast cancers that codes for a histone:lysine methyltransferase. WHSC1L1 lies in the 8p11:p12 amplicon, a region of gene amplification that is strongly associated with breast cancer. In this study, we performed shRNA knockdown of the catalytically inactive short isoform of WHSC1L1 in SUM44PE breast cancer cells and found that expression of the short isoform of WHSC1L1 is necessary for expression of the estrogen receptor in this highly ER:positive cell line. In addition, we found that the estrogen receptor binds chromatin extensively in the absence of exogenous estrogen, including several actively transcribed canonical ER target genes, indicating that estrogen receptor signaling is active in SUM44 cells in estrogen free conditions. These findings represent a novel model for ER biology in luminal B breast cancers harboring amplification of WHSC1L1 and provide insight into the mechanisms by which ER: positive breast cancers become unresponsive to SERMs or aromatase inhibitors.
2016-05-07 | E-MTAB-3739 | biostudies-arrayexpress
Project description:A critical mechanism for transcription regulation by estrogen receptor α (ER) is the tethering of ER to DNA via other transcription factors, such as AP-1. However, genome-wide assessment of the overlap in chromatin binding repertoires of these two transcription factors has not been reported. Here, we show that the AP-1 transcription factor c-Jun interacts with ER and is recruited globally to ER binding regions. Interestingly, we identify differential motif enrichment between unique ER binding regions and unique c-Jun binding regions, with FoxA1 motif enriched in both sets of binding regions, whereas GATA3 motif only specifically enriched in the unique ER binding regions but not in the unique Jun binding regions. We demonstrate that the primary mechanism for estrogen/ER-dependent transcriptional responses is the tethering of ER to DNA under conditions where it cooperates with AP-1. We provide evidence that c-Jun overexpression causes reduced sensitivity to tamoxifen in ER+ breast cancer cells. Integrated omics data reveal TGFBI as one of the most perturbed genes regulated by c-Jun. TGFBI knockdown suppresses the growth of breast cancer cells and is critical for increasing the sensitivity of tamoxifen-resistant cells to tamoxifen. We show that TGFBI expression is elevated in breast cancer than in normal breast and the basal-like tumors express high levels of TGFBI. TGFBI expression is associated with poor patient survival in ER+ breast cancer receiving endocrine therapy, highlighting a role of AP-1 via TGFBI signaling as a major determinant of endocrine response in ER+ breast tumor.
2018-03-02 | GSE102410 | GEO
Project description:Estrogen Receptor alpha (ERα)-positive, HER2-negative breast cancers are less aggressive than other subtypes and generally show good patient clinical outcome because they are likely to respond to endocrine therapies. Unfortunately, therapy-resistant metastases may develop and start an inexorable downhill course. ESR1 mutations leading to ligand-independent ERa activation and resistance to endocrine therapy are prevalent in 20 - 55% of patients with ER+ metastatic breast cancer. Here, we found that glucocorticoid receptor (GR) activation by dexamethasone in ESR1 mutant metastases-bearing mice decreases liver metastases, enhances chemotherapy responsiveness, and prolongs survival. Transcriptomic profiling and proteomics profiling revealed that GR activation not only downregulates estrogen reponse signature but also induces dramatic loss of ER itself, therefore uncovering an estrogen receptor silencing action of GR. ChIP-Seq analysis revealed that prolonged Dex treatment almost completely abrogates ER chromatin binding and that GR binds a subset of ER-related genes including ESR1 itself. This was accompanied by loss of H3K27 acetylation and enhancer acetylation, hence inhibiting transcription. Finally, we found that GR activation in patient-derived organoids reduces the number of ER+ cancer cells and ERα abundance, and predicts good outcome in patients with ER+ breast cancer, using publicly available data. These data imply that administration of synthetic glucocorticoids reduces ER+ cell proliferation, inhibits metastatic ability, enhances chemotherapy efficacy and hence can be beneficial for patients with ER+ metastatic breast cancer, particularly the treatment of refractory ESR1 mutant metastases.
2025-10-15 | GSE286891 | GEO
Project description:Estrogen Receptor alpha (ERα)-positive, HER2-negative breast cancers are less aggressive than other subtypes and generally show good patient clinical outcome because they are likely to respond to endocrine therapies. Unfortunately, therapy-resistant metastases may develop and start an inexorable downhill course. ESR1 mutations leading to ligand-independent ERa activation and resistance to endocrine therapy are prevalent in 20 - 55% of patients with ER+ metastatic breast cancer. Here, we found that glucocorticoid receptor (GR) activation by dexamethasone in ESR1 mutant metastases-bearing mice decreases liver metastases, enhances chemotherapy responsiveness, and prolongs survival. Transcriptomic profiling and proteomics profiling revealed that GR activation not only downregulates estrogen reponse signature but also induces dramatic loss of ER itself, therefore uncovering an estrogen receptor silencing action of GR. ChIP-Seq analysis revealed that prolonged Dex treatment almost completely abrogates ER chromatin binding and that GR binds a subset of ER-related genes including ESR1 itself. This was accompanied by loss of H3K27 acetylation and enhancer acetylation, hence inhibiting transcription. Finally, we found that GR activation in patient-derived organoids reduces the number of ER+ cancer cells and ERα abundance, and predicts good outcome in patients with ER+ breast cancer, using publicly available data. These data imply that administration of synthetic glucocorticoids reduces ER+ cell proliferation, inhibits metastatic ability, enhances chemotherapy efficacy and hence can be beneficial for patients with ER+ metastatic breast cancer, particularly the treatment of refractory ESR1 mutant metastases.
2025-10-15 | GSE286890 | 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 | 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