NGS data of ER+/HER2- breast carcinoma patients
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PROVIDER: PRJEB58369 | ENA |
REPOSITORIES: ENA
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Project description:Hormones and growth factors accelerate cell proliferation of breast cancer cells, and these molecules are well investigated targets for drug development and application. The mechanisms of cell proliferation of breast cancers lacking estrogen receptor (ER) and HER2 have not been fully understood. The purpose of the present study is to find genes that are differentially expressed in breast cancers and that might significantly contribute to cell proliferation in these cancers. Forty tumor samples, consisting of ten each of immunohistochemically ER(+)/HER2(-), ER(+)/HER2(+), ER(-)/HER2(+), and ER(-)/HER2(-) cancer were analyzed using oligonucleotide microarrays. Both genes and tumor samples were subjected to hierarchical clustering. ER(+)/HER2(-) breast cancers and ER(-)/HER2(-) cancers tended to form a tumor cluster, but HER2 positive breast cancers were split into different tumor clusters. Significant differential expression between IHC-ER(-)/HER2(-) and other tumors was defined as having an expression level at least 2-fold higher or 2-fold lower, and analyzed by multi-step two-way ANOVA. Genes overexpressed differently in IHC-ER(-)/HER2(-) breast cancers compared to other all three types were 8 genes (FABP7, GABRP, GAL, CXCL13, CDC42EP4, C2F, FOXM1, CSDA), and underexpressed genes were nine including ITGB5, KIAA0310, MAGED2, PRSS11, SORL1, TGFB3, KRT18, CPE, BCAS1. No gene was directly related to cell proliferation such as cyclins, cyclin-dependent kinase, p53, p16, and the pRb and p21 families. We had a particular focus on a transcriptional factor E2F-5 from a list of genes overexpressed in ER negative breast cancers compared to ER positive breast cancers, and further examined. Gene amplification of E2F-5 was detected in 5/57 (8.8%) in breast cancers by FISH. No point mutation was found at the binding domain with DNA or dimerization partner of E2F-5. Immunohistochemically E2F-5 positive cancers were more frequent in ER(-)/HER2(-) cancer (14/27, 51.9%) than in other types of cancer (5/30, 16.7%) (p=0.05). E2F-5 positive cancers had higher Ki-67 labeling index (59.5%) than E2F-5 negative cancers (36.3%). E2F-5 positive cancers showed higher histological grade including metaplastic carcinoma, and worse clinical outcome with shorter disease free survival in node negative patients. In conclusion, we demonstrated that there is a population of breast cancer with overexpression of a cell cycle related transcriptional factor E2F-5. E2F-5 positive breast cancers were frequent in ER(-)/HER2(-) group with high Ki-67 labeling index, high histological grade and worse clinical outcome. Keywords: immunohistochemical phenotype
2009-03-14 | GSE6367 | GEO
Project description:Diagnostic samples from female breast cancer patients with ER-positive and HER2-normal tumors selected for neoadjuvant chemotehrapy.
2023-05-09 | GSE231629 | GEO
Project description:Hormone receptor (HR)-positive, HER2-positive breast cancers often develop resistance to endocrine and anti-HER2 therapies due to the heterogeneous expression of estrogen receptor (ER) and HER2 and the crosstalk of these growth-promoting pathways. However, how anti-HER2 agents activate ER and other growth-promoting pathways remains unknown. Single-cell RNA sequencing of BT474 breast cancer cells identified Bromodomain Containing Protein 8 (BRD8), an acetyl-lysine reader protein in the histone acetylase EP400 complex, as a pivotal mediator to activate ER in response to neratinib treatment. BRD8 expression was rapidly induced by various anti-HER2 agents (neratinib, lapatinib, and trastuzumab), and its depletion disrupted the crosstalk between ER and HER2 signaling pathways and rendered HR+/HER2+ cells and tumor organoids more sensitive to anti-HER2 agents. BRD8, ER, and ER target genes are co-induced by neratinib in single-nucleus (sn) RNA sequencing of a patient-derived xenograft (PDX). Concomitantly, SnATAC-seq reveals that the activated genes share open chromatin regions enriched in transcription factors (TF) binding motifs of ER, forkhead box (FOX), and ETS family. Since EP400 enhances H2AZ deposition and acetylation on chromatin, we performed H2AZ and H2AZac ChIP-sequencing in the presence or absence of BRD8 and neratinib treatment. Upon neratinib treatment, BRD8 activates ER, FOX, and ETS target genes through modulating H2AZac deposition and chromatin decompaction. This finding coincides with RNA-sequencing, where BRD8 promotes cell growth in an ER-dependent and independent manner. In line with these findings, patients who responded poorly to the anti-HER2 therapies exhibited higher BRD8 gene signatures. Furthermore, BRD8 knockdown ablates the ER and HER2 signaling crosstalk and re-sensitizes neratinib-resistant HR+/HER2+ cells to neratinib. Together, this work not only explains why ER signaling is activated upon anti-HER2 therapies but also identifies BRD8 as a druggable vulnerability in HR+/HER2+ breast cancer.
2026-03-19 | GSE286038 | GEO
Project description:Hormone receptor (HR)-positive, HER2-positive breast cancers are resistant to endocrine and anti-HER2 therapies due to crosstalk between estrogen receptor (ER) and HER2. However, how anti-HER2 agents activate ER as a mechanism of resistance remains unknown. Using single-cell RNA sequencing, we identified Bromodomain Containing Protein 8 (BRD8) as a major mediator of ER activation in response to neratinib, a HER2 tyrosine kinase inhibitor. BRD8 expression was rapidly induced by various anti-HER2 agents (neratinib, lapatinib and trastuzumab) and its expression positively correlates with ER. BRD8 regulates both ER-dependent and -independent growth promoting pathways. Moreover, BRD8 ablation re-sensitizes fulvestrant- or neratinib-resistant HR+/HER2+ cells to neratinib, suggesting that combinatorial targeting of BRD8 and HER2 attenuates signal crosstalk and possibly overcomes treatment resistance to dual anti-ER/HER2 blockade therapy. This work identifies BRD8 as not only a central hub for ER signaling activation upon anti-HER2 treatment, but also a druggable vulnerability for treating HR+/HER2+ breast cancer.
2026-03-20 | GSE230327 | GEO
Project description:Hormone receptor (HR)-positive, HER2-positive breast cancers are resistant to endocrine and anti-HER2 therapies due to crosstalk between estrogen receptor (ER) and HER2. However, how anti-HER2 agents activate ER as a mechanism of resistance remains unknown. Using single-cell RNA sequencing, we identified Bromodomain Containing Protein 8 (BRD8) as a major mediator of ER activation in response to neratinib, a HER2 tyrosine kinase inhibitor. BRD8 expression was rapidly induced by various anti-HER2 agents (neratinib, lapatinib and trastuzumab) and its expression positively correlates with ER. BRD8 regulates both ER-dependent and -independent growth promoting pathways. Moreover, BRD8 ablation re-sensitizes fulvestrant- or neratinib-resistant HR+/HER2+ cells to neratinib, suggesting that combinatorial targeting of BRD8 and HER2 attenuates signal crosstalk and possibly overcomes treatment resistance to dual anti-ER/HER2 blockade therapy. This work identifies BRD8 as not only a central hub for ER signaling activation upon anti-HER2 treatment, but also a druggable vulnerability for treating HR+/HER2+ breast cancer.
2026-03-20 | GSE230326 | GEO
Project description:Estrogen receptor positive (ER+) breast cancers that develop resistance to therapies that target the ER are the most common cause of breast cancer death. Beyond mutations in ER, which occur in 25-30% of patients treated with aromatase inhibitors (AIs), our understanding of clinical mechanisms of resistance to ER-directed therapies remains incomplete. We identified activating HER2 mutations in metastatic biopsies from eight patients with ER+ metastatic breast cancer who had developed resistance to ER-directed agents, including AIs, tamoxifen, and fulvestrant. Examination of treatment-naïve primary tumors in five patients revealed no evidence of pre-existing mutations in four of five patients, suggesting that these mutations were acquired under the selective pressure of ER-directed therapy. These mutations were mutually exclusive with ER mutations, suggesting a distinct mechanism of acquired resistance to ER-directed therapies. In vitro analysis confirmed that these mutations conferred estrogen independence. In addition, and in contrast to ER mutations, these mutations resulted in resistance to tamoxifen, fulvestrant, and the CDK4/6 inhibitor palbociclib. Resistance was overcome by combining ER-directed therapy with the irreversible HER2 kinase inhibitor neratinib, highlighting an effective treatment strategy in these patients.
2018-10-19 | GSE121411 | GEO
Project description:Hormone receptor (HR)-positive, HER2-positive breast cancers often develop resistance to endocrine and anti-HER2 therapies due to the heterogeneous expression of estrogen receptor (ER) and HER2 and the crosstalk of these growth-promoting pathways. However, how anti-HER2 agents activate ER and other growth-promoting pathways remains unknown. Single-cell RNA sequencing of BT474 breast cancer cells identified Bromodomain Containing Protein 8 (BRD8), an acetyl-lysine reader protein in the histone acetylase EP400 complex, as a pivotal mediator to activate ER in response to neratinib treatment. Since EP400 enhances H2AZ deposition and acetylation on chromatin, we performed H2AZ and H2AZac ChIP-sequencing in the presence or absence of BRD8 and neratinib treatment. This will help us address how BRD8 regulates ER as well as other growth factors.
2026-03-19 | GSE283036 | GEO
Project description:Acquired HER2 mutations in ER+ metastatic breast cancer confer resistance to ER-directed therapies
| PRJNA497449 | ENA
Project description:Microarray gene expression profiles from female ER-positive HER2-normal breast cancer patients
| PRJNA967036 | ENA
Project description:Background MicroRNA expression is frequently dysregulated in cancer and it could be used potentially as a disease classifier and a prognostic tool in cancer. It has been reported that the cancer associated specific microRNAs were stably detected in blood. The objective of this study was to discover a panel of circulating microRNAs as potential ER+/HER2- breast cancer biomarkers. Methods We compared levels of circulating microRNAs in blood samples from 11 ER+/HER2- advanced breast cancer patients with age-matched 5 control subjects by using microarray-based expression profiling. We validated the level of microRNAs by real-time quantitative polymerase cycle reaction (RT-qPCR) in 40 control subjects, 180 early breast cancer patients (EBC), and 52 metastatic breast cancer patients (MBC). Then, we assessed the association between the levels of microRNA and clinical outcomes of ER+/HER2- metastatic breast cancer. Background MicroRNA expression is frequently dysregulated in cancer and it could be used potentially as a disease classifier and a prognostic tool in cancer. It has been reported that the cancer associated specific microRNAs were stably detected in blood. The objective of this study was to discover a panel of circulating microRNAs as potential ER+/HER2- breast cancer biomarkers. Methods We compared levels of circulating microRNAs in blood samples from 11 ER+/HER2- advanced breast cancer patients with age-matched 5 control subjects by using microarray-based expression profiling. We validated the level of microRNAs by real-time quantitative polymerase cycle reaction (RT-qPCR) in 40 control subjects, 180 early breast cancer patients (EBC), and 52 metastatic breast cancer patients (MBC). Then, we assessed the association between the levels of microRNA and clinical outcomes of ER+/HER2- metastatic breast cancer. Controls: 5 cases; ER +/HER2- breast cancer patients : 11 cases
2013-12-12 | E-GEOD-53179 | biostudies-arrayexpress