Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA102769 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Purpose: A number of microarray studies have reported distinct molecular profiles of breast cancers (BC): basal-like, ErbB2-like and two to three luminal-like subtypes. These were associated with different clinical outcomes. However, although the basal and the ErbB2 subtypes are repeatedly recognized, identification of estrogen receptor (ER)-positive subtypes has been inconsistent. Refinement of their molecular definition is therefore needed. Materials and methods: We have previously reported a gene-expression grade index (GGI) which defines histological grade based on gene expression profiles. Using this algorithm, we assigned ER-positive BC to either high or low genomic grade subgroups and compared these to previously reported ER-positive molecular classifications. As further validation, we classified 666 ER-positive samples into subtypes and assessed their clinical outcome. Results: Two ER-positive molecular subgroups (high and low genomic grade) could be defined using the GGI. Despite tracking a single biological pathway, these were highly comparable to the previously described luminal A and B classification and significantly correlated to the risk groups produced using the 21-gene recurrence score. The two subtypes were associated with statistically distinct clinical outcome in both systemically untreated and tamoxifen-treated populations. Conclusions: The use of genomic grade can identify two clinically distinct ER-positive molecular subtypes in a simple and highly reproducible manner across multiple datasets. This study emphasizes the important role of proliferation-related genes in predicting prognosis in ER-positive BC. Experiment Overall Design: dataset of microarray experiments from primary breast tumors used to assess the reationship between GGI, molecular subtypes, and tamoxifen resistance. Experiment Overall Design: No replicate, no reference sample.
2008-06-20 | E-GEOD-6532 | biostudies-arrayexpress
Project description:Gene expression profiling of invasive breast cancer events from the tamoxifen prevention trial validates low estrogen receptor mRNA level as the main determinant of tamoxifen resistance in estrogen receptor positive breast cancer. In NSABP Breast Cancer Prevention Trial (BCPT), tamoxifen reduced the incidence of estrogen receptor (ER) positive tumors but not estrogen receptor negative breast cancer. More importantly, only 69% of estrogen receptor positive tumors were prevented by tamoxifen. The ER positive tumors arising in tamoxifen arm provides an ideal clinical model for acquired tamoxifen resistance. Based on data from NSABP trial B14 which showed linear prediction of the degree of benefit from adjuvant tamoxifen by the levels of ESR1 mRNA coding for ER-alpha, we hypothesized a priori that level of ESR1 mRNA would be lower in ER positive tumors arising in tamoxifen arm compared to those in placebo arm of BCPT. Keywords: Gene expression profiling analysis
2011-12-08 | GSE12665 | GEO
Project description:Tamoxifen is an anti-estrogen drug used in the treatment of Estrogen Receptor (ER) positive breast cancer. Effects and side effects of tamoxifen is the sum of tamoxifen and all its metabolites. Using concentrations that mimic the clinical situation we examined effects of 4OHtam, 4OHNDtam and NDtam on global gene expression in 17beta-estradiol (E2) treated MCF-7 cells.
2014-10-24 | E-MTAB-2729 | biostudies-arrayexpress
Project description:Gene expression profiling of invasive breast cancer events from the tamoxifen prevention trial validates low estrogen receptor mRNA level as the main determinant of tamoxifen resistance in estrogen receptor positive breast cancer. In NSABP Breast Cancer Prevention Trial (BCPT), tamoxifen reduced the incidence of estrogen receptor (ER) positive tumors but not estrogen receptor negative breast cancer. More importantly, only 69% of estrogen receptor positive tumors were prevented by tamoxifen. The ER positive tumors arising in tamoxifen arm provides an ideal clinical model for acquired tamoxifen resistance. Based on data from NSABP trial B14 which showed linear prediction of the degree of benefit from adjuvant tamoxifen by the levels of ESR1 mRNA coding for ER-alpha, we hypothesized a priori that level of ESR1 mRNA would be lower in ER positive tumors arising in tamoxifen arm compared to those in placebo arm of BCPT. Keywords: Gene expression profiling analysis Formalin fixed paraffin embedded tumor blocks with enough tumor tissue for RNA extraction were available from 108 cases (69 from placebo arm and 39 from tamoxifen arm) of the 264 that experienced invasive breast cancer (175 in placebo arm and 89 in tamoxifen arm) in BCPT before unblindings . Central ER immunohistochemistry identified 84 of them as ER positive (57 from placebo arm and 27 from tamoxifen arm). A novel protocol was developed and used to obtain microarray gene expression profiling from the degraded or fragmented RNA extracted from formalin fixed paraffin blocks.Hybridization intensity data were compiled using Partek Genomic Suite. After quantile normalization, genes with mean intensity below 500 were filtred out, which left 7743 probes with informative data. Data were log2 transformed for statistical analysis.
2011-12-08 | E-GEOD-12665 | biostudies-arrayexpress
Project description:56 estrogen receptor positive breast cancer tissues from patients treated with tamoxifen upon recurrence (32 Good outcome vs 24 Poor outcome) have been microdissected to obtain a pure population of epithelial tumor cells. Breast tumor enriched tissues have been sonicated and proteins have been in-solution digested and analyzed via a LTQ-Orbitrap coupled online with a nano-LC system. Thermo output .RAW files were analyzed through MaxQuant (version 1.4.1.2) using the human proteome FASTA (version 2012-09, human canonical proteome) as search library.
2015-08-21 | PXD000484 | Pride
Project description:56 Estrogen Receptor Positive Breast cancer tissues coming from patients treated with tamoxifen upon recurrence (41 Good outcome vs 15 Poor outcome) have been microdissected to enrich for breast cancer tumor cells. Enriched tissue has been lysed and proteins digested and analyzed in an LTQ-Orbitrap coupled online with a Dionex nLC system. Thermo output .RAW files were analyzed through MaxQuant (version 1.4.1.2) using the human proteome FASTA (version 2012-09, human canonical proteome) as search library. LFQ parameters in MaxQuant have been enabled (Fast LFQ) and other settings have been kept as default.
2015-08-21 | PXD000485 | Pride
Project description:Tamoxifen is an effective anti-estrogen treatment for patients with estrogen receptor-positive (ER+) breast cancer. However, about 30% of such patients receiving tamoxifen as an adjuvant therapy experience recurrence within 15 years, and most patients with advanced disease eventually develop resistance to tamoxifen. To elucidate the underlying molecular mechanisms of tamoxifen resistance, we performed a systematic analysis of miRNA-mediated gene regulation in three clinically-relevant tamoxifen-resistant human breast cancer cell lines (TamRs) compared to their parental tamoxifen-sensitive MCF-7/S0.5 cell line. Alterations in the expression of 131 miRNAs in tamoxifen-resistant vs. parental cell lines were identified, 22 of which were common to all TamRs using both sequencing and LNA-based quantitative PCR technologies.
2015-08-01 | GSE56411 | GEO
Project description:The aim of the study is to understand the role of the transcription factor PAX2 in estrogen receptor positive breast cancer cell line by using GRO-seq. MCF-7-PAX2 stable cells were cultured in full media and treated with doxycycline (50ng/ml) for 16 hours to induce overexpression of PAX2. Then cells were treated with 4-OH-tamoxifen (1μM) for 6 hours. All 4 treatments (Veh, Tam, Dox, DoxTam) were performed in duplicates. After treatments, nuclei were isolated and used for nuclear run-on and subsequent GRO-seq library preparation. Libraries were sequenced and data analysis showed that PAX2 could repress estrogen target genes and induce genes enriched in cytokine (TNF-alpha and INF-gamma) related pathways. When combined with tamoxifen, PAX2 could further repress estrogen target genes to a higher degree, and induce genes enriched in p53 related pathway. Moreover, PAX2 could induce the transcription of some intergenic transcripts (potential enhancers) to activate the transcription of nearby genes with could predict good outcome in estrogen receptor positive breast cancer. Overall our finding suggests that PAX2 could benifit ER positive breast cancer by 1) repressing estrogen target genes, and this effect is enhanced by tamoxifen 2) activating cell death/growth arrest related pathways, which is enhanced by potential enhancer transcription induced by PAX2 itself.
2019-11-06 | GSE139928 | GEO
Project description:Adjuvant tamoxifen is a valid treatment option for women with estrogen receptor (ER)-positive breast cancer. However, up to 40% of patients experience distant or local recurrence or die. MicroRNAs have been suggested to be important prognosticators in breast cancer. This study aims to identify microRNAs with the potential to predict tamoxifen response. We performed a global microRNA screen in primary tumours of six matched pairs of postmenopausal, ER-positive breast cancer patients treated with tamoxifen, who were either recurrence free or had developed a recurrence. Patients were treated at the Robert Bosch Hospital, Stuttgart, Germany, between 1986 and 2005.
2014-07-01 | GSE46823 | GEO
Project description:A specific form of endometrial cancer (EC) can develop in breast cancer patients previously treated with tamoxifen (ET), an antagonist of estrogen receptor (ER) α that inhibits proliferation of ER positive breast cancer. ET tumors have a different phenotype than endometrial tumors which typically develop de novo without previous exposure to tamoxifen (EN). Here we aimed to identify specific protein markers that could serve as specific molecular targets in either phenotype. A set of total 45 formalin-fixed paraffin-embedded (FFPE) endometrial tumor tissue and adjacent myometrial tissue samples were analyzed using LC-MS/MS in SWATH-MS mode. We found that calcyphosin (CAPS) levels were elevated in EN tumors compared to ET tumors. The higher CAPS level in EC tissue invading to myometrium support its relationship to EC aggressiveness. Further, stathmin (STMN1) levels were found significantly elevated in ET vs. EN tumors and significantly associated with patient survival. This finding connects elevated levels of this cell cycle regulating, proliferation-associated protein with tamoxifen exposure. In a summary, using SWATH-MS we show that CAPS and STMN1 should be recognized as clinicopathologically different EC markers of which STMN1 is specifically connected with a previous tamoxifen exposition.
2020-05-05 | PXD017217 | Pride