Breast cancer / tamoxifen monotherapy (whole tissue tumor biopsies)
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE1379 | GEO | 2004/06/07
SECONDARY ACCESSION(S): PRJNA90165
REPOSITORIES: GEO
Similar Datasets
Project description:dataset of 60 patients with ER-positive primary breast cancer and treated with tamoxifen monotherapy for 5 years. Data were generated from LCMed cancer cells. Sample_keyword: breast cancer, tamoxifen, recurrence Keywords: other
2004-06-07 | GSE1378 | GEO
Project description:Purpose: Despite the benefits of estrogen receptor (ER)-targeted endocrine therapies in breast cancer, many tumors develop resistance. MicroRNAs (miRNAs) have been suggested as promising biomarkers and we here evaluated whether a miRNA profile could be identified, sub-grouping ER+ breast cancer patients treated with adjuvant Tamoxifen with regards to probability of recurrence. Experimental design: Global miRNA analysis was performed on 152 ER+ primary tumors from high-risk breast cancer patients with an initial discovery set of 52 patients, followed by 2 independent test sets (N=60 and N=40). All patients had received adjuvant Tamoxifen as mono-therapy (median clinical follow-up: 4.6 years) and half had developed distant recurrence (median time-to-recurrence: 3.5 years). MiRNA expression was examined by unsupervised hierarchical clustering and supervised analysis, including clinical parameters as co-variables.
2012-04-19 | GSE37405 | 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: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. Total RNA from FFPE tissue from 12 postmenopausal patients with ER-positive breast cancer (6 patients with and 6 patients without recurrence) was extracted. Hybridisation of biotin-labelled RNA was performed on Affymetrix GeneChip miRNA_2.0 Arrays.
2014-07-01 | E-GEOD-46823 | biostudies-arrayexpress
Project description:The beneficial effect of the selective estrogen receptor modulator (SERM) tamoxifen in the treatment and prevention of breast cancer is assumed to be through its ability to antagonize the stimulatory actions of estrogen, although tamoxifen can also have some estrogen-like agonist effects. Here we report that in addition to these mixed agonist/antagonist actions, tamoxifen can also selectively regulate a unique set of more than 60 genes in estrogen receptor alpha (ERa)-positive MCF-7 human breast cancer cells which are minimally regulated by estradiol or raloxifene. This gene regulation by tamoxifen is mediated by ERa and is reversed by estradiol or ICI 182,780. We find that the introduction of ERbeta into MCF-7 cells reverses tamoxifen action on approximately 75% of these genes, suggesting that ERbeta is capable of repressing certain actions of tamoxifen. To examine whether these genes might serve as markers of tamoxifen sensitivity and/or the development of resistance, the expression level of these genes was examined in breast tumors of women who had received treatment with tamoxifen. High expression of two of the tamoxifen stimulated genes, YWHAZ/14-3-3z and LOC441453, was found to correlate significantly with disease recurrence following tamoxifen treatment in women with ER-positive tumors, and hence appear to be markers of a poor prognosis. Our data indicate a new dimension in tamoxifen action, involving gene expression regulation that is tamoxifen-preferential, and identify genes that might serve as markers of tumor responsiveness or resistance to tamoxifen therapy. Keywords: ligand response in two ER backgrounds
2006-07-28 | GSE4025 | GEO
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: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:The beneficial effect of the selective estrogen receptor (ER) modulator tamoxifen in the treatment and prevention of breast cancer is assumed to be through its ability to antagonize the stimulatory actions of estrogen, although tamoxifen can also have some estrogen-like agonist effects. Here, we report that, in addition to these mixed agonist/antagonist actions, tamoxifen can also selectively regulate a unique set of >60 genes, which are minimally regulated by estradiol (E2) or raloxifene in ERalpha-positive MCF-7 human breast cancer cells. This gene regulation by tamoxifen is mediated by ERalpha and reversed by E2 or ICI 182,780. Introduction of ERbeta into MCF-7 cells reverses tamoxifen action on approximately 75% of these genes. To examine whether these genes might serve as markers of tamoxifen sensitivity and/or the development of resistance, their expression level was examined in breast cancers of women who had received adjuvant therapy with tamoxifen. High expression of two of the tamoxifen-stimulated genes, YWHAZ/14-3-3z and LOC441453, was found to correlate significantly with disease recurrence following tamoxifen treatment in women with ER-positive cancers and hence seem to be markers of a poor prognosis. Our data indicate a new dimension in tamoxifen action, involving gene expression regulation that is tamoxifen preferential, and identify genes that might serve as markers of tumor responsiveness or resistance to tamoxifen therapy. This may have a potential effect on the choice of tamoxifen versus aromatase inhibitors as adjuvant endocrine therapy.
2007-10-02 | E-GEOD-4025 | biostudies-arrayexpress
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: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. ER+ and tamoxifen sensitive breast cancer cell line (MCF-7/S0.5) and its derived tamoxifen resistant clones: TAMR-1, TAMR-4 and TAMR-8 were miRNA expression profiled in triplicates of each using Exiqon's miRCURY LNA based microRNA Ready-to-use PCR, Human panel I+II, V2.R (Exiqon, product number 203608).
2015-08-01 | E-GEOD-56411 | biostudies-arrayexpress