Homo sapiens
Ontology highlight
ABSTRACT:
OTHER RELATED OMICS DATASETS IN: E-GEOD-2225
PROVIDER: PRJNA91481 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:MCF-7aro cells were used to generate a cell culture model system that is resistant to 3 aromatase inhibitors (AIs), letrozole, anastrozole and exemestane. For comparison, the MCF-7aro cells were also used to generate the tamoxifen-resistant cells as well as long-term estrogen deprived, LTEDaro. Affymetrix microarray analysis was performed to determine changes in gene expression that are unique to AI-resistance. Experiment Overall Design: For control purposes, MCF-7aro cells were cultured without any hormone or inhibitor as well as a hormone-only control (T-only). Resistant cells were grown in the presence of testosterone, T+LET R (letrozole), T+ANA R (anastrozole), T+EXE R (exemestane), T+TAM R (Tamoxifen). In addition, testosterone-free resistant lines were generated, LTEDaro, ANA R and EXE R. 6 replicates were generated for the hormone-containing resistant lines and 3 replicates for the hormone-free resistant lines.
2008-04-04 | E-GEOD-10911 | biostudies-arrayexpress
Project description:MCF-7aro cells were used to generate a cell culture model system that is resistant to 3 aromatase inhibitors (AIs), letrozole, anastrozole and exemestane. For comparison, the MCF-7aro cells were also used to generate the tamoxifen-resistant cells as well as long-term estrogen deprived, LTEDaro. Affymetrix microarray analysis was performed to determine changes in gene expression that are unique to AI-resistance. Keywords: cell lines, aromatase inhibitor resistance, tamoxifen resistance
2008-03-22 | GSE10911 | GEO
Project description:Resistance to endocrine therapy agents has presented a clinical obstacle in the treatment of hormone-dependent breast cancer. Our laboratory has initiated a study of microRNA regulation of signaling pathways that may result in breast cancer progression on aromatase inhibitors (AI). Microarray analysis of microRNA expression identified 115 significantly regulated microRNAs, of which 49 microRNAs were believed to be hormone-responsive. Within the AI-resistant cells, microRNAs were differentially expressed between the steroidal and non-steroidal AI-resistant lines. Also, a group of microRNAs were inversely expressed in the AI-resistant lines versus LTEDaro and tamoxifen-resistant. We focused our work on hsa-miR-128a which was hormone-responsive and up-regulated in the letrozole-resistant cell lines. Human miR-128a was shown to negatively target TGFBRI protein expression by binding to the 3âUTR region of the gene. Loss of TGFBRI resulted in compromised sensitivity to the growth inhibitory effects of TGFB in the letrozole-resistant lines. Inhibition of endogenous miR-128a resulted in re-sensitization of the letrozole-resistant lines to TGFB growth inhibitory effects. This data suggests that the hormone-responsive miR-128a can modulate TGFB signaling and survival of the letrozole-resistant cell lines. To our knowledge, this is the first study to address the role of microRNA regulation as well as TGFB signaling in AI-resistant breast cancer cell lines. We believe that in addition to estrogen-modulation of gene expression, hormone-regulated microRNAs may provide an additional level of post-transcriptional regulation of signaling pathways critically involved in breast cancer progression and AI-resistance. To look at microRNA expression profiles of breast cancer cell lines derived from MCF-7 cells that are resistant to endocrine therapy agents. MCF-7 cells that overexpress aromatase (MCF-7aro) were cultured long-term in the presence of endocrine therapy agents until cells acquired resistance. Three different aromatase inhibitors (letrozole, anastrozole or exemestane) were used, as well as the ER antagonist tamoxifen, or the hormone-free long-term estrogen deprived cells (LTED). Three replicates of the control cells (MCF-7aro) and all resistant cells were used for microarray experiments. Total of 23 samples were analyzed by microarray.
2010-05-16 | E-GEOD-17775 | biostudies-arrayexpress
Project description:Anti-estrogens and aromatase inhibitors are important drugs in the treatment of estrogen-dependent breast cancer. In order to investigate the effects of these drugs on gene expression in breast cancer cells, we treated estrogen receptor-positive MCF-7 cells, stably transfected with the aromatase gene (known as MCF-7aro cells), with testosterone, 17β-estradiol, two aromatase inhibitors (letrozole and anastrozole), and an anti-estrogen (tamoxifen). Microarray analyses using Affymetrix Human Genome U133A GeneChips were carried out using total RNA isolated from the control and treated cells. When comparing the effect of each inhibitor on gene expression we observe that letrozole and anastrozole are more similar in terms of the genes they affect, compared to treatment with tamoxifen. The results of this study provide us with a better understanding of the actions of both aromatase inhibitors and anti-estrogens at the molecular level. We believe that the results of this study serve as the first step in identifying unique expression patterns following drug treatment, and that this will ultimately be useful in customizing patient treatment strategies for estrogen-dependent breast cancer. The data presented here have been processed using the R-Project Bioconductor statistical tools package using the affy library. The following were applied: RMA background correction, pmonly probe-level correction, quantile normalization, avgdiff summary method. Raw data is provided in the form of .CEL files.
2007-10-27 | E-GEOD-2225 | biostudies-arrayexpress
Project description:Anti-estrogens and aromatase inhibitors are important drugs in the treatment of estrogen-dependent breast cancer. In order to investigate the effects of these drugs on gene expression in breast cancer cells, we treated estrogen receptor-positive MCF-7 cells, stably transfected with the aromatase gene (known as MCF-7aro cells), with testosterone, 17β-estradiol, two aromatase inhibitors (letrozole and anastrozole), and an anti-estrogen (tamoxifen). Microarray analyses using Affymetrix Human Genome U133A GeneChips were carried out using total RNA isolated from the control and treated cells. When comparing the effect of each inhibitor on gene expression we observe that letrozole and anastrozole are more similar in terms of the genes they affect, compared to treatment with tamoxifen. The results of this study provide us with a better understanding of the actions of both aromatase inhibitors and anti-estrogens at the molecular level. We believe that the results of this study serve as the first step in identifying unique expression patterns following drug treatment, and that this will ultimately be useful in customizing patient treatment strategies for estrogen-dependent breast cancer. The data presented here have been processed using the R-Project Bioconductor statistical tools package using the affy library. The following were applied: RMA background correction, pmonly probe-level correction, quantile normalization, avgdiff summary method. Raw data is provided in the form of .CEL files. Keywords = estrogen-dependent breast cancer Keywords = aromatase Keywords: other
2006-02-02 | GSE2225 | GEO
Project description:breast cancer. Combined IGF and estrogen-targeted therapy may improve the benefit of hormonal therapy alone. We employed a postmenopausal model of estrogen-dependent breast cancer in vitro and in vivo using the aromatase-expressing MCF-7/AC-1cells. Using this model, we investigated the anti-tumor effects of the dual IGF-1R/InsR tyrosine kinase inhibitor, BMS-754807 alone and in combination with letrozole or tamoxifen in vivo. We used microarrays to compare gene expression changes of MCF7 breast xenograft treated with either BMS754807, or Tamoxifen or Letrozole alone; or Tamoxifen or Letrozole in combination with BMS754807 for 28 days Breast xenograft MCF7 bearing mice treated with either BMS754807, or Tamoxifen or Letrozole alone; or Tamoxifen or Letrozole in combination with BMS754807 for 28 days. RNA were extracted from tumors and hybridizedon Affymetrix microarrays to compare gene expression changes
2011-11-02 | E-GEOD-33366 | biostudies-arrayexpress
Project description:breast cancer. Combined IGF and estrogen-targeted therapy may improve the benefit of hormonal therapy alone. We employed a postmenopausal model of estrogen-dependent breast cancer in vitro and in vivo using the aromatase-expressing MCF-7/AC-1cells. Using this model, we investigated the anti-tumor effects of the dual IGF-1R/InsR tyrosine kinase inhibitor, BMS-754807 alone and in combination with letrozole or tamoxifen in vivo. We used microarrays to compare gene expression changes of MCF7 breast xenograft treated with either BMS754807, or Tamoxifen or Letrozole alone; or Tamoxifen or Letrozole in combination with BMS754807 for 28 days
2011-11-02 | GSE33366 | GEO
Project description:Background: AZD4547 is a potent and selective inhibitor of FGFR-1, 2 and 3 receptor tyrosine kinases. Phase 1 studies both in Europe and Japan have shown that the compound is well tolerated and shows activity in patients with solid tumours. Here, we hypothesised that AZD4547 could reverse resistance to AIs such as anastrozole and letrozole. Methods: After a safety run-in study in which 6 patients had PK and safety assessments on combined AI plus AZD4547, we recruited 52 eligible patients with metastatic breast cancer who had progressed on treatment with anastrozole or letrozole. The primary objective of the phase lla study was to assess the efficacy of AZD4547 based on the change in tumour size when used in combination with either anastrozole or letrozole in ER positive breast cancer patients who have progressed on treatment with either anastrozole or letrozole in any setting. Results:. According to centrally reviewed RECIST criteria, five partial response (PR) and 8 stable disease (SD) patients were observed from a total of 50 assessable cases, giving a Clinical Benefit Rate (PR + SD) of 26% (95% CI: 14.6-40.3%). RNA-Seq was done on a subset of patients’ samples: 6 differentially-expressed-genes could distinguish those who benefited from the addition of AZD4547. Eleven patients had retinal pigment epithelial detachments (RPEDs) either in one or both eyes which was asymptomatic and reversible, although RPED recurred in one patient on re-treatment. Twenty six (50%) and 7(13%) patients had elevated phosphate and calcium, respectively. Conclusions: in a group of unselected ER positive women with aromatase inhibitor-resistant metastatic breast cancer, FGFR pathway inhibition combined with letrozole or anastrozole provided clinical benefit in a significant proportion of patients with manageable toxicity.
2022-03-18 | GSE198650 | GEO
Project description:The overarching goal of this study was to explore the antitumor activity of Z-endoxifen, a tamoxifen metabolite, with first-line endocrine therapies tamoxifen and letrozole in the letrozole-sensitive MCF7 aromatase expressing model (MCF7AC1), and with second-line endocrine therapies including tamoxifen, fulvestrant, exemestane, and exemestane plus everolimus, in letrozole-resistant MCF7 model (MCF7LR) in vivo. We used microarray to identify genes that are commonly and differently reguated by Z-endoxifen and tamoxifen treatments in the letrozole-resistant MCF7LR tumors.
2020-03-13 | GSE146911 | GEO
Project description:Since differential miRNA expression patterns associated with acquired AI resistance have been poorly investigated, the aim of this study was to delineate the deregulation of miRNA expression associated with aromatase inhibitor (AI) response failure in new cellular models of AI resistance. For this purpose, we generated and characterized novel cellular models of acquired resistance to letrozole (Res-Let cells) and to anastrozole (Res-Ana cells) and performed microarray experiments to identify miRNAs whose expression was either deregulated between control (MCF-7aro) and resistant cells (Res-Let or Res-Ana). With the aim to select relevant miRNAs, two independent cell culture replicates were performed for each experimental condition.
2013-01-30 | GSE43766 | GEO