GEO DataSets

(Submitter supplied) Purpose: Development of resistance to tamoxifen is an important clinical issue in the treatment of patients with breast cancer. Tamoxifen resistance may be the result of the acquisition of epigenetic regulation such as DNA methylation within breast cancer cells resulting in changed mRNA expression of genes being pivotal for estrogen dependent growth. Alternatively, tamoxifen resistance may be due to selection of preexisting resistant cells, which may exhibit cancer stem-like characteristics or a combination of the two mechanisms. more...

Organism:

Homo sapiens

Type:

Expression profiling by high throughput sequencing; Methylation profiling by high throughput sequencing

Platform:

GPL11154

10 Samples

Download data: TXT

(Submitter supplied) The goal of this study was to identify genes that were differentially regulated by ATF2 in TAMR cells (tamoxifen-resistant MCF7 derivatives) when compared to the tamoxifen-sensitive MCF7.

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL10558

28 Samples

Download data: TXT

(Submitter supplied) 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. more...

Organism:

Homo sapiens

Type:

Expression profiling by RT-PCR

Platform:

GPL18510

12 Samples

Download data: XLS

(Submitter supplied) 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). more...

Organism:

human gammaherpesvirus 4; JC polyomavirus; Human gammaherpesvirus 8; Betapolyomavirus macacae; Murid gammaherpesvirus 4; Betapolyomavirus hominis; Homo sapiens; Human alphaherpesvirus 1; Human betaherpesvirus 5; Murid betaherpesvirus 1; Human immunodeficiency virus 1

Type:

Non-coding RNA profiling by array

Platforms:

GPL15462 GPL14149 GPL13703

153 Samples

Download data: TXT

(Submitter supplied) Endocrine therapy is the most used treatment for hormone receptor positive breast cancers. Despite the clear benefit of endocrine therapy for patients with ER+ breast cancer, resistance to treatment is a critical clinical issue affecting a large number of patients. While many studies have shown that genetics is an important factor in therapy resistance, recent publications have also reported that epigenetics might play a major role in the acquisition of resistance to endocrine therapies. more...

Organism:

Homo sapiens

Type:

Methylation profiling by genome tiling array

Platform:

GPL21145

40 Samples

Download data: TXT

(Submitter supplied) Compare the expression pattern of 17b-estradiol responsive genes in parent, OHT-resistant and ICI-resistant breast cancer cells. Keywords: 17b-estradiol responsive genes, OHT resistance, Fulvestrand resistance

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL570

24 Samples

Download data

(Submitter supplied) genome-wide expression profiling of MCF-7, MCF-7/TamR and CAP-treated MCF-7/TamR cell. In result, cold atmospheric plasma re-sensitizes the Tamoxifen-resistant MCF-7 (MCF-7/TamR) breast cancer cell to the drug.

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL10558

3 Samples

Download data: TXT

(Submitter supplied) Targeting the estrogen signaling pathway has proved to be of great value in the treatment of human breast cancer. Tamoxifen, a selective estrogen receptor modulator (SERM), is the most widely used antiestrogen. However, only 40-50% of patients with estrogen receptor (ER) positive breast cancer benefit from tamoxifen treatment and 30-50% acquire resistance and the disease progresses. Continuous treatment with conventional therapy may contribute to cancer progression in recurring cancers through the accumulation of drug resistant cancer progenitors. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL570

8 Samples

Download data: CEL

(Submitter supplied) To elucidate the molecular mechanisms of tamoxifen resistance in breast cancer, we performed gene array analysis and identified 366 genes with altered expression in four unique tamoxifen resistant (TamR) cell lines vs the parental tamoxifen sensitive MCF7/S0.5 cell line. Most of these genes were funcationally linked to cell proliferation, death and control gene expression, and include FYN, PRKCA, ITPR1, DPYD, DACH1, LYN, GBP1 and PRLR. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL570

18 Samples

Download data: CEL

(Submitter supplied) We performed RNA-sequencing on 7 tamoxifen-resistant (MCF-7 Tam1, T-47D Tam1, T-47D Tam2, ZR-75-1 Tam1, ZR-75-1 Tam2, BT474 Tam1 and BT-474 Tam2) and their isogenic parental (MCF-7, T-47D, ZR-75-1 and BT-474) breast cancer cell lines. The tamoxifen-resistant cell lines were generated from the parentel cell lines by continuous administration of 1 µM 4-OH-tamoxifen for eight to twelve months. RNA- sequencing was performed to determine the changes in the expression of genes in the resistant clones as well as pathways. more...

Organism:

Homo sapiens

Type:

Expression profiling by high throughput sequencing; Third-party reanalysis

Platform:

GPL11154

11 Samples

Download data: TXT

(Submitter supplied) 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. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL571

42 Samples

Download data: CEL

(Submitter supplied) The transcription factor FOXM1 coordinates the expression of cell cycle-related genes and plays a pivotal role in tumorigenesis and cancer progression. We have previously shown that FOXM1 acts downstream of 14-3-3ζ signaling, which correlates with a more aggressive tumor phenotype. However, the role that FOXM1 might play in engendering the resistance to endocrine treatments in estrogen receptor-positive (ER+) patients when tumor FOXM1 is high, has not been clearly defined. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL96

7 Samples

Download data: CEL

(Submitter supplied) To support cellular homeostasis and mitigate chemotherapeutic stress, cancer cells must gain a series of adaptive intracellular processes. Here we identify that NUPR1, a tamoxifen (Tam)-induced transcriptional coregulator, is necessary for the maintenance of Tam resistance through physical interaction with ESR1 in breast cancers. Mechanistically, NUPR1 binds to the promoter regions of several genes involved in autophagy process and drug resistance such as BECN1, GREB1, RAB31, PGR, CYP1B1, and regulates their transcription. more...

Organism:

Homo sapiens

Type:

Expression profiling by high throughput sequencing

Platform:

GPL16791

3 Samples

Download data: TXT

(Submitter supplied) Trascriptome analysis of mcf7 cell lines were performed

Organism:

Homo sapiens

Type:

Expression profiling by high throughput sequencing

Platform:

GPL11154

9 Samples

Download data: TXT

(Submitter supplied) RNA-seq was performed on MCF-7 cells expressing vector control (LXSN), PELP1-wt, and PELP1-cyto

Organism:

Homo sapiens

Type:

Expression profiling by high throughput sequencing

Platform:

GPL16791

9 Samples

Download data: CSV

(Submitter supplied) Postmenopausal breast cancer patients benefit from aromatase inhibitors (AIs) that reduce the levels of estrogens critical for the growth of estrogen receptor (ER)-positive tumors. Unfortunately, many tumors are resistant to AI, and we are only beginning to understand the complex mechanisms underlying treatment resistance. Here we set out to determine whether epigenetic changes could contribute to therapy resistance. more...

Organism:

Homo sapiens

Type:

Methylation profiling by genome tiling array

Platform:

GPL5082

2 Samples

Download data: BAR, CEL

(Submitter supplied) This SuperSeries is composed of the SubSeries listed below.

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL96

12 Samples

Download data: CEL, CHP

(Submitter supplied) Invasive lobular breast cancer (ILC) is an understudied malignancy with distinct clinical, pathological, and molecular features that distinguish it from the more common invasive ductal carcinoma (IDC). Mounting evidence suggests that estrogen receptor-alpha positive (ER+) ILC has a poor response to Tamoxifen (TAM), but the mechanistic drivers of this are undefined. In the current work, we comprehensively characterize the SUM44/LCCTam ILC model system through integrated analysis of gene expression, copy number, and mutation, with the goal of identifying actionable alterations relevant to clinical ILC that can be co-targeted along with ER to improve treatment outcomes. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL96

6 Samples

Download data: CEL, CHP

(Submitter supplied) This SuperSeries is composed of the SubSeries listed below.

Organism:

Homo sapiens

Type:

Expression profiling by array; Methylation profiling by array

Platforms:

GPL6884 GPL8490

38 Samples

Download data

(Submitter supplied) Background: Patient-derived tumour xenografts are an attractive model for preclinical testing of anti-cancer drugs. Insights into tumour biology and biomarkers predictive of responses to chemotherapeutic drugs can also be gained from investigating xenograft models. As a first step towards examining the equivalence of epigenetic profiles between xenografts and primary tumours in paediatric leukaemia, we performed genome-scale DNA methylation and gene expression profiling on a panel of 10 paediatric B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) tumours that were stratified by prednisolone response. more...

Organism:

Homo sapiens

Type:

Methylation profiling by array

Platform:

GPL8490

20 Samples

Download data: TXT