GEO DataSets

(Submitter supplied) Tamoxifen is the most widely prescribed anti-estrogen treatment for patients with ER-positive breast cancer. However, there is still a need for biomarkers that reliably predict endocrine sensitivity in breast cancers and these may well be expressed in a dynamic manner. In this study we assessed gene expression changes at multiple time points (days 1, 2, 4, 7, 14) after tamoxifen treatment in the ER-positive ZR-75-1 xenograft model that displays significant changes in apoptosis, proliferation and angiogenesis within 2 days of therapy. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL506

32 Samples

Download data: TXT

(Submitter supplied) Acquired resistance to endocrine therapy occurs with high frequency in patients with luminal breast cancer (LBC). We report here the establishment of four patient-derived xenograft models of LBC with acquired resistance in vivo to tamoxifen and estrogen deprivation.

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL11532

30 Samples

Download data: CEL

(Submitter supplied) Altered expression of microRNAs (miRNAs), an abundant class of small non-protein-coding RNAs that mostly function as negative regulators of protein-coding gene expression, is common in cancer. Here we analyze the regulation of miRNA expression in response to estrogen, a steroid hormone that is involved in the development and progression of breast carcinomas and that is acting via the estrogen receptors (ER) transcription factors. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL5175

9 Samples

Download data: CEL

(Submitter supplied) In the present investigation, we have exploited the opportunity provided by neoadjuvant treatment of a group of postmenopausal women with large operable or locally advanced breast cancer (in which therapy is given with the primary tumour remaining within the breast) to take sequential biopsies of the same cancers before and after 10-14 days or 90 days treatment with letrozole. RNA extracted from the biopsies has been subjected to Affymetrix microarray analysis and the data from paired biopsies interrogated to discover genes whose expression is most influenced by oestrogen deprivation. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL96

176 Samples

Download data: CEL

(Submitter supplied) In the present investigation, we have exploited the opportunity provided by neoadjuvant treatment of a group of postmenopausal women with large operable or locally advanced breast cancer (in which therapy is given with the primary tumour remaining within the breast) to take sequential biopsies of the same cancers before and after 10-14 days treatment with letrozole. RNA extracted from the biopsies has been subjected to Affymetrix microarray analysis and the data from paired biopsies interrogated to discover genes whose expression is most influenced by oestrogen deprivation. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Dataset:

GDS3116

Platform:

GPL96

116 Samples

Download data: CEL

Analysis of breast cancer tumors following treatment with letrozole for 14 days. The aromatase inhibitor letrozole is an anti-estrogen drug used to treat postmenopausal women with breast cancer. Results provide insight into the molecular mechanism of action of letrozole in breast cancer.

Organism:

Homo sapiens

Type:

Expression profiling by array, count, 2 agent, 58 individual sets

Platform:

GPL96

Series:

GSE5462

116 Samples

Download data: CEL

(Submitter supplied) To investigate molecular mechanisms of resistance, we used two different in vivo xenograft models of estrogen receptor-positive (ER+) breast cancer, with or without HER2 over-expression (MCF7/HER2-18 and MCF7 wt, respectively). Mice with established tumors were assigned to the following treatment groups: continued estrogen supplementation (E2), estrogen deprivation (ED), ED plus tamoxifen (Tam), all with or without the EGFR tyrosine kinase inhibitor gefinitinib (G). more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL570

65 Samples

Download data: CEL

(Submitter supplied) To investigate molecular mechanisms of resistance, we used two different in vivo xenograft models of estrogen receptor-positive (ER+) breast cancer, with or without HER2 over-expression (MCF7/HER2-18 and MCF7 wt, respectively). Mice with established tumors were assigned to the following treatment groups: continued estrogen supplementation (E2), estrogen deprivation (ED), ED plus tamoxifen (Tam), all with or without the EGFR tyrosine kinase inhibitor gefinitinib (G). more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL570

14 Samples

Download data: CEL, XLS

(Submitter supplied) To investigate molecular mechanisms of resistance, we used two different in vivo xenograft models of estrogen receptor-positive (ER+) breast cancer, with or without HER2 over-expression (MCF7/HER2-18 and MCF7 wt, respectively). Mice with established tumors were assigned to the following treatment groups: continued estrogen supplementation (E2), estrogen deprivation (ED), ED plus tamoxifen (Tam), all with or without the EGFR tyrosine kinase inhibitor gefinitinib (G). more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL570

51 Samples

Download data: CEL, TXT

(Submitter supplied) Menopausal estrogen (E2) replacement therapy increases the risk of estrogen receptor (ER)-positive epithelial ovarian cancers (EOC). Whether E2 is tumorigenic or promotes expansion of undiagnosed pre-existing disease is unknown. To determine E2 effects on tumor promotion, we developed an intraperitoneal mouse xenograft model using ZsGreen fluorescent ER- 2008 and ER+ PEO4 human EOC cells. Tumor growth was quantified by in vivo fluorescent imaging. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Dataset:

GDS4066

Platform:

GPL570

15 Samples

Download data: CEL

Analysis of estrogen receptor (ER)+PEO4 or ER-2008 human epithelial ovarian cancer (EOC) cells laser captured from intraperitoneal xenografts of mice treated with estrogen (E2). Menopausal E2 replacement therapy increases risk of ER+ EOC. Results provide insight into E2 effects on tumor promotion.

Organism:

Homo sapiens

Type:

Expression profiling by array, transformed count, 2 agent, 2 cell type, 2 genotype/variation sets

Platform:

GPL570

Series:

GSE22600

15 Samples

Download data: CEL

(Submitter supplied) Aromatase inhibitors are first-line postmenopausal agents for estrogen receptor alpha (ERa)-positive breast cancer. However, there is considerable response heterogeneity and women frequently relapse. Estrogen deprivation does not completely arrest ERa activity, and transactivation of the unliganded receptor may continue through cross-talk with growth factor pathways. In contrast with aromatase inhibitors, the selective ER downregulator fulvestrant also abrogates ligand-independent ERa activity. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL6884

76 Samples

Download data: TXT

(Submitter supplied) To investigate response or resistance to endocrine therapy, mice with targeted over-expression of Esr1 or CYP19A1 to mammary epithelial cells were employed, representing two direct pathophysiological interventions in estrogen pathway signaling. Both Esr1 and CYP19A1 over-expressing mice responded to letrozole with reduced HAN prevalence and decreased mammary epithelial cell proliferation. CYP19A1 over-expressing mice were tamoxifen-sensitive but Esr1 over-expressing mice were tamoxifen-resistant. more...

Organism:

Mus musculus

Type:

Expression profiling by high throughput sequencing

Platform:

GPL13112

17 Samples

Download data: TXT

(Submitter supplied) A functional genetic screen to identify genes causing tamoxifen resistance in an estrogen-dependent human breast cancer cell model was performed. By insertion of defective retrovirus into the genome, individual genetic changes were introduced at random in ZR-75-1 cells. Subsequently, infected cells were selected for their ability to proliferate while being exposed to tamoxifen, and from these cultures stable cell lines were established. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL4035

224 Samples

Download data: TXT

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

Organism:

Homo sapiens

Type:

Expression profiling by high throughput sequencing

Platform:

GPL21290

16 Samples

Download data: TXT

(Submitter supplied) Purpose: Increasing evidence suggests that epigenetic reprogramming contributes significantly to the development of endocrine therapy resistance in breast cancer. The goal of this work is to explore how the histone methyltransferase EZH2 interacts with ER signaling and drives the insensitiveness of breast cancer cells to the antagonistic effect of tamoxifen on ER activity. Therefore, we comprehensively analyzed the transcriptional program regulated by EZH2 in EZH2 overexpressed MCF-7 cells. more...

Organism:

Homo sapiens

Type:

Expression profiling by high throughput sequencing

Platform:

GPL21290

12 Samples

Download data: TXT

(Submitter supplied) Purpose: Increasing evidence suggests that epigenetic reprogramming contributes significantly to the development of endocrine therapy resistance in breast cancer. The goal of this work is to explore how the histone methyltransferase EZH2 interacts with ER signaling and drives the insensitiveness of breast cancer cells to the antagonistic effect of tamoxifen on ER activity. Therefore, we comprehensively analyzed the transcriptional program regulated by EZH2 in tamoxifen-resistant (TamR) MCF-7 cells. more...

Organism:

Homo sapiens

Type:

Expression profiling by high throughput sequencing

Platform:

GPL21290

4 Samples

Download data: TXT

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

Organism:

Homo sapiens

Type:

Non-coding RNA profiling by array; Expression profiling by array

Platforms:

GPL5639 GPL13746

16 Samples

Download data: GPR

(Submitter supplied) Recent analyses have identified heterogeneity in estrogen receptor (ER)-positive breast cancer. There are so-called luminal A and luminal B subtypes, and the characteristics, such as response to endocrine therapy and chemotherapy and prognosis, are different in these two subtypes of breast cancer. In this study, expression profiles of microRNAs (miRNAs) and mRNAs in ER-positive breast cancer tissues were compared between highly and incompletely endocrine responsive tumors by miRNA and mRNA microarrays. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL5639

8 Samples

Download data: GPR

(Submitter supplied) Recent analyses have identified heterogeneity in estrogen receptor (ER)-positive breast cancer. There are so-called luminal A and luminal B subtypes, and the characteristics, such as response to endocrine therapy and chemotherapy and prognosis, are different in these two subtypes of breast cancer. In this study, expression profiles of microRNAs (miRNAs) and mRNAs in ER-positive breast cancer tissues were compared between highly and incompletely endocrine responsive tumors by miRNA and mRNA microarrays. more...

Organism:

Homo sapiens

Type:

Non-coding RNA profiling by array

Platform:

GPL13746

8 Samples

Download data: GPR