GEO DataSets

(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

(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

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) Sequential patient-matched samples treated with extended neoadjuvant therapy were studied. Long-term treatment (letrozole) induced changes in dormant and resistant patients were determined. Samples were classified as pre-treatment (timepoint1, <0 days), early-on treatment (timepoint2, 0-120 days) and long-term treatment (timepoint4, >120 days).

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL10558

101 Samples

Download data: TXT

(Submitter supplied) Purpose Aromatase inhibitors (AIs) have an established role in breast cancer treatment. Response rates are only 50-70% in the neoadjuvant setting and lower in advanced disease. Accurate biomarkers are urgently needed to predict response in these settings and to determine which individuals will benefit from adjuvant AI therapy. Participants and Methods Pre- and on-treatment (after 2 weeks and 3 months) biopsies were obtained from 89 post-menopausal women with ER+ breast cancer receiving neoadjuvant letrozole for transcript profiling. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL10558

75 Samples

Download data: TXT

(Submitter supplied) Invasive lobular cancer (ILC) accounts for approximately 10-15% of breast carcinomas and although it responds poorly to neoadjuvant chemotherapy, it appears to respond well to endocrine therapy. Pre- and on-treatment (after 2 weeks and 3 months) biopsies and surgical samples were obtained from 14 post-menopausal women with ER+ histologically confirmed ILC who responded to 3 months of neoadjuvant letrozole and were compared with a cohort of 14 responding infiltrating ductal carcinomas (IDCs) matched on clinicopathological features by gene expression profiling. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL10558

36 Samples

Download data: TXT

(Submitter supplied) To identify in clinical breast cancer those genes and pathways most associated with resistance to aromatase inhibitors by examining the global transcriptional effects of aromatase inhibitor (AI) treatment. Analysis of gene-expression measured in core-cut biopsies at baseline and surgery from patients received 2-week’s presurgical AI revealed: i) the molecular response to AI treatment varies greatly between patients, consistent with the variable clinical benefit from AI treatment; ii) higher baseline expression of an inflammatory signature is associated with poor antiproliferative response, and should be assessed further as a novel biomarker and potential target for AI-treated patients.

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL13376

162 Samples

Download data: TXT

(Submitter supplied) Endocrine therapy reduces breast cancer mortality by 40%; but resistance remains a major clinical problem. Identification of gene signatures associated with resistance during endocrine treatment should enable rational therapeutic choices to be made to combat this in individual patients. Here we present an in-depth analysis of global gene-expression that was measured on pairs of core-cut biopsies taken at baseline and at surgery from 254 patients with ER-positive primary breast cancer randomised to receive 2-week’s presurgical AI (n=198) or no presurgical treatment (Control n=56) in the POETIC trial, using changes-in and residual-of the proliferation marker, Ki67 as end-points, to investigate the impact of aromatase inhibitor (AI) therapy on gene expression and identify gene modules representing key biological pathways that relate to early AI-therapy resistance. more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL10558

178 Samples

Download data: TXT

(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) Transcriptome of 17 tru-cut biopsies and 13 matched surgical samples from ER+ breast tumor patients, treated for 3 months with Anastrozole were anayzed to identify a robust expression signature predictive of response to Anastrozole neoadjuvant treatment in ER+ breast cancer patients and, at the same time, to delineate treatment effects.

Organism:

Homo sapiens

Type:

Expression profiling by array

Platforms:

GPL6848 GPL6480

60 Samples

Download data: TXT

(Submitter supplied) 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). more...

Organism:

Homo sapiens

Type:

Expression profiling by array

Dataset:

GDS1873

Platform:

GPL96

18 Samples

Download data: CEL, EXP

Analysis of estrogen receptor positive, aromatase transfected MCF-7 cells after treatment with an antiestrogen (AE) or an aromatase inhibitor (AI). AEs and AIs are used to treat estrogen-dependent breast cancer. Cells also treated with androgen which is converted to estrogen by aromatase.

Organism:

Homo sapiens

Type:

Expression profiling by array, count, 6 agent, 4 other sets

Platform:

GPL96

Series:

GSE2225

18 Samples

Download data: CEL, EXP

(Submitter supplied) Agilent gene expression arrays were used to compare proliferation signatures between pre-treatment and 2-4 weeks post treatment samples from Z1031B patients.

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL6480

218 Samples

Download data: TXT

(Submitter supplied) Analysis of reciprocal modulation of Runx2 and E2 signaling in BCA. Our objective was to investigate whether the interaction between estrogen and Runx2 signaling in breast cancer (BCa) could help refine an estrogen-responsive gene signature with improved prognostic value.

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL6883

10 Samples

Download data: TXT

(Submitter supplied) 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. more...

Organism:

Homo sapiens

Type:

Non-coding RNA profiling by array

Platform:

GPL9081

23 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) 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) This SuperSeries is composed of the SubSeries listed below.

Organism:

Homo sapiens

Type:

Expression profiling by array; Genome variation profiling by genome tiling array

Platforms:

GPL6480 GPL9128

248 Samples

Download data: TXT

(Submitter supplied) aCGH data was used in Paradigm analysis for exploration of networks affected by copy number and gene expression changes based on mutation spectra of recurrently mutated genes in breast cancer.

Organism:

Homo sapiens

Type:

Genome variation profiling by genome tiling array

Platform:

GPL9128

124 Samples

Download data: TXT

(Submitter supplied) Expression data was used in Paradigm analysis for exploration of networks affected by copy number and gene expression changes based on mutation spectra of recurrently mutated genes in breast cancer.

Organism:

Homo sapiens

Type:

Expression profiling by array

Platform:

GPL6480

124 Samples

Download data: TXT