Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA317765 | ENA |
REPOSITORIES: ENA
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Project description:Core needle biopsy (Cx) primary cancer specimens were collected at Okayama University Hospital in Japan from hormone receptor positive /HER2 negative patients that subsequently received two weeks of neoadjuvant hormone therapy. Thirty clinical TNM stage I and II women were enrolled in this study. The study was approved by the Institutional Review Board and all patients signed informed consent forms. Patients received preoperative hormone therapy daily for two weeks before surgery. Premenopausal patients received tamoxifen (40 mg) and postmenopausal patients received letrozole (2.5 mg). All patients underwent a mastectomy or breast-conserving surgery. Surgical samples after treatment were also collected. Hormone and HER2 receptor statuses were determined in the diagnostic Cx specimens before hormone therapy. Cases with ≥1% positive nuclear staining for estrogen receptors (ER) or progesterone receptors (PgR) with IHC were considered hormone receptor-positive. Cases with either 0 or 1 positive IHC staining for HER2 or with an HER2 gene copy number < 2.0 by fluorescent in situ hybridization (FISH) analysis were considered HER2−. Specimens for gene expression analysis were collected into RNA and later stored at -80°C. Gene expression profiling was performed using Affymetrix U133A gene chips. Expression data were normalized using the MAS5 algorithm, mean centered to 600, and log2 transformed before further analysis.
2017-04-19 | GSE80077 | GEO
Project description:Estrogen receptor positive breast cancer is the most prevalent form of breast cancer. Although a number of available drugs are highly effective at blocking estrogen mediated receptor activity, thousands of patients die every year from ER positive breast cancers because the disease progresses to a stage at which these drugs are no longer effective. Thus, it is crucial to establish a comprehensive understanding of the biology of the estrogen receptor (ER) in ER:positive breast cancers that progress despite hormone therapy, a gap in knowledge that remains a serious impediment to successful treatment of patients with ER positive breast cancer. A key question that must be answered is how the estrogen receptor retains the capacity to activate transcription in the absence or near absence of estrogen. We have found a partial answer to this question upon investigating the effect of amplification and overexpression of Wolf Hirschhorn Syndrome Candidate 1:Like 1 (WHSC1L1), a gene that is amplified in 15% of breast cancers that codes for a histone:lysine methyltransferase. WHSC1L1 lies in the 8p11:p12 amplicon, a region of gene amplification that is strongly associated with breast cancer. In this study, we performed shRNA knockdown of the catalytically inactive short isoform of WHSC1L1 in SUM44PE breast cancer cells and found that expression of the short isoform of WHSC1L1 is necessary for expression of the estrogen receptor in this highly ER:positive cell line. In addition, we found that the estrogen receptor binds chromatin extensively in the absence of exogenous estrogen, including several actively transcribed canonical ER target genes, indicating that estrogen receptor signaling is active in SUM44 cells in estrogen free conditions. These findings represent a novel model for ER biology in luminal B breast cancers harboring amplification of WHSC1L1 and provide insight into the mechanisms by which ER: positive breast cancers become unresponsive to SERMs or aromatase inhibitors.
2016-05-07 | E-MTAB-3739 | biostudies-arrayexpress
Project description:The vast majority of all breast cancers are driven by oestrogen receptor alpha (ERα) activation, and endocrine therapy represents the mainstay treatment for these patients. However, resistance is common and tumours progress despite years of systemic endocrine suppression. Periodic fasting enhances the efficacy of standard endocrine drugs and delay acquired resistance to them, although the underlying mechanisms remain unclear. Here, we show that fasting, in combination with endocrine therapy, induces extensive epigenetic reprogramming in hormone receptor-positive (HR+) breast cancer xenografts, with large-scale activation of glucocorticoid receptor (GR) and progesterone receptor (PR) signalling, and impairment of activator protein-1 (AP-1) family activity. GR-driven gene programs were selectively activated after fasting, and GR knockout perturbed the beneficial effects of fasting in combination with tamoxifen, in vivo. Exogenous administration of GR-ligands fully recapitulated the observed fasting-enhanced anti-oestrogen action, resulting in tumour regression. Finally, elevated progesterone and cortisol levels were detected in the blood of breast cancer patients after fasting, thus providing clinical validation of our animal findings. Our results indicate GR activation to play a pivotal role in fasting’s ability to enhance endocrine drug activity against hormone-receptor positive breast cancer and suggest that corticosteroid administration should be evaluated as an adjuvant to endocrine therapy in this condition.
2025-10-14 | PXD049477 | Pride
Project description:Elucidation of chromatin interactions for hormone therapy- resistance of ER positive breast cancer
| PRJDB6357 | ENA
Project description:hormone receptor-positive early breast cancer by Nanostring BC360 panel
| EGAD00010001994 | EGA
Project description:Effects of combined tamoxifen and short-term starvation on the gene expression profile of hormone receptor-positive breast cancer cells
| PRJNA497212 | ENA
Project description:Hyperactivation of phosphatidylinositol-3 kinase (PI3K) promotes escape from hormone dependence in estrogen receptor-positive breast cancer. A significant fraction of breast cancers exhibit de novo or acquired resistance to estrogen deprivation. We used gene expression microarrays to identify genes and pathways that are commonly dysregulated in ER+ cell lines with acquired hormone-independent growth. MCF-7, ZR75-1, MDA-361, and HCC-1428 ER+, estrogen-responsive breast cancer cells were cultured under hormone-depleted conditions (10% DCC-FBS) for several months until sustainable hormone-independent cell populations emerged. Parental and long-term estrogen-deprived (LTED) cells were treated with 10% dextran-coated charcoal-treated fetal bovine serum (DCC-FBS) x 24 hrs prior to RNA harvest for array analysis.
2010-06-23 | E-GEOD-19639 | biostudies-arrayexpress
Project description:PI3K inhibition results in enhanced estrogen receptor function and dependence in hormone receptor-positive breast cancer
| PRJNA269919 | ENA
Project description:Estrogen deprivation using aromatase inhibitors is currently the standard of care for patients with estrogen-receptor (ER)-positive breast cancer. Unfortunately, prolonged estrogen deprivation leads to drug resistance (i.e. hormone-independent growth). We therefore used DNA microarray analysis to study the gene expression profiles of wild-type MCF-7 cells (which are sensitive to antihormone therapy) and long-term estrogen deprived MCF-7:5C and MCF-7:2A breast cancer cells (which are resistance to estrogen-deprivation; aromatase inhibitor resistant). Transcriptional profiling of wild-type MCF-7 cells and estrogen deprived MCF-7:5C and MCF-7:2A cells was performed using Affymetrix Human Genome U133 Plus 2.0 Array. Keywords: breast cancer cells, estrogen
2008-03-19 | GSE10879 | GEO
Project description:miRNA profile of single hormone receptor positive breast cancer patients
| PRJNA649524 | ENA