Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA255496 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Molecular changes in lobular breast cancers in response to endocrine therapy
| PRJNA239428 | ENA
Project description:Evolution of ER+ breast cancer cells and tumors during endocrine therapy
| PRJNA1023282 | ENA
Project description:PURPOSE: To develop a predictive test for response and survival following neoadjuvant taxane-anthracycline chemotherapy for HER2-negative invasive breast cancer. METHODS: We developed a microarray-based gene expression test from pre-treatment tumor biopsies (310 patients) to predict favorable outcome based on estrogen receptor (ER) status,pathologic response to chemotherapy, 3-year disease outcomes, and sensitivity to endocrine therapy. Tumors were classified as treatment-sensitive if predicted to have pathologic response (and not resistance) to chemotherapy, or sensitive to endocrine therapy. We tested predictive accuracy, with 95% confidence interval (CI), for pathologic response (PPV, positive predictive value), distant relapse-free survival (DRFS), and absolute risk reduction at median follow-up in 198 other patients. Independence from clinical-pathologic factors was assessed in a multivariate Cox regression analysis based on the likelihood ratio test. Other evaluable, published response predictors (genomic grade index (GGI), intrinsic subtype (PAM50), pCR predictor (DLDA30)) were compared. Neoadjuvant validation cohort of 198 HER2-negative breast cancer cases treated with taxane-anthracycline chemotherapy pre-operatively and endocrine therapy if ER-positive. Response was assessed at the end of neoadjuvant treatment and distant-relapse-free survival was followed for at least 3 years post-surgery.
2011-05-11 | E-GEOD-25065 | 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:The estrogen receptor alpha (ERa) drives the growth of two-thirds of all breast cancers. Endocrine therapy impinges on estrogen-induced ERa activation to block tumor growth. However, half of ERa-positive breast cancers are tolerant or acquire endocrine therapy resistance. Here we demonstrate that breast cancer cells undergo genome-wide reprogramming of their chromatin landscape, defined by epigenomic maps and chromatin openness, as they acquire resistance to endocrine therapy. This reveals a role for the Notch pathway while excluding classical ERa signaling. In agreement, blocking Notch signaling, using gamma-secretase inhibitors, or targeting its downstream gene PBX1 abrogates growth of endocrine therapy-resistant breast cancer cells. Moreover Notch signaling through PBX1 directs a transcriptional program predictive of tumor outcome and endocrine therapy response. Comparing histone modifications (H3K4me2 and H3K36me3), chromatin openness (FAIRE) and PBX1 binding between endocrine therapy sensitive MCF7 and resistant MCF7-LTED cells.
2013-05-01 | E-GEOD-37323 | biostudies-arrayexpress
Project description:Prediction of breast cancer pathological complete response to anthracycline/taxane chemotherapy.
| PRJNA99107 | ENA
Project description:Expression of estrogen receptor (ESR1) determines whether a breast cancer patient receives endocrine therapy as part of their adjuvant care, but does not guarantee patient response. However, the molecular factors that define endocrine response in ESR1-positive breast cancer patients remain poorly understood. Here, we characterize the DNA methylome of endocrine sensitivity and demonstrate the potential impact of differential DNA methylation on endocrine response in breast cancer. We show that DNA hypermethylation occurs predominantly at estrogen-responsive enhancers and is associated with reduced ESR1 binding and decreased gene expression of key regulators of ESR1-activity; thus providing a novel mechanism by which endocrine response is abated in ESR1-positive breast cancers. Conversely, we delineate that ESR1-responsive enhancer hypomethylation is critical in transition from normal mammary epithelial cells to endocrine responsive ESR1-positive cancer. Cumulatively these novel insights highlight the potential of ESR1-responsive enhancer methylation to both predict ESR1-positive disease and stratify ESR1-positive breast cancer patients as responders to endocrine therapy. Methylation profiling with Illumina's HumanMethylation450K array was performed on ESR1-positive hormone sensitive MCF7 cells, and three different well characterised endocrine resistant MCF7-derived cell lines; tamoxifen-resistant (TAMR), fulvestrant-resistant (FASR) and estrogen deprivation resistant (MCF7X) cells. For each cell line two biological replicates were profiled bringing the number of samples to eight.
2015-07-01 | E-GEOD-69118 | biostudies-arrayexpress
Project description:Expression of estrogen receptor (ESR1) determines whether a breast cancer patient receives endocrine therapy as part of their adjuvant care, but does not guarantee patient response. However, the molecular factors that define endocrine response in ESR1-positive breast cancer patients remain poorly understood. Here, we characterize the DNA methylome of endocrine sensitivity and demonstrate the potential impact of differential DNA methylation on endocrine response in breast cancer. We show that DNA hypermethylation occurs predominantly at estrogen-responsive enhancers and is associated with reduced ESR1 binding and decreased gene expression of key regulators of ESR1-activity; thus providing a novel mechanism by which endocrine response is abated in ESR1-positive breast cancers. Conversely, we delineate that ESR1-responsive enhancer hypomethylation is critical in transition from normal mammary epithelial cells to endocrine responsive ESR1-positive cancer. Cumulatively these novel insights highlight the potential of ESR1-responsive enhancer methylation to both predict ESR1-positive disease and stratify ESR1-positive breast cancer patients as responders to endocrine therapy.
2015-07-01 | GSE69118 | GEO
Project description:Expression profile of the endocrine therapy sensitive breast cancer cells MCF7 depleted of PBX1
| PRJNA170843 | ENA
Project description:Genome-wide reprogramming of the chromatin landscape underlies endocrine therapy resistance in breast cancer
| PRJNA159579 | ENA