Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA92235 | ENA |
REPOSITORIES: ENA
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Project description:In this study, we examined the effect of inorganic arsenic (iAs) on the estrogen response (E2) in MCF-7 cells that are estrogen receptor positive/progesterone receptor positive (ER+/PR+). Understanding the changes in the transcriptomic response after iAs exposure and the retention of such responses during recovery from iAs exposure can identify driver mechanisms of breast cancer progression and improve therapies for patients with ER+ cancers exposed to iAs.
2020-10-21 | E-MTAB-9498 | biostudies-arrayexpress
Project description:The prognosis of a patient with Estrogen Receptor (ER) and/or Progesterone Receptor (PR)-positive breast cancer is highly variable. Therefore, we developed a gene-expression based outcome predictor for ER+ and/or PR+ (i.e. Luminal) breast cancer patients using biological properties of the tumors. First, we identified estrogen-regulated genes using the ER+ MCF-7 breast cancer cell line treated with estrogen. The estrogen-induced gene set was then used to hierarchically cluster a training set of 65 ER+ and/or PR+ tumors into 2 group, which showed survival differences (p=0.0004). Next, supervised analyses based upon these two groups was performed and identified 822 genes that optimally defined these two groups, with the poor prognosis Group IIE tumors showing a proliferation signature and high expression of anti-apoptosis genes and the good outcome Group IE showing the high expression of estrogen and GATA3-induced genes. Centroids were created for each group and applied to ER+ and/or PR+ tumors from three published datasets. For all datasets, Kaplan-Meier survival analyses showed a statistically significant difference in Relapse-Free Survival (and Overall) between Group IE and IIE tumors. Multivariate Cox analysis of the largest test dataset also showed that this predictor was adding independent information. This study provides new biological information concerning differences within Luminal/ER+ breast cancers and a means of predicting long term outcomes in ER+ and/or PR+ breast cancer patients. Keywords: other
2005-12-01 | GSE2740 | 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:Progesterone receptors (PR) are co-expressed in over half of estrogen receptor (ER) positive breast cancers and predict positive response to endocrine therapy. PR can directly and globally modify ER action to attenuate tumor growth. However, whether this suppression occurs solely through PR-ER interactions remains unknown. We assessed tumor growth in two highly ER and PR positive breast cancer patient-derived xenografts (PDX) and found that natural and synthetic progestins potently antagonize the mitogenic effects of estrogens. Here we probed the genome-wide mechanisms by which this occurs. Chronic progestin treatment reversed expression of up to half of estrogen up- and downregulated genes at the transcript level. However, fewer than a quarter of ER DNA binding events were altered by progesterone. The PR cistrome showed an interesting bimodal distribution. In the first group, more than half of PR binding sites were co-occupied by ER, with a propensity for both receptors to coordinately gain or lose binding in the presence of progesterone. In the second group, PR, but not ER, was associated with a large fraction of RNA polymerase III (Pol III)-transcribed tRNA genes regardless of hormone treatment. Furthermore, PR formed a physical association with the Pol III holoenzyme. Select tRNAs with colocalization of PR and POLR3A at their promoters were reduced in tumors grown with estrogen plus progestin compared to estrogen alone. These data uncover a mechanism in solid tumors by which PR modulates the bioavailability of translational molecules that are necessary for robust tumor growth, which could indirectly impede ER action.
2017-02-28 | GSE93944 | GEO
Project description:The lymphatic system is a common avenue for the spread of breast cancer cells and dissemination through it occurs at least as frequently as hematogenous metastasis. Approximately 75% of primary breast cancers are estrogen receptor (ER) positive and the majority of these maintain receptor expression as lymph node (LN) metastases. However, it is unknown if ER function is equivalent in cancer cells growing in the breast and in the LNs. We have developed a model to assess estrogen responsiveness in ER(+) breast tumors and LN metastases. Fluorescent ER(+) MCF-7 tumors were grown in ovariectomized nude mice supplemented with estradiol. Once axillary LN metastasis arose, estradiol was withdrawn (EWD), for 1 or 4 weeks, or continued, to assess estradiol responsiveness. On EWD, proliferation rates fell similarly in tumors and LN metastases. However, estradiol-dependent ER down-regulation and progesterone receptor induction were deficient in LN metastases, indicating that ER-dependent transcriptional function was altered in the LN. Cancer cells from estradiol-treated and EWD primary tumors and matched LN metastases were isolated by laser capture microdissection. Global gene expression profiling identified transcripts that were regulated by the tissue microenvironment, by hormones, or by both. Interestingly, numerous genes that were estradiol regulated in tumors lost estradiol sensitivity or were regulated in the opposite direction by estradiol in LN metastases. We propose that the LN microenvironment alters estradiol signaling and may contribute to local antiestrogen resistance. Experiment Overall Design: 10 samples, including 3 each of estrogen and estrogen withdrawn axillary lymph nodes and 2 each of estrogen and estrogen withdrawn primary mammary gland tumors.
2008-06-11 | E-GEOD-11317 | biostudies-arrayexpress
Project description:Poly (ADP-ribose) polymerase-1 (PARP-1), a multifunctional chromatin-modulating protein, has gained considerable attention as a target for therapeutic inhibitors in breast cancers. Accumulating evidence suggests a pathological role for PARP-1 in breast cancer through its effects on the transcription of tumor-related genes. Here we report the role of PARP-1 in estrogen-dependent transcription in estrogen receptor alpha (ERα)-positive breast cancers. Global nuclear run-on and sequencing (GRO-seq) analyses suggest that PARP-1 controls the expression of estrogen-regulated genes in ER-positive (ER+) MCF-7 breast cancer cells. Further, ChIP-seq analyses revealed that PARP-1 directly regulates the ligand-dependent binding of ERa and FoxA1 to a subset of its genomic binding sites. Finally, we uncovered that the expression levels of the PARP-1 and estrogen coregulated gene set are enriched in luminal molecular-subtype of breast tumors and high PARP-1 expression in ER+ cases correlates with poor survival. Additionally, treatment with PARP-1 selective inhibitors showed attenuated estrogen-dependent growth of ER+ breast cancer cells. Taken together, the current study suggests that PARP-1 regulates critical molecular pathways that underlie proliferation of ER+ breast cancer cells.
2021-10-13 | GSE166168 | GEO
Project description: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. In ER+ tumors, E2 significantly increased size, induced progesterone receptors, and promoted lymph node metastasis, confirming that ER are functional and foster aggressiveness. Laser captured human EOC cells from ER- and ER+ xenografted tumors were profiled for expression of E2-regulated genes. Three classes of E-regulated EOC genes were defined, but less than 10% were shared with E-regulated breast cancer genes. Since breast cancer selective ER modulators (SERM) are therapeutically ineffective in EOC, we suggest that our EOC-specific E-regulated genes can assist pharmacologic discovery of ovarian targeted SERM.
2011-05-13 | GSE22600 | GEO
Project description: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. In ER+ tumors, E2 significantly increased size, induced progesterone receptors, and promoted lymph node metastasis, confirming that ER are functional and foster aggressiveness. Laser captured human EOC cells from ER- and ER+ xenografted tumors were profiled for expression of E2-regulated genes. Three classes of E-regulated EOC genes were defined, but less than 10% were shared with E-regulated breast cancer genes. Since breast cancer selective ER modulators (SERM) are therapeutically ineffective in EOC, we suggest that our EOC-specific E-regulated genes can assist pharmacologic discovery of ovarian targeted SERM. 15 samples were included in this experiment with a 2x2 factorial design with 2 different cell lines (2008 and PEO4) and 2 different hormone treatments (E for Estrogen and C for Placebo Control) and 4 replicates per treatment. 1 sample was excluded (a replicate of PEO4 with C treatment) because of poor quality.
2011-05-13 | E-GEOD-22600 | biostudies-arrayexpress
Project description:Resistance to endocrine treatments and CDK4/6 inhibitors is considered a near-inevitability in most patients with estrogen receptor positive breast cancers (ER + BC). By genomic and metabolomics analyses of patients' tumours, metastasis-derived patient-derived xenografts (PDX) and isogenic cell lines we demonstrate that a fraction of metastatic ER + BC is highly reliant on oxidative phosphorylation (OXPHOS). Treatment by the OXPHOS inhibitor IACS-010759 strongly inhibits tumour growth in multiple endocrine and palbociclib resistant PDX. Mutations in the PIK3CA/AKT1 genes are significantly associated with response to IACS-010759. At the metabolic level, in vivo response to IACS-010759 is associated with decreased levels of metabolites of the glutathione, glycogen and pentose phosphate pathways in treated tumours. In vitro, endocrine and palbociclib resistant cells show increased OXPHOS dependency and increased ROS levels upon IACS-010759 treatment. Finally, in ER + BC patients, high expression of OXPHOS associated genes predict poor prognosis. In conclusion, these results identify OXPHOS as a promising target for treatment resistant ER + BC patients.
2023-06-27 | MTBLS3342 | MetaboLights
Project description:Breast cancer is a heterogeneous disease encompassing a number of phenotypically diverse tumours. Expression levels of the estrogen, progesterone and HER2/neu receptors which characterise clinically distinct breast tumors have been shown to change during disease progression and in response to systemic therapies. Mi(cro)RNAs play critical roles in diverse biological processes and are aberrantly expressed in several human neoplasms including breast cancer, where they function as regulators of tumour behaviour and progression. The aims of this study were to identify miRNA signatures that accurately predict the oestrogen receptor (ER), progesterone receptor (PR) and HER2/neu receptor status of breast cancer patients to provide insight into the regulation of breast cancer phenotypes and progression. Expression profiling of 353 microRNAs was performed in 29 early stage breast cancer specimens. MiRNA signatures associated with ER, PR and HER2/neu status were generated using artificial neural networks (ANN) and expression of specific microRNAs was validated using RQ-PCR. Results: Stepwise artificial neural network (ANN) analysis identified predictive miRNA signatures corresponding with estrogen (miR-342, miR-299, miR-217, miR -190, miR-135b, miR-218), progesterone (miR-520g, miR-377, miR-527-518a, miR-520f-520c) and HER2/neu (miR-520d, miR-181c, miR-302c, miR-376b, miR-30e) receptor status. MiR-342 and miR-520g expression was further analysed in 95 breast tumours. MiR-342 expression was highest in ER and HER2/neu positive luminal B tumours and lowest in triple-negative tumours. MiR-520g expression was elevated in ER and PR negative tumours.
2010-05-18 | E-GEOD-15885 | biostudies-arrayexpress