Antitumor Activity of Z-endoxifen in Aromatase Inhibitor-Sensitive and Resistant Estrogen Receptor-Positive Breast Cancer
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PROVIDER: PRJNA612349 | ENA |
REPOSITORIES: ENA
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Project description:The overarching goal of this study was to explore the antitumor activity of Z-endoxifen, a tamoxifen metabolite, with first-line endocrine therapies tamoxifen and letrozole in the letrozole-sensitive MCF7 aromatase expressing model (MCF7AC1), and with second-line endocrine therapies including tamoxifen, fulvestrant, exemestane, and exemestane plus everolimus, in letrozole-resistant MCF7 model (MCF7LR) in vivo. We used microarray to identify genes that are commonly and differently reguated by Z-endoxifen and tamoxifen treatments in the letrozole-resistant MCF7LR tumors.
2020-03-13 | GSE146911 | GEO
Project description:BackgroundThe tamoxifen metabolite, Z-endoxifen, demonstrated promising antitumor activity in endocrine-resistant estrogen receptor-positive (ER+) breast cancer. We compared the antitumor activity of Z-endoxifen with tamoxifen and letrozole in the letrozole-sensitive MCF7 aromatase expressing model (MCF7AC1), as well as with tamoxifen, fulvestrant, exemestane, and exemestane plus everolimus in a letrozole-resistant MCF7 model (MCF7LR).MethodsMCF7AC1 tumor-bearing mice were randomized to control (no drug), letrozole (10 μg/day), tamoxifen (500 μg/day), or Z-endoxifen (25 and 75 mg/kg). Treatment in the letrozole arm was continued until resistance developed. MCF7LR tumor-bearing mice were then randomized to Z-endoxifen (50 mg/kg) or tamoxifen for 4 weeks and tumors harvested for microarray and immunohistochemistry analysis. The antitumor activity of Z-endoxifen in the MCF7LR tumors was further compared in a second in vivo study with exemestane, exemestane plus everolimus, and fulvestrant.ResultsIn the MCF7AC1 tumors, both Z-endoxifen doses were significantly superior to control and tamoxifen in reducing tumor volumes at 4 weeks. Additionally, the 75 mg/kg Z-endoxifen dose was additionally superior to letrozole. Prolonged letrozole exposure resulted in resistance at 25 weeks. In MCF7LR tumor-bearing mice, Z-endoxifen significantly reduced tumor volumes compared to tamoxifen, letrozole, and exemestane, with no significant differences compared to exemestane plus everolimus and fulvestrant. Additionally, compared to tamoxifen, Z-endoxifen markedly inhibited ERα target genes, Ki67 and Akt expression in vivo.ConclusionIn endocrine-sensitive and letrozole-resistant breast tumors, Z-endoxifen results in robust antitumor and antiestrogenic activity compared to tamoxifen and aromatase inhibitor monotherapy. These data support the ongoing development of Z-endoxifen.
| S-EPMC7238733 | biostudies-literature
Project description:<p>Highly variable outcomes are observed in patients with estrogen receptor positive (ER+) breast cancer who undergo preoperative estrogen deprivation therapy with aromatase inhibitors (AI). In this study, 46 baseline tumor and normal genomes and 31 baseline tumor/normal exomes of participants selected from two clinical trials of neoadjuvant AI therapy on ER+ breast cancer were sequenced to identify somatic alterations that correlate with response to AI, to screen for therapeutic targets and to elucidate the genetic landscape of ER+ breast cancer. From the same set of patients we later performed deep genomic characterization of a subset of matched primary tumors after four months of AI therapy, generating comprehensive information about the range of changes that occur when ER+ breast cancers are subjected to estrogen deprivation. This data includes whole genome sequence and transcriptome data. To better understand tumor heterogeneity and the evolution of resistance to estrogen-deprivation therapy, a subset of these tumours, along with 38 additional cases were sequenced to greater depth using targeted capture with a gene panel.</p>
| phs000472 | dbGaP
Project description: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). Microarray analyses using Affymetrix Human Genome U133A GeneChips were carried out using total RNA isolated from the control and treated cells. When comparing the effect of each inhibitor on gene expression we observe that letrozole and anastrozole are more similar in terms of the genes they affect, compared to treatment with tamoxifen. The results of this study provide us with a better understanding of the actions of both aromatase inhibitors and anti-estrogens at the molecular level. We believe that the results of this study serve as the first step in identifying unique expression patterns following drug treatment, and that this will ultimately be useful in customizing patient treatment strategies for estrogen-dependent breast cancer. The data presented here have been processed using the R-Project Bioconductor statistical tools package using the affy library. The following were applied: RMA background correction, pmonly probe-level correction, quantile normalization, avgdiff summary method. Raw data is provided in the form of .CEL files.
2007-10-27 | E-GEOD-2225 | biostudies-arrayexpress
Project description:<p>Highly variable outcomes are observed in patients with estrogen receptor positive (ER+) breast cancer who undergo preoperative estrogen deprivation therapy with aromatase inhibitors (AI). In this study, 46 tumor and normal genomes and 31 exomes of participants selected from two clinical trials of neoadjuvant AI therapy on ER+ breast cancer were sequenced to identify somatic alterations that correlate with response to AI, to screen for therapeutic targets and to elucidate the genetic landscape of ER+ breast cancer. Of the significantly mutated genes, GATA3 mutations correlated with low post-treatment Ki67 and up-regulation of IGF1R mRNA. TP53 mutations associated with multiple markers of poor outcome and mutations in MAP3K1 associated with inferior clinical response. Mutations in MAP3K1 and MAP2K4 were mutually exclusive and positively associated with mutations in PIK3CA. The majority of tumors were multiclonal, as defined by distinct mutation clusters. A number of potential therapeutic targets were provided by both common and rare variants. Potential therapeutically relevant mutations of tryosine kinase included ERBB2, KIT, PDGFRA, DDR1, CSF1R, and MET.</p>
| phs000472.v1.p1 | EGA
Project description:Understanding the complex molecular mechanisms underlying resistance to endocrine therapy is a major challenge in the treatment of estrogen receptor-positive (ER+) breast cancers. We have previously demonstrated that glial cell line-derived neurotrophic factor (GDNF) signaling via the receptor tyrosine kinase RET promotes estrogen independent activation of ER. Here we have addressed the relevance of GDNF-RET signaling in response to aromatase inhibitor treatment and explored the efficacy of using RET inhibitors in breast cancer models of aromatase inhibitor response and resistance. A GDNF-response gene set, identified from gene expression profiling, was demonstrated to be an independent prognostic marker of poor patient outcome and, importantly, to be predictive of poor response to aromatase inhibitor treatment and development of resistance. The relevance of these findings was validated first by demonstrating an association of RET protein expression in an independent cohort of aromatase inhibitor resistant patient samples. Second, in in vitro models, GDNF-mediated RET signaling was demonstrated to enhance the survival of aromatase inhibitor resistant cells and to increase resistance in aromatase inhibitor sensitive cells. These effects could be reversed by targeting GDNF/RET signaling with the RET selective inhibitor NVP-BBT594 thus identifying GDNF-RET signaling as a potential therapeutic target, particularly in breast cancers resistant to aromatase inhibitors.<br>MCF7 cells were E2-deprived by culturing in phenol red-free RPMI 1640 supplemented with 10% DCC for 3 days and then serum-starved overnight in the presence or absence of fulvestrant (ICI182,780) (100 nM). The following day, cells were treated with GDNF (20 ng/ml) for 0, 4, 8, 24 and 48 hours in the presence or absence of fulvestrant (ICI182,780) (100 nM).
2013-01-17 | E-MEXP-3662 | biostudies-arrayexpress
Project description:We performed the single-cell analysis to reveal the mechanism of estrogen-induced cell cycle arrest using an Aromatase inhibitor-resistant patient-derived xenograft model (named GS3).
2021-02-21 | GSE156752 | GEO
Project description: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. Keywords: cell lines, aromatase inhibitor resistance, tamoxifen resistance
2008-03-22 | GSE10911 | GEO
Project description:In this study, we have utilized wild-type (WT) and aromatase knockout (ArKO; estrogen free) mouse ovaries as an in vivo model to profile estrogen dependent genes. RNA from each individual ovary (n=3) was analyzed by a microarray-based screen using Illumina Sentrix Mouse WG-6 BeadChip (45,281 transcripts).
2010-09-15 | E-MEXP-2824 | biostudies-arrayexpress
Project description:The main goal of the study is to define miR expression levels related to clinical and biological parameters. Now in particular, miR expression levels of fresh frozen (estrogen receptor-positive) primary tumors were related to PIK3CA genotype and with progression-free survival in breast cancer patients with metastatic breast cancer that received first-line aromatase inhibitor therapy.
2016-03-03 | GSE78870 | GEO