RNA-seq of breast cancer cell lines post ligand treatment II
Ontology highlight
ABSTRACT: Goal: study the impact of estrogen receptor ligands on gene expression in HR+ breast cancer cells Methods: RNA sequencing Results: Ligand 4-OH tamoxifen, a selective ER modulator (SERM), promotes transcriptional activation of ER and mimics the transcriptional effect of natural ligand E2 for a subset of ER target genes, consistently across the seven breast cell lines (MDA-MB-134 VI, MDA-MB-330, EFM-19, T-47D, and BT-474). Selective ER degraders (SERD) fulvestrant and GDC-0927 on the other hand do not induce, or induce very weakly the expression of ER target genes. The effect of GDC-0810 depends on the cellular context.
Project description:Goal: study the impact of estrogen receptor ligands on gene expression in HR+ breast cancer cells Methods: RNA sequencing Results: Ligand 4-OH tamoxifen, a selective ER modulator (SERM), promotes transcriptional activation of ER and mimics the transcriptional effect of natural ligand E2 for a subset of ER target genes, consistently across the seven breast cell lines (MCF-7, HCC1500, MDA-MB-330, EFM-19, T-47D, BT-474, and CAMA-1). Selective ER degraders (SERD) fulvestrant and GDC-0927 on the other hand do not induce, or induce very weakly the expression of ER target genes. The effect of GDC-0810 depends on the cellular context.
Project description:Goal: study the impact of estrogen receptor ligands on chromatin accessibility in MCF-7 cells Methods: Assay for Transposase-Accessible Chromatin using Sequencing (ATAC-Seq) Results: Ligand 4-OH tamoxifen, a selective ER modulator (SERM), significantly alters chromatin accessibility and partially mimics the effect of natural ligand E2 on chromatin accessibility in MCF-7 breast cells. Selective ER degraders (SERD) fulvestrant and GDC-0927 on the other hand have very little impact on chromatin accessibility.
Project description:Goal: study the impact of estrogen receptor (ER) ligands on ER binding to chromatin in MCF-7 cells Methods: ER Chromatin Immunoprecipitation and Sequencing (ChIP-seq) Results: All tested ligands increase binding of ER onto DNA in MCF-7 breast cells. These ligands thus promote an association between ER and DNA, irrespective of their mode of action: selective ER modulator (SERM) 4-OH tamoxifen, and selective ER degraders (SERD) fulvestrant and GDC-0927.
Project description:Global gene expression analysis of HCC1428-LTED (long term estrogen deprived) breast cancer cell lines was evaluated after overnight treatment with 6 selective estrogen receptor degarders (SERDs). Two gene expression signatures were identified. GDC-0810 and AZD9496 have a similar gene expression profile which is distinct from fulvestrant. SAR439859 gene expression signature clusters closely with fulvestrant. Replacing the carboxylic side chain of GDC-0810 and AZD9496 with a basic side chain of SAR439859 to make novel SERDs, GDC-SAR and AZD-SAR, respectively, shifts the gene expression signature to more closely align to that of fulvestrant. The effect of SERDs on gene expression can be used to further differentiate classes of SERDs.
Project description:The goal of the study was to understand whether mutations in ERa can promote resistance to various ERa antagonists of the SERD and SERM class. We found that ESR1 mutations can maintain higher ER pathway activity relative to control lines following short-term treatment with ERa antagonists raloxifene or fulvestrant.
Project description:In order to identify the microRNAs differentially expressed according to the estrogen receptor status, total RNAs in triplicate from six breast cancer cell lines with different ERalpha status (ER+: T47D, BT-474, MDA-MB-483; ER-: MDA-MD-436, MDA-MB-231, MDA-MB-468) was extracted by using Trizol reagent and used for microarray experiments.
Project description:Oral selective estrogen receptor degraders (SERDs) could become the backbone endocrine therapy (ET) for estrogen receptor-positive (ER+) breast cancer, as they achieve greater inhibition of ER-driven cancers than current ETs and overcome key resistance mechanisms. This dataset was aimed at exploring the preclinical effects of the next-generation oral SERD camizestrant (AZD9833) on 7 PDX models. Mice were treated with fulvestrant or camizestrant for 4, 24, 48, 72 hours, with at least four replicates per condition.
Project description:We report that neurofibromin, a tumor suppressor and Ras-GAP (GTPase Activating Protein), is also an estrogen receptor-alpha (ER) transcriptional co-repressor through leucine/isoleucine-rich motifs that are functionally independent of GAP activity. GAP activity, in turn, does not impact ER binding. Consequently, neurofibromin-depletion causes estradiol hypersensitivity and tamoxifen agonism, explaining the poor prognosis associated with neurofibromin-loss in endocrine therapy-treated ER+ breast cancer. Neurofibromin-deficient ER+ breast cancer cells initially retain sensitivity to selective estrogen receptor degraders (SERDs). However, Ras activation does play a role in acquired SERD resistance, which can be reversed upon MEK inhibitor addition, and SERD/MEK inhibitor combinations induce tumor regression. Thus, neurofibromin is a dual repressor for both Ras and ER signaling, and co-targeting may treat neurofibromin-deficient ER+ breast tumors.
Project description:The objective of this experiment was to determine the affect of H3B-5942 treatment on global gene expression in an estrogen-deprived setting (agonist mode) and to compare to treatment with a saturated analog of H3B-5942, GDC-0810, and standard of care agents tamoxifen and fulvestrant.