SiRIP140 and gene expression effects in E2-treated MCF7 cells
Ontology highlight
ABSTRACT: This experiment is designed to assess the role of RIP140 in estrogen receptor-dependent gene expression in MCF7 luminal breast cancer cells. MCF7 cells were transfected with an siRNA to target RIP140 or siControl, and subsequently depleted from hormones for three days. Thereafter, cells were treated for 6 hours with 10nM Estradiol and RNA was isolated and further processed for expression analyses.
Project description:This experiment is designed to assess the role of RIP140 in estrogen receptor-dependent gene expression in MCF7 luminal breast cancer cells. MCF7 cells were transfected with an siRNA to target RIP140 or siControl, and subsequently depleted from hormones for three days. Thereafter, cells were treated for 6 hours with 10nM Estradiol and RNA was isolated and further processed for expression analyses.
Project description:Arsenic is reportedly a biphasic inorganic compound for its toxicity and anticancer effects in humans. Recent studies have shown that certain arsenic compounds including arsenic hexoxide (AS4O6; hereafter, AS6) induce programmed cell death and cell cycle arrest in human cancer cells and murine cancer models. However, the mechanisms by which AS6 suppresses cancer cells are incompletely understood. In this study, we report the mechanisms of AS6 through transcriptome analyses. In particular, the cytotoxicity and global gene expression regulation by AS6 were compared in human normal and cancer breast epithelial cells. Using RNA-sequencing and bioinformatics analyses, differentially expressed genes in significantly affected biological pathways in these cell types were validated by real-time quantitative polymerase chain reaction and immunoblotting assays. Our data show markedly differential effects of AS6 on cytotoxicity and gene expression in human mammary epithelial normal cells (HUMEC) and Michigan Cancer Foundation 7 (MCF7), a human mammary epithelial cancer cell line. AS6 selectively arrests cell growth and induces cell death in MCF7 cells without affecting the growth of HUMEC in a dose-dependent manner. AS6 alters the transcription of a large number of genes in MCF7 cells, but much fewer genes in HUMEC. Importantly, we found that the cell proliferation, cell cycle, and DNA repair pathways are significantly suppressed whereas cellular stress response and apoptotic pathways increase in AS6-treated MCF7 cells. Together, we provide the first evidence of differential effects of AS6 on normal and cancerous breast epithelial cells, suggesting that AS6 at moderate concentrations induces cell cycle arrest and apoptosis through modulating genome-wide gene expression, leading to compromised DNA repair and increased genome instability selectively in human breast cancer cells.
Project description:Gene expression from MCF7 breast cancer cells at different times of TNFa incubation:pcs2 and 14-3-3 transduced cells Keywords: Expression Profiling by array We analyzed 2 arrays from each condition:MCF7-control tnf 0, MCF7-control tnf 20min, MCF-control tnf 90min, MCF7-14-3-3 tnf 0, MCF7-14-3-3 tnf 20min, MCF7-14-3-3 tnf 90min
Project description:This submission is a part of two separate studies: a study of estrogen receptor-alpha (ERalpha)-mediated gene expression in response to different ligands and a study examining the roles of ERalpha and ERbeta in gene regulation in breast cancer cells. Comparison of estrogen-treated versus vehicle-treated MCF7 parental cells. Each comparison was performed in biological duplicate, with dye swapping.
Project description:To identify novel therapeutic opportunities for patients with acquired resistance to endocrine treatments in breast cancer, we applied high-throughput screening to explore currently marketed drugs. The Ec50 values were determined for MCF7 and LTED cell lines to identify the compounds showing higher inhibition of LTED cells. The best compound was YC-1 and gene microarray studies were done in vitro for mechanistic exploration. MCF7 and LTED cells were treated with YC-1 for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Estrogen signaling pathway is critical for breast cancer development and has remained the major adjuvant therapeutic target for this disease. Tamoxifen has been used in clinic for many years to treat ER-positive breast cancer. However a great many (30%) suffer relapse due to drug resistance. In this study, the bromodomain inhibitor JQ1 was found to down-regulate ERalpha gene expression and have anti-tumor effect in cultured tamoxifen-resisant breast cancer cells. We used microarrays to detail the global programme of gene expression in tamoxifen-resistant MCF7 cells treated with the bromodomain inhibitor JQ1. Tamoxifen-resistant breast cancer MCF7 cells were treated with DMSO (vehicle) or JQ1 (0.2 uM) for 24 hours before total RNA was purified for microarray. Each sample was triplicated.
Project description:The initiation of breast cancer is associated with increased expression of tumor-promoting estrogen receptor α (ERα) protein and decreased expression of tumor-suppressive ERβ protein. However, the mechanism underlying this process is unknown. Here we show that Pescadillo/PES1, an estrogen-inducible protein that is over-expressed in breast cancer, can regulate the balance between ERα and ERβ. PES1 enhances transcriptional activity of ERα and reduces that of ERβ, and modulates many estrogen-responsive genes. Consistent with this regulation of ERα and ERβ transcriptional activity, PES1 increases the stability of the ERα protein and decreases that of ERβ through the ubiquitin-proteasome pathway, mediated by the carboxyl terminus of Hsc70-interacting protein (CHIP). Moreover, PES1 can transform normal human mammary epithelial cells and is required for estrogen-induced breast tumor growth in nude mice. Further analysis of clinical samples showed that expression of PES1 correlates positively with ERα expression and negatively with ERβ expression, and predicts good clinical outcome in breast cancer. Our data demonstrate that PES1 contributes to breast tumor growth through regulating the balance between ERα and ERβ and may be a better target for the development of drugs that selectively regulate ERα and ERβ activities. Three samples: Control siRNA -E2 vs. Control siRNA +E2, Control siRNA -E2 vs. PES1 siRNA -E2,Control siRNA -E2 vs. PES1 siRNA +E2
Project description:Cadmium is a metalloestrogen known to activate the estrogen receptor and promote breast cancer cell growth. Previous studies have implicated cadmium in the development of more malignant tumors; however the molecular mechanisms behind this cadmium-induced malignancy remain elusive. Using clonal cell lines derived by exposing breast cancer cells to cadmium for over 6 month (MCF7-Cd4, -Cd6, -Cd7, -Cd8 and -Cd12), this study aims to identify gene expression signatures associated with chronic cadmium exposure. Our results demonstrate that prolonged exposure does not merely result in the deregulation of genes but actually leads to a distinctive expression profile. The genes deregulated in cadmium-exposed cells are involved in multiple biological processes (i.e cell growth, apoptosis, etc.) and molecular functions (i.e. cadmium/metal ion binding, transcription factor activity, etc). Hierarchical clustering demonstrates that the five clonal cadmium cell lines share a common gene expression signature of breast cancer associated genes, clearly differentiating control from cadmium exposed cells. The results presented in this study offer insights into the cellular and molecular impacts of cadmium on breast cancer carcinogenesis and emphasize the importance of studying chronic cadmium exposure as one possible mechanism of promoting breast cancer progression. To understand the effects of chronic cadmium exposure on gene expression in breast cancer, two control MCF7 parental cell lines and five different clonal cadmium-adapted cell lines (MCF7-Cd4, -Cd6, -Cd7, -Cd8, and -Cd12) - previously derived from cells chronically exposed to cadmium - were used for microarray analysis.
Project description:While the roles of individual nuclear receptor (NR) in human diseases have been well characterized, interplays among NRs have not been extensively characterized due, in part, to technical difficulties in simultaneously monitoring molecular activities of all 48 NR genes. Using systems-level analysis of publically available gene expression data from NCI-60 cell lines, we uncovered novel interaction between ESR1 and orphan receptor NR2E3. Expression of NR2E3 is significantly associated with expression of ESR1 in NCI-60 cell lines as well as in breast cancer patients. To investigate how NR2E3 gene signatures are globally correlated with ESR1 signaling pathway, we performed microarray after knocking down NR2E3 or ESR1 in MCF-7 cells. Keywords: DNA microarray (Illumina human Ht12 V3) 3 shControl, 3 shNR2E3, 3 siLuc, 3 siESR1
Project description:Estrogen overproduction is closely associated with the development of estrogen receptor-positive breast cancer. Aromatase, encoded by the cytochrome P450 19 (CYP19) gene, regulates estrogen biosynthesis. This study aimed to identify active flavones that inhibit CYP19 expression and to explore the underlying mechanisms. CYP19 expression was evaluated using reverse transcription PCR, quantitative real-time PCR, and immunoblot analysis. The role of transcription factor early growth response gene 1 (EGR-1) in CYP19 expression was assessed using the short-hairpin RNA (shRNA)-mediated knockdown of EGR-1 expression in estrogen receptor-positive MCF-7 breast cancer cells. We screened 39 flavonoids containing 26 flavones and 13 flavanones using the EGR1 promoter reporter activity assay and observed that chrysoeriol exerted the highest inhibitory activity on tumor necrosis factor alpha (TNFα)-induced EGR-1 expression. We further characterized and demonstrated that chrysoeriol inhibits TNFα-induced CYP19 expression through inhibition of extracellular signal-regulated kinase 1/2 (ERK1/2)-mediated EGR-1 expression. Chrysoeriol may be beneficial as a dietary supplement for the prevention of estrogen receptor-positive breast cancer, or as a chemotherapeutic adjuvant in the treatment of this condition.