Project description:Androgen-stimulated growth of the molecular apocrine breast cancer is mediated by an androgen receptor (AR)-regulated transcriptional program. Through profiling the genomic licalizations of AR and its co-regulators FOXA1 and TCF7L2 in MDA-MB-453 breast cancer cells, we revealed the molecular details of the AR-centered regulatory network. We further identified that c-MYC is a key downstream target co-regulated by AR, FOXA1 and TCF7L2, and reinforces the transctiopnal activation of androgen-responsive genes in this subtype of breast cancers. AR and FOXA1 ChIP-seq were performed in MDA-MB-453 breast cancer cells with treatment of 5a-dihydrotestosterone (DHT) for 16 h. TCF7L2 ChIP-seq was performed in MDA-MB-453 cells treated with vehicle or DHT for 16 h, respectively. MYC ChIP-seq was performed in MDA-MB-453 cells following 6 h DHT stimulation.
Project description:Androgen-stimulated growth of the molecular apocrine breast cancer is mediated by an androgen receptor (AR)-regulated transcriptional program. Through profiling the genomic licalizations of AR and its co-regulators FOXA1 and TCF7L2 in MDA-MB-453 breast cancer cells, we revealed the molecular details of the AR-centered regulatory network. We further identified that c-MYC is a key downstream target co-regulated by AR, FOXA1 and TCF7L2, and reinforces the transctiopnal activation of androgen-responsive genes in this subtype of breast cancers. MDA-MB-453 breast cancer cells were transfected with control of MYC siRNA for 48 h, followed by treatment with 10nM DHT or vehicle for 6 h. The cells were subjected to mRNA purification and library praparation for RNA-seq on Illumina HiSeq2000 platform.
Project description:This SuperSeries is composed of the following subset Series: GSE28305: Effect of 5a-dihydrotestosterone on breast cancer cell line MDA-MB-453 GSE28788: Androgen receptor cistrome in breast cancer cell line MDA-MB-453 with 5a-dihydrotestosterone (DHT) stimulation Refer to individual Series
Project description:Androgen receptor (AR) is expressed in 60-70% of breast cancers independent of estrogen receptor (ER) expression, however its function in breast cancer is largely unknown. Our study identified the high level of AR in ERâ??/HER2+ breast tumors and andorgen and AR greatly stimulated growth of MDA-MB-453 breast cancer cells. To define the genome-wide AR binding sites, we performed AR ChIP-seq using MDA-MB-453 breast cancer cells followig stimulation of DHT. We also identified FOXA1 is a crucial AR cofactor in MDA-MB-453 cells and the FOXA cistrome showed signaficant overlap with AR at both early and late time points of DHT stimulation. AR ChIP was performed in MDA-MB-453 breast cancer cells following 5a-dihydrotestosterone (DHT) stimulation for 4h and 16h respectively. FOXA1 ChIP-seq was performed after 4h DHT stimulation in MDA-MB-453 cells.
Project description:Analysis of MDA-MB-453 breast cancer cells treated with the androgen 5a-dihydrotestosterone (DHT) for 6h, 16h and 48h to define the genes that are differentially regulated in response to DHT. MDA-MB-453 breast cancer cells were treated with 5a-dihydrotestosterone (DHT) for time course, followed by RNA extraction and hybridization on Affymetrix microarrays, in order to obtain the gene expression profiles at three time points. The vehicle treated samples are used as control.
Project description:The effect of transient transfection of a construct designed to over-express the androgen receptor (AR) variant AR-V7 on gene expression in MDA-MB-453 cells was assessed using Affymetrix Gene 2.0 ST arrays. Transfection of an AR-expressing construct or an empty construct served as controls. AR-V7, AR or empty vector was transfected into MDA-MB-453 cells. Cells were treated with vehicle control or DHT.
Project description:The discovery that enhancers are regulated transcription units, encoding eRNAs, has raised new questions about the mechanisms of their activation. Here, we report an unexpected molecular mechanism that underlies ligand-dependent enhancer activation, based on DNA nicking to relieve torsional stress from eRNA synthesis. Using dihydrotestosterone (DHT)-induced binding of androgen receptor (AR) to prostate cancer cell enhancers as a model, we show rapid recruitment, within minutes, of DNA topoisomerase I (TOP1) to a large cohort of AR-regulated enhancers. Furthermore, we show that the DNA nicking activity of TOP1 is a prerequisite for robust eRNA synthesis and enhancer activation and is kinetically accompanied by the recruitment of ATR and the MRN complex, followed by additional components of DNA damage repair machinery to the AR-regulated enhancers. Together, our studies reveal a linkage between eRNA synthesis and ligand-dependent TOP1-mediated nicking - a strategy exerting quantitative effects on eRNA expression in regulating AR-bound enhancer-dependent transcriptional programs. Genome-wide binding analysis of AR, TOP1, MRE11 in prostate cancer cell line LNCaP with or without 5alpha-dihydrotestosterone (DHT) treatment. Nascent RNA analysis by global nuclear run-on (GRO-seq) in LNCaP cells transfected with siRNA with or without DHT treatment. Distribution of transcriptionally engaged RNA Pol II in LNCaP cells with or without DHT treatment by precision nuclear run-on and sequencing (PRO-seq).
Project description:This SuperSeries is composed of the following subset Series: GSE39718: Time-course effect of estradiol and ERa17p on Early Gene expression in MDA-MB-231 cells GSE39719: Time-course effect of estradiol and ERa17p on Early Gene expression in SKBR3 cells GSE39720: Time-course effect of estradiol and ERa17p on Early Gene expression in T47D cells Refer to individual Series
Project description:The long-term goal of our study is to understand the genetic and epigenetic mechanisms of breast cancer metastasis in human and to discover new possible genetic markers for use in clinical practice. We have used microarray technology (Human OneArray microarray, phylanxbiotech.com) to compare gene expression profiles of non-invasive MCF-7 and invasive MDA-MB-231 cells exposed to dioscin (DS), a steroidal saponin isolated from the roots of wild yam, (Dioscorea villosa). Initially the differential expression of genes (DEG) was identified that followed pathway enrichment analysis (PEA). Of the genes queried on OneArray, we identified 4641 DEG changed between MCF-7 and MDA-MB-231 cells (vehicle-treated) with cut-off log2 |fold change|⧠1. Among these genes, 2439 genes are upregulated and 2002 genes are downregulated. DS exposure (2.30 ïM, 72 h) to these cells identified 801 (MCF-7) and 96 (MDA-MB-231) DEG that showed significant difference compared to untreated cells (p<0.05). Within these gene sets, DS is able to upregulate 395 genes and downregulate 406 genes in MCF-7 and upregulate 36 and downregulate 60 genes in MDA-MB-231 cells. Further comparison of DEG between MCF-7 and MDA-MB-231 cells exposed to DS identified 3626 DEG of which 1700 were upregulated and 1926 genes were down-regulated. From PEA, 12 canonical pathways were significantly altered between these two cell lines (MCF-7 and MDA-MB-231). However, no alteration in any of these pathways was noticed in MCF-7 cell, while in MDA-MB-231 cells only MAPK pathway showed significant alteration. When PEA comparison was made on DS exposed cells, it was observed that only 2 pathways were significantly affected. Further, to identify shared DEG, which are targeted by DS and overlapped in both MCF-7 and MDA-MB-231 cells, we performed intersection analysis (Venn diagram). We found that only 7 DEG are overlapped of which six are reported in the database. This study highlights the diverse gene networks and pathways through which DS exhibits its effect on breast cancer cells. Two condition experiment. Human breast cancer Cell line MCF-7 groups: Vehicle control and dioscin treated; Human breast cancer cell line MDA-MB-231 cell group; vehicle control and dioscin-treated. Biological replicates: MCF-7 control compared to MCF-7 dioscin treated; MDA-MB-231 control compated to MDA-MB-231 dioscin-treated; MCF-7 control compared to MDA-MB-231 control; MCF-7 dioscin treated compared to MDA-MB-231 dioscin-treated. duplicate array