Project description:We performed ChIP seq experiment in MDA-MB-134 cell line in order to map the estrogen receptor alpha (ER) binding sites following the estrogen treatment in an ILC model. We have characterized the genome wide recruit of ER and scaned the binding sites for the presence of cofactor motifs. The binding peaks were also correlated to E2 regulated genes in this ILC model. Four samples were subjected to high throughput sequencing: E-ER (estrogen treated followed by ER IP), E-IgG (estrogen treated followed by IgG), V-ER (EtOH treated followed by ER IP) and Input (MCF7 genomic DNA)
Project description:We report genome-wide distribution of germ cell-specific linker histone variant H1T in cancer cell line AGS, MDA-MB-231, and mouse embryonic stem cells (mESCs). We found that H1T expressed not only testis but also non-germ cells such as cancer cells and pluripotent stem cells and showed the biased distribution at rDNA repeat unit. Moreover, on the rDNA region, H1T regulated the chromatin structure and pre-rRNA expression. This study using ChIP-seq analysis provides genomic distribution of H1T in non-germinal cells. ChIP-seq analysis of linker histone H1T in AGS, MDA-MB-231 and mESCs
Project description:Identification of DNA binding sites of the transcription factor ZEB1 in the human breast cancer cell line MDA-MB-231 by chromatin-immunoprecipitation followed by sequencing (ChIP-seq).
Project description:Exosomes are nanosized (30-100 nm) membrane vesicles secreted by most cell types. Exosomes have been found to contain various RNA species including miRNA, mRNA and long non-protein coding RNAs. A number of cancer cells produce elevated levels of exosomes. Because exosomes have been isolated from most body fluids they may provide a source for non-invasive cancer diagnostics. Transcriptome profiling that uses deep-sequencing technologies (RNA-Seq) offers enormous amount of data that can be used for biomarkers discovery, however, in case of exosomes this approach was applied only for the analysis of small RNAs. In this study, we utilized RNA-Seq technology to analyze RNAs present in microvesicles secreted by human breast cancer cell lines. Exosomes were isolated from the media conditioned by two human breast cancer cell lines, MDA-MB-231 and MDA-MB-436. Exosomal RNA was profiled using the Ion Torrent semiconductor chip-based technology. Exosomes were found to contain various classes of RNA with the major class represented by fragmented ribosomal RNA (rRNA), in particular 28S and 18S rRNA subunits. Analysis of exosomal RNA content revealed that it reflects RNA content of the donor cells. Although exosomes produced by the two cancer cell lines shared most of the RNA species, there was a number of non-coding transcripts unique to MDA-MB-231 and MDA-MB-436 cells. This suggests that RNA analysis might distinguish exosomes produced by low metastatic breast cancer cell line (MDA-MB-436) from that produced by highly metastatic breast cancer cell line (MDA-MB-231). The analysis of gene ontologies (GOs) associated with the most abundant transcripts present in exosomes revealed significant enrichment in genes encoding proteins involved in translation and rRNA and ncRNA processing. These GO terms indicate most expressed genes for both, cellular and exosomal RNA. For the first time, using RNA-seq, we examined the transcriptomes of exosomes secreted by human breast cancer cells. We found that most abundant exosomal RNA species are the fragments of 28S and 18S rRNA subunits. This limits the number of reads from other RNAs. To increase the number of detectable transcripts and improve the accuracy of their expression level the protocols allowing depletion of fragmented rRNA should be utilized in the future RNA-seq analyses on exosomes. Present data revealed that exosomal transcripts are representative of their cells of origin and thus could form basis for detection of tumor specific markers.
Project description:We report the chromatin binding sites of HOXB7 transcription factor in BT-474 breast cancer cell line using ChIP-sequencing. We validated the chromatin binding sites in BT-474, MDA-MB-361, MCF7 and T-47D breast cancer cell lines using ChIP-qPCR. The ChIP experiments have been performed using HOXB7 antibody and IgG non-specific antibody as a negative control. The direct downstream target genes of HOXB7 were identified by analyzing the expression of genes located nearby HOXB7 binding sites in HOXB7 knockdown versus control cells using qRT-PCR. Examination of chromatin binding sites of HOXB7 in BT-474 breast cancer cell line using ChIP-seq. Four parallel IgG samples were sequenced, merged together and used as a control data set. Two parallel HOXB7 ChIP samples were sequenced and merged for each replicate, AF1 and AF2. Both HOXB7 ChIP replicates (AF1 and AF2) contained approximately the same amount of reads as the merged IgG control data set.
Project description:We report the genome-wide chromatin binding profiles of ERα and phosphorylated CREB1 (pCREB1) upon stimulation of human MDA-MB-134 breast cancer cells with estradiol or cAMP. We highlight the unique and the shared cistromes for each transcription factor. Overall design: ChIP-seq of ERα and phosphorylated CREB1 with human MDA-MB-134 breast cancer cells; duplicate samples were treated with vehicle (DMSO), estradiol or cAMP
Project description:UNLABELLED:Overexpression of ribosomal RNA processing 1 homolog B (RRP1B) induces a transcriptional profile that accurately predicts patient outcome in breast cancer. However, the mechanism by which RRP1B modulates transcription is unclear. Here, the chromatin-binding properties of RRP1B were examined to define how it regulates metastasis-associated transcription. To identify genome-wide RRP1B-binding sites, high-throughput ChIP-seq was performed in the human breast cancer cell line MDA-MB-231 and HeLa cells using antibodies against endogenous RRP1B. Global changes in repressive marks such as histone H3 lysine 9 trimethylation (H3K9me3) were also examined by ChIP-seq. Analysis of these samples identified 339 binding regions in MDA-MB-231 cells and 689 RRP1B-binding regions in HeLa cells. Among these, 136 regions were common to both cell lines. Gene expression analyses of these RRP1B-binding regions revealed that transcriptional repression is the primary result of RRP1B binding to chromatin. ChIP-reChIP assays demonstrated that RRP1B co-occupies loci with decreased gene expression with the heterochromatin-associated proteins, tripartite motif-containing protein 28 (TRIM28/KAP1), and heterochromatin protein 1-? (CBX5/HP1?). RRP1B occupancy at these loci was also associated with higher H3K9me3 levels, indicative of heterochromatinization mediated by the TRIM28/HP1? complex. In addition, RRP1B upregulation, which is associated with metastasis suppression, induced global changes in histone methylation. IMPLICATIONS:RRP1B, a breast cancer metastasis suppressor, regulates gene expression through heterochromatinization and transcriptional repression, which helps our understanding of mechanisms that drive prognostic gene expression in human breast cancer.
Project description:This experiment aims to study transcriptional alterations induced by reconstitution of wild type E-cadherin expression in human lobular breast cancer cells harbouring deleterious, somatic CDH-1 mutations Two cell lines (IPH-926 and MDA-MB-134) expressing synthetic Ecad (EcadEGFP) or not (EGFP) were compared against each other. Analysis were conducted in triplicates (IPH-926) and quadruplicates (MDA-MB-134), respectively.