Project description:The molecular signature at histone H3K4 involved in epigenetic regulation of normal (MCF10A) and transformed (MCF7, MDA-MB-231) breast cells using ChIP-Seq technology. This study examines the dynamic distribution of H3K4me3 and H3K4ac histone modification associated with active chromatin to provide an understanding of the changes in epigenetic regulation associated with the unique breast cancer subtypes. H3K4me3 and H3K4ac histone modification study in normal (MCF10A) and transformed (MCF7, MDA-MB-231) breast cells using ChIP-Seq technology
Project description:A number of studies have shown that apoptosis resistance can be observed in multiple human tumors; however the detailed mechanism remains unclear. In the present study, we demonstrated that the abnormal overexpression of the C terminus of Hsc70-interacting protein (CHIP) induced apoptosis resistance by regulating the AKT/FoxO/Bim signaling pathway in the breast cancer cell MCF7 and the human non-tumorigenic cell MCF10A. We found that CHIP overexpression in MCF7 and MCF10A cells activated AKT and inhibited the Forkhead box O (FoxO) transcription factors FoxO1, FoxO3, and FoxO4, thereby inhibiting transcription of the target genes bim and pten. Inhibition of PI3K by a chemical reagent revealed that these events may be critical for CHIP-induced apoptosis resistance. We also determined that inhibition of FoxO3 by CHIP led to the decrease in PTEN and further activated the AKT survival pathway. We corroborated our findings in breast cancer tissues. In general, the CHIP-modulated AKT/FoxO/Bim signaling pathway was shown to induce apoptosis resistance by decreasing the protein level of the tumor suppressor PTEN in both transcriptional and post-translational regulations.
Project description:RNA-seq data from HT-29 cells treated with IFN-γ for 24 hr, MCF10A cells, and MDA-MB-436 cells. mRNA profiles of HT-29, MCF10A, and MDA-MB-436 were generated by deep sequencing using Illumina HiSeq 2000. All RNA sequencing data was generated by the Genomics Services Lab at the HudsonAlpha Institute for Biotechnology (Huntsville, AL).
Project description:RNA-seq data from HT-29 cells treated with IFN-M-NM-3 for 24 hr, MCF10A cells, and MDA-MB-436 cells. mRNA profiles of HT-29, MCF10A, and MDA-MB-436 were generated by deep sequencing using Illumina HiSeq 2000. All RNA sequencing data was generated by the Genomics Services Lab at the HudsonAlpha Institute for Biotechnology (Huntsville, AL).
Project description:Our study reports the first genome-wide atlas of functional nodes that mediate proviral silencing in ESCs. It provides evidences for the comprehensive, interconnected and multi-layered genetic/epigenetic machineries by which ESCs maintain the repressive state of provirus and ERVs. ChIP-seq analysis of Chaf1a, Trim28, Sumo2 and Zfp809 to demonstrate the mechanism of the silencing of Endogenous retroviruses
Project description:Motif enrichment analysis of transcription factor ChIP-seq data can help identify transcription factors that cooperate or compete. Previously, little attention has been given to comparative motif enrichment analysis of pairs of ChIP-seq experiments, where the binding of the same transcription factor is assayed under different conditions. Such comparative analysis could potentially identify the distinct regulatory partners/competitors of the assayed transcription factor under different conditions or at different stages of development.We describe a new methodology for identifying sequence motifs that are differentially enriched in one set of DNA or RNA sequences relative to another set, and apply it to paired ChIP-seq experiments. We show that, using paired ChIP-seq data for a single transcription factor, differential motif enrichment analysis identifies all the known key transcription factors involved in the transformation of non-cancerous immortalized breast cells (MCF10A-ER-Src cells) into cancer stem cells whereas non-differential motif enrichment analysis does not. We also show that differential motif enrichment analysis identifies regulatory motifs that are significantly enriched at constrained locations within the bound promoters, and that these motifs are not identified by non-differential motif enrichment analysis. Our methodology differs from other approaches in that it leverages both comparative enrichment and positional enrichment of motifs in ChIP-seq peak regions or in the promoters of genes bound by the transcription factor.We show that differential motif enrichment analysis of paired ChIP-seq experiments offers biological insights not available from non-differential analysis. In contrast to previous approaches, our method detects motifs that are enriched in a constrained region in one set of sequences, but not enriched in the same region in the comparative set. We have enhanced the web-based CentriMo algorithm to allow it to perform the constrained differential motif enrichment analysis described in this paper, and CentriMo's on-line interface (http://meme.ebi.edu.au) provides dozens of databases of DNA- and RNA-binding motifs from a full range of organisms. All data and output files presented here are available at http://research.imb.uq.edu.au/t.bailey/supplementary\_data/Lesluyes2014.