Project description:Epigenetic regulators have emerged as critical factors governing the biology of cancer. Here, in the context of melanoma, we show that RNF2 is prognostic, exhibiting progression-correlated expression in human melanocytic neoplasms. Through a series of gain of function and loss of function studies, we establish that RNF2 is oncogenic and pro-metastatic. Mechanistically, RNF2-mediated invasive behavior is dependent on its ability to mono-ubiquitinate H2AK119 at the promoter of LTBP2, resulting in silencing of this negative regulator of TGFβ signaling. In contrast, RNF2's oncogenic activity did not require its catalytic activity nor derives from its canonical gene repression function, rather RNF2 drives proliferation through direct transcriptional up-regulation of the cell cycle regulator CCND2. In summary, RNF2 regulates distinct biological processes in the genesis and progression of melanoma via distinct molecular mechanisms, underscoring the complex and multi-faceted actions of epigenetic regulators in cancer. RNF2 is overexpressed in immortalized human melanocytes HMEL-BRAFV600E to address impact of RNF2 overexpression in melanoma and identify RNF2 target genes. ChIP was performed to identify RNF2 binding sites using antibody against the V5 tag.
Project description:Little is known about the epigenomics of liposarcoma (LPS). Here, we profiled the global expression of 9 epigenetic marks in well differentiated (WD) and dedifferentiated (DD) LPS from 151 patients and found increased H3K9me3 among DDLPS tumors. We performed ChIP-seq and gene expression profiling of patient derived cell lines to discover functionally significant regions of differential H3K9me3 enrichment between WDLPS and DDLPS associated with concomitant gene expression changes. We performed genome-wide transcriptional profiling of H3K9me3 in dedifferentiated liposarcoma DDLPS and well differentiated liposarcoma WDLPS cell lines.
Project description:Instructive mechanisms are present for induction of DNA methylation, as shown by methylation of specific CpG islands (CGIs) by specific inducers and in specific cancers. However, instructive factors involved are poorly understood, except for involvement of low transcription and trimethylation of histone H3 lysine 27 (H3K27me3). Here, we used methylated DNA immunoprecipitation (MeDIP) combined with a CGI oligonucleotide microarray analysis, and identified 5510 and 521 genes with promoter CGIs resistant and susceptible, respectively, to DNA methylation in prostate cancer cell lines. Expression analysis revealed that the susceptible genes had low transcription in a normal prostatic epithelial cell line. Chromatin immunoprecipitation with microarray hybridization (CHiP-chip) analysis of RNA polymerase II (Pol II) and histone modifications showed that, even among the genes with low transcription, the presence of Pol II was associated with marked resistance to DNA methylation (OR = 0.22; 95% CI = 0.12-0.38), and H3K27me3 was associated with increased susceptibility (OR = 11.20; 95% CI = 7.14-17.55). The same was true in normal human mammary epithelial cells for 5430 and 733 genes resistant and susceptible, respectively, to DNA methylation in breast cancer cell lines. These results showed that the presence of Pol II, active or stalled, and H3K27me3 can predict the epigenetic fate of promoter CGIs independently of transcription levels. To analyze DNA methylation status in normal and cancer cells, MeDIP-CGI oligonucleotide microarray analysis was performed. To analyze expression and histone modification status in normal cells, GeneChip analysis and ChIP-oligonucleotide microarray analysis were performed.
Project description:Somatic cells can be directly reprogrammed to pluripotency by exogenous expression of transcription factors, classically Oct4, Sox2, Klf4 and c-Myc. While distinct types of somatic cells can be reprogramed with varying efficiencies and by different modified reprogramming protocols, induced pluripotent stem cell (iPSC) induction remains inefficient and stochastic where a fraction of the cells converts into iPSCs. The nature of rate limiting barrier(s) preventing majority of cells to convert into iPSCs remains elusive. Here we show that neutralizing Mbd3, a core member of the Mbd3/NURD co-repressor and chromatin-remodeling complex, results in deterministic and synchronized reprogramming of multiple differentiated cell types to pluripotency. 100% of Mbd3 depleted mouse and human somatic cells convert into iPSCs after seven days of reprogramming factor induction. Our findings delineate a critical pathway blocking the reestablishment of pluripotency, and offer a novel platform for future dissection of epigenetic dynamics leading to iPSC formation at high resolution. Samples include Mbd3+/+, Mbd3flox/- and Mbd3-/- cells from mouse ES cells and mouse embryonic fibroblast (MEF) before and after DOX induction (initiating reprogramming by OSKM factors). Two histone modifications are given: H3K4me3, H3K27me3. In addition binding data of Mbd3 and Mi2B in various stages.
Project description:Pluripotency can be induced in somatic cells by ectopic expression of defined transcription factors, however the identity of epigenetic regulators driving the progression of cellular reprogramming requires further investigation. Here we uncover a non-redundant role for the JmjC-domain-containing protein histone H3 methylated Lys 27 (H3K27) demethylase Utx, as a critical regulator for the induction, but not for the maintenance, of primed and naM-CM-/ve pluripotency in mice and in humans. Utx depletion results in aberrant H3K27me3 repressive chromatin demethylation dynamics, which subsequently hampers the reactivation of pluripotency promoting genes during reprogramming. Remarkably, Utx deficient primordial germ cells (PGCs) display a cell autonomous aberrant epigenetic reprogramming in vivo during their embryonic maturation, resulting in the lack of functional contribution to the germ-line lineage. H3K27me3 and H3K4me3 were measured genome-wide in the following cell types: Utx+/Y (WT) and Utx-/Y (KO) mouse ES cells and mouse embryonic fibroblast (MEF) before and after DOX induction (initiating reprogramming by OSKM factors).
Project description:modENCODE_submission_6300 This submission comes from a modENCODE project of Jason Lieb. For full list of modENCODE projects, see http://www.genome.gov/26524648 Project Goal: The focus of our analysis will be elements that specify nucleosome positioning and occupancy, control domains of gene expression, induce repression of the X chromosome, guide mitotic segregation and genome duplication, govern homolog pairing and recombination during meiosis, and organize chromosome positioning within the nucleus. Our 126 strategically selected targets include RNA polymerase II isoforms, dosage-compensation proteins, centromere components, homolog-pairing facilitators, recombination markers, and nuclear-envelope constituents. We will integrate information generated with existing knowledge on the biology of the targets and perform ChIP-seq analysis on mutant and RNAi extracts lacking selected target proteins. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf EXPERIMENT TYPE: CHIP-seq. BIOLOGICAL SOURCE: Strain: N2; Developmental Stage: L3 Larva; Genotype: wild type; Sex: mixed Male and Hermaphrodite population; EXPERIMENTAL FACTORS: Developmental Stage L3 Larva; temp (temperature) 20 degree celsius; Strain N2; Antibody SDQ4663 RPC1 (target is RPC-1)
Project description:Genomewide mapping of D. melanogaster Snail protein binding during embryonic development at 2-4 hrs after egg-laying. Two independent repeats were assayed and preimmune-serum was used as a control. The enriched DNA was hybridized to high density Affymetrix GeneChip Drosophila Tiling 1.0R array
Project description:Genomewide mapping of D. melanogaster Tramtrack69 protein binding at 6-8hrs after egg laying. Two different rabbit antibodies were used to precipitate the Tramtrack69 protein isoform in 3 biological replicates. Additionally a rabbit preimmune-serum was used as a control for every precipitation. The enriched DNA was hybridized to high density Affymetrix GeneChip Drosophila Tiling 1.0R array.
Project description:Genomewide mapping of D. melanogaster Lame duck protein binding at 6-8hrs after egg laying. Two different rabbit antibodies were used to precipitate the Lmd protein isoform in biological replicates. Additionally a rabbit preimmune-serum was used as a control. The enriched DNA was hybridized to high density Affymetrix GeneChip Drosophila Tiling 1.0R array.
Project description:A large fraction of our genome consists of mobile genetic elements. Governing transposons in germ cells is critically important, and failure to do so compromises genome integrity, leading to sterility. In animals, the piRNA pathway is the key to transposon constraint, yet the precise molecular details of how piRNAs are formed and how the pathway represses mobile elements remain poorly understood. In an effort to identify general requirements for transposon control and novel components of the piRNA pathway, we carried out a genome-wide RNAi screen in Drosophila ovarian somatic sheet cells. We identified and validated 87 genes necessary for transposon silencing. Among these were several novel piRNA biogenesis factors. We also found CG3893 (asterix) to be essential for transposon silencing, most likely by contributing to the effector step of transcriptional repression. Asterix loss leads to decreases in H3K9me3 marks on certain transposons but has no effect on piRNA levels. We sequenced small RNAs, RNA-seq and ChIP-seq from either tj-Gal4 driven hpRNA knockdown flies or P-element insertion flies