Project description:Pharmacological inhibition of chromatin co-regulatory factors represents a clinically validated strategy to modulate oncogenic signaling through selective attenuation of gene expression. Here, we demonstrate that CBP/EP300 bromodomain inhibition preferentially abrogates the viability of multiple myeloma cell lines. Phenotypic effects are preceded by the direct transcriptional suppression of the lymphocyte-specific transcription factor IRF4 and the subsequent down-regulation of the IRF4 transcriptional program. Ectopic expression of IRF4 antagonizes the phenotypic effects of CBP/EP300 bromodomain inhibition and prevents the suppression of the IRF4 target c-MYC. These findings suggest that CBP/EP300 bromodomain inhibition represents a viable therapeutic strategy for targeting multiple myeloma and other lymphoid malignancies dependent on the IRF4 network. A total of 13 ChIP-seq samples were sequenced. Samples were treated with control (DMSO) or test compound (2.5 uM SGC-CBP30 or 0.25uM CPI267203) for 6 hours. Signal from input samples was included to subtract background signal from each ChIP-seq sample. Antibodies used were against p300, H3K18ac, H3K27ac, or BRD4.
Project description:The goal of this gene expression study was to identify genes whose expression depends on the transription factor IRF4 by knocking down it's expression using shRNA in two IRF4+ myeloma cell lines. Keywords: time series design Two myeloma lines were analyzed over a time course of IRF4-targeted shRNA induction. There are 3 time courses: two using KMS12 (biological replicates) and one with SKMM1. Within each time course there are technical replicates.
Project description:ChIP-seq data for the transcription factors (TFs) IRF4, PU.1 and SPIB from the cell lines OCI-LY3, OCI-LY10 and H929, and BATF from the cell lines OCI-Ly3 and OCI-Ly10. In addition ChIP-seq for the TFs IRF4, PU.1 and SPIB from the cell line OCI-LY3 following transfections of scramble/SPIB-siRNA. ChIP-seq data for the transcription factors (TFs) IRF4, PU.1 and SPIB from the cell lines OCI-LY3, OCI-LY10 and H929, and BATF from the cell lines OCI-Ly3 and OCI-Ly10. In addition ChIP-seq for the TFs IRF4, PU.1 and SPIB from the cell line OCI-LY3 following transfections of scramble/SPIB-siRNA.
Project description:Pharmacological inhibition of chromatin co-regulatory factors represents a clinically validated strategy to modulate oncogenic signaling through selective attenuation of gene expression. Here, we demonstrate that CBP/EP300 bromodomain inhibition preferentially abrogates the viability of multiple myeloma cell lines. Phenotypic effects are preceded by the direct transcriptional suppression of the lymphocyte-specific transcription factor IRF4 and the subsequent down-regulation of the IRF4 transcriptional program. Ectopic expression of IRF4 antagonizes the phenotypic effects of CBP/EP300 bromodomain inhibition and prevents the suppression of the IRF4 target c-MYC. These findings suggest that CBP/EP300 bromodomain inhibition represents a viable therapeutic strategy for targeting multiple myeloma and other lymphoid malignancies dependent on the IRF4 network.
Project description:To identify IRF4 transcription factor binding on chromatin at 5' regulatory regions of genes in myeloma cell line models. Keywords: binding site identification design Formaldehyde cross-linked, sonicated chromatin is prepared from cell lines Kms12 (test) and Ly19 (control). Chromatin immunoprecipated with anti-IRF4 antibody is labeled with Cy5 and co-hybridized on Agilent Human Promoter Set arrays with chromatin immunoprecipated with normal sera labeled with Cy3 . Two biological replicates were performed for the Kms12 and Ly19 experiments.
Project description:The goal of this gene expression study was to identify genes whose expression depends on the transription factor IRF4 by knocking down it's expression using shRNA in two IRF4+ myeloma cell lines. Keywords: time series design
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.