Project description:Using RNA interference to identify IRF4 target genes. Keywords: time series design Gene expression was analyzed using Lymphochip cDNA spotted arrays. Myeloma cell lines were infected with control (shluc, Cy3) or shIRF4 (Cy5) constructs, and changes in gene expression were monitored over time after induction of the shRNA with doxycyclin.
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: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:To identify IRF4 transcription factor binding on chromatin at 5' regulatory regions of genes in myeloma cell line models. Keywords: binding site identification design
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:Determine irf4 target genes in mouse B cells undergoing LPS differentiation to plasma cells in vitro. Determine targets of IRF4 by overexpression in a human GCB cell line. Keywords: cell type comparison design
Project description:Multiple myeloma (MM) is an incurable malignancy of plasma cells that exploits transcriptional networks driven by IRF4. To discover unique molecular vulnerabilities in MM centered on IRF4, we employ a multi-omics approach integrating functional genomics screening, spatial proteomics, and global chromatin mapping. We find that ARID1A, a member of the SWI/SNF chromatin remodeling complex, is both required for IRF4 expression and functionally associated with IRF4 protein on chromatin. Deletion of Arid1a in activated murine B cells thwarts subsequent plasma cell differentiation by disrupting IRF4-dependent transcriptional networks, therefore defining ARID1A as a novel plasma cell vulnerability. Targeting ARID1A-dependent SWI/SNF activity via SMARCA2/4 inhibition induces a rapid loss of IRF4-target gene expression and quenches global amplification of oncogenic gene expression driven by MYC, resulting in profound toxicity to MM cells. Notably, MM patients with aggressive disease have markers of SWI/SNF activity, and SMARCA2/4 inhibitors retain their activity in immunomodulatory drug (IMiD)-resistant MM cells. To fully harness the potential of these drugs, we use combinatorial drug screens to uncover profound synergistic toxicity between SMARCA2/4 and MEK inhibitors. Thus, targeting SWI/SNF activity potently represses an IRF4-MYC feed forward loop and provides a feasible path to effectively treat this incurable disease.
Project description:RNA interference screens identified the transcription factor IRF4 as essential for the survival of the activated B-cell-like subtype of diffuse large B-cell lymphoma (ABC-DLBCL). Analysis of IRF4 genomic targets in ABC-DLBCL and Multiple Myeloma (MM) revealed that IRF4 regulates distinct networks in these cancers. IRF4 peaks in ABC-DLBCL, but not MM, were enriched for a composite ETS-IRF DNA motif that can be bound by heterodimers of IRF4 and the ETS-family transcription factor SPIB, whose expression is also essential for ABC-DLBCL survival. Gene expression and ChIP-Seq analysis identified essential genes co-regulated by IRF4 and SPIB. Together, these factors regulate a critical oncogenic loop by activating CARD11, which controls ABC-DLBCL survival via the NF-kB pathway. The interaction between IRF4 and SPIB presents an attractive therapeutic target in this aggressive lymphoma.
Project description:Transcriptional profiling of T-cells isolated from spleen of IRF4 -/- mice and cultured under Th17 polarizing conditions for 42 hrs compared to cells similarly isolated and cultured from spleen of IRF4 +/- mice. The aim of the study was to identify global misexpression of genes in IRF4 -/- cells and hence identify key pathways regulated by IRF4 during Th17 differentiation. Two-condition experiment, IRF4 -/- vs IRF4 +/- Th17 cells at 42hrs. Biological replicates: 3 for each condition