Project description:This SuperSeries is composed of the following subset Series: GSE40970: ChIP-seq analysis of H3K27me3 histone modification in EZH2 mutant and wild type DLBCL cell lines GSE40971: Gene expression profiling of EZH2 mutant and wild type DLBCL cell lines treated with EZH2 inhibitor GSE41239: Gene expression profiling of two DLBCL cell lines upon shRNA mediated knockdown of EZH2 Refer to individual Series
Project description:We studied transcriptional changes by Affymetrix human microarrays in 2 DLBCL cell lines as a result of shRNA mediated knockdown of EZH2. In eukaryotes, epigenetic post-translational modification of histones is critical for regulation of chromatin structure and gene expression. EZH2 is the catalytic subunit of the Polycomb Repressive Complex 2 (PRC2) and is responsible for repressing target gene expression through methylation of histone H3 on lysine 27 (H3K27). Over-expression of EZH2 is implicated in tumorigenesis and correlates with poor prognosis in multiple tumor types. Recent reports have identified somatic heterozygous mutations of Y641 and A677 residues within the catalytic SET domain of EZH2 in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). The Y641 residue is the most frequently mutated residue, with 22% of GCB (Germinal Cell B-cell) DLBCL and FL harboring mutations at this site. These lymphomas exhibit increased H3K27 tri-methylation (H3K27me3) due to altered substrate preferences of the mutant enzymes. However, it is unknown whether direct inhibition of EZH2 methyltransferase activity alone will be effective in treating lymphomas carrying activating EZH2 mutations. Herein, we demonstrate that GSK126, a potent, highly-selective, SAM-competitive, small molecule inhibitor of EZH2 methyltransferase activity, decreases global H3K27me3 levels and reactivates silenced PRC2 target genes. GSK126 effectively inhibits the proliferation of EZH2 mutant DLBCL cell lines and dramatically inhibits the growth of EZH2 mutant DLBCL xenografts in mice. Together, these data demonstrate that pharmacological inhibition of EZH2 activity may provide a promising treatment for EZH2 mutant lymphoma. Pfeiffer and KARPAS-422 cells were treated with either shRNA targeting EZH2 (shEZH2) or a non targeting control (shNTC) for 10 days.
Project description:We studied transcriptional changes by Affymetrix human microarrays in 2 DLBCL cell lines as a result of shRNA mediated knockdown of EZH2. In eukaryotes, epigenetic post-translational modification of histones is critical for regulation of chromatin structure and gene expression. EZH2 is the catalytic subunit of the Polycomb Repressive Complex 2 (PRC2) and is responsible for repressing target gene expression through methylation of histone H3 on lysine 27 (H3K27). Over-expression of EZH2 is implicated in tumorigenesis and correlates with poor prognosis in multiple tumor types. Recent reports have identified somatic heterozygous mutations of Y641 and A677 residues within the catalytic SET domain of EZH2 in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). The Y641 residue is the most frequently mutated residue, with 22% of GCB (Germinal Cell B-cell) DLBCL and FL harboring mutations at this site. These lymphomas exhibit increased H3K27 tri-methylation (H3K27me3) due to altered substrate preferences of the mutant enzymes. However, it is unknown whether direct inhibition of EZH2 methyltransferase activity alone will be effective in treating lymphomas carrying activating EZH2 mutations. Herein, we demonstrate that GSK126, a potent, highly-selective, SAM-competitive, small molecule inhibitor of EZH2 methyltransferase activity, decreases global H3K27me3 levels and reactivates silenced PRC2 target genes. GSK126 effectively inhibits the proliferation of EZH2 mutant DLBCL cell lines and dramatically inhibits the growth of EZH2 mutant DLBCL xenografts in mice. Together, these data demonstrate that pharmacological inhibition of EZH2 activity may provide a promising treatment for EZH2 mutant lymphoma.
Project description:Knockdown of EZH2 in colorectal cancer cells by lentivirus-mediated shRNA, and use total RNA for sequencing analysis after determining the efficiency of EZH2 knockdown in order to analyze the gene expression affected by EZH2.
Project description:We studied transcriptional changes by Affymetrix human microarrays in DLBCL cell lines as a result of treatment with GSK126, a potent, highly-selective, SAM-competitive, small molecule inhibitor of EZH2 In eukaryotes, epigenetic post-translational modification of histones is critical for regulation of chromatin structure and gene expression. EZH2 is the catalytic subunit of the Polycomb Repressive Complex 2 (PRC2) and is responsible for repressing target gene expression through methylation of histone H3 on lysine 27 (H3K27). Over-expression of EZH2 is implicated in tumorigenesis and correlates with poor prognosis in multiple tumor types. Recent reports have identified somatic heterozygous mutations of Y641 and A677 residues within the catalytic SET domain of EZH2 in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). The Y641 residue is the most frequently mutated residue, with 22% of GCB (Germinal Cell B-cell) DLBCL and FL harboring mutations at this site. These lymphomas exhibit increased H3K27 tri-methylation (H3K27me3) due to altered substrate preferences of the mutant enzymes. However, it is unknown whether direct inhibition of EZH2 methyltransferase activity alone will be effective in treating lymphomas carrying activating EZH2 mutations. Herein, we demonstrate that GSK126, a potent, highly-selective, SAM-competitive, small molecule inhibitor of EZH2 methyltransferase activity, decreases global H3K27me3 levels and reactivates silenced PRC2 target genes. GSK126 effectively inhibits the proliferation of EZH2 mutant DLBCL cell lines and dramatically inhibits the growth of EZH2 mutant DLBCL xenografts in mice. Together, these data demonstrate that pharmacological inhibition of EZH2 activity may provide a promising treatment for EZH2 mutant lymphoma. 10 DLBCL cell lines (7 mutant and 3 wild type EZH2), that were differentially sensitive to GSK126 in proliferation assays, were treated for 72 hours, in duplicate (n=2), with either DMSO (vehicle) or 500nM of GSK126, a potent selective EZH2 inhibitor. EZH2 mutant cell lines are Pfeiffer, KARPAS-422, WSU-DLCL2, SU-DHL-10, SU-DHL-6, DB and SU-DHL-4. EZH2 wildtype cell lines are HT, OCI-LY-19 and Toledo.
Project description:Cereblon (CRBN), a substrate receptor of the E3 ubiquitin ligase complex CRL4CRBN, is the target of the immunomodulatory drugs lenalidomide and pomalidomide. Recently, it was demonstrated that binding of these drugs to CRBN promotes the ubiquitination and subsequent degradation of two common substrates, transcription factors Aiolos and Ikaros. Here we report that the pleiotropic pathway modifier CC-122, a new chemical entity termed pleiotropic pathway modifier binds CRBN and promotes degradation of Aiolos and Ikaros in diffuse large B-cell lymphoma (DLBCL) and T cells in vitro, in vivo and in patients, resulting in both cell autonomous as well as immunostimulatory effects. In DLBCL cell lines, CC-122-induced degradation or shRNA mediated knockdown of Aiolos and Ikaros correlates with increased transcription of interferon stimulated genes (ISGs) independent of interferon α, β, γ production and/or secretion and results in apoptosis in both ABC and GCB-DLBCL cell lines. Our results provide mechanistic insight into the cell of origin independent anti-lymphoma activity of CC-122, in contrast to the ABC subtype selective activity of lenalidomide. Microarray analysis of the OCI-LY10 activated B-cell diffuse large B-cell lymphoma (ABC-DLBCL) cell line treated with the compound CC-122 for 18 hours
Project description:Constitutive activation of the nuclear factor-kappa B (NF-kB) pathway is a hallmark of the activated B-cell-like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL). Recurrent mutations of NF-kB regulators that cause constitutive activity of this oncogenic pathway have been identified. However, it remains unclear how specific target genes are regulated. We identified the IkB-like protein NFKBIZ that binds NF-kB subunits and enhances transactivation of some NF-kB target genes while repressing others, to be upregulated in ACB compared to GCB DLBCL primary patient samples (p=5.1 x 10^-37). Knockdown of NFKBIZ by RNA interference was toxic to ABC but not GCB DLBCL cell lines. Gene expression profiling following NFKBIZ knockdown significantly downregulated a large number of NF-kB target genes, suggesting a central role in regulating NF-kB signaling. To further investigate the molecular mechanisms of how NFKBIZ mediates NF-kB signaling in ABC DLBCL, we performed immunoprecipitations and detected an interaction of NFKBIZ with both p50 and p52 NF-kB subunits, indicating that both the canonical and non-canonical NF-kB pathways are regulated by NFKBIZ. Collectively, our data imply that NFKBIZ is required for NF-kB signaling in ABC DLBCL and thus might represent a promising molecular target for future therapies. The complete dataset is comprised of three experiments with the male HBL-1 ABC DLBCL cell line: a) 8 paired GEP measurements after NFKBIZ inhibition by shRNA, b) 6 paired GEP measurements after applying the MLN inhibitor and c) 4 two-color measurements after applying a MALT inhibitor. This dataset includes 8 paired GEP measurements after NFKBIZ inhibition by shRNA.
Project description:The goals of this project are to study the transcriptome profiling (RNA-seq) of human fribroblast cells undergoing H3K27me3 decrease by histone mutants incorporation (H3.1K27A/M vs H3.1wt) or shRNA-mediated knockdown of specific histone H3K27me3 methyl-transferase EZH2 (shEZH2 vs shNC)
Project description:Cereblon (CRBN), a substrate receptor of the E3 ubiquitin ligase complex CRL4CRBN, is the target of the immunomodulatory drugs lenalidomide and pomalidomide. Recently, it was demonstrated that binding of these drugs to CRBN promotes the ubiquitination and subsequent degradation of two common substrates, transcription factors Aiolos and Ikaros. Here we report that the pleiotropic pathway modifier CC-122, a new chemical entity termed pleiotropic pathway modifier binds CRBN and promotes degradation of Aiolos and Ikaros in diffuse large B-cell lymphoma (DLBCL) and T cells in vitro, in vivo and in patients, resulting in both cell autonomous as well as immunostimulatory effects. In DLBCL cell lines, CC-122-induced degradation or shRNA mediated knockdown of Aiolos and Ikaros correlates with increased transcription of interferon stimulated genes (ISGs) independent of interferon α, β, γ production and/or secretion and results in apoptosis in both ABC and GCB-DLBCL cell lines. Our results provide mechanistic insight into the cell of origin independent anti-lymphoma activity of CC-122, in contrast to the ABC subtype selective activity of lenalidomide.