Targeting EZH2 methyltransferase activity in ARID1A mutated cells as a synthetic lethal therapeutic strategy
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE54979 | GEO | 2015/01/20
SECONDARY ACCESSION(S): PRJNA238190
REPOSITORIES: GEO
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Project description:ARID1A, an epigentic modifier, is often mutated in ovarian clear cell carcinoma (OCCC). In addition, EZH2 is frequently upregulated in OCCC. Inhibtion of EZH2 with an inhibitor (GSK126) selectively inhibits ARID1A-mutated cells. This study was designed to understand changes in gene expression profiles following EZH2 inhibition or ARID1A restoration. Chromatin remodelers such as ARID1A are frequently mutated in a broad array of cancers. However, targeted cancer therapy based on ARID1A mutation status has not been described. Intriguingly, ARID1A mutated cancers typically lack genomic instability, suggesting significant involvement of epigenetic mechanisms. Here we show that inhibition of the EZH2 methyltransferase acts in a synthetic lethal manner in ARID1A mutated cells. Remarkably, ARID1A mutation status correlated with response to EZH2 inhibitor. Genome-wide profiling revealed antagonistic roles of ARID1A and EZH2 in gene regulation. Further, we identified PIK3IP1 as a direct ARID1A/EZH2 target gene whose upregulation contributes to the observed synthetic lethality in the EZH2 inhibitor treated ARID1A mutated cells. Significantly, EZH2 inhibitor caused the regression of established ARID1A mutated tumors in vivo. Together, this data demonstrate a synthetic lethality between ARID1A mutation and EZH2 inhibition. They indicate that pharmacological inhibition of EZH2 represents a novel treatment strategy for ARID1A mutated cancers.
2015-01-20 | E-GEOD-54979 | biostudies-arrayexpress
Project description:The SWI/SNF chromatin remodeling complex is altered in ~20% of human cancers. ARID1A, a component of the SWI/SNF chromatin-remodeling complex, is the most frequently mutated epigenetic regulator in human cancers. Inactivation of the SWI/SNF complex is synthetically lethal with inhibition of EZH2 activity. EZH2 inhibitors are entering clinical trials for specific tumor types with SWI/SNF mutations. However, mechanisms of de novo or acquired resistance to EZH2 inhibitors in cancers with inactivating SWI/SNF mutations are unknown. Here we show that the switch of the SWI/SNF catalytic subunits from SMARCA4 to SMARCA2 drives resistance to EZH2 inhibitors in ARID1A-mutated ovarian cancer cells.
2019-02-10 | GSE110449 | GEO
Project description:The SWI/SNF chromatin remodeling complex is altered in ~20% of human cancers. ARID1A, a component of the SWI/SNF chromatin-remodeling complex, is the most frequently mutated epigenetic regulator in human cancers. Inactivation of the SWI/SNF complex is synthetically lethal with inhibition of EZH2 activity. EZH2 inhibitors are entering clinical trials for specific tumor types with SWI/SNF mutations. However, mechanisms of de novo or acquired resistance to EZH2 inhibitors in cancers with inactivating SWI/SNF mutations are unknown. Here we show that the switch of the SWI/SNF catalytic subunits from SMARCA4 to SMARCA2 drives resistance to EZH2 inhibitors in ARID1A-mutated ovarian cancer cells.
2019-02-10 | GSE110448 | GEO
Project description:Ovarian clear cell carcinoma (OCCC) is a cancer of unmet need characterized by ARID1A mutation. Prior work identified an ARID1A/ATR synthetic lethality, information that led to phase II clinical trials. Using genome-wide CRISPR-Cas9 mutagenesis and interference screens, we identified protein phosphatase 2A (PP2A) subunits, including PPP2R1A, as determinants of ATRi sensitivity in ARID1A mutant OCCC. Analysis of an OCCCs cohort indicated that >1/3 possessed both PPP2R1A and ARID1A loss-of-function mutations. CRISPR-prime editing demonstrated that oncogenic PPP2R1A p.R183 missense mutations enhance in vitro and in vivo ATRi sensitivity in ARID1A mutant OCCC. OCCC patients with both ARID1A and PPP2R1A mutations also showed clinical responses to ATRi in a phase II trial. Mechanistically, this synthetic lethal effect is dependent upon WNK1 kinase, which opposes PP2A function. This data suggests that co-occurrence of PPP2R1A and ARID1A mutations in OCCC should be assessed as a biomarker of ATRi response in on-going clinical trials.
2023-05-10 | PXD040422 | Pride
Project description:ARID1A is frequently mutated in ovarian clear-cell carcinoma (OCCC) and often co-exists with activating mutations of PIK3CA. Although induction of pro-inflammatory cytokines has been observed in this cancer, the mechanism by which the two mutations synergistically activate cytokine genes remains elusive. Here we established an in vitro model of OCCC by introducing ARID1A knock-down and mutant PIK3CA in a normal human ovarian epithelial cell line, which resulted in cell transformation and cytokine gene induction. We demonstrate that loss of ARID1A impairs the recruitment of the Sin3A-HDAC complex, while PIK3CA mutation releases RelA from IkB, leading to cytokine gene activation. We show that an NF-kB inhibitor partly attenuates proliferation of OCCC and improves the efficacy of carboplatin both in cell culture and a mouse model. Our study thus reveals the mechanistic link between ARID1A/PIK3CA mutations and cytokine gene induction in OCCC, and suggests NF-kB inhibition can be a potential therapeutic option.
2016-09-15 | GSE86004 | GEO
Project description:ARID1A, encoding a subunit of the SWI/SNF chromatin remodeling complex, is the most mutated epigenetic regulator in human cancers. ARID1A and TP53 mutations are typically mutually exclusive. Therapeutic approaches that correlate with ARID1A mutational status remain a challenge. Here, we show that HDAC6 activity is essential in ARID1A-mutated ovarian cancers. Inhibition of HDAC6 activity using a clinically applicable small molecule inhibitor significantly improved the survival of mice bearing ARID1A-mutated ovarian tumors. This correlated with the suppression of growth and dissemination of ARID1A-mutated, but not wild-type, tumors. The dependence on HDAC6 activity in ARID1A-mutated cells correlated with a direct transcriptional repression of HDAC6 by ARID1A. HDAC6 inhibition selectively promoted apoptosis of ARID1A-mutated cells. HDAC6 directly deacetylated the Lysine 120 residue of p53, a pro-apoptotic post-translational modification. Thus, ARID1A mutation inactivates p53’ apoptotic function by upregulating HDAC6. These results indicate that pharmacological inhibition of HDAC6 is a novel therapeutic strategy involving ARID1A-mutation
2017-07-14 | GSE84405 | GEO
Project description:ARID1A, encoding a subunit of the SWI/SNF chromatin remodeling complex, is the most frequently mutated epigenetic regulators in human cancers. ARID1A is mutated in over 50% ovarian clear cell carcinoma, a disease currently has no effective therapy. Here we show that ARID1A-mutated ovarian cancer cells are selectively sensitive to inhibition of HDAC2 activity. HDAC2 interacts with EZH2 in an ARID1A status dependent manner. HDAC2 knockdown inhibits the growth of ARID1A inactivated by not proficient ovarian cancer cells. HDAC2 functions as a co-repressor of EZH2 to suppress the expression of EZH2/ARID1A target tumor suppressor genes such as PIK3IP1, an inhibitor of PI3K/AKT signaling, to inhibit proliferation and promote apoptosis. Indeed, a FDA-approved pan-HDAC inhibitor suberoylannilide hydroxamine (SAHA) significantly suppressed the growth and reduced the ascites of the ARID1A-inactivated ovarian cancers in both orthotopic and genetic mouse models. This correlated with a significant improvement of survival of mice bearing ARID1A-mutated ovarian cancers.
2018-03-09 | GSE107201 | GEO
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.
2012-10-12 | E-GEOD-40971 | biostudies-arrayexpress
Project description:ARID1A, a subunit of SWI/SNF chromatin remodeling complex. SWI/SNF complex can regulate expression of genes involved in vital biological processes such as cell cycle, DNA damage repair and development. ARID1A is known to have high mutation rate in human cancers including bladder cancer, leading to its loss of function. Publicly available whole exome sequencing data for muscle invasive and non-muscle invasive bladder cancers, show fraction of tumors with truncated ARID1A. Thus identifying therapeutic strategies for ARID1A mutant cancers is of high importance. EZH2, a histone methyltransferase is known to over-express and play pivotal role in aggressive bladder cancer. Our preliminary studies show that treatment of EZH2 inhibitor (GSK126) on ARID1A mutant bladder cancer cells significantly reduced cancer cell viability, invasion and colony formation relative to wild type ARID1A containing cells. Here, we performed microarray experiments to assess the effect of EZH2 inhibitor on global transcriptome of both ARID1A mutant and wild type bladder cancer cell line.
2023-05-01 | GSE150249 | GEO
Project description:Alterations in components of the SWI/SNF chromatin-remodeling complex occur in ~20% of all human cancers. For example, ARID1A is mutated in up to 62% of clear cell ovarian carcinoma (OCCC), a disease currently lacking effective therapies. Here we show that ARID1A mutation creates a dependence on glutamine metabolism. SWI/SNF represses glutaminase I (GLS1) and ARID1A inactivation upregulates GLS1. ARID1A inactivation increases glutamine utilization and metabolism through the tricarboxylic acid cycle to support aspartate synthesis. Indeed, glutaminase inhibitor CB-839 suppresses the growth of ARID1A mutant, but not wildtype, OCCCs in both orthotopic and patient-derived xenografts. In addition, glutaminase inhibitor CB-839 synergizes with immune checkpoint blockade anti-PDL1 antibody in a genetic OCCC mouse model driven by conditional Arid1a inactivation. Our data indicate that pharmacological inhibition of glutaminase alone or in combination with immune checkpoint blockade represents a novel therapeutic strategy for cancers involving alterations in the SWI/SNF complex such as ARID1A mutations.
2020-10-21 | MSV000086347 | MassIVE