CRISPR activation screens identify the SWI-SNF ATPases as suppressors of ferroptosis [NGS4183_ATAC]
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE245248 | GEO | 2024/07/01
REPOSITORIES: GEO
Similar Datasets
Project description:Ferroptosis is an iron-dependent cell death mechanism characterized by an accumulation of toxic lipid peroxides and membrane rupture. The glutathione dependent enzyme, GPX4 (glutathione peroxidase 4), prevents ferroptosis by reducing these lipid peroxides into non-toxic lipid alcohols. Ferroptosis induction by GPX4 inhibition has emerged as a vulnerability of cancer cells, thus highlighting the need to identify ferroptosis regulators that may be exploited therapeutically. Through genome-wide screens and a series of genetic, genomic, and quantitative imaging approaches, we identify the SWI-SNF ATPases BRM and BRG1 as ferroptosis suppressors. Mechanistically, they directly bind to and catalytically increase chromatin accessibility at NRF2 target loci, thus boosting NRF2 transcriptional output. This primes cells to counter lipid peroxidation and confers resistance to GPX4 inhibition and ferroptosis. Importantly, we demonstrate that the BRM/BRG1-ferroptosis connection can be leveraged to enhance the paralog dependency of BRG1-mutant lung cancer cells on BRM, especially in lines that are less sensitive to BRM inhibition or degradation. Our data reveal ferroptosis induction as a potential avenue for broadening the efficacy of BRM degraders/inhibitors and define a specific genetic context for exploiting GPX4 dependency.
2024-07-01 | GSE245247 | GEO
Project description:Ferroptosis is an iron-dependent cell death mechanism characterized by an accumulation of toxic lipid peroxides and membrane rupture. The glutathione dependent enzyme, GPX4 (glutathione peroxidase 4), prevents ferroptosis by reducing these lipid peroxides into non-toxic lipid alcohols. Ferroptosis induction by GPX4 inhibition has emerged as a vulnerability of cancer cells, thus highlighting the need to identify ferroptosis regulators that may be exploited therapeutically. Through genome-wide screens and a series of genetic, genomic, and quantitative imaging approaches, we identify the SWI-SNF ATPases BRM and BRG1 as ferroptosis suppressors. Mechanistically, they directly bind to and catalytically increase chromatin accessibility at NRF2 target loci, thus boosting NRF2 transcriptional output. This primes cells to counter lipid peroxidation and confers resistance to GPX4 inhibition and ferroptosis. Importantly, we demonstrate that the BRM/BRG1-ferroptosis connection can be leveraged to enhance the paralog dependency of BRG1-mutant lung cancer cells on BRM, especially in lines that are less sensitive to BRM inhibition or degradation. Our data reveal ferroptosis induction as a potential avenue for broadening the efficacy of BRM degraders/inhibitors and define a specific genetic context for exploiting GPX4 dependency.
2024-07-01 | GSE245246 | GEO
Project description:Ferroptosis is an iron-dependent cell death mechanism characterized by an accumulation of toxic lipid peroxides and membrane rupture. The glutathione dependent enzyme, GPX4 (glutathione peroxidase 4), prevents ferroptosis by reducing these lipid peroxides into non-toxic lipid alcohols. Ferroptosis induction by GPX4 inhibition has emerged as a vulnerability of cancer cells, thus highlighting the need to identify ferroptosis regulators that may be exploited therapeutically. Through genome-wide screens and a series of genetic, genomic, and quantitative imaging approaches, we identify the SWI-SNF ATPases BRM and BRG1 as ferroptosis suppressors. Mechanistically, they directly bind to and catalytically increase chromatin accessibility at NRF2 target loci, thus boosting NRF2 transcriptional output. This primes cells to counter lipid peroxidation and confers resistance to GPX4 inhibition and ferroptosis. Importantly, we demonstrate that the BRM/BRG1-ferroptosis connection can be leveraged to enhance the paralog dependency of BRG1-mutant lung cancer cells on BRM, especially in lines that are less sensitive to BRM inhibition or degradation. Our data reveal ferroptosis induction as a potential avenue for broadening the efficacy of BRM degraders/inhibitors and define a specific genetic context for exploiting GPX4 dependency.
2024-07-01 | GSE245244 | GEO
Project description:Ferroptosis is an iron-dependent cell death mechanism characterized by an accumulation of toxic lipid peroxides and membrane rupture. The glutathione dependent enzyme, GPX4 (glutathione peroxidase 4), prevents ferroptosis by reducing these lipid peroxides into non-toxic lipid alcohols. Ferroptosis induction by GPX4 inhibition has emerged as a vulnerability of cancer cells, thus highlighting the need to identify ferroptosis regulators that may be exploited therapeutically. Through genome-wide screens and a series of genetic, genomic, and quantitative imaging approaches, we identify the SWI-SNF ATPases BRM and BRG1 as ferroptosis suppressors. Mechanistically, they directly bind to and catalytically increase chromatin accessibility at NRF2 target loci, thus boosting NRF2 transcriptional output. This primes cells to counter lipid peroxidation and confers resistance to GPX4 inhibition and ferroptosis. Importantly, we demonstrate that the BRM/BRG1-ferroptosis connection can be leveraged to enhance the paralog dependency of BRG1-mutant lung cancer cells on BRM, especially in lines that are less sensitive to BRM inhibition or degradation. Our data reveal ferroptosis induction as a potential avenue for broadening the efficacy of BRM degraders/inhibitors and define a specific genetic context for exploiting GPX4 dependency.
2024-07-01 | GSE245243 | GEO
Project description:Ferroptosis is an iron-dependent cell death mechanism characterized by an accumulation of toxic lipid peroxides and membrane rupture. The glutathione dependent enzyme, GPX4 (glutathione peroxidase 4), prevents ferroptosis by reducing these lipid peroxides into non-toxic lipid alcohols. Ferroptosis induction by GPX4 inhibition has emerged as a vulnerability of cancer cells, thus highlighting the need to identify ferroptosis regulators that may be exploited therapeutically. Through genome-wide screens and a series of genetic, genomic, and quantitative imaging approaches, we identify the SWI-SNF ATPases BRM and BRG1 as ferroptosis suppressors. Mechanistically, they directly bind to and catalytically increase chromatin accessibility at NRF2 target loci, thus boosting NRF2 transcriptional output. This primes cells to counter lipid peroxidation and confers resistance to GPX4 inhibition and ferroptosis. Importantly, we demonstrate that the BRM/BRG1-ferroptosis connection can be leveraged to enhance the paralog dependency of BRG1-mutant lung cancer cells on BRM, especially in lines that are less sensitive to BRM inhibition or degradation. Our data reveal ferroptosis induction as a potential avenue for broadening the efficacy of BRM degraders/inhibitors and define a specific genetic context for exploiting GPX4 dependency.
2024-07-01 | GSE245242 | GEO
Project description:Ferroptosis is an iron-dependent cell death mechanism characterized by an accumulation of toxic lipid peroxides and membrane rupture. The glutathione dependent enzyme, GPX4 (glutathione peroxidase 4), prevents ferroptosis by reducing these lipid peroxides into non-toxic lipid alcohols. Ferroptosis induction by GPX4 inhibition has emerged as a vulnerability of cancer cells, thus highlighting the need to identify ferroptosis regulators that may be exploited therapeutically. Through genome-wide screens and a series of genetic, genomic, and quantitative imaging approaches, we identify the SWI-SNF ATPases BRM and BRG1 as ferroptosis suppressors. Mechanistically, they directly bind to and catalytically increase chromatin accessibility at NRF2 target loci, thus boosting NRF2 transcriptional output. This primes cells to counter lipid peroxidation and confers resistance to GPX4 inhibition and ferroptosis. Importantly, we demonstrate that the BRM/BRG1-ferroptosis connection can be leveraged to enhance the paralog dependency of BRG1-mutant lung cancer cells on BRM, especially in lines that are less sensitive to BRM inhibition or degradation. Our data reveal ferroptosis induction as a potential avenue for broadening the efficacy of BRM degraders/inhibitors and define a specific genetic context for exploiting GPX4 dependency.
2024-07-01 | GSE245245 | GEO
Project description:Invariant natural killer T (iNKT) cells are a group of innate like T cells that plays important roles in immune homeostasis and activation. We found that iNKT cells, compared to CD4+ T cells, have significantly higher levels of lipid peroxidation in both mice and humans. Proteomic analysis also demonstrated that iNKT cells express higher levels of Glutathione peroxidase 4 (Gpx4), a major antioxidant enzyme that reduces lipid peroxidation and prevents ferroptosis. T cell specific deletion of Gpx4 reduces iNKT cell population, most prominently the IFNg producing NKT1 subset. RNAseq analysis revealed IFNg signaling, cell cycle regulation, as well as mitochondrial function are perturbed by Gpx4 deletion in iNKT cells. Consistently, we detected impaired cytokine production, elevated cell proliferation and cell death, and accumulation of lipid peroxides and mitochondrial ROS in Gpx4 KO iNKT cells. Ferroptosis inhibitor, iron chelator, vitamin E and vitamin K2 can prevent ferroptosis induced by Gpx4 deficiency in iNKT cells and ameliorate the impaired function of iNKT cells due to Gpx4 inhibition. Lastly, vitamin E rescued iNKT cell population in Gpx4 KO mice. Altogether, our findings reveal the critical role of Gpx4 in regulating iNKT cell homeostasis and function, through controlling lipid peroxidation and ferroptosis.
2024-08-20 | GSE270485 | GEO
Project description:Ferroptosis is a form of regulated cell death characterized by iron-dependent overaccumulation of lipid peroxides. It can be prevented by cellular mechanisms such as GPX4-mediated elimination of the lipid peroxides at the cost of glutathione (GSH). Since originally being discovered as a property of RAS-mutant cancer cells, ferroptosis has been shown to be regulated by several important oncogenes and tumor suppressors. In particular, LIFR, the receptor of the pleiotropic cytokine LIF, has recently been shown to be required for ferroptosis, as loss of Lifr in mouse liver tumor confers the cells resistance to ferroptosis. In this study, however, we found that the LIFR-targeting drugs, EC330 and EC359, are potent inducers of ferroptosis, thus reflecting an interesting “gain-of-function” effect of EC330/EC359 on LIFR-associated ferroptosis. Treatment of various types of cells with EC330/EC359 causes a rapid nonapoptotic cell death with characteristic morphology of ferroptosis, which can be inhibited by iron chelator (DFO) and lipid ROS scavenger (Fer-1), but not pan-caspase inhibitor (z-VAD-fmk). Consistent with previous observations, the efficiency of EC330/EC359 appears to be correlated with the expression levels of LIF and LIFR. RNA-seq analysis showed that the EC330/EC359 treatment leads to (i) a gene expression profile highly resembling that of RSL3, the GPX4-targeting ferroptosis inducer, and (ii) a specific decrease of expression of a few gene encoding membrane-located proteins, especially those located on the mitochondria (e.g., TOMM6 and COX14), implying defects in cellular/mitochondrial membrane functions. Indeed, transmission electron microscopy imaging of the EC330/EC359-treated cells shows shrunken mitochondria and loss of mitochondrial cristae. EC330/EC359 also decreases the activity of GPX4 in the cells to the level comparable with RSL3; meanwhile, the intracellular level of GSH is also decreased, and thus GPX4 inactivation and GSH depletion may jointly disable the cells to eliminate the toxic lipid peroxides. Lastly, although the STAT3 and AKT signaling pathways downstream of LIFR are inhibited by EC330/EC359, inhibition of these pathways per se can only induce non-ferroptotic cell death, suggesting that the EC330/EC359-induced ferroptosis is independent of these downstream pathways; the LIFR-NFkB-LCN2 axis discovered recently in mouse liver tumor cells might not explain the EC330/EC359-induced ferroptosis either, because LCN2 is not detectable in the herein used cell lines. Taken together, these results reveal an unexpected role of the LIFR-targeting drugs EC330/EC359 as potent inducer of ferroptosis and, in combination with previous studies, suggest that there could be either unknown mechanism for the LIFR-associated ferroptosis or unknown target for EC330/EC359 to effect the ferroptosis induction.
2023-07-06 | GSE201493 | GEO
Project description:Earlier studies linked sorafenib effectiveness to induction of ferroptosis. Herein we demonstrate sorafenib and mTKIs downregulate DDX5 in vitro and in vivo. To understand the effect of DDX5 downregulation, we compared TCGA-derived HCCs expressing low vs. high DDX5 focusing on ferroptosis-related genes. Glutathione Peroxidase 4 (GPX4), a key ferroptosis regulator, was significantly overexpressed in DDX5LOW HCCs. Importantly, DDX5-knockdown (DDX5KD) HCC cell lines lacked lipid peroxidation by GPX4 inhibition, indicating DDX5 downregulation suppresses ferroptosis. RNAseq analyses comparing wild type vs. DDX5KD cells in the presence or absence of sorafenib, identified a unique set of genes repressed by DDX5 and upregulated by sorafenib. This set significantly overlaps genes from Wnt/β-catenin and non-canonical NF-κB pathways, including NF-κB inducing Kinase required for non-canonical NF-κB activation. Pharmacologic inhibition of these pathways in combination with sorafenib reduced DDX5KD cell viability. Mechanistically, sorafenib-mediated NF-κB activation induced NRF2 transcription, while DDX5KD extended NRF2 half/life by stabilizing p62/SQSTM1, leading to enhanced expression of GPX4 and ferroptosis escape. Conclusion: Sorafenib/mTKI-mediated DDX5 downregulation results in adaptive mTKI resistance by enhancing NRF2 expression, leading to ferroptosis escape. We propose inhibition of the pathways leading to NRF2 expression will enhance the therapeutic effectiveness of sorafenib/mTKIs.
2023-12-01 | GSE199092 | GEO
Project description:Ferroptosis is a recently identified program of regulated cell death, defined by excessive accumulation of hydroperoxy-arachidonoyl (C20:4)- or adrenoyl (C22:4)- phosphatidyl-ethanolamine (OOH-PE). The selenium-dependent glutathione peroxidase 4 (GPX4) inhibits ferroptosis, converting unstable ferroptotic lipid hydroperoxides to non-toxic lipid alcohols. The effect of GPX4 ablation is divergent among cells and tissues, suggesting that additional regulators may guard trophoblasts against ferroptosis. While placental oxidative stress and lipotoxicity are hallmarks of placental dysfunction, the possible role of ferroptosis in placental function has not been hitherto investigated. Here we found that placental dysfunction is associated with ferroptosis, and that inhibition of GPX4 causes trophoblast injury and ferroptosis in vitro and in vivo during mouse pregnancy. Importantly, we uncover a role for the phospholipase PLA2G6 (PNPLA9, iPLA2beta), known to metabolizes OOH-PE to lyso-PE and oxidized fatty acid, in mitigating ferroptosis induced by GPX4 inhibition in vitro or by hypoxia-reoxygenation injury in vivo. Together, we identified ferroptosis in the human and mouse placenta, and established a novel role for PLA2G6 in attenuating trophoblastic ferroptosis. Our data provide mechanistic insights to the ill-defined entity of placental lipotoxicity, and may inspire new therapeutic strategies that target PLA2G6 as a means to modulate ferroptosis in placental and non-placental tissue.
2020-09-27 | GSE147625 | GEO