Nonapoptotic cell death is important for human health and disease. Here, we show how various tools and techniques drawn from the chemical biology field have played a central role in the discovery and ...characterization of nonapoptotic cell death pathways. Focusing on the example of ferroptosis, we describe how phenotypic screening, chemoproteomics, chemical genetic analysis, and other methods enabled the elucidation of this pathway. Synthetic small-molecule inducers and inhibitors of ferroptosis identified in early studies have now been leveraged to identify an even broader set of compounds that affect ferroptosis and to validate new chemical methods and probes for various ferroptosis-associated processes. A number of limitations associated with specific chemical biology tools or techniques have also emerged and must be carefully considered. Nevertheless, the study of ferroptosis provides a roadmap for how chemical biology methods may be used to discover and characterize nonapoptotic cell death mechanisms.
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Nonapoptotic cell death is important for normal and disease biology. In this review, Armenta and Dixon summarize how chemical biology approaches have been used to discover and characterize nonapoptotic cell death pathways, such as ferroptosis, and also consider some of the limitations of these approaches.
Ferroptosis regulation by the NGLY1/NFE2L1 pathway Forcina, Giovanni C; Pope, Lauren; Murray, Magdalena ...
Proceedings of the National Academy of Sciences - PNAS,
03/2022, Letnik:
119, Številka:
11
Journal Article
Recenzirano
Odprti dostop
SignificanceFerroptosis is an oxidative form of cell death whose biochemical regulation remains incompletely understood. Cap'n'collar (CNC) transcription factors including nuclear factor ...erythroid-2-related factor 1 (NFE2L1/NRF1) and NFE2L2/NRF2 can both regulate oxidative stress pathways but are each regulated in a distinct manner, and whether these two transcription factors can regulate ferroptosis independent of one another is unclear. We find that NFE2L1 can promote ferroptosis resistance, independent of NFE2L2, by maintaining the expression of glutathione peroxidase 4 (GPX4), a key protein that prevents lethal lipid peroxidation. NFE2L2 can also promote ferroptosis resistance but does so through a distinct mechanism that appears independent of GPX4 protein expression. These results suggest that NFE2L1 and NFE2L2 independently regulate ferroptosis.
Ferroptosis is an important mediator of pathophysiological cell death and an emerging target for cancer therapy. Whether ferroptosis sensitivity is governed by a single regulatory mechanism is ...unclear. Here, based on the integration of 24 published chemical genetic screens combined with targeted follow-up experimentation, we find that the genetic regulation of ferroptosis sensitivity is highly variable and context-dependent. For example, the lipid metabolic gene acyl-coenzyme A (CoA) synthetase long chain family member 4 (ACSL4) appears far more essential for ferroptosis triggered by direct inhibition of the lipid hydroperoxidase glutathione peroxidase 4 (GPX4) than by cystine deprivation. Despite this, distinct pro-ferroptotic stimuli converge upon a common lethal effector mechanism: accumulation of lipid peroxides at the plasma membrane. These results indicate that distinct genetic mechanisms regulate ferroptosis sensitivity, with implications for the initiation and analysis of this process in vivo.
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•An integrated genetic network reveals high variability in ferroptosis regulation•ACSL4 is most important for ferroptosis in response to direct GPX4 inhibition•AGPS is not required for ferroptosis in all contexts•Ferroptotic stimuli converge on plasma membrane lipid peroxidation
The genetic regulation of ferroptosis remains poorly understood. Magtanong et al. demonstrate that ACSL4, AGPS, and other lipid metabolic genes are context-dependent ferroptosis regulators that are not universally essential for this process. Results suggest that there may not exist a single ferroptosis genetic regulatory mechanism in all cells and conditions.
Copper-induced cell death Kahlson, Martha A; Dixon, Scott J
Science (American Association for the Advancement of Science),
03/2022, Letnik:
375, Številka:
6586
Journal Article
Recenzirano
Excess copper causes mitochondrial protein aggregation and triggers a distinct form of cell death.
Malignant tumors exhibit heterogeneous metabolic reprogramming, hindering the identification of translatable vulnerabilities for metabolism-targeted therapy. How molecular alterations in tumors ...promote metabolic diversity and distinct targetable dependencies remains poorly defined. Here we create a resource consisting of lipidomic, transcriptomic, and genomic data from 156 molecularly diverse glioblastoma (GBM) tumors and derivative models. Through integrated analysis of the GBM lipidome with molecular datasets, we identify CDKN2A deletion remodels the GBM lipidome, notably redistributing oxidizable polyunsaturated fatty acids into distinct lipid compartments. Consequently, CDKN2A-deleted GBMs display higher lipid peroxidation, selectively priming tumors for ferroptosis. Together, this study presents a molecular and lipidomic resource of clinical and preclinical GBM specimens, which we leverage to detect a therapeutically exploitable link between a recurring molecular lesion and altered lipid metabolism in GBM.
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•Molecular and lipidomic resource of over 150 GBM tumors and derivative models•Unbiased multi-omic analysis identifies CDKN2A as a regulator of lipid metabolism•CDKN2A deletion reduces oxidizable PUFA sequestration into lipid droplets•GBMs with CDKN2A deletion are susceptible to lipid peroxidation and ferroptosis
Minami et al. integrate lipidomic, transcriptomic, and genomic profiling data to identify altered lipid metabolism in CDKN2A-deleted glioblastoma (GBM). CDKN2A deletion remodels the distribution of polyunsaturated fatty acids into different lipid compartments, sensitizing GBMs with CDKN2A loss to lipid peroxidation and ferroptosis in vitro and in vivo.
Synthetic lethality is a genetic interaction wherein two otherwise nonessential genes cause cellular inviability when knocked out simultaneously. Drugs can mimic genetic knock-out effects; therefore, ...our understanding of promiscuous drugs, polypharmacology-related adverse drug reactions, and multi-drug therapies, especially cancer combination therapy, may be informed by a deeper understanding of synthetic lethality. However, the colossal experimental burden in humans necessitates in silico methods to guide the identification of synthetic lethal pairs. Here, we present SINaTRA (Species-INdependent TRAnslation), a network-based methodology that discovers genome-wide synthetic lethality in translation between species. SINaTRA uses connectivity homology, defined as biological connectivity patterns that persist across species, to identify synthetic lethal pairs. Importantly, our approach does not rely on genetic homology or structural and functional similarity, and it significantly outperforms models utilizing these data. We validate SINaTRA by predicting synthetic lethality in S. pombe using S. cerevisiae data, then identify over one million putative human synthetic lethal pairs to guide experimental approaches. We highlight the translational applications of our algorithm for drug discovery by identifying clusters of genes significantly enriched for single- and multi-drug cancer therapies.
The selenoprotein glutathione peroxidase 4 (GPX4) prevents ferroptosis by converting lipid peroxides into nontoxic lipid alcohols. GPX4 has emerged as a promising therapeutic target for cancer ...treatment, but some cancer cells are resistant to ferroptosis triggered by GPX4 inhibition. Using a chemical-genetic screen, we identify LRP8 (also known as ApoER2) as a ferroptosis resistance factor that is upregulated in cancer. Loss of LRP8 decreases cellular selenium levels and the expression of a subset of selenoproteins. Counter to the canonical hierarchical selenoprotein regulatory program, GPX4 levels are strongly reduced due to impaired translation. Mechanistically, low selenium levels result in ribosome stalling at the inefficiently decoded GPX4 selenocysteine UGA codon, leading to ribosome collisions, early translation termination and proteasomal clearance of the N-terminal GPX4 fragment. These findings reveal rewiring of the selenoprotein hierarchy in cancer cells and identify ribosome stalling and collisions during GPX4 translation as ferroptosis vulnerabilities in cancer.
Necroptosis is an important form of lytic cell death triggered by injury and infection, but whether mixed lineage kinase domain-like (MLKL) is sufficient to execute this pathway is unknown. In a ...genetic selection for human cell mutants defective for MLKL-dependent necroptosis, we identified mutations in IPMK and ITPK1, which encode inositol phosphate (IP) kinases that regulate the IP code of soluble molecules. We show that IP kinases are essential for necroptosis triggered by death receptor activation, herpesvirus infection, or a pro-necrotic MLKL mutant. In IP kinase mutant cells, MLKL failed to oligomerize and localize to membranes despite proper receptor-interacting protein kinase-3 (RIPK3)-dependent phosphorylation. We demonstrate that necroptosis requires IP-specific kinase activity and that a highly phosphorylated product, but not a lowly phosphorylated precursor, potently displaces the MLKL auto-inhibitory brace region. These observations reveal control of MLKL-mediated necroptosis by a metabolite and identify a key molecular mechanism underlying regulated cell death.
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•IP kinases are critical for necroptosis induced by TNF and viral infection•MLKL fails to oligomerize in IP kinase mutants despite phosphorylation by RIPK3•Necroptosis requires IP kinase activity to produce the IP code•IP6—but not IP3—displaces the MLKL auto-inhibitory brace region
Dovey et al. report an unexpected layer of regulation governing a form of cell death termed necroptosis. They find that the inositol phosphate code controls the executioner protein MLKL to induce cell lysis. This study deepens our understanding of cell death mechanisms important for infection, inflammation, and cancer.
Ferroptosis is a regulated form of cell death associated with the iron-dependent accumulation of phospholipid hydroperoxides. Inducing ferroptosis is a promising approach to treat therapy-resistant ...cancer. Ferroptosis suppressor protein 1 (FSP1) promotes ferroptosis resistance in cancer by generating the antioxidant form of coenzyme Q10 (CoQ). Despite the important role of FSP1, few molecular tools exist that target the CoQ-FSP1 pathway. Through a series of chemical screens, we identify several structurally diverse FSP1 inhibitors. The most potent of these compounds, ferroptosis sensitizer 1 (FSEN1), is an uncompetitive inhibitor that acts selectively through on-target inhibition of FSP1 to sensitize cancer cells to ferroptosis. Furthermore, a synthetic lethality screen reveals that FSEN1 synergizes with endoperoxide-containing ferroptosis inducers, including dihydroartemisinin, to trigger ferroptosis. These results provide new tools that catalyze the exploration of FSP1 as a therapeutic target and highlight the value of combinatorial therapeutic regimes targeting FSP1 and additional ferroptosis defense pathways.
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•Identification of structurally diverse small molecule inhibitors of FSP1•FSEN1 is an uncompetitive FSP1 inhibitor that sensitizes cancer cells to ferroptosis•FSEN1 synergizes with GPX4 inhibitors and endoperoxide-based ferroptosis inducers
Hendricks et al. identify a set of structurally diverse small molecules that inhibit FSP1, a CoQ oxidoreductase that suppresses ferroptosis. The most potent FSP1 inhibitor, ferroptosis sensitizer 1 (FSEN1) sensitizes cancer cells to ferroptosis and synergizes with several ferroptosis inducers, including GPX4 inhibitors and endoperoxide-containing molecules such as DHA.
Colorectal cancer (CRC) is the third most common cancer and a leading cause of cancer-related mortality. Observed during CRC tumorigenesis is loss of post-transcriptional regulation of ...tumor-promoting genes such as COX-2, TNFα and VEGF. Overexpression of the RNA-binding protein HuR (ELAVL1) occurs during colon tumorigenesis and is abnormally present within the cytoplasm, where it post-transcriptionally regulates genes through its interaction with 3'UTR AU-rich elements (AREs). Here, we examine the therapeutic potential of targeting HuR using MS-444, a small molecule HuR inhibitor. Treatment of CRC cells with MS-444 resulted in growth inhibition and increased apoptotic gene expression, while similar treatment doses in non-transformed intestinal cells had no appreciable effects. Mechanistically, MS-444 disrupted HuR cytoplasmic trafficking and released ARE-mRNAs for localization to P-bodies, but did not affect total HuR expression levels. This resulted in MS-444-mediated inhibition of COX-2 and other ARE-mRNA expression levels. Importantly, MS-444 was well tolerated and inhibited xenograft CRC tumor growth through enhanced apoptosis and decreased angiogenesis upon intraperitoneal administration. In vivo treatment of MS-444 inhibited HuR cytoplasmic localization and decreased COX-2 expression in tumors. These findings provide evidence that therapeutic strategies to target HuR in CRC warrant further investigation in an effort to move this approach to the clinic.
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