Therapeutics that discriminate between the genetic makeup of normal cells and tumour cells are valuable for treating and understanding cancer. Small molecules with oncogene-selective lethality may reveal novel functions of oncoproteins and enable the creation of more selective drugs 1 . Here we describe the mechanism of action of the selective anti-tumour agent erastin, involving the RAS-RAF-MEK signalling pathway functioning in cell proliferation, differentiation and survival. Erastin exhibits greater lethality in human tumour cells harbouring mutations in the oncogenes HRAS, KRAS or BRAF. Using affinity purification and mass spectrometry, we discovered that erastin acts through mitochondrial voltage-dependent anion channels (VDACs)-a novel target for anti-cancer drugs. We show that erastin treatment of cells harbouring oncogenic RAS causes the appearance of oxidative species and subsequent death through an oxidative, non-apoptotic mechanism. RNA-interference-mediated knockdown of VDAC2 or VDAC3 caused resistance to erastin, implicating these two VDAC isoforms in the mechanism of action of erastin. Moreover, using purified mitochondria expressing a single VDAC isoform, we found that erastin alters the permeability of the outer mitochondrial membrane. Finally, using a radiolabelled analogue and a filter-binding assay, we show that erastin binds directly to VDAC2. These results demonstrate that * These authors contributed equally to this work.Supplementary Information is linked to the online version of the paper at www.nature.com/nature. Author Contributions N.Y. designed and performed the RNAi and VDAC overexpression, quantitative PCR, erastin analogue viability and chemical characterization experiments. E.Z. performed two-dimensional western analysis, PARP-1 and pro-caspase-3 cleavage, and cytochrome c release experiments. E.Z. and N.Y. performed transmission electron microscopy experiments. A.J.B., D.J.F. and N.Y. performed the NADH oxidation and direct binding experiments. W.S.Y. characterized sensitivity to erastin in the BJderived cell series. A.J.W. performed the MEK1/2 inhibitor experiment. I.S. and A.J.B. synthesized erastin analogues. R.S. and S.L.L. provided BRAF shRNAs, analysis of BRAF knockdown and the phospho-ERK western analysis. J.M.P., J.J.B. and S.S. were responsible for setting up the technology platform to pull down proteins binding to small molecule compounds. M.v.R. and J.M.P. performed the pull-down experiments. J.J.B., J.M.P. and S.S. designed, reviewed and supervised the pull-down experiments, and contributed to the analysis of the data. B.R.S. conceived of and supervised the project, designed and analysed experiments, and performed the anti-oxidant studies. B.R.S. and N.Y. prepared the manuscript. (Fig. 1a , Supplementary Fig. 1 and ref. 3 ). This cell death was not dependent on the rate of cell division, nor was it idiosyncratic to these cells ( Fig. 1a and Supplementary Fig. 2), because cell lines engineered in a similar way responded similarly. Author InformationWe found th...

Apoptosis is known as programmed cell death. Some non-apoptotic cell death is increasingly recognized as genetically controlled, or ‘regulated’. However, the full extent and diversity of these alternative cell death mechanisms remains uncharted. Here, we surveyed the landscape of pharmacologically-accessible cell death mechanisms. Of 56 caspase-independent lethal compounds, modulatory profiling revealed ten inducing three types of regulated non-apoptotic cell death. Lead optimization of one of the ten resulted in the discovery of FIN56, a specific inducer of ferroptosis. Ferroptosis occurs when the lipid repair enzyme GPX4 is inhibited. We found that FIN56 promotes degradation of GPX4. We performed chemoproteomics to reveal that FIN56 also binds to and activates squalene synthase, an enzyme involved in the cholesterol synthesis, in a manner independent of GPX4 degradation. These discoveries reveal that dysregulation of lipid metabolism is associated with ferroptosis. This systematic approach is a means to discover and characterize novel cell death phenotypes.

Cell death is a complex process that plays a vital role in development, homeostasis, and disease. Our understanding of and ability to control cell death is impeded by an incomplete characterization of the full range of cell death processes that occur in mammalian systems, especially in response to exogenous perturbations. We present here a general approach to address this problem, which we call modulatory profiling. Modulatory profiles are composed of the changes in potency and efficacy of lethal compounds produced by a second cell death-modulating agent in human cell lines. We show that compounds with the same characterized mechanism of action have similar modulatory profiles. Furthermore, clustering of modulatory profiles revealed relationships not evident when clustering lethal compounds based on gene expression profiles alone. Finally, modulatory profiling of compounds correctly predicted three previously uncharacterized compounds to be microtubule-destabilizing agents, classified numerous compounds that act nonspecifically, and identified compounds that cause cell death through a mechanism that is morphologically and biochemically distinct from previously established ones.apoptosis | chemical biology | small molecules C ell death has historically been viewed as a binary phenomenon. Cells were described to die in one of two ways-through a controlled and ordered process (apoptosis) or an unregulated and chaotic process (necrosis) (1, 2). Not only were these often considered the only two possible mechanisms, but they were also frequently viewed as morphologically and biochemically uniform (3, 4). A great deal of research in recent decades has not only shown the complexity and heterogeneity of apoptotic and necrotic signaling, but also that cells can die in physiological and nonphysiological contexts through processes morphologically and biochemically distinct from both apoptosis and necrosis.Activation of caspases, a family of cysteine proteases, is essential for producing the full morphological characteristics of apoptosis. There are at least three distinct pathways that can lead to the activation of effector caspases-the extrinsic death receptor pathway, the intrinsic mitochondrial pathway, and the Granzyme B pathway (5)-but numerous mechanisms feed into these three pathways. There is substantial evidence that necrosis, long considered to be a disorganized and unregulated process, can proceed through an evolutionarily conserved pathway in a highly orchestrated fashion. Necrosis-like morphology has been observed after death receptor stimulation (6-12), after treatment with DNA-damaging agents (13-15), and in Caenorhabditis elegans in response to a variety of stresses (16,17). These examples illustrate the heterogeneity of cell death processes resembling necrosis. A widely debated nonapoptotic, nonnecrotic cell death mechanism is autophagic cell death, which has been implicated in vivo in the involution of the salivary gland in Drosophila (18) and in death because of the hypersensitivity response in Arabidopsi...

Links between oncogenic drivers and cancer cell metabolism have emerged over the past several decades, indicating that constitutive oncogenic growth signaling can render cancers susceptible to metabolic interventions. While significant progress has been achieved in the identification of metabolic vulnerabilities of cancer cells, the complexity of the tumor microenvironment (TME) and the dynamic nature of organismal circadian metabolism challenge the precision of targeting cancer metabolism. Here current progress in the areas of cancer metabolism and TME metabolism is reviewed, highlighting how cancer metabolism can be accurately and precisely targeted.