title: RAS-RAF-MEK-dependent oxidative cell death involving voltage-dependent anion channels.
abstract: 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. 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 ligands to VDAC proteins can induce non-apoptotic cell death selectively in some tumour cells harbouring activating mutations in the RAS-RAF-MEK pathway.
authors.affiliation: Department of Biological Sciences, Fairchild Center, 1212 Amsterdam Avenue, MC 2406, New York, New York 10027, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Yagoda
authors.forename: Moritz
authors.initials: M
authors.lastname: von Rechenberg
authors.forename: Elma
authors.initials: E
authors.lastname: Zaganjor
authors.forename: Andras J
authors.initials: AJ
authors.lastname: Bauer
authors.forename: Wan Seok
authors.initials: WS
authors.lastname: Yang
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Fridman
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Wolpaw
authors.forename: Inese
authors.initials: I
authors.lastname: Smukste
authors.forename: John M
authors.initials: JM
authors.lastname: Peltier
authors.forename: J Jay
authors.initials: JJ
authors.lastname: Boniface
authors.forename: Richard
authors.initials: R
authors.lastname: Smith
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Lessnick
authors.forename: Sudhir
authors.initials: S
authors.lastname: Sahasrabudhe
authors.forename: Brent R
authors.initials: BR
authors.lastname: Stockwell
mesh_terms: D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*; D010766:Phosphorylation / Q000187:drug effects; D010879:Piperazines / Q000494:pharmacology* / Q000633:toxicity; D012680:Sensitivity and Specificity; D015398:Signal Transduction / Q000187:drug effects*; D050996:Voltage-Dependent Anion Channel 2 / Q000378:metabolism*; D048490:raf Kinases / Q000378:metabolism*; D018631:ras Proteins / Q000378:metabolism*
chemical_list: D010879:Piperazines; D050996:Voltage-Dependent Anion Channel 2; C477224:erastin; D048490:raf Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; D018631:ras Proteins