Smac mimetic triggers necroptosis in pancreatic carcinoma cells when caspase activation is blocked.
Evasion of apoptosis represents a key mechanism of treatment resistance of pancreatic cancer (PC) and contributes to the poor prognosis of this cancer type. Here, we report that induction of necroptosis is an alternative strategy to trigger programmed cell death in apoptosis-resistant PC cells. We show that the second mitochondrial activator of caspases (Smac) mimetic BV6 that antagonizes inhibitor of apoptosis (IAP) proteins induces necroptosis in PC cells in which apoptosis is blocked by the caspase inhibitor zVAD.fmk. Intriguingly, BV6 switches autocrine/paracrine production of tumor necrosis factor (TNF)α by PC cells into a death signal and also acts in concert with exogenously supplied TNFα to trigger necroptosis, when caspase activation is simultaneously blocked. BV6 stimulates TNFα production and formation of the receptor-interacting protein (RIP)1/RIP3-containing necrosome complex in PC cells. Knockdown of TNF receptor 1 (TNFR1) protects PC cells from BV6- or BV6/TNFα-mediated cell death, demonstrating that TNFα autocrine/paracrine signaling by PC cells contributes to BV6-induced necroptosis. Importantly, genetic silencing of receptor interacting protein kinase 3 (RIPK3) or mixed lineage kinase domain-like protein (MLKL) significantly rescues PC cells from BV6- or BV6/TNFα-induced cell death. Similarly, pharmacological inhibition of RIP1, RIP3 or MLKL significantly reduces BV6- or BV6/TNFα-stimulated cell death. By demonstrating that Smac mimetics can bypass resistance to apoptosis by triggering necroptosis as an alternative form of programmed cell death, our findings have important implications for the design of new treatment concepts for PC.
Institute for Experimental Cancer Research in Pediatrics, Goethe-University, Komturstr. 3a, 60528 Frankfurt, Germany; General and Visceral Surgery, Goethe-University, Frankfurt, Germany.
Sabine
S
Hannes
Institute for Experimental Cancer Research in Pediatrics, Goethe-University, Komturstr. 3a, 60528 Frankfurt, Germany.
Behnaz Ahangarian
BA
Abhari
Institute for Experimental Cancer Research in Pediatrics, Goethe-University, Komturstr. 3a, 60528 Frankfurt, Germany; German Cancer Consortium (DKTK), Heidelberg, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany. Electronic address: simone.fulda@kgu.de.
Simone
S
Fulda
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins; D019898:Autocrine Communication / Q000187:drug effects; D000067558:Biological Mimicry; D061945:Caspase Inhibitors / Q000494:pharmacology*; D020169:Caspases / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000494:pharmacology*; D019169:Jurkat Cells; D020930:MAP Kinase Kinase Kinases / Q000235:genetics / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000494:pharmacology*; D009336:Necrosis; D028861:Nuclear Pore Complex Proteins / Q000235:genetics / Q000378:metabolism; D009842:Oligopeptides / Q000494:pharmacology*; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D019899:Paracrine Communication / Q000187:drug effects; D034622:RNA Interference; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
C119724:AGFG1 protein, human; D000590:Amino Acid Chloromethyl Ketones; D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; C582180:BV6 peptide; D061945:Caspase Inhibitors; C412403:DIABLO protein, human; D051034:Inhibitor of Apoptosis Proteins; D047908:Intracellular Signaling Peptides and Proteins; D024101:Mitochondrial Proteins; D028861:Nuclear Pore Complex Proteins; D009842:Oligopeptides; D016601:RNA-Binding Proteins; D047888:Receptors, Tumor Necrosis Factor, Type I; C506235:TNFRSF1A protein, human; D014409:Tumor Necrosis Factor-alpha; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C119705:RIPK3 protein, human; D053422:Receptor-Interacting Protein Serine-Threonine Kinases; D020930:MAP Kinase Kinase Kinases; C433243:MAP3K9 protein, human; D020169:Caspases
Cell death; IAP proteins; Necroptosis; Pancreatic carcinoma; Smac mimetic