title: Nitric oxide boosts chemoimmunotherapy via inhibition of acid sphingomyelinase in a mouse model of melanoma.
abstract: Cisplatin is one of the most effective anticancer drugs, but its severe toxic effects, including depletion of immune-competent cells, limit its efficacy. We combined the systemic treatment with cisplatin with intratumor delivery of dendritic cells (DC) previously treated ex vivo with a pulse of nitric oxide (NO) released by the NO donors (z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]-diazen-1-ium-1,2-diolate or isosorbide dinitrate. We found that this chemoimmunotherapy, tested in the B16 mouse model of melanoma, was significantly more efficacious than cisplatin alone, leading to tumor regression and animal survival at low doses of cisplatin that alone had no effect. Tumor cure was not observed when combining cisplatin with DCs not exposed to NO donors, indicating the key role of the pretreatment with NO. We investigated the mechanisms responsible for the synergic effect of NO-treated DCs and cisplatin and found that NO-treated DCs were protected both in vitro and in vivo from cisplatin-induced cytotoxicity. Cisplatin triggered DC apoptosis through increased expression and activation of acid sphingomyelinase; pretreatment of DCs with NO donors prevented such activation and inhibited activation of the downstream proapoptotic events, including generation of ceramide, activation of caspases 3 and 9, and mitochondrial depolarization. The effects of NO were mediated through generation of its physiologic messenger, cyclic GMP. We conclude that NO and NO generating drugs represent promising tools to increase the efficacy of chemoimmunotherapies in vivo, promoting the survival and increasing the function of injected cells by targeting a key pathway in cisplatin-induced cytotoxicity.
authors: H. San Raffaele Scientific Institute, Italy.
authors: Cristiana
authors: C
authors: Perrotta
authors: Laura
authors: L
authors: Bizzozero
authors: Sestina
authors: S
authors: Falcone
authors: Patrizia
authors: P
authors: Rovere-Querini
authors: Alessandro
authors: A
authors: Prinetti
authors: Edward H
authors: EH
authors: Schuchman
authors: Sandro
authors: S
authors: Sonnino
authors: Angelo A
authors: AA
authors: Manfredi
authors: Emilio
authors: E
authors: Clementi
mesh_terms: D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D002945:Cisplatin / Q000008:administration & dosage; D003131:Combined Modality Therapy; D003713:Dendritic Cells / Q000276:immunology*; D004357:Drug Synergism; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D016219:Immunotherapy, Adoptive / Q000379:methods*; D007548:Isosorbide Dinitrate / Q000008:administration & dosage; D008546:Melanoma, Experimental / Q000188:drug therapy / Q000201:enzymology / Q000276:immunology / Q000628:therapy*; D051379:Mice; D008810:Mice, Inbred C57BL; D020030:Nitric Oxide Donors / Q000008:administration & dosage; D009603:Nitroso Compounds / Q000008:administration & dosage; D013108:Sphingomyelin Phosphodiesterase / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D020030:Nitric Oxide Donors; D009603:Nitroso Compounds; C094210:2,2'-(hydroxynitrosohydrazono)bis-ethanamine; D013108:Sphingomyelin Phosphodiesterase; D007548:Isosorbide Dinitrate; D002945:Cisplatin