Perrotta Cristiana, Bizzozero Laura, Falcone Sestina, Rovere-Querini Patrizia, Prinetti Alessandro, Schuchman Edward H, Sonnino Sandro, Manfredi Angelo A, Clementi Emilio
H. San Raffaele Scientific Institute, Italy.
Cancer Res. 2007 Aug 15;67(16):7559-64. doi: 10.1158/0008-5472.CAN-07-0309.
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.
顺铂是最有效的抗癌药物之一，但其严重的毒性作用，包括免疫活性细胞的耗竭，限制了其疗效。我们将顺铂的全身治疗与肿瘤内递送树突状细胞（DC）相结合，这些树突状细胞是之前在体外经一氧化氮（NO）供体（Z）-1-[2-（2-氨基乙基）-N-（2-氨乙基）氨基]-重氮-1-鎓-1,2-二醇盐或硝酸异山梨酯释放的一氧化氮脉冲处理过的。我们发现，这种在黑色素瘤B16小鼠模型中测试的化学免疫疗法比单独使用顺铂显著更有效，在低剂量顺铂单独使用无效的情况下导致肿瘤消退和动物存活。当顺铂与未暴露于NO供体的DC联合使用时未观察到肿瘤治愈，这表明NO预处理的关键作用。我们研究了负责NO处理的DC和顺铂协同作用的机制，发现NO处理的DC在体外和体内均受到保护，免受顺铂诱导的细胞毒性。顺铂通过酸性鞘磷脂酶表达和激活的增加触发DC凋亡；用NO供体预处理DC可防止这种激活，并抑制下游促凋亡事件的激活，包括神经酰胺的生成、半胱天冬酶3和9的激活以及线粒体去极化。NO的作用是通过其生理信使环鸟苷酸的生成介导的。我们得出结论，NO和产生NO的药物是提高体内化学免疫疗法疗效的有前景的工具，通过靶向顺铂诱导的细胞毒性中的关键途径促进注射细胞的存活并增强其功能。
