UCP2 inhibition induces ROS/Akt/mTOR axis: Role of GAPDH nuclear translocation in genipin/everolimus anticancer synergism
UCP2 inhibition induces ROS/Akt/mTOR axis: Role of GAPDH nuclear translocation in genipin/everolimus anticancer synergism
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DOI：
10.1016/j.freeradbiomed.2017.09.022
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发表时间：
2017-12-01
影响因子：
7.4
通讯作者：
Donadelli, Massimo
中科院分区：
文献类型：
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作者：
Dando, Ilaria;Pacchiana, Raffaella;Donadelli, Massimo
一些研究表明，线粒体解偶联蛋白2(UCP2)通过减少线粒体代谢产生的活性氧(ROS)和维持对过量抗癌药物的化疗耐药，在癌症的发生发展中发挥关键作用。在这里，我们证明了抑制UCP2在胰腺癌细胞中以一种ROS依赖的机制触发Akt/mTOR通路。这一事件减少了京尼平抑制UCP2的抗增殖结果，为mTOR抑制剂伊维洛莫斯协同对抗癌细胞生长创造了条件。京尼平和依维莫司对胰腺癌细胞生长的抑制和对细胞凋亡的诱导作用与胞浆糖酵解酶3-磷酸甘油醛脱氢酶的核转位有关。合成化合物(S)-benzyl-2-amino-2-(S)-3-bromo-4，5-dihydroisoxazol-5-yl-acetate(AXP3009)与GAPDH结合在其氧化还原敏感的Cys152上，恢复了京尼平和伊维洛莫斯联合处理影响的细胞活力，表明ROS的产生在GAPDH核转位中发挥作用。自噬抑制剂3-甲基腺嘌呤进一步增强了由genipin和everolimus诱导的Caspasase诱导的细胞凋亡，显示了对Beclin1诱导的自噬的保护作用。小鼠胰腺癌异种移植进一步证实了联合用药的抗增殖效果，且对动物无毒性作用。注射UCP2和mTOR抑制剂的小鼠肿瘤肿块显示，肿瘤体积和有丝分裂数显著减少，与显著的GAPDH核阳性相关。总之，这些结果揭示了UCP2促进癌细胞增殖的新机制，并支持联合抑制UCP2和Akt/mTOR通路作为治疗胰腺癌的新策略。
Several studies indicate that mitochondrial uncoupling protein 2 (UCP2) plays a pivotal role in cancer development by decreasing reactive oxygen species (ROS) produced by mitochondrial metabolism and by sustaining chemoresistance to a plethora of anticancer drugs. Here, we demonstrate that inhibition of UCP2 triggers Akt/mTOR pathway in a ROS-dependent mechanism in pancreatic adenocarcinoma cells. This event reduces the antiproliferative outcome of UCP2 inhibition by genipin, creating the conditions for the synergistic counteraction of cancer cell growth with the mTOR inhibitor everolimus. Inhibition of pancreatic adenocarcinoma cell growth and induction of apoptosis by genipin and everolimus treatment are functionally related to nuclear translocation of the cytosolic glycolytic enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The synthetic compound (S)-benzyl-2-amino-2-(S)-3-bromo-4,5-dihydroisoxazol-5-yl-acetate (AXP3009), which binds GAPDH at its redox-sensitive Cys152, restores cell viability affected by the combined treatment with genipin and everolimus, suggesting a role for ROS production in the nuclear translocation of GAPDH. Caspasemediated apoptosis by genipin and everolimus is further potentiated by the autophagy inhibitor 3-methyladenine revealing a protective role for Beclin1-mediated autophagy induced by the treatment. Mice xenograft of pancreatic adenocarcinoma further confirmed the antiproliferative outcome of drug combination without toxic effects for animals. Tumor masses from mice injected with UCP2 and mTOR inhibitors revealed a strong reduction in tumor volume and number of mitosis associated with a marked GAPDH nuclear positivity. Altogether, these results reveal novel mechanisms through which UCP2 promotes cancer cell proliferation and support the combined inhibition of UCP2 and of Akt/mTOR pathway as a novel therapeutic strategy in the treatment of pancreatic adenocarcinoma.