Mitochondrial transmembrane potential and reactive oxygen species generation regulate the enhanced effect of CCCP on TRAIL-induced SNU-638 cell apoptosis
Mitochondrial transmembrane potential and reactive oxygen species generation regulate the enhanced effect of CCCP on TRAIL-induced SNU-638 cell apoptosis
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DOI：
10.1292/jvms.70.537
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发表时间：
2008-06-01
影响因子：
1.2
通讯作者：
Park, Sang-Youel
中科院分区：
文献类型：
--
作者：
Chaudhari, Atul A.;Seol, Jae-Won;Park, Sang-Youel
TRAIL是肿瘤坏死因子家族的成员，通过募集和快速激活caspase-8参与细胞凋亡。本研究探讨了氧化磷酸化的经典解偶联剂羰基氰间氯苯腙（CCCP）对TRAIL诱导的人胃癌细胞SNU-638细胞凋亡的影响。结果发现，与单独用TRAIL处理相比，用CCCP处理后再用TRAIL孵育显著增强凋亡2倍。这种作用伴随着线粒体跨膜电位的降低和活性氧的产生。N-乙酰-L-半胱氨酸可抑制这种致敏作用，恢复线粒体跨膜电位，减少活性氧的产生。用N-乙酰-L-半胱氨酸处理也抑制凋亡蛋白如Bax和Smac的表达，并废除caspase-8的活化。此外，在用TRAIL诱导之前用N-乙酰-L-半胱氨酸处理增加了抗凋亡Bcl-2蛋白的表达。这些数据表明，CCCP通过线粒体跨膜电位和活性氧的耗散增强了TRAIL诱导的凋亡，表明用CCCP与TRAIL联合治疗可以是诱导肿瘤细胞死亡的有效方法，特别是对TRAIL诱导的凋亡有抗性的细胞。
TRAIL is a member of the tumor necrosis factor family and engages apoptosis via recruitment and rapid activation of caspase-8. This study investigated the effect of carbonyl cyanide m-chlorophenylhydrazone (CCCP), a classic uncoupler of oxidative phosphorylation, on TRAIL-induced apoptosis in SNU-638 cells derived from human gastric cancer cells. It was found that treatment with CCCP followed by incubation with TRAIL markedly enhanced apoptosis by 2 fold compared with treatment with TRAIL alone. This effect was accompanied by reduction in mitochondrial transmembrane potential and generation of reactive oxygen species. This sensitization was inhibited by N-acetyl-l-cysteine, which restored the mitochondrial transmembrane potential and reduced reactive oxygen species generation. Treatment with N-acetyl-L-cysteine also inhibited expression of apoptotic proteins such as Bax and Smac and abrogated caspase-8 activation. Moreover, treatment with N-acetyl-L-cysteine prior to induction with TRAIL increased expression of the anti-apoptotic Bcl-2 protein. These data indicate that CCCP enhanced TRAIL-induced apoptosis by dissipation of mitochondrial transmembrane potential and reactive oxygen species, suggesting that treatment with CCCP combined with that with TRAIL can be an efficient method to induce death of tumor cells, particularly cells that are resistant to TRAIL-induced apoptosis.