Minnelide/Triptolide Impairs Mitochondrial Function by Regulating SIRT3 in P53-Dependent Manner in Non-Small Cell Lung Cancer.
Minnelide/Triptolide Impairs Mitochondrial Function by Regulating SIRT3 in P53-Dependent Manner in Non-Small Cell Lung Cancer.
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DOI：
10.1371/journal.pone.0160783
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
D'Cunha J
中科院分区：
文献类型：
--
作者：
Kumar A;Corey C;Scott I;Shiva S;D'Cunha J
明奈利德/雷公藤甲内酯（TL）最近成为一种治疗非小细胞肺癌（NSCLC）的有效抗癌药物。然而，其作用的确切机制仍不清楚。在这项研究中，我们阐明了在p53状态下tl诱导细胞死亡的分子基础。p53缺陷细胞的线粒体生物能量功能障碍导致细胞死亡，其特征是线粒体呼吸、稳态ATP水平和膜电位下降，但活性氧（ROS）增加。在tl处理的细胞中，ROS生成增加导致氧化应激。这表现为核中氧化还原敏感转录因子nf - e2相关因子-2 （NRF2）水平升高，以及细胞谷胱甘肽（GSH）含量减少。我们进一步证明，在p53缺失的情况下，TL减弱了线粒体SIRT3的表达，引发NDUAF9和琥珀酸脱氢酶的乙酰化增加，这是电子传递链（ETC）复合物I和II的组成部分。tl介导的复合物I和II蛋白的超乙酰化，这些复合物的酶活性下降。我们也提供了P53通过蛋白酶体通路调控SIRT3稳态水平的证据。最后，强制过表达Sirt3，而非Sirt3脱乙酰酶缺陷突变体（H243Y），通过挽救线粒体生物能量学来恢复TL对p53缺陷细胞的有害作用。相反，野生型p53背景下Sirt3缺乏触发TL诱导的线粒体损伤，这与p53缺陷细胞中的TL效应相呼应。这些发现说明了TL发挥其对线粒体功能和最终非小细胞肺癌肿瘤生存能力的强大影响的新机制。
Minnelide/Triptolide (TL) has recently emerged as a potent anticancer drug in non-small cell lung cancer (NSCLC). However, the precise mechanism of its action remains ambiguous. In this study, we elucidated the molecular basis for TL-induced cell death in context to p53 status. Cell death was attributed to dysfunction of mitochondrial bioenergetics in p53-deficient cells, which was characterized by decreased mitochondrial respiration, steady-state ATP level and membrane potential, but augmented reactive oxygen species (ROS). Increased ROS production resulted in oxidative stress in TL-treated cells. This was exhibited by elevated nuclear levels of a redox-sensitive transcriptional factor, NF-E2-related factor-2 (NRF2), along with diminished cellular glutathione (GSH) content. We further demonstrated that in the absence of p53, TL blunted the expression of mitochondrial SIRT3 triggering increased acetylation of NDUAF9 and succinate dehydrogenase, components of complexes I and II of the electron transport chain (ETC). TL-mediated hyperacetylation of complexes I and II proteins and these complexes displayed decreased enzymatic activities. We also provide the evidence that P53 regulate steady-state level of SIRT3 through Proteasome-Pathway. Finally, forced overexpression of Sirt3, but not deacetylase-deficient mutant of Sirt3 (H243Y), restored the deleterious effect of TL on p53-deficient cells by rescuing mitochondrial bioenergetics. On contrary, Sirt3 deficiency in the background of wild-type p53 triggered TL-induced mitochondrial impairment that echoed TL effect in p53-deficeint cells. These findings illustrate a novel mechanism by which TL exerts its potent effects on mitochondrial function and ultimately the viability of NSCLC tumor.