Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, ROC.
Chem Biol Interact. 2013 Sep 5;205(1):20-8. doi: 10.1016/j.cbi.2013.06.004. Epub 2013 Jun 15.
Glioblastomas, the most common primary gliomas, are characterized by increased invasion and difficult therapy. Major clinical medicines for treating gliomas merely extend the survival time for a number of months. Therefore, development of new agents against gliomas is important. Autophagy, a process for degrading damaged organelles and proteins, is an adaptive response to environmental stress. However, the role of autophagy in glioblastoma development still needs to be further investigated. Evodiamine, a major alkaloid isolated from Evodia rutaecarpa Bentham, has various pharmacological activities, such as inhibiting tumor growth and metastatic properties. However, the effects of evodiamine on glioblastomas and their detailed molecular mechanisms and autophagy formation are not well understood. In this study, we observed that evodiamine induced dose- and time-dependent apoptosis in glioma cells. Blockade of calcium channels in endoplasmic reticulum (ER) significantly reduced evodiamine-induced cytosolic calcium elevation, apoptosis, and mitochondrial depolarization, which suggests that evodiamine induces a calcium-mediated intrinsic apoptosis pathway. Interestingly, autophagy was also enhanced by evodiamine, and had reached a plateau by 24h. Pharmacological inhibition of autophagy resulted in increased apoptosis and reduced cell viability. Inhibition of ER calcium channel activation also significantly reduced evodiamine-induced autophagy. Inactivation of c-Jun N-terminal kinases (JNK) suppressed evodiamine-mediated autophagy accompanied by increased apoptosis. Furthermore, evodiamine-mediated JNK activation was abolished by BAPTA-AM, an intracellular calcium scavenger, suggesting that evodiamine mediates autophagy via a calcium-JNK signaling pathway. Collectively, these results suggest that evodiamine induces intracellular calcium/JNK signaling-mediated autophagy and calcium/mitochondria-mediated apoptosis in glioma cells.
胶质母细胞瘤是最常见的原发性神经胶质瘤，其特征为侵袭性增加和治疗困难。治疗神经胶质瘤的主要临床药物仅能延长数月的生存时间。因此，开发针对神经胶质瘤的新药物非常重要。自噬是一种降解受损细胞器和蛋白质的过程，是对环境应激的适应性反应。然而，自噬在胶质母细胞瘤发展中的作用仍需要进一步研究。吴茱萸碱是从吴茱萸（Evodia rutaecarpa Bentham）中分离得到的主要生物碱，具有多种药理活性，如抑制肿瘤生长和转移特性。然而，吴茱萸碱对神经胶质瘤的作用及其详细的分子机制和自噬形成尚不清楚。在这项研究中，我们观察到吴茱萸碱诱导神经胶质瘤细胞剂量和时间依赖性凋亡。内质网（ER）钙通道阻断剂显著降低了吴茱萸碱诱导的细胞质钙离子升高、凋亡和线粒体去极化，这表明吴茱萸碱诱导了钙介导的内在凋亡途径。有趣的是，吴茱萸碱还能增强自噬，在 24 小时时达到平台期。自噬的药理学抑制导致凋亡增加和细胞活力降低。ER 钙通道激活抑制剂也显著降低了吴茱萸碱诱导的自噬。c-Jun N-末端激酶（JNK）抑制剂抑制了吴茱萸碱介导的自噬，同时增加了凋亡。此外，BAPTA-AM，一种细胞内钙离子清除剂，可消除吴茱萸碱介导的 JNK 激活，表明吴茱萸碱通过钙-JNK 信号通路介导自噬。总之，这些结果表明，吴茱萸碱诱导神经胶质瘤细胞内钙/JNK 信号通路介导的自噬和钙/线粒体介导的凋亡。
