Department of Immunobiology, College of Life Science and Technology, Jinan University, Guangzhou, China.
Department of Cell Biology, College of Life Science and Technology, Jinan University, Guangzhou, China.
Apoptosis. 2019 Apr;24(3-4):312-325. doi: 10.1007/s10495-019-01515-1.
Gasdermin E (GSDME) has an important role in inducing secondary necrosis/pyroptosis. Upon apoptotic stimulation, it can be cleaved by activated caspase-3 to generate its N-terminal fragment (GSDME-NT), which executes pyroptosis by perforating the plasma membrane. GSDME is expressed in many human lung cancers including A549 cells. Paclitaxel and cisplatin are two representative chemotherapeutic agents for lung cancers, which induce apoptosis via different action mechanisms. However, it remains unclear whether they can induce GSDME-mediated secondary necrosis/pyroptosis in lung A549 cancer cells. Here we showed that both paclitaxel and cisplatin evidently induced apoptosis in A549 cells as revealed by the activation of multiple apoptotic markers. Notably, some of the dying cells displayed characteristic morphology of secondary necrosis/pyroptosis, by blowing large bubbles from the cellular membrane accompanied by caspase-3 activation and GSDME-NT generation. But the ability of cisplatin to induce this phenomenon was much stronger than that of paclitaxel. Consistent with this, cisplatin triggered much higher activation of caspase-3 and generation of GSDME-NT than paclitaxel, suggesting that the levels of secondary necrosis/pyroptosis correlated with the levels of active caspase-3 and GSDME-NT. Supporting this, caspase-3 specific inhibitor (Ac-DEVD-CHO) suppressed cisplatin-induced GSDME-NT generation and concurrently reduced the secondary necrosis/pyroptosis. Besides, GSDME knockdown significantly inhibited cisplatin- but not paclitaxel-induced secondary necrosis/pyroptosis. These results indicated that cisplatin induced higher levels of secondary necrosis/pyroptosis in A549 cells than paclitaxel, suggesting that cisplatin may provide additional advantages in the treatment of lung cancers with high levels of GSDME expression.
Gasdermin E (GSDME) 在诱导继发坏死/细胞焦亡中起重要作用。在凋亡刺激下，它可以被激活的 caspase-3 切割生成其 N 端片段（GSDME-NT），后者通过穿孔质膜执行细胞焦亡。GSDME 在包括 A549 细胞在内的多种人类肺癌中表达。紫杉醇和顺铂是两种用于肺癌的代表性化疗药物，它们通过不同的作用机制诱导细胞凋亡。然而，目前尚不清楚它们是否能在肺癌 A549 细胞中诱导 GSDME 介导的继发坏死/细胞焦亡。在这里，我们发现紫杉醇和顺铂都明显诱导了 A549 细胞的凋亡，这表现为多种凋亡标志物的激活。值得注意的是，一些死亡细胞显示出继发坏死/细胞焦亡的特征形态，即细胞膜上出现大泡，伴随着 caspase-3 的激活和 GSDME-NT 的生成。然而，顺铂诱导这种现象的能力比紫杉醇强得多。与之一致的是，顺铂诱导的 caspase-3 激活和 GSDME-NT 的生成水平明显高于紫杉醇，这表明继发坏死/细胞焦亡的程度与活性 caspase-3 和 GSDME-NT 的水平相关。支持这一点的是，caspase-3 特异性抑制剂（Ac-DEVD-CHO）抑制了顺铂诱导的 GSDME-NT 生成，同时减少了继发坏死/细胞焦亡。此外，GSDME 敲低显著抑制了顺铂而非紫杉醇诱导的继发坏死/细胞焦亡。这些结果表明，顺铂在 A549 细胞中诱导的继发坏死/细胞焦亡水平高于紫杉醇，提示顺铂可能在治疗 GSDME 高表达的肺癌方面具有额外优势。
