Ying Jun, Yang Wei, Xie Chun-Ying, Ni Qin-Chun, Pan Xue-Diao, Dong Jin-Hua, Liu Zhi-Min, Wang Xi-Sha
Center for Drug Non-Clinical Research and Evaluation of Pharmaceutical Industrial Research Institute in Guangzhou, Guangdong, China.
Yakugaku Zasshi. 2011;131(9):1383-94. doi: 10.1248/yakushi.131.1383.
δ-Elemene, an antitumor component, is a chemical compound isolated from Curcuma wenyujin, a Chinese traditional herb. We examined whether δ-elemene could inhibit cell growth and cell cycle progression and induce apoptosis in human leukemia HL-60 cells. The results demonstrated that δ-elemene induces significant apoptosis of HL-60 cells, as shown by MTT assay, annexin V (AnV) binding of externalized phosphatidylserine (PS), and the mitochondrial probe JC-1 using flow cytometry. HL-60 cells treated with δ-elemene showed high percentages in the early apoptotic and late apoptoctic/necrotic stages, as well as caspase-3 activation of HL-60 cells. By monitoring the changes in cell cycle profiles, we confirmed that δ-elemene could interfere with the cell cycle in the G2/M phase and induce apoptosis in HL-60 cells in a time-dependent manner. Caspase-3 plays a direct role in proteolytic cleavage of the cellular proteins responsible for progression to apoptosis. Therefore we examined apoptosis in HL-60 cells after exposure to δ-elemene and measured caspase-3 activities with or without Z-Val-Ala-Asp-fluoromethylketone (z-VAD-fmk, a broad-spectrum caspase inhibitor) pretreatment using flow cytometric analysis. The results showed that δ-elemene could induce caspase-3 activation as detected by the decrease in δ-elemene-induced caspase-3 activities after treatment with z-VAD-fmk. In the present study, δ-elemene activated typical caspase-dependent apoptosis in HL-60 cells, as demonstrated by an inhibitory effect of z-VAD-fmk on this cell death. During δ-elemene-induced apoptosis, cytochrome c and apoptosis-inducing factor were released into the cytosol and BAX was translocated from the cytosol to mitochondria. However, these were not prevented by z-VAD-fmk. In conclusion, our study demonstrated that δ-elemene could induce G2/M cell cycle transition and trigger apoptosis through a caspase-3-dependent pathway.
榄香烯是一种从传统中药莪术中分离得到的抗肿瘤化合物。我们研究了榄香烯是否能够抑制人白血病HL - 60细胞的生长和细胞周期进程，并诱导其凋亡。结果表明，通过MTT法、膜联蛋白V（AnV）结合外翻磷脂酰丝氨酸（PS）以及使用流式细胞术检测线粒体探针JC - 1，榄香烯可显著诱导HL - 60细胞凋亡。用榄香烯处理的HL - 60细胞在早期凋亡和晚期凋亡/坏死阶段呈现高比例，同时HL - 60细胞的半胱天冬酶 - 3被激活。通过监测细胞周期谱的变化，我们证实榄香烯能够干扰细胞周期的G2/M期，并以时间依赖性方式诱导HL - 60细胞凋亡。半胱天冬酶 - 3在负责凋亡进程的细胞蛋白的蛋白水解切割中起直接作用。因此，我们在榄香烯处理后检测HL - 60细胞的凋亡情况，并使用流式细胞术分析在有无Z - 缬氨酸 - 丙氨酸 - 天冬氨酸 - 氟甲基酮（z - VAD - fmk，一种广谱半胱天冬酶抑制剂）预处理的情况下测量半胱天冬酶 - 3的活性。结果显示，在用z - VAD - fmk处理后，榄香烯诱导的半胱天冬酶 - 3活性降低，表明榄香烯可诱导半胱天冬酶 - 3激活。在本研究中，z - VAD - fmk对这种细胞死亡具有抑制作用，证明榄香烯在HL - 60细胞中激活了典型的半胱天冬酶依赖性凋亡。在榄香烯诱导的凋亡过程中，细胞色素c和凋亡诱导因子释放到细胞质中，BAX从细胞质转位到线粒体。然而，这些并未被z - VAD - fmk阻止。总之，我们的研究表明榄香烯可诱导G2/M细胞周期转变，并通过半胱天冬酶 - 3依赖性途径触发凋亡。
