c-Jun氨基末端激酶1和半胱天冬酶3在他莫昔芬诱导的大鼠胶质瘤细胞凋亡中的激活作用。
Activation of c-Jun N-terminal kinase 1 and caspase 3 in the tamoxifen-induced apoptosis of rat glioma cells.
作者信息
Tseng Sheng-Hong, Wang Chih-Hsien, Lin Swei-Ming, Chen Chia-Kang, Huang Hsin-Yi, Chen Yun
机构信息
Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, 7 Chung-Shan S. Road, Taipei, Taiwan.
出版信息
J Cancer Res Clin Oncol. 2004 May;130(5):285-93. doi: 10.1007/s00432-004-0546-y. Epub 2004 Mar 2.
PURPOSE
The mechanisms of the antitumor effects of tamoxifen upon gliomas are still unclear. In this study, we investigated the role of c-Jun N-terminal kinase-1 (JNK1) and caspase 3 in the tamoxifen-induced apoptosis of rat glioma cells.
METHODS
Glioma cells were treated with tamoxifen, followed by a cytotoxicity assay to study its effects on the cells, and then a flow-activated cell sorter (FACS) analysis was performed to analyze the cellular apoptosis of the glioma cells. The expression of JNK1 and phospho-specific JNK1 in glioma cells treated with tamoxifen was investigated by Western blot analysis. The activity of caspase 3 in glioma cells was analyzed by caspase activity assay.
RESULTS
Tamoxifen was demonstrated to exert cytotoxic effects upon and induced apoptosis of the glioma cells in a concentration- and time-dependent manner (P<0.05). Western blot analysis demonstrated that tamoxifen increased the expression of phospho-specific JNK1 in glioma cells, and an increasing concentration of tamoxifen induced an increasing expression of phospho-specific JNK1. Four-hour 50-microM tamoxifen treatment increased the expression of phospho-specific JNK1 to 3.2 times that of the control level in glioma cells. Tamoxifen also increased the activity of caspase 3 in glioma cells. Pretreatment of glioma cells with the antisense oligonucleotide (OGN) of JNK1 immediately prior to tamoxifen treatment suppressed the expression of phospho-specific JNK1 and the activity of caspase 3. The apoptosis fraction of glioma cells induced by 4-h treatment with 50 microM tamoxifen was decreased from 51% to 28% by pretreatment with the antisense OGN of JNK1 (P<0.003), and to 20% by pretreatment with caspase 3 inhibitor (DEVD-CHO) (P<0.0008).
CONCLUSIONS
The results suggest that the tamoxifen-induced apoptosis of rat glioma cells is related to the activation of the JNK1/caspase 3 signaling pathway; however, the confirmation of the occurrence of such activation in vivo needs further investigation.
目的
他莫昔芬对胶质瘤的抗肿瘤作用机制尚不清楚。在本研究中，我们调查了c-Jun氨基末端激酶-1（JNK1）和半胱天冬酶3在他莫昔芬诱导大鼠胶质瘤细胞凋亡中的作用。
方法
用他莫昔芬处理胶质瘤细胞，随后进行细胞毒性试验以研究其对细胞的影响，然后进行流式细胞仪分析以分析胶质瘤细胞的细胞凋亡情况。通过蛋白质免疫印迹分析研究用他莫昔芬处理的胶质瘤细胞中JNK1和磷酸化特异性JNK1的表达。通过半胱天冬酶活性测定分析胶质瘤细胞中半胱天冬酶3的活性。
结果
他莫昔芬被证明对胶质瘤细胞具有细胞毒性作用，并以浓度和时间依赖性方式诱导其凋亡（P<0.05）。蛋白质免疫印迹分析表明，他莫昔芬增加了胶质瘤细胞中磷酸化特异性JNK1的表达，且他莫昔芬浓度增加会诱导磷酸化特异性JNK1表达增加。用50μM他莫昔芬处理4小时后，胶质瘤细胞中磷酸化特异性JNK1的表达增加至对照水平的3.2倍。他莫昔芬还增加了胶质瘤细胞中半胱天冬酶3的活性。在用他莫昔芬处理之前立即用JNK1反义寡核苷酸（OGN）预处理胶质瘤细胞可抑制磷酸化特异性JNK1的表达和半胱天冬酶3的活性。用JNK1反义OGN预处理使50μM他莫昔芬处理4小时诱导的胶质瘤细胞凋亡率从51%降至28%（P<0.003），用半胱天冬酶3抑制剂（DEVD-CHO）预处理则降至20%（P<0.0008）。
结论
结果表明，他莫昔芬诱导大鼠胶质瘤细胞凋亡与JNK1/半胱天冬酶3信号通路的激活有关；然而，这种激活在体内发生的确认需要进一步研究。
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