Rapid induction of IAP family proteins and Smac/DIABLO expression after proapoptotic stimulation with doxorubicin in RPMI 8226 multiple myeloma cells
Rapid induction of IAP family proteins and Smac/DIABLO expression after proapoptotic stimulation with doxorubicin in RPMI 8226 multiple myeloma cells
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DOI：
10.1016/j.yexmp.2007.04.001
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发表时间：
2007-12-01
影响因子：
3.6
通讯作者：
Kitagawa, Masanobu
中科院分区：
文献类型：
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作者：
Abe, Shinya;Hasegawa, Maki;Kitagawa, Masanobu
我们研究了阿霉素作用于人多发性骨髓瘤细胞系RPMI8226及其耐药变异体DRR后，凋亡抑制蛋白(IAP)家族成员和Smac/DIABLO的表达动态。经阿霉素促凋亡刺激后，RPMI8226细胞中IAPs的mRNA和蛋白表达迅速升高，随后表达逐渐下降。Smac/Diablo是已知的中和IAP的药物，治疗后在mRNA水平上表达增加，但Western印迹分析显示蛋白质含量略有下降。免疫沉淀分析显示阿霉素治疗后Smac/DIABLO与cIAP1或XIAP相关。与RPMI8226细胞不同的是，DRR细胞不会因阿霉素治疗而发生凋亡。经阿霉素处理后，DRR细胞IAPs在mRNA水平上有较高水平的表达，而cIAP1、cIAP2、XIAP和Survivin的mRNAs表达没有明显的高峰或下降。此外，Smac/Diablo基因的表达在治疗后未见上调。这些结果表明，Smac/DIABLO在促凋亡刺激后不久抑制IAPs的表达可能在诱导细胞凋亡的机制中起作用，治疗后IAPs的高表达和Smac/DIABLO的低表达可能导致多发性骨髓瘤细胞对阿霉素的耐药。(C)2007 Elsevier Inc.保留所有权利。
We studied the expression dynamics of inhibitor of apoptosis protein (IAP) family members and Smac/DIABLO after treatment with doxorubicin in human multiple myeloma cell line RPMI 8226 and its doxorubicin-resistant variant DRR. Proapoptotic stimulation with doxorubicin rapidly induced the overexpression of mRNA as well as protein for IAPs in RPMI 8226 cells followed by a gradual decrease of their expression. Smac/DIABLO, which is known to neutralize IAPs, showed increased expression at the mRNA level after treatment; however, Western blot analysis revealed a slight decrease of the amount of protein. Immunoprecipitation analysis revealed the association of Smac/DIABLO with cIAP1 or XIAP after treatment with doxorubicin. In contrast to the RPMI 8226 cells, DRR cells did not undergo apoptosis in response to doxorubicin treatment. The DRR cells had higher levels of IAPs expression at the mRNA level and did not show a remarkable peak or decrease in the expression of mRNAs for cIAP1, cIAP2, XIAP, and survivin after treatment with doxorubicin. Furthermore, the expression of Smac/DIABLO mRNA was not up-regulated after treatment. These findings indicate that the suppression of IAPs expression by Smac/DIABLO shortly after proapoptotic stimulation might play a role in the mechanisms of apoptotic induction, and that the maintenance of high IAPs expression and low Smac/DIABLO expression after treatment might lead to the doxorubicin-resistance of multiple myeloma cells. (c) 2007 Elsevier Inc. All rights reserved.