Absence of death receptor translocation into lipid rafts in acquired TRAIL-resistant NSCLC cells
Absence of death receptor translocation into lipid rafts in acquired TRAIL-resistant NSCLC cells
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获得性 TRAIL 抗性 NSCLC 细胞中不存在死亡受体易位至脂筏中
DOI：
10.3892/ijo.2012.1748
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发表时间：
2013-02-01
影响因子：
5.2
通讯作者：
Xie, Conghua
中科院分区：
文献类型：
--
作者：
Ouyang, Wen;Yang, Chunxu;Xie, Conghua
肿瘤坏死因子相关凋亡诱导配体（TRAIL）的耐药性是其临床应用的主要限制。TRAIL抗性的机制主要是在对TRAIL具有内在抗性的细胞系的背景下研究的。然而，人们对TRAIL治疗过程中导致获得性耐药的分子改变知之甚少。本研究从TRAIL敏感的人肺癌细胞系H460中建立了获得性TRAIL耐药的等基因细胞系H460 R，以探讨获得性耐药的机制。获得的TRAIL耐药的H460 R细胞对顺铂保持敏感。死亡受体4（DR 4）和死亡受体5（DR 5）的mRNA和蛋白质表达水平没有改变的TRAIL处理的细胞系。然而，DR 4或DR 5基因过表达或沉默的试验表明，死亡受体的表达是必需的，但不足以TRAIL诱导的细胞凋亡。与亲本TRAIL敏感的H460细胞相比，H460 R细胞显示出减少TRAIL诱导的DR 4/DR 5向脂筏的移位。进一步的研究表明制霉菌素部分抑制了H460细胞中脂筏的聚集和DR 4、DR 5的聚集，并再次减少了细胞凋亡。凋亡相关分子分析显示，H460细胞中caspase-8、FADD、caspase-3和Bid表达较H460 R细胞高，而cFLIP表达较H460 R细胞低。我们的研究结果表明，缺乏死亡受体再分布的负面影响DISC组装在脂筏，这至少部分地导致了获得性耐药的H460 R细胞中的TRAIL的发展。
Resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a major limitation for its clinical use. The mechanisms of TRAIL resistance have been mostly studied in the context of cell lines that are intrinsically resistant to TRAIL. However, little is known about the molecular alterations that contribute to the development of acquired resistance during treatment with TRAIL. In this study, we established H460R, an isogenic cell line with acquired TRAIL resistance, from the TRAIL-sensitive human lung cancer cell line H460 to investigate the mechanisms of acquired resistance. The acquired TRAIL-resistant H460R cells remained sensitive to cisplatin. The mRNA and protein expression levels of death receptor 4 (DR4) and death receptor 5 (DR5) were not altered in either of the TRAIL-treated cell lines. Nevertheless, tests in which the DR4 or DR5 gene was overexpressed or silenced suggest that death receptor expression is necessary but not sufficient for TRAIL-induced apoptosis. Compared with parental TRAIL-sensitive H460 cells, H460R cells showed a decreased TRAIL-induced translocation of DR4/DR5 into lipid rafts. Further studies showed that nystatin partially prevented lipid raft aggregation and DR4 and DR5 clustering and reduced apoptosis in H460 cells again. Analysis of apoptotic molecules showed that more pro-caspase-8, FADD, caspase-3 and Bid, but less cFLIP in H460 cells than in H460R cells. Our findings suggest that the lack of death receptor redistribution negatively impacts DISC assembly in lipid rafts, which at least partially leads to the development of acquired resistance to TRAIL in H460R cells.