Temozolomide-modulated glioma proteome: Role of interleukin-1 receptor-associated kinase-4 (IRAK4) in chemosensitivity
Temozolomide-modulated glioma proteome: Role of interleukin-1 receptor-associated kinase-4 (IRAK4) in chemosensitivity
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DOI：
10.1002/pmic.201200261
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发表时间：
2013-07-01
期刊：
影响因子：
3.4
通讯作者：
Somasundaram, Kumaravel
中科院分区：
文献类型：
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作者：
Kumar, Durairaj M.;Patil, Vikas;Somasundaram, Kumaravel
目前治疗胶质母细胞瘤的方法包括替莫唑胺(TMZ)化疗，但其作用机制尚不完全清楚。在这里，我们用2D DGE研究了TMZ对人脑胶质瘤细胞系U251蛋白质组的影响。我们发现，在TMZ处理后，95个蛋白点的表达发生了显著变化。MS发现了四个上调的点：天冬氨酸tRNA合成酶、谷胱甘肽合成酶、白细胞介素1受体相关激酶-4(IRAK4)和乳腺癌扩增序列-1和一个下调的点：视神经磷酸酶。RT-qPCR和Western印迹分析验证了TMZ对这5个基因的调控作用。RNAi介导的IRAK4是Toll样受体信号转导和化疗耐药的重要中介，使胶质瘤细胞对TMZ产生耐药。TMZ诱导高水平的IRAK4导致IRAK1下调，抑制NFkB通路。内源性IRAK4蛋白，而不是胶质瘤细胞系中的转录水平，与TMZ的敏感性相关。因此，我们已经鉴定了几个TMZ调节蛋白，并发现IRAK4通过抑制Toll样受体信号和NFkB途径在决定胶质瘤细胞对TMZ敏感性方面发挥了重要的新作用。
The current treatment for glioblastoma includes temozolomide (TMZ) chemotherapy, yet the mechanism of action of TMZ is not thoroughly understood. Here, we investigated the TMZ-induced changes in the proteome of the glioma-derived cell line (U251) by 2D DIGE. We found 95 protein spots to be significantly altered in their expression after TMZ treatment. MS identified four upregulated spots: aspartyl tRNA synthetase glutathione synthetase, interleukin-1 receptor-associated kinase-4 (IRAK4), and breast carcinoma amplified sequence-1 and one downregulated spot: optineurin. TMZ-induced regulation of these five genes was validated by RT-qPCR andWestern blot analysis. RNAi-mediated knockdown of IRAK4, an important mediator of Toll-like receptors signaling and chemoresistance, rendered the glioma cells resistant to TMZ. High levels of IRAK4 induced upon TMZ treatment resulted in IRAK1 downregulation and inhibition of NFkB pathway. Endogenous IRAK4 protein, but not transcript levels in glioma cell lines, correlated with TMZ sensitivity. Thus, we have identified several TMZ-modulated proteins and discovered an important novel role for IRAK4 in determining TMZ sensitivity of glioma cells through its ability to inhibit Toll-like receptor signaling and NFkB pathway.