Loss of Collapsin Response Mediator Protein1, as Detected by iTRAQ Analysis, Promotes Invasion of Human Gliomas Expressing Mutant EGFRvIII
Loss of Collapsin Response Mediator Protein1, as Detected by iTRAQ Analysis, Promotes Invasion of Human Gliomas Expressing Mutant EGFRvIII
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DOI：
10.1158/0008-5472.can-09-1778
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发表时间：
2009-11-15
期刊：
影响因子：
11.2
通讯作者：
Guha, Abhijit
中科院分区：
文献类型：
--
作者：
Mukherjee, Joydeep;DeSouza, Leroi V.;Guha, Abhijit
多形性胶质母细胞瘤（GBM）是最常见和致命的原发性人类脑肿瘤。 GBM 的特点是存在多种基因改变，其中表皮生长因子受体 (EGFRvIII) 的致癌突变最为常见。与表达野生型 (wt) EGFR 的 GBM 相比，携带 EGFRvIII 的 GBM 具有增强的增殖和侵袭特征。为了确定这种增加的致瘤表型的分子基础，我们使用 iTRAQ 标记的差异蛋白质组分析。在几种差异表达的蛋白质中，我们选择了CRMP1，一种与细胞侵袭有关的蛋白质，在表达EGFRvIII的GBM中显着减少，以进行进一步研究。通过定量实时 PCR、蛋白质印迹和免疫组织化学分析，在一组表达 wtEGFR 或突变型 EGFRvIII 的人 GBM 细胞系和手术标本中证实了 CRMP1 的差异表达。在人类 GBM 样本中，CRMP1 表达降低与 EGFRvIII 阳性相关。 siARNA 敲低 CRMP1 导致表达 wtEGFR 的人 GBM 细胞（U87 和 U373）对同基因 GBM 细胞的侵袭增加。这些表达 wtEGFR 的 GBM 细胞中 EGFRvIII 的外源表达促进了它们的侵袭能力，并伴随着 CRMP1 表达的降低。拯救 CRMP1 表达通过倾斜 Rac 和 Rho 之间的平衡来减少表达 EGFRvIII 的 GBM 细胞的侵袭。总的来说，这些结果表明 CRMP1 的缺失导致表达突变型 EGFRvIII 的人类 GBM 的侵袭表型增加。 [癌症研究 2009;69(22):8545-54]
Glioblastoma multiforme (GBM) is the most common and lethal primary human brain tumor. GBMs are characterized by a variety of genetic alterations, among which oncogenic mutations of epidermal growth factor receptor (EGFRvIII) is most common. GBMs harboring EGFRvIII have increased proliferation and invasive characteristics versus those expressing wildtype (wt) EGFR. To identify the molecular basis of this increased tumorgenic phenotype, we used iTRAQ-labeling differential proteomic analysis. Among several differentially expressed proteins, we selected CRMP1, a protein implicated in cellular invasion that was markedly decreased in GBMs expressing EGFRvIII, for further study. The differential expression of CRMP1 was confirmed in a panel of human GBM cell lines and operative specimens that express wtEGFR or mutant EGFRvIII by quantitative real-time PCR, Western blot, and immunohistochemical analysis. In human GBM samples, decreased expression of CRMP1 correlated with EGFRvIII positivity. Knockdown of CRMP1 by siARNA resulted in increased invasion of wtEGFR expressing human GBM cells (U87 and U373) to those found in isogenic GBM cells. Exogenous expression of EGFRvIII in these wtEGFR-expressing GBM cells promoted their ability to invade and was accompanied by decreased expression of CRMP1. Rescuing CRMP1 expression decreased invasion of the EGFRvIII-expressing GBM cells by tilting the balance between Rac and Rho. Collectively, these results show that the loss of CRMP1 contribute to the increased invasive phenotype of human GBMs expressing mutant EGFRvIII. [Cancer Res 2009;69(22):8545-54]