Rignall Benjamin, Ittrich Carina, Krause Eberhard, Appel Klaus E, Buchmann Albrecht, Schwarz Michael
Department of Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, University of Tubingen, Germany.
J Proteome Res. 2009 Aug;8(8):3987-94. doi: 10.1021/pr9002933.
Mouse liver tumors frequently harbor activating mutations in the Ha-ras protooncogene. In addition, mutations are also found in the B-raf gene leading to constitutive activation of the B-Raf kinase. In two previous studies, we have investigated by microarray analysis the effect of the mutations on the mRNA expression patterns of the respective tumors. In the present study, we analyzed proteome changes in Ha-ras and B-raf mutated liver tumors by 2-D gel-electrophoretic separation of proteins followed by their identification by mass spectrometry. In total, 104 significantly altered protein spots were identified in Ha-ras mutated tumors and 111 in B-raf mutated tumors when compared to the corresponding normal liver tissue. The changes in protein expression patterns were highly correlated between Ha-ras and B-raf mutated tumors, and in the majority of the cases, both tumor types showed the respective alteration. Most of the tumor-specific changes in protein expression were reflected by similar changes in their mRNAs except for some up-regulated proteins without accompanying changes in mRNA levels. Interestingly, Ha-ras but not B-raf mutated tumors showed high levels of the phosphorylated (activated) form of the Ras/Raf/MEK effector kinase ERK which was, however, not associated with any detectable difference in the transcriptome or protein setup of the tumors.
小鼠肝肿瘤中常常存在原癌基因Ha-ras的激活突变。此外，在B-raf基因中也发现了导致B-Raf激酶组成性激活的突变。在之前的两项研究中，我们通过微阵列分析研究了这些突变对相应肿瘤mRNA表达模式的影响。在本研究中，我们通过二维凝胶电泳分离蛋白质，随后用质谱进行鉴定，分析了Ha-ras和B-raf突变的肝肿瘤中的蛋白质组变化。与相应的正常肝组织相比，在Ha-ras突变的肿瘤中总共鉴定出104个显著改变的蛋白点，在B-raf突变的肿瘤中鉴定出111个。Ha-ras和B-raf突变的肿瘤之间蛋白质表达模式的变化高度相关，并且在大多数情况下，两种肿瘤类型都显示出各自的改变。除了一些mRNA水平没有相应变化但上调的蛋白质外，大多数肿瘤特异性蛋白质表达变化都反映在其mRNA的相似变化中。有趣的是，Ha-ras突变而非B-raf突变的肿瘤显示出高水平的Ras/Raf/MEK效应激酶ERK的磷酸化（激活）形式，然而，这与肿瘤转录组或蛋白质组成中任何可检测到的差异无关。
