Department of Biochemistry, Jim Ayers Institute for Precancer Detection and Diagnosis, Vanderbilt University School of Medicine , Nashville, Tennessee 37232-6350, United States.
J Proteome Res. 2012 Feb 3;11(2):1184-95. doi: 10.1021/pr2009109. Epub 2011 Dec 13.
The proteomic effects of specific cancer-related mutations have not been well characterized. In colorectal cancer (CRC), a relatively small number of mutations in key signaling pathways appear to drive tumorigenesis. Mutations in adenomatous polyposis coli (APC), a negative regulator of Wnt signaling, occur in up to 60% of CRC tumors. Here we examine the proteomic consequences of a single gene mutation by using an isogenic CRC cell culture model in which wildtype APC expression has been ectopically restored. Using LC-MS/MS label free shotgun proteomics, over 5000 proteins were identified in SW480Null (mutant APC) and SW480APC (APC restored). We observed 155 significantly differentially expressed proteins between the two cell lines, with 26 proteins showing opposite expression trends relative to gene expression measurements. Protein changes corresponded to previously characterized features of the APCNull phenotype: loss of cell adhesion proteins, increase in cell cycle regulators, alteration in Wnt signaling related proteins, and redistribution of β-catenin. Increased expression of RNA processing and isoprenoid biosynthetic proteins occurred in SW480Null cells. Therefore, shotgun proteomics reveals proteomic differences associated with a single gene change, including many novel differences that fall outside known target pathways.
特定癌症相关突变的蛋白质组学效应尚未得到很好的描述。在结直肠癌（CRC）中，少数关键信号通路的突变似乎驱动了肿瘤的发生。腺瘤性息肉病基因（APC）是 Wnt 信号的负调节剂，其突变发生在多达 60%的 CRC 肿瘤中。在这里，我们通过使用 APC 野生型表达被异位恢复的同源 CRC 细胞培养模型来检查单个基因突变的蛋白质组学后果。使用 LC-MS/MS 无标记 shotgun 蛋白质组学，在 SW480Null（突变 APC）和 SW480APC（APC 恢复）中鉴定出超过 5000 种蛋白质。我们观察到这两种细胞系之间有 155 种差异表达的显著蛋白，其中 26 种蛋白的表达趋势与基因表达测量结果相反。蛋白变化与 APCNull 表型的先前特征相一致：细胞粘附蛋白丢失、细胞周期调节剂增加、Wnt 信号相关蛋白改变以及β-连环蛋白重分布。SW480Null 细胞中 RNA 处理和异戊二烯生物合成蛋白的表达增加。因此，shotgun 蛋白质组学揭示了与单个基因变化相关的蛋白质组学差异，包括许多不在已知靶途径范围内的新差异。
