Worthington Jenny, Spain Georgia, Timms John F
From the ‡Women's Cancer, Institute for Women's Health, University College London, Gower Street, London WC1E 6BT, United Kingdom.
From the ‡Women's Cancer, Institute for Women's Health, University College London, Gower Street, London WC1E 6BT, United Kingdom
Mol Cell Proteomics. 2017 Apr;16(4):608-621. doi: 10.1074/mcp.M116.061267. Epub 2017 Feb 7.
Most breast cancers arise from luminal epithelial cells, and 25-30% of these tumors overexpress the ErbB2/HER2 receptor that correlates with disease progression and poor prognosis. The mechanisms of ErbB2 signaling and the effects of its overexpression are not fully understood. Herein, stable isotope labeling by amino acids in cell culture (SILAC), expression profiling, and phosphopeptide enrichment of a relevant, non-transformed, and immortalized human mammary luminal epithelial cell model were used to profile ErbB2-dependent differences in protein expression and phosphorylation events triggered via EGF receptor (EGF treatment) and ErbB3 (HRG1β treatment) in the context of ErbB2 overexpression. Bioinformatics analysis was used to infer changes in cellular processes and signaling events. We demonstrate the complexity of the responses to oncogene expression and growth factor signaling, and we identify protein changes relevant to ErbB2-dependent altered cellular phenotype, in particular cell cycle progression and hyper-proliferation, reduced adhesion, and enhanced motility. Moreover, we define a novel mechanism by which ErbB signaling suppresses basal interferon signaling that would promote the survival and proliferation of mammary luminal epithelial cells. Numerous novel sites of growth factor-regulated phosphorylation were identified that were enhanced by ErbB2 overexpression, and we putatively link these to altered cell behavior and also highlight the importance of performing parallel protein expression profiling alongside phosphoproteomic analysis.
大多数乳腺癌起源于管腔上皮细胞，其中25%-30%的肿瘤过度表达ErbB2/HER2受体，该受体与疾病进展和不良预后相关。ErbB2信号传导机制及其过表达的影响尚未完全了解。在此，利用细胞培养中的氨基酸稳定同位素标记（SILAC）、表达谱分析以及对一种相关的、未转化的、永生化的人乳腺管腔上皮细胞模型进行磷酸肽富集，以描绘在ErbB2过表达情况下，通过表皮生长因子受体（EGF处理）和ErbB3（HRG1β处理）触发的蛋白质表达和磷酸化事件中依赖于ErbB2的差异。采用生物信息学分析来推断细胞过程和信号传导事件的变化。我们证明了对癌基因表达和生长因子信号反应的复杂性，并确定了与ErbB2依赖性细胞表型改变相关的蛋白质变化，特别是细胞周期进程和过度增殖、黏附减少以及运动性增强。此外，我们定义了一种新机制，通过该机制ErbB信号传导抑制基础干扰素信号传导，而基础干扰素信号传导原本会促进乳腺管腔上皮细胞的存活和增殖。鉴定出许多生长因子调节的磷酸化新位点，这些位点在ErbB2过表达时增强，我们推测将这些位点与细胞行为改变联系起来，并强调了在磷酸化蛋白质组分析的同时进行平行蛋白质表达谱分析的重要性。
