An Internal Standard-Assisted Synthesis and Degradation Proteomic Approach Reveals the Potential Linkage between VPS4B Depletion and Activation of Fatty Acid β-Oxidation in Breast Cancer Cells.
An Internal Standard-Assisted Synthesis and Degradation Proteomic Approach Reveals the Potential Linkage between VPS4B Depletion and Activation of Fatty Acid β-Oxidation in Breast Cancer Cells.
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DOI：
10.1155/2013/291415
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Yang AJ
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文献类型：
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作者：
Liao Z;Thomas SN;Wan Y;Lin HH;Ann DK;Yang AJ
内体/溶酶体系统，特别是转运所需的内体分选复合物（ESCRT），在调节内吞受体及其相关信号分子的运输和目的地中起重要作用。最近，我们已经表明，功能障碍和下调空泡蛋白分选4 B（VPS 4 B），ESCRT-III相关蛋白，在缺氧条件下，可导致异常积累的表皮生长因子受体（EGFR）和异常的EGFR信号在乳腺癌中。然而，VPS 4 B功能障碍的病理生理学后果在很大程度上仍然难以捉摸。在这项研究中，我们使用了内标辅助合成和降解质谱（iSDMS）方法，该方法允许直接测量蛋白质的合成，降解和蛋白质的动态表达，以解决VPS 4 B功能障碍在改变EGF介导的蛋白质表达的影响。我们的初步结果表明，VPS 4 B下调降低了参与糖酵解途径的许多蛋白质的表达，而在VPS 4 B缺失的细胞中，线粒体脂肪酸β-氧化中起作用的蛋白质的表达增加。这一观察结果也与我们先前的发现一致，即缺氧可诱导VPS 4 B下调，表明采用脂肪酸β-氧化可能潜在地作为乳腺癌细胞响应缺氧介导的VPS 4 B功能障碍的替代能量来源和存活机制。
The endosomal/lysosomal system, in particular the endosomal sorting complexes required for transport (ESCRTs), plays an essential role in regulating the trafficking and destination of endocytosed receptors and their associated signaling molecules. Recently, we have shown that dysfunction and down-regulation of vacuolar protein sorting 4B (VPS4B), an ESCRT-III associated protein, under hypoxic conditions can lead to the abnormal accumulation of epidermal growth factor receptor (EGFR) and aberrant EGFR signaling in breast cancer. However, the pathophysiological consequences of VPS4B dysfunction remain largely elusive. In this study, we used an internal standard-assisted synthesis and degradation mass spectrometry (iSDMS) method, which permits the direct measurement of protein synthesis, degradation and protein dynamic expression, to address the effects of VPS4B dysfunction in altering EGF-mediated protein expression. Our initial results indicate that VPS4B down-regulation decreases the expression of many proteins involved in glycolytic pathways, while increased the expression of proteins with roles in mitochondrial fatty acid β-oxidation were up-regulated in VPS4B-depleted cells. This observation is also consistent with our previous finding that hypoxia can induce VPS4B down-regulated, suggesting that the adoption of fatty acid β-oxidation could potentially serve as an alternative energy source and survival mechanism for breast cancer cells in response to hypoxia-mediated VPS4B dysfunction.