Human epidermal growth factor receptor 2 (HER2)-positive is a particularly aggressive type of the breast cancer. Because of the evidence has revealed that accurate HER2 status detection is crucial for prognosis and treatment strategy selection, great effort has been taken to develop assays for sensitive and accurate quantification of HER2. However, nonspecific amplification effect of most current assays limits the quantification accuracy of low abundance HER2. In the present work, we developed an LC-MS/MS-based quasi-targeted proteomics strategy coupled with hybridization chain reaction (HCR) for amplification of the HER2 protein signal. In the described strategy, the aptamer triggered the HCR system to undergo a cascade of hybridization events, with the two locked hairpins conjugated to the substrate peptide to form aptamer-HCR peptide probes. The membrane protein HER2 was recognized by probe and the signal was to be converted and then amplified into the mass response of the reporter peptide, which could be quantified using LC-MS/MS. The signal intensity was approximately five fold greater than that without signal amplification. Finally, the developed assay was applied for the quantitative analysis of HER2 in breast cell lines and monitor the dynamic change of HER2 in drug induced HER2 negative cells. The result demonstrated that combination of HCR signal amplification and mass spectrometry provides a novel approach for simple, accurate, and quantitative monitoring of low abundance protein.

中文翻译：

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一种使用准目标蛋白质组学方法结合适体触发的杂交链反应检测HER2的扩增策略。

人表皮生长因子受体2（HER2）阳性是乳腺癌的一种特别侵袭性类型。由于有证据表明，准确的HER2状态检测对于预后和治疗策略的选择至关重要，因此已做出巨大的努力来开发用于HER2敏感和准确定量的检测方法。但是，大多数当前测定的非特异性扩增作用限制了低丰度HER2的定量准确性。在目前的工作中，我们开发了一种基于LC-MS / MS的准靶向蛋白质组学策略，并结合了杂交链反应（HCR）来扩增HER2蛋白信号。在所描述的策略中，适体触发HCR系统经历一系列级联的杂交事件，其中两个锁定的发夹缀合至底物肽以形成适体-HCR肽探针。膜蛋白HER2被探针识别，信号将被转换，然后放大为报告肽的质量响应，可以使用LC-MS / MS进行定量。信号强度比没有信号放大的强度大大约五倍。最后，将开发的检测方法用于乳腺癌细胞系中HER2的定量分析，并监测药物诱导的HER2阴性细胞中HER2的动态变化。结果表明，HCR信号放大和质谱的结合为低丰度蛋白的简单，准确和定量监测提供了一种新颖的方法。信号强度比没有信号放大的强度大大约五倍。最后，将开发的检测方法用于乳腺癌细胞系中HER2的定量分析，并监测药物诱导的HER2阴性细胞中HER2的动态变化。结果表明，HCR信号放大和质谱的结合为低丰度蛋白的简单，准确和定量监测提供了一种新方法。信号强度比没有信号放大的强度大大约五倍。最后，将开发的检测方法用于乳腺癌细胞系中HER2的定量分析，并监测药物诱导的HER2阴性细胞中HER2的动态变化。结果表明，HCR信号放大和质谱的结合为低丰度蛋白的简单，准确和定量监测提供了一种新方法。