Metastasis of breast cancer to distal organs is fatal. However, few studies have identified biomarkers that are associated with distant metastatic breast cancer. Furthermore, the inability of current biomarkers, such as HER2, ER, and PR, to differentiate between distant and nondistant metastatic breast cancers accurately has necessitated the development of novel biomarker candidates. An integrated proteomics approach that combined filter-aided sample preparation, tandem mass tag labeling (TMT), high pH fractionation, and high-resolution MS was applied to acquire in-depth proteomic data from FFPE distant metastatic breast cancer tissues. A bioinformatics analysis was performed with regard to gene ontology and signaling pathways using differentially expressed proteins (DEPs) to examine the molecular characteristics of distant metastatic breast cancer. In addition, real-time polymerase chain reaction (RT-PCR) and invasion/migration assays were performed to validate the differential regulation and function of our protein targets. A total of 9441 and 8746 proteins were identified from the pooled and individual sample sets, respectively. Based on our criteria, TUBB2A was selected as a novel biomarker candidate. The metastatic activities of TUBB2A were subsequently validated. In our bioinformatics analysis using DEPs, we characterized the overall molecular features of distant metastasis and measured differences in the molecular functions of distant metastatic breast cancer between breast cancer subtypes. Our report is the first study to examine the distant metastatic breast cancer proteome using FFPE tissues. The depth of our dataset allowed us to discover a novel biomarker candidate and a proteomic characteristics of distant metastatic breast cancer. Distinct molecular features of various breast cancer subtypes were also established. Our proteomic data constitute a valuable resource for research on distant metastatic breast cancer.

中文翻译：

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通过定量蛋白质组学分析鉴定 TUBB2A 作为预测远处转移性乳腺癌的新型生物标志物。

乳腺癌向远端器官的转移是致命的。然而，很少有研究确定与远处转移性乳腺癌相关的生物标志物。此外，目前的生物标志物（如 HER2、ER 和 PR）无法准确区分远处和非远处转移性乳腺癌，因此有必要开发新的生物标志物候选物。将过滤辅助样品制备、串联质量标签标记 (TMT)、高 pH 分级和高分辨率 MS 相结合的综合蛋白质组学方法应用于从 FFPE 远处转移性乳腺癌组织中获取深入的蛋白质组学数据。使用差异表达蛋白 (DEP) 对基因本体和信号通路进行生物信息学分析，以检查远处转移性乳腺癌的分子特征。此外，还进行了实时聚合酶链式反应 (RT-PCR) 和侵袭/迁移测定，以验证我们的蛋白质靶标的差异调节和功能。分别从合并和单个样本集中鉴定出总共 9441 和 8746 种蛋白质。根据我们的标准，TUBB2A 被选为新的生物标志物候选者。随后验证了 TUBB2A 的转移活性。在我们使用 DEP 进行的生物信息学分析中，我们描述了远处转移的整体分子特征，并测量了乳腺癌亚型之间远处转移性乳腺癌分子功能的差异。我们的报告是第一项使用 FFPE 组织检查远处转移性乳腺癌蛋白质组的研究。我们数据集的深度使我们能够发现一种新的候选生物标志物和远处转移性乳腺癌的蛋白质组学特征。还确定了各种乳腺癌亚型的不同分子特征。我们的蛋白质组学数据构成了研究远处转移性乳腺癌的宝贵资源。我们数据集的深度使我们能够发现一种新的候选生物标志物和远处转移性乳腺癌的蛋白质组学特征。还确定了各种乳腺癌亚型的不同分子特征。我们的蛋白质组学数据构成了研究远处转移性乳腺癌的宝贵资源。我们数据集的深度使我们能够发现一种新的候选生物标志物和远处转移性乳腺癌的蛋白质组学特征。还确定了各种乳腺癌亚型的不同分子特征。我们的蛋白质组学数据构成了研究远处转移性乳腺癌的宝贵资源。