BACKGROUND Circulating tumor cells (CTCs) are important for metastatic dissemination of cancer. They can provide useful information, regarding biological features and tumor heterogeneity; however, their detection and characterization are difficult due to their limited number in the bloodstream and their mesenchymal characteristics. Therefore, new biomarkers are needed to address these questions. METHODS Bioinformatics functional enrichment analysis revealed a subgroup of 24 genes, potentially overexpressed in CTCs. Among these genes, the chemokine receptor CXCR4 plays a central role. After prioritization according to the CXCR4 corresponding pathways, five molecules (JUNB, YWHAB, TYROBP, NFYA, and PRDX1) were selected for further analysis in biological samples. The SKBR3, MDA-MB231, and MCF7 cell lines, as well as PBMCs from normal (n = 10) blood donors, were used as controls to define the expression pattern of all the examined molecules. Consequently, 100 previously untreated metastatic breast cancer (mBC) patients (n = 100) were analyzed using the following combinations of antibodies: CK (cytokeratin)/CXCR4/JUNB, CK/NFYA/ΥWHΑΒ (14-3-3), and CK/TYROBP/PRDX1. A threshold value for every molecule was considered the mean expression in normal PBMCs. RESULTS Quantification of CXCR4 revealed overexpression of the receptor in SKBR3 and in CTCs, following the subsequent scale (SKBR3>CTCs>Hela>MCF7>MDA-MB231). JUNB was also overexpressed in CTCs (SKBR3>CTCs>MCF7>MDA-MB231>Hela). According to the defined threshold for each molecule, CXCR4-positive CTCs were identified in 90% of the patients with detectable tumor cells in their blood. In addition, 65%, 75%, 14.3%, and 12.5% of the patients harbored JUNB-, TYROBP-, NFYA-, and PRDX-positive CTCs, respectively. Conversely, none of the patients revealed YWHAB-positive CTCs. Interestingly, JUNB expression in CTCs was phenotypically and statistically enhanced compared to patients' blood cells (p = 0.002) providing a possible new biomarker for CTCs. Furthermore, the detection of JUNB-positive CTCs in patients was associated with poorer PFS (p = 0.015) and OS (p = 0.002). Moreover, JUNB staining of 11 primary and 4 metastatic tumors from the same cohort of patients revealed a dramatic increase of JUNB expression in metastasis. CONCLUSIONS CXCR4, JUNB, and TYROBP were overexpressed in CTCs, but only the expression of JUNB was associated with poor prognosis, providing a new biomarker and a potential therapeutic target for the elimination of CTCs.

中文翻译：

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JUNB阳性CTC在转移性乳腺癌中的预后价值：从生物信息学到表型表征。

背景技术循环肿瘤细胞（CTC）对于癌症的转移性传播很重要。它们可以提供有关生物学特征和肿瘤异质性的有用信息；然而，由于其在血流中的数量有限和其间充质特征，它们的检测和表征是困难的。因此，需要新的生物标记物来解决这些问题。方法生物信息学功能富集分析揭示了24个基因的亚组，可能在CTC中过表达。在这些基因中，趋化因子受体CXCR4起着核心作用。根据CXCR4相应的途径确定优先级后，选择了五个分子（JUNB，YWHAB，TYROBP，NFYA和PRDX1）进行生物样品的进一步分析。SKBR3，MDA-MB231和MCF7细胞系，以及来自正常（n = 10）献血者的PBMC，被用作对照来定义所有检查分子的表达模式。因此，使用以下抗体组合对100例先前未接受治疗的转移性乳腺癌（mBC）患者（n = 100）进行了分析：CK（细胞角蛋白）/ CXCR4 / JUNB，CK / NFYA /ΥWHA（14-3-3）和CK / TYROBP / PRDX1。每个分子的阈值被认为是正常PBMC中的平均表达。结果CXCR4的定量显示，在随后的规模（SKBR3> CTC> Hela> MCF7> MDA-MB231）之后，受体在SKBR3和CTC中过表达。JUNB在CTC中也过表达（SKBR3> CTC> MCF7> MDA-MB231> Hela）。根据每个分子的定义阈值，在90％血液中可检测到肿瘤细胞的患者中鉴定出CXCR4阳性CTC。此外，分别有65％，75％，14.3％和12.5％的患者携带JUNB-，TYROBP-，NFYA-和PRDX阳性CTC。相反，没有患者显示出YWHAB阳性CTC。有趣的是，与患者的血细胞相比（p = 0.002），CTC中的JUNB表达在表型和统计学上均得到增强，这为CTC提供了可能的新生物标记。此外，患者中JUNB阳性CTC的检测与较差的PFS（p = 0.015）和OS（p = 0.002）相关。此外，来自同一组患者的11例原发性和4例转移性肿瘤的JUNB染色显示转移中JUNB表达的显着增加。结论CXCR4，JUNB和TYROBP在CTC中过表达，