Dissection of major cancer gene variants in subsets of circulating tumor cells in advanced breast cancer
Dissection of major cancer gene variants in subsets of circulating tumor cells in advanced breast cancer
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DOI：
10.1038/s41598-019-53660-x
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发表时间：
2019-11-21
影响因子：
4.6
通讯作者：
Silvestris, Franco
中科院分区：
文献类型：
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作者：
D'Oronzo, Stella;Lovero, Domenica;Silvestris, Franco
循环肿瘤细胞（ctc）的计数可能反映乳腺癌（BC）的转移潜力。通过使用DEPArray，我们研究了ctc的上皮到间质转化表型，并通过组织活检比较了它们的基因组异质性。17例IV期BC患者入组。预富集的CTC悬液用荧光标记的上皮(E)和间充质(M)标记物抗体进行染色。用DEPArray系统对CTC样品进行处理，并根据其标记物进行聚类。通过下一代测序对来自ctc和原发肿瘤样本的DNA进行测序，以评估50个主要癌症相关基因的突变状态。我们确定了四个不同的CTC亚群，其中包含不同的基因变体。最异质的CTC亚群包括M+/E-表型，然而，它只表达7个重复突变的基因，而在M-/E+亚群中，多个突变只影响50个基因中的2个。在匹配CTC亚群的所有基因变异时，只有4个基因共享少量突变，即ATM、FGFR3、PIK3CA和TP53，而这些基因在原发肿瘤中是不存在的。我们的结果假设，在所有CTC亚群中检测到的突变可能被认为是转移性传播的基因组标记，在BC的早期阶段进行研究。
Enumeration of circulating tumor cells (CTCs) may reflect the metastatic potential of breast cancer (BC). By using the DEPArray, we investigated CTCs with respect to their epithelial-to-mesenchymal transition phenotype and compared their genomic heterogeneity with tissue biopsies. Seventeen stage IV BC patients were enrolled. Pre-enriched CTC suspensions were stained with fluorescent-labeled antibodies to epithelial (E) and mesenchymal (M) markers. CTC samples were processed by DEPArray system and clustered in relation to their markers. DNA from CTCs, as well as from primary tumor samples, was sequenced by next generation sequencing to assess the mutational state of 50 major cancer-related genes. We identified four different CTC subsets that harbored different gene variants. The most heterogenous CTC subsets included the M+/E- phenotype, which, however, expressed only 7 repeatedly mutated genes, while in the M-/E+ subset multiple mutations affected only 2 out of 50 genes. When matching all gene variants among CTC subsets, a small number of mutations was shared by only 4 genes, namely ATM, FGFR3, PIK3CA, and TP53 that, however, were absent in primary tumors. Our results postulate that the detected mutations in all CTC subsets may be considered as genomic markers of metastatic dissemination to be investigated during early stages of BC.