Institute of Head and Neck Studies and Education, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK.
School of Biomedical Sciences, Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
Br J Cancer. 2023 Nov;129(10):1590-1598. doi: 10.1038/s41416-023-02428-2. Epub 2023 Sep 21.
Circulating tumour cells (CTCs) are a potential cancer biomarker, but current methods of CTC analysis at single-cell resolution are limited. Here, we describe high-dimensional single-cell mass cytometry proteomic analysis of CTCs in HNSCC.
Parsortix microfluidic-enriched CTCs from 14 treatment-naïve HNSCC patients were analysed by mass cytometry analysis using 41 antibodies. Immune cell lineage, epithelial-mesenchymal transition (EMT), stemness, proliferation and immune checkpoint expression was assessed alongside phosphorylation status of multiple signalling proteins. Patient-matched tumour gene expression and CTC EMT profiles were compared. Standard bulk CTC RNAseq was performed as a baseline comparator to assess mass cytometry data.
CTCs were detected in 13/14 patients with CTC counts of 2-24 CTCs/ml blood. Unsupervised clustering separated CTCs into epithelial, early EMT and advanced EMT groups that differed in signalling pathway activation state. Patient-specific CTC cluster patterns separated into immune checkpoint low and high groups. Patient tumour and CTC EMT profiles differed. Mass cytometry outperformed bulk RNAseq to detect CTCs and characterise cell phenotype.
We demonstrate mass cytometry allows high-plex proteomic characterisation of CTCs at single-cell resolution and identify common CTC sub-groups with potential for novel biomarker development and immune checkpoint inhibitor treatment stratification.
循环肿瘤细胞（CTCs）是一种有潜力的癌症生物标志物，但目前对 CTC 进行单细胞分辨率分析的方法有限。在这里，我们描述了用于头颈部鳞状细胞癌（HNSCC）的 CTC 的高维单细胞质谱流式细胞术蛋白质组学分析。
使用 41 种抗体，通过质谱流式细胞术分析，对头颈部鳞状细胞癌（HNSCC）患者中的 14 名未经治疗的患者的 Parsortix 微流控富集 CTC 进行分析。评估免疫细胞谱系、上皮-间充质转化（EMT）、干性、增殖和免疫检查点表达，以及多种信号蛋白的磷酸化状态。比较患者匹配的肿瘤基因表达和 CTC EMT 谱。进行标准的批量 CTC RNAseq 作为基线比较器来评估质谱流式细胞术数据。
在 14 名患者中有 13 名患者检测到了 CTC，CTC 计数为 2-24 CTC/ml 血液。无监督聚类将 CTC 分为上皮、早期 EMT 和晚期 EMT 组，这些组在信号通路激活状态上有所不同。患者特异性 CTC 聚类模式分为免疫检查点低和高组。患者肿瘤和 CTC EMT 谱不同。质谱流式细胞术优于批量 RNAseq 检测 CTC 并描绘细胞表型。
我们证明了质谱流式细胞术允许在单细胞分辨率下对 CTC 进行高通量蛋白质组学表征，并确定了具有潜在新生物标志物开发和免疫检查点抑制剂治疗分层能力的常见 CTC 亚群。
