Plasticity between Epithelial and Mesenchymal States Unlinks EMT from Metastasis-Enhancing Stem Cell Capacity

In this study we studied the presence of tumor cells that underwent epithelial-to-mesenchymal transition within polyoma middle T antigen (PyMT) breast tumors. For this we dissociated tumors and isolated Ecad positive tumor cells by FACS sorting. We confirmed that PyMT tumors contain a small set of tumor cells that have undergone EMT in the primary tumor and that E-cadherin can be used as a marker on single cell level for mesenchymal status in this model. Overall design: (i) We isolated primary tumors from mice, dissociated the tumors and FACS-sorted for single Ecad positive tumor cells, after this we performed single cell sequencing of the cells. (ii) We isolated CTCs and solid tumor cells from mice, dissociated the tumors and FACS-sorted for single Ecad positive and negative cells, after this we performed single cell sequencing of the cells.

本研究探究了多瘤病毒中间T抗原（PyMT）乳腺肿瘤中发生上皮间质转化（epithelial-to-mesenchymal transition, EMT）的肿瘤细胞的存在情况。为此，我们解离肿瘤组织，并通过荧光激活细胞分选（FACS）分离得到E-钙粘蛋白（Ecad）阳性的肿瘤细胞。我们证实，PyMT乳腺肿瘤的原发灶中存在少量发生EMT的肿瘤细胞，且在该模型中，E-钙粘蛋白可作为单细胞水平检测间质状态的标志物。总体实验设计：(i) 从小鼠体内分离原发肿瘤，解离肿瘤组织并通过FACS分选得到单细胞级的E-钙粘蛋白阳性肿瘤细胞，随后对这些细胞进行单细胞测序。(ii) 从小鼠体内分离循环肿瘤细胞（Circulating Tumor Cells, CTCs）与实体瘤细胞，解离实体瘤组织并通过FACS分选得到单细胞级的E-钙粘蛋白阳性及阴性肿瘤细胞，随后对这些细胞进行单细胞测序。