|Differential Contributions of Pre- and Post-EMT Tumor Cells in Breast Cancer Metastasis.
|Year of Publication
|Lourenco ARita, Ban Y, Crowley MJ, Lee SB, Ramchandani D, Du W, Elemento O, George JT, Jolly MKumar, Levine H, Sheng J, Wong ST, Altorki NK, Gao D
|2020 01 15
|Breast Neoplasms, Cell Line, Tumor, Epithelial-Mesenchymal Transition, Humans, Lung Neoplasms, Phenotype
Metastases are responsible for the majority of breast cancer-associated deaths. The contribution of epithelial-to-mesenchymal transition (EMT) in the establishment of metastases is still controversial. To obtain evidence of EMT in metastasis, we established an EMT lineage tracing (Tri-PyMT) model, in which tumor cells undergoing EMT would irreversibly switch their fluorescent marker from RFP to GFP due to mesenchymal-specific Cre expression. Surprisingly, we found that lung metastases were predominantly derived from the epithelial compartment of breast tumors. However, concerns were raised on the fidelity and sensitivity of RFP-to-GFP switch of this model in reporting EMT of metastatic tumor cells. Here, we evaluated Tri-PyMT cells at the single-cell level using single-cell RNA-sequencing and found that the Tri-PyMT cells exhibited a spectrum of EMT phenotypes, with EMT-related genes concomitantly expressed with the activation of GFP. The fluorescent color switch in these cells precisely marked an unequivocal change in EMT status, defining the pre-EMT and post-EMT compartments within the tumor. Consistently, the pre-EMT cells played dominant roles in metastasis, while the post-EMT cells were supportive in promoting tumor invasion and angiogenesis. Importantly, the post-EMT (GFP) cells in the Tri-PyMT model were not permanently committed to the mesenchymal phenotype; they were still capable of reverting to the epithelial phenotype and giving rise to secondary tumors, suggesting their persistent EMT plasticity. Our study addressed major concerns with the Tri-PyMT EMT lineage tracing model, which provides us with a powerful tool to investigate the dynamic EMT process in tumor biology. SIGNIFICANCE: These findings confirm the fidelity and sensitivity of the EMT lineage tracing (Tri-PyMT) model and highlight the differential contributions of pre- and post-EMT tumor cells in breast cancer metastasis..
|PubMed Central ID
|R01 CA205418 / CA / NCI NIH HHS / United States
U01 CA188388 / CA / NCI NIH HHS / United States