Single-Cell Transcriptomic Analysis of Primary and Metastatic Tumor Ecosystems in Esophageal Squamous Cell Carcinoma

We profiled the transcriptome of 85, 263 single cells from ESCC patients with lymph node metastasis (LNM) and clustered 7, 196 myeloid cells into 18 subclusters including nine for macrophage cells, one for neutrophils, two for monocytes, two for mast cells, one for tolerogenic dendritic cells, one for plasmacytoid dendritic cells and two for conventional dendritic cells. In this study, we not only provides a high-resolution landscape of the tumor, immune and stromal compartments in metastatic lymph node, but also highlights metastatic-specific patterns comparing with primary tumor. These findings provide insights that may help to shape the tumor microenvironment and inform the development of new strategies against these pro-metastatic non-tumor components for inhibiting tumor growth and overcoming metastasis. Overall design: Four patients who were pathologically diagnosed with ESCC were enrolled in this study and no patient received preoperative treatment. Fresh sterile biopsies were collected from normal tissue adjacent to the primary tumor, matched primary tumor site and lymph node site by endoscopy for every patient, and then were all fresh-processed for scRNA-seq using 10X Genomics platform. Three of four patients have lymph node metastasis but the remaining patient not.