Abstract 5982: Single-cell RNA sequencing (scRNA-Seq) from mice model reveals metastatic and stemness signatures in esophageal squamous cell carcinoma (ESCC)

Abstract

Abstract Remote oligometastases are the predominant roots of the unsatisfactory 5-year survival rate in esophageal squamous cell carcinoma (ESCC) patients. The title of metastatic-initiating cells (MICs) has been designated to describe tumor subpopulation with heterogeneous genetic background and behaviors that potentially displays stemness features and favors metastatic lesion formation. However, preceding studies have overpassed the early surviving MICs due to limitations in bulk transcriptomic sequencing at macrometastatic stage. With the aim of denoting and characterizing MICs in ESCC, we established the pulmonary metastatic mice model via intravenous injection and followed by multiplex single-cell RNA sequencing (scRNA-Seq) of tumor cells collected from lung tissues along longitudinal end-points. The scRNA-Seq results uncover a 7-gene surface marker signature panel that could depict the early surviving MICs of ESCC, including CD44, TACSTD2, TM4SF1, S100A14, RHOD, CST6, and C19orf33. In silico gene ontology (GO) enrichment of the early surviving MICs subpopulation reveals numerous migration and adhesion-related biological processes (p<0.05). In addition to scRNA-Seq, immunohistochemistry (IHC) staining of tumor cells in mice lungs collected in sequential order evidenced the survival heterogeneity of tumor subpopulations. Likewise, flow cytometry fluorescence-activated cell sorting (FACS) of signature-enriched tumor cells was performed to resemble the target MICs. CD44Pos ESCC cells are found to show distinctively greater wound-healing (p<0.01), foci formation (p<0.05), migration (p<0.01) and invasion (p<0.01) ability than CD44Neg cells in vitro, and longer survival patterns (p<0.05) upon implantation in vivo. Multi-color immunofluorescence (mIF) staining of these gene signatures is underway in mice models and clinical samples for comprehensive validation. We anticipate this surface marker signature to accelerate development for clinical diagnosis together with molecular targeting in metastatic ESCC patients. Citation Format: Ching Ngar Wong, Yu Zhang, Beibei Ru, Hong Yu Zhou, Kwong Yiu Lam, Xin Yuan Guan. Single-cell RNA sequencing (scRNA-Seq) from mice model reveals metastatic and stemness signatures in esophageal squamous cell carcinoma (ESCC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5982.