Single-cell transcriptomic data reveal the cellular heterogeneity of glutamine metabolism in gastric premalignant lesions and early gastric cancer

Glutamine metabolism is a hallmark of cancer metabolism. This study aims to perform a comprehensive and systematic single-cell profile of glutamine metabolism in premalignant and malignant gastric lesions. We use single-cell transcriptomics data from chronic atrophic gastritis (CAG) and early gastric cancer (EGC) lesions and investigate glutamine metabolism features at the single-cell level. Experiments are implemented to validate the expression and biological role of ERO1LB in gastric cancer (GC). A single-cell atlas based on 22511 cells from premalignant and early-malignant gastric lesions is established. Among these cells, epithelial cells constitute the dominant cell population in both CAG and EGC lesions. The activity of glutamine metabolism is higher in epithelial cells from EGC lesions than in those from CAG lesions. Among the epithelial cell subpopulations, glutamine metabolism is more active in the epithelial cell subpopulation cluster_4 in EGCs than in CAG lesions. As a key marker gene of this subpopulation, <i>ERO1LB</i> is experimentally proven to be overexpressed in human GC tissue lesions. In both <i>in vitro</i> and <i>in vivo</i> experiments, overexpression of ERO1LB in GC cells increases glutamine metabolism, facilitates cell growth and migration and prevents cell apoptosis, and vice versa. This study provides insight into the cellular heterogeneityof glutamine metabolism within the gastric mucosa in premalignant and malignant gastric lesions and identifies ERO1LB as a key orchestrator of glutamine metabolism, which may help to identify markers for GC prevention and contribute to our understanding of GC pathogenesis.