統合された単一細胞および空間的トランスクリプトミクスによる胃上皮系統進行の分化ドライバーの解明

Gastric cancer (GC) develops through a sequence from chronic gastritis to intestinal metaplasia (IM) and carcinoma, with Helicobacter pylori (HP) as a key driver; however, the molecular mediators linking inflammation to malignant transformation remain unclear. We integrated single-cell RNA sequencing and spatial transcriptomics of gastric mucosal samples from atrophic gastritis, IM, and GC, including HP positive (+) and HP negative (-) cases, to map cellular heterogeneity, differentiation trajectories, and pathway activities. Our analyses revealed that IM epithelium represents a transitional state between normal and malignant epithelial lineages, characterized by enhanced WNT signaling that promotes neoplastic progression, whereas H. pylori-associated inflammation activates NF-κB signaling. Across analysis, UPP1 was consistently upregulated in malignant and H. pylori-positive epithelium, increasing along pseudotime toward cancer-like states. Spatial mapping and organoid experiments confirmed that UPP1-high cells had higher intestinal differentiation scores, while UPP1 knockout promoted IM-like morphology in WNT-depleted cultures. Clinically, UPP1 was elevated in GC versus normal tissues, correlated with advanced TNM stage, predicted poor survival, and was higher in HP⁺ tissues. Knockdown in GC cell lines reduced clonogenicity and migration. Collectively, these findings identify UPP1 as a key regulator of epithelial reprogramming and IM, linking H. pylori-driven inflammation with WNT-mediated differentiation, and highlight its potential as a prognostic biomarker and therapeutic target in GC.