Abstract

RYK is highly enriched on the plasma membrane of metastatic GC cells. • B3GNT2 promotes RYK trafficking to the plasma membrane via glycosylation. • The B3GNT2/RYK axis regulates GC cell metastatic ability. Background Gastric cancer (GC) is characterized by a high metastatic propensity, which constitutes the primary cause of poor patient prognosis. Receptor-like tyrosine kinase (RYK) is associated with GC metastasis, but its regulatory mechanism remains unclear. Methods Primary and metastatic GC tissues, together with their matched adjacent non-tumor samples, were collected. GC cell models were established to systematically evaluate the driver role of RYK in GC metastasis. We further integrated clinical specimens, GC cell models, and a mouse model of GC liver metastasis, and combined immunohistochemistry, real-time quantitative PCR, Western blot, flow cytometry, immunofluorescence, wound-healing assays, 3D sphere invasion assays, and co-immunoprecipitation to elucidate the biological functions and molecular mechanisms of RYK in GC metastasis. Results RYK expression was higher in both primary and metastatic tumor tissues than in adjacent normal tissues. Overexpression of RYK markedly enhanced the invasion and migration capacities of GC cells and induced epithelial-to-mesenchymal transition; blocking its membrane localization promptly attenuated this pro-metastatic effect. Mechanistically, β-1,3- N -acetylglucosaminyltransferase 2 (B3GNT2) bound to RYK and catalyzed its N-glycosylation, thereby promoting RYK trafficking to the plasma membrane. In GC cell models and a liver-metastasis mouse model, GC cells overexpressing B3GNT2 displayed significantly increased metastatic ability, whereas treatment with an N-glycosylation inhibitor effectively suppressed this phenomenon. Conclusion B3GNT2 promotes the trafficking of RYK to the plasma membrane of GC cells by mediating its N-glycosylation, thereby driving GC metastasis.