UGGT1 mediates N-glycosylation of LGALS3BP to induce angiogenesis in liver cancer via the NOTCH signaling pathway

Abstract Background Liver cancer (LC) is one of the leading causes of cancer-related deaths worldwide. Its complex vascular regulatory network and drug resistance severely limit clinical efficacy. Although LGALS3BP is highly expressed in various malignant tumors, its biological function and molecular regulatory mechanisms in LC angiogenesis remain to be elucidated. Methods Bioinformatics analysis was used to examine the expression of LGALS3BP in hepatocellular carcinoma (HCC) and its relationship with angiogenesis and the NOTCH signaling pathway. qRT-PCR, Western blot (WB), and ELISA were performed to validate the mRNA, protein expression, and secretion levels of LGALS3BP. The effects of LGALS3BP on HCC cell viability, proliferation, and invasion were assessed using CCK-8, colony formation, and Transwell assays. A co-culture system of HCC cells and human umbilical vein endothelial cells was established to evaluate pro-angiogenic effects. qRT-PCR and WB were used to detect mRNA and protein expression of the NOTCH pathway. Bioinformatics analysis combined with Co-IP and IF validated the interaction between UGGT1 and LGALS3BP. N-glycosylation sites of LGALS3BP were analyzed, and the role of UGGT1 in LGALS3BP N-glycosylation was investigated through protein stability assays, WB, and ELISA. The impact of UGGT1-mediated LGALS3BP N-glycosylation on the NOTCH pathway and HCC angiogenesis was explored via qRT-PCR, WB, functional cell assays, and co-culture experiments. Finally, in vivo validation was conducted using a xenograft tumor model. Results LGALS3BP was significantly overexpressed in HCC tissues and cells. Knockdown of LGALS3BP inhibited HCC cell proliferation and invasion, reduced VEGF-A expression, and suppressed tube formation in human umbilical-vein endothelial cells. Mechanistically, UGGT1 maintained LGALS3BP protein stability by mediating its N-glycosylation modification. LGALS3BP promoted VEGF-A expression by activating the NOTCH pathway. Animal experiments demonstrated that UGGT1 knockdown significantly inhibited tumor growth and angiogenesis, an effect that could be partially rescued by LGALS3BP overexpression. Conclusion This study reveals that UGGT1 promotes angiogenesis in HCC by mediating N-glycosylation of LGALS3BP and activating the NOTCH/VEGF-A signaling axis, providing a potential target for anti-angiogenic therapy in HCC.