The β-1,4 GalT-V Interactome-Potential Therapeutic Targets and a Network of Pathways Driving Cancer and...

UDP-Gal-β-1,4 galactosyltransferase-V (GalT-V) is a member of a large family of galactosyltransferases whose function is to transfer galactose from the nucleotide sugar UDP-galactose to a glycosphingolipid glucosylceramide, to generate lactosylceramide (LacCer). It also causes the N and O glycosylation of proteins in the Trans Golgi area. LacCer is a bioactive lipid second messenger that activates an "oxidative stress pathway", leading to critical phenotypes, e.g., cell proliferation, migration angiogenesis, autophagy, and apoptosis. It also activates an "inflammatory pathway" that contributes to the progression of disease pathology. β-1,4-GalT-V gene expression is regulated by the binding of the transcription factor Sp-1, one of the most O-GlcNAcylated nuclear factors. This review elaborates the role of the Sp-1/GalT-V axis in disease phenotypes and therapeutic approaches targeting not only Sp-1 but also Notch-1, Wnt-1 frizzled, hedgehog, and β-catenin. Recent evidence suggests that β-1,4GalT-V may glycosylate Notch-1 and, thus, regulate a VEGF-independent angiogenic pathway, promoting glioma-like stem cell differentiation into endothelial cells, thus contributing to angiogenesis. These findings have significant implications for cancer and cardiovascular disease, as tumor vascularization often resumes aggressively following anti-VEGF therapy. Moreover, LacCer can induce angiogenesis independent of VEGF and its level are reported to be high in tumor tissues. Thus, targeting both VEGF-dependent and VEGF-independent pathways may offer novel therapeutic strategies. This review also presents an up-to-date therapeutic approach targeting the β-1,4-GalT-V interactome. In summary, the β-1,4-GalT-V interactome orchestrates a broad network of signaling pathways essential for maintaining cellular homeostasis. Conversely, its dysregulation can promote unchecked proliferation, angiogenesis, and inflammation, contributing to the initiation and progression of multiple diseases. Environmental factors and smoking can influence β-1,4-GalT-V expression and its interactome, whereas elevated β-1,4-GalT-V expression may serve as a diagnostic biomarker of colorectal cancer, inflammation-exacerbated by factors that may worsen pre-existing cancer malignancies, such as smoking and a Western diet-and atherosclerosis, amplifying disease progression. Increased β-1,4-GalT-V expression is frequently associated with tumor aggressiveness and chronic inflammation, underscoring its potential as both a biomarker and therapeutic target in colorectal and other β-1,4-GalT-V-driven cancers, as well as in cardiovascular and inflammatory diseases.