N-glycosylation of Wnt3 regulates the progression of hepatocellular carcinoma by affecting Wnt/β-catenin signal pathway

BACKGROUND Wnt/FZD-mediated signaling pathways are activated in more than 90%of hepatocellular carcinoma(HCC)cell lines.As a well-known secretory glycoprotein,Wnt3 can interact with FZD receptors on the cell surface,thereby activating the Wnt/β-catenin signaling pathway.However,the N-glycosylation modification site of Wnt3 and the effect of this modification on the biological function of the protein are still unclear.AIM To investigate the effect of Wnt3 N-glycosylation on the biological function of HCC cells.METHODS Site-directed mutagenesis was used to verify the Wnt3 N-glycosylation sites,actinomycin D treatment was used to detect the stability of Wnt3 after site-directed mutation,the binding of the N-glycosylation site-directed mutant Wnt3 to FZD7 was observed by laser confocal microscopy,and the effects of the N-glycosylation site-directed mutation of Wnt3 on the Wnt/β-catenin signaling pathway and the progression of HCC cells were detected by western blot and cell function experiments.RESULTS Wnt3 has two N-glycosylation-modified sites(Asn90 and Asn301);when a single site at amino acid 301 is mutated,the stability of Wnt3 is weakened;the binding ability of Wnt3 to FZD7 decreases when both sites are mutated simultaneously;and the level of proteins related to the Wnt/β-catenin signaling pathway is downregulated.Cell proliferation,migration and invasion are also weakened in the case of single 301 site and double-site mutations.CONCLUSION These results indicate that by inhibiting the N-glycosylation of Wnt3,the proliferation,migration,invasion and colony formation abilities of liver cancer cells can be weakened,which might provide new therapeutic strategies for clinical liver cancer in the future.