Fucosylated glycan inhibition of human hepatocellular carcinoma cell migration through binding to chemokine receptors

SMMC-7721 hepatocellular carcinoma cells (HCC) were incubated with fucosylated glycoproteins that had been isolated from retinoic acid-treated cells by affinity chromatography. HCC migration was significantly inhibited by AAL- and LCA-glycoproteins. Glycopeptides, obtained by digestion of the glycoproteins with trypsin and papain, were found to have a similar inhibitory effect on HCC migration as the corresponding glycoproteins. The inhibitory actions of the glycoproteins were almost abolished after digestion with alpha-L-1,3/4- or alpha-L-1,2-fucosidase. Induction of HCC migration with chemokines including interleukin-8 (IL-8), lymphotactin, monocyte chemoattractant protein-1, and stroma cell-derived factor-1 was examined and IL-8 was found to be the most potent. Interestingly, the isolated glycoproteins significantly inhibited HCC migration and F-actin aggregation induced by IL-8, whereas the glycans themselves did not induce F-actin assembly. From receptor binding analysis AAL-glycan was found to bind IL-8 receptors especially CXCR2 directly and such binding could be blocked by 3'- or 2'-fucosyllactose. After CXCR2 silence by target RNAi, the cells almost lost the response to AAL-glycan inhibition. Our findings suggest that fucosylation plays an important role in the interaction between IL-8 and its receptors inducing HCC migration.