Effect of all-trans-retinoic acid and phorbol 12-myristate 13-acetate on the activity of human hepatocellular carcinoma cell-surface β-1,4-galactosyltransferase

A human hepatocellular carcinoma cell line, SMMC-7721, was treated with all-trans-retinoic acid (RA) and phorbol 12-myristate 13-acetate (PMA) to induce its differentiation and proliferation respectively. A biantennary sugar chain fluorescently labelled with 2-aminopyridine (PA), GlcNAcβ1-2Manα1-6(GlcNAcβ1-2Manα1-3)Manβ1-4GlcNAcβ1-4GlcNAc-PA, was used to detect the activity of β-1,4-galactosyltransferase on the cell surface by HPLC. The results show that the activity of β-1,4-galactosyltransferase on the cell surface increases when the cell is treated with RA, but decreases when it is treated with PMA, whereas the activities of the whole cell remain stable during the treatments.