Abstract: Modification of sialic acid is an important form of glycosylation, which is correlated with the occurrence and development of carcinoma closely. Under the influence of saliva acyltransferase, sialic acid is transferred to galactose which is at the end of glycoprotein or glycolipid through glyosidic bond. It is reported that high expression of sialic acid on cell surface plays a vital role on oncogenesis and clinical prognostic. Nowadays, more and more researchers pay attention to the molecular research about antigen of sialic acid relating to the target of carcinoma formation. Studies have shown that in the process of carcinogenesis, the acyltransferase expression and activity are corresponding to the change of sugar chain structure in saliva acid. The role of ST6Gal-I in the development of tumor and the change of its expression and activity during oncogenesis were discussed in this review.

Key words: ST6Gal-I, liver cancer, invasion, metastasis, apoptosis