中文摘要：

各种唾液酸转移酶应用共同的供体单磷酸胞苷活化的唾液酸（CMP—Neu5Ac），对糖链末端进行唾液酸化修饰。研究表明，各种唾液酸转移酶在正常细胞和肿瘤细胞中的表达有显著差异，它们通过改变细胞膜末端糖链唾液酸化的结构或者数量，影响肿瘤进展和转移。研究肿瘤细胞中各种唾液酸转移酶的表达，对肿瘤防治有重要意义。

英文摘要：

Sialyhransferases are a family of glycosyhransferases which catalyze the transfer of sialic acid from eytidine monophosphate N- aeetylneuraminic acid （ CMP- NenSAc） to non- reducing terminal positions on sugar chains of glycoconjugates. Studies show the expression of sialyhransferases in the normal cells and tumor cells has significant difference, They alter structure or quantity of sialylation of cell membrane terminal glycoconjugates, which can influence on tumor progression and transformation. Accordingly, research on the aberrant expression of sialyhransferases has great significance for tumor prevention and treatment.