双丁酰环磷酸腺苷耐人肝癌细胞株SMMC－7721表面N－糟链类型及天线数的影响

本文采用系列凝集素柱层析法，并配合外切精苷酶研究了在双丁酰环磷酸腺苷（ｄＢ－ｃＡＭＰ）作用１～５天过程中人肝癌细胞株ＳＭＭＣ－７７２１细胞表面Ｎ－糖链类型及复杂型糖链天线数的变化。结果表明，ｄＢ－ｃＡＭＰ促进３Ｈ—Ｍａｎ参入细胞表面Ｎ－糖链，使高甘露糖型Ｎ－糖链的百分比下降，并促进二天线Ｎ－糖链的生物合成。使多天线特别是四天线和Ｃ２Ｃ２Ｃ６三天线Ｎ－糖链的百分比减少．结果提示，Ｎ－糖链结构的这些变化可能是ｄＢ－ｃＡＭＰ诱导ＳＭＭＣ－７７２１细胞向正常方向分化的结果。

Effect of Dibutyryl cAMP on the Type and Antennary Number of N-glycans on the Surface of Human Hepatocarcinoma Cell Line SMMC-7721

H-mannose labeled N-glycans were prepared from the cell surface of human hepatocarcinoma cell line SMMC-7721 treated with dibutyryl cAMP (dB-cAMP)for 1-5 days and studied in comparison with undreamed control cells by serial lectin affinity chromatography combined with exoglycosidase treatment. The results showed that dB-cAMP stimulated incorporation of 3H-mannose into the N-glycans of glycoprotein on the cultured cell anrfaoe, decreased the percentage of high mannose type, accelerated the biosynthesis of biantennary complex type,and decreased the percentage of more than two antennarys, especially tetra-and C2C2C6 triantennary complex type of N-glycans. It is suggested that the structural changes of N-glycans are associated with the cell differentiation induced by dB-cAMP.