小鼠肝癌及肝正常组织B4GalT糖基转移酶家族mRNA表达差异及其对细胞膜相关糖链的影响

摘要

探讨肝癌模型鼠与正常小鼠肝组织B4GalT(β-1,4-半乳糖转移酶)家族mRNA表达差异以及对细胞膜相关糖链的影响.采用RT-PCR方法检测肝癌模型鼠和正常对照小鼠肝癌组织中B4GalT家族7个成员以及唾液酸α-2,3转移酶ST3GalⅢ、ST3GalⅣ、ST3GalⅥ、α-1,6-岩藻糖转移酶FUT8 mRNA表达差异,应用凝集素芯片检测细胞膜表面半乳糖、岩藻糖、唾液酸表达情况.结果显示:与正常对照组相比,肝癌模型鼠肝组织中B4GalT-1和B4GalT-3、ST3GalⅣ和ST3GalⅥ、FUT8呈现高表达,肝癌细胞膜半乳糖、岩藻糖、唾液酸类型糖链增加,提示B4GalT-1和B4GalT-3与肝癌细胞膜半乳糖链增加相关.由于细胞Galβ-1,4-GlcNAc糖表位在ST3GalⅢ、ST3GalⅣ或ST3GalⅥ催化下与唾液酸α-2,3连接生成s-lewisx抗原前体,本实验中B4GalT-1和B4GalT-3与ST3GalⅣ、ST3Gal V、FUT8 mRNA表达具有相关性,提示B4GalT-1和B4GalT-3可能与ST3GalⅣ、ST3GalⅥ以及FUT4协同作用,导致肝癌细胞膜半乳糖、岩藻糖、唾液酸类型糖链增加.%To investigate different expression of mRNA in B4GalT (β-1, 4-Galactosyltransferase) family between mouse hepatocellular carcinoma and normal liver tissues and its influence on relevant sugar chain of membrane. The different expression of mRNAs in 7 members of B4GalT family and α-2, 3 sialyltransferase ST3Gal I, ST3Gal IV, ST3Gal VI and fucosyltransferase FUT8 were detected with RT-PCR. The expression levels of galactose, fucose and sialic acid on cell membrane surface were analyzed by lectin array. The results showed that compared with normal mouse tissues, B4GalT-l, B4GalT-3, ST3Gal IV, ST3Gal VI and FUT8 in mouse hepatocellular carcinoma were identified highly expressed. Galactose, fucose and sialic acid on cell membrane surface were increased, indicating that B4GalT-l and B4GalT-3 are related with the increasing of the galactose epitope. Because sialic acids were added to Galβ-1, 4-GlcNAc epitopes to form slewis x antigen precursor by ST3Gal Ⅲ, ST3Gal IV or ST3Gal VI, the relationship between the mRNA expression ofB4GalT-l and B4GalT-3 with ST3gGal IV, ST3Gal V and FUT8 in the experiment indicates that B4GalT-l and B4GalT3 may effect synergistically with ST3Gal IV, ST3Gal VI and FUT4, which results in the increase of galactose, fucose and sialic acid on hepatocellular carcinoma cell membrane.