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

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-lewis x抗原前体,本实验中B4GalT-1和B4GalT-3与ST3GalⅣ、ST3GalⅤ、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.

Different Expression of mRNA in B4GalT Glycosyltransferase Family Between Mouse Hepatocellular Carcinoma and Normal Liver Tissues and its Influence on Relevant Sugar Chain of Membrane

To investigate different expression of mRNA in B4GalT(β-1,4-Galactosyltransferase) family be-tween 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 Ⅲ,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 re-sults showed that compared with normal mouse tissues,B4GalT-1,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-1 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 anti-gen precursor by ST3Gal Ⅲ,ST3Gal Ⅳ or ST3Gal Ⅵ,the relationship between the mRNA expression of B4GalT-1 and B4GalT-3 with ST3gGal Ⅳ,ST3Gal Ⅴ and FUT8 in the experiment indicates that B4GalT-1 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.