N-乙酰氨基葡萄糖转移酶II促进小鼠乳腺癌细胞迁移

Promoting Effect of N-Acetylglucosaminyltransferase II on the Migration of Mouse Breast Cancer Cell

It is well documented that altered biosynthesis of cell surface N-linked oligosaccharides is associated with the transformed cells and tumors. N-acetylglucosaminyltransferase II (GnT-II; EC 2.4.1.143) is a medial Golgi enzyme that catalyses the incorporation of a GlcNAc residue in β-1,2 linkage to the Man-α-1,6 arm of the N-glycan core. This is an essential step in the biosynthetic pathway leading from hybrid to complex N-glycans. Because functional GnT-II is an prerequisite of N-Acetylglucosaminyltransferase V performance, we speculated that GnT-II was involved in cancer development and progression. In this study, the expression of GnT-II in mouse breast cancer cells 67NR and 4T1 which have different behavior of metastasis was analysed using RT-PCR. The amounts of GnT-II in the highly metastatic cell 4T1 increased to 1.53 times of the lowly metastatic cell 67NR. To determine the association of GnT-II with tumor progression, the GnT-II encoding gene was amplified with RT-PCR and cloned into retrovirus vector pMSCV, resulting in pMSCV-GnT-II. The recombinant plasmid was transfected into 4T1 and the transfected cells were selected in the medium containing puromycin, which were harvested to detect the adhesion ability to fibronection and the migration potential by transwell system. The cell adhesion to fibronectin was weakened by 67% and migration potential was increased by 82%. Our data indicates that GnT-II mediates cell adhesion and migration, thus may play an important role in cancer metastasis.