UDP-GlcNAc2-epimerase regulates cell surface sialylation and cell adhesion to extracellular matrix in Burkitt's lymphoma.
UDP-GlcNAc2-epimerase regulates cell surface sialylation and cell adhesion to extracellular matrix in Burkitt's lymphoma.
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UDP-GlcNAc2-差向异构酶调节伯基特淋巴瘤中的细胞表面唾液酸化和细胞与细胞外基质的粘附。
DOI：
10.3892/ijo.20.5.1005
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发表时间：
2002
影响因子：
5.2
通讯作者：
M. Abe
中科院分区：
文献类型：
--
作者：
Osamu Suzuki;Y. Nozawa;T. Kawaguchi;M. Abe
细胞表面糖缀合物的改变在包括侵袭和转移在内的许多生物现象中起着至关重要的作用。在本研究中，我们研究了人伯基特淋巴瘤细胞系HBL-8的两个克隆（3G3和3D2）对细胞外基质的粘附特性与细胞表面唾液化的关系。流式细胞术分析发现3G3克隆细胞表面高度唾液化，3D2克隆细胞表面低唾液化。3G3克隆细胞表面唾液酸含量显著高于3D2克隆。体外黏附实验表明，与3D2克隆细胞相比，3G3克隆细胞的细胞表面唾液化可能降低了它们对IV型胶原和纤维连接蛋白的附着。利用几种唾液酸前体进行的唾液酸代谢互补分析表明，3D2克隆的低羟基化是由于尿苷二磷酸- n -乙酰氨基葡萄糖-2-外亚胺酶（udp - glcnac2 -外亚胺酶）活性低所致，该酶是唾液酸生物合成的关键酶。通过RT-PCR分析，发现两个HBL-8克隆中udp - glcnac2 - epimase mRNA的表达与唾液酸含量相关。因此，UDP-GlcNAc2-epimerase mRNA的表达可能调节唾液糖缀合物的表达，从而影响淋巴瘤细胞对IV型胶原和纤维连接蛋白的粘附。
Alteration of cell surface glycoconjugates plays a crucial role in many biological phenomenon, including invasion and metastasis. In the present study, we investigated the relationship between cell surface sialylation and the adhesive properties of two clones (3G3 and 3D2) of a human Burkitt's lymphoma cell line, HBL-8 to extracellular matrix. By flow cytometric analysis we found that the cell surface of 3G3 clone was highly sialylated and that of the 3D2 clone were hyposialylated. Moreover, cell surface sialic acid content was significantly greater in the 3G3 clone than in the 3D2 clone. In vitro adhesion assays showed that cell surface sialylation in the 3G3 clone cells might reduce their attachment to collagen type IV and fibronectin, compared to 3D2 clone. Sialic acid metabolic complementation assays using several precursors of sialic acid suggested that hyposialylation in the 3D2 clone resulted from low activities of uridine diphosphate-N-acetylglucosamine-2-epimerase (UDP-GlcNAc2-epimerase) which is a key enzyme in sialic acid biosynthesis. From RT-PCR analysis the expression of UDP-GlcNAc2-epimerase mRNA was found to be correlated with sialic acid content in the two clones of HBL-8. Therefore, expression of UDP-GlcNAc2-epimerase mRNA may regulate the expression of sialoglycoconjugates which affect the adhesion of lymphoma cells to collagen type IV and fibronectin.