Gangliosides are expressed in nervous systems and some neuroectoderm-derived tumors at high levels and play pivotal roles. However, mechanisms for the regulation of glycosyltransferase genes responsible for the ganglioside synthesis are not well understood. In this study, we analyzed DNA methylation patterns of promoter regions of GD3 synthase (ST8SIA1) as well as mRNA levels and ganglioside expression using human glioma cell lines. Among 5 cell lines examined, 4 lines showed changes in the expression levels of related genes after treatment with 5-aza-dC. LN319 showed up-regulation of St8sia1 and increased b-series gangliosides after 5-aza-dC treatment, and an astrocytoma cell line, AS showed high expression of ST8SIA1 and b-series gangliosides persistently before and after 5-Aza-2’-deoxycytidine treatment. Using these 2 cell lines, DNA methylation patterns of the promoter regions of the gene were analyzed by bisulfite-sequencing. Consequently, 2 regions that were methylated before 5-Aza-2’-deoxycytidine treatment were demethylated in LN319 after the treatment, while those regions were persistently demethylated in AS. These 2 regions corresponded with sites defined as promoter regions by Luciferase assay. Taken together, it was suggested that ST8SIA1 gene is regulated by DNA methylation at the promoter regions, leading to the regulation of tumor phenotypes.

神经节苷脂在神经系统和一些神经外胚层衍生的肿瘤中以高水平表达并发挥关键作用。然而，负责神经节苷脂合成的糖基转移酶基因的调控机制尚不清楚。在这项研究中，我们使用人神经胶质瘤细胞系分析了GD3 合酶( ST8SIA1 )启动子区域的 DNA 甲基化模式以及 mRNA 水平和神经节苷脂表达。在检查的 5 个细胞系中，4 个细胞系在用 5-aza-dC 处理后显示出相关基因表达水平的变化。LN319 在 5-aza-dC 处理后显示 St8sia1 上调和 b 系列神经节苷脂增加，星形细胞瘤细胞系 AS 显示 ST8SIA1 高表达和 b 系列神经节苷脂在 5-Aza-2'-脱氧胞苷治疗前后持续存在。使用这 2 个细胞系，通过亚硫酸氢盐测序分析基因启动子区域的 DNA 甲基化模式。因此，在 5-Aza-2'-脱氧胞苷处理之前甲基化的 2 个区域在处理后在 LN319 中去甲基化，而这些区域在 AS 中持续去甲基化。这 2 个区域对应于荧光素酶测定定义为启动子区域的位点。总之，表明ST8SIA1基因受启动子区域的 DNA 甲基化调节，从而导致肿瘤表型的调节。