Analysis of stem-cell differentiation mechanism by using DNA microarray and novel bisulfite modification.

我们对永生化的人间充质干细胞克隆进行了DNA微阵列分析。其中，克隆12表现出最高的分化成骨细胞，软骨细胞和脂肪细胞的能力，其分析表明基因表达的特征模式。为了了解干细胞分化与DNA甲基化之间的关系，我们接下来通过使用CpG甲基化阵列系统对分化过程中的干细胞克隆进行全局甲基化分析。因此，我们分离了11个成骨细胞分化过程中的基因和4个脂肪细胞分化过程中的基因作为甲基化状态的上调或下调基因的候选者。此外，我们分离出82个基因，通过使用新的亚硫酸氢盐修饰，在干细胞分化过程中改变其甲基化水平，从而使全基因组范围内识别甲基化位点成为可能。这些基因被认为对调节干细胞分化和重建甲基化状态很重要。这些结果可能有助于干细胞研究和再生医学的最新进展。

We performed DNA microarray analysis of immortalized human mesenchymal stem cell clones. Among them, clone no.12 showed highest ability of differentiation to osteoblasts, chondrocytes and adipocytes, and its profiling analysis showed characteristic patterns of gene expression. In order to know the relationship between stem cell differentiation and DNA methylation, we next performed global methylation analysis of stem cell clones under differentiation processes by using CpG methylation array system. As a result, we isolated 11 genes under osteoblastic differentiation process and four genes under adipocytic differentiation process as candidates of up-regulated or down-regulated genes of methylation status. Furthermore, we isolated 82 genes varying their methylation levels during stem cell differentiation by using novel bisulfite modification with which genome-wide identification of methylation sites may become possible. These genes were supposed to be important for regulation of stem cell differentiation and reconstruction of methylation status. These results may contribute to the progress of stem cell research and regeneration medicine up to date.