Additional file 19: Table S18. of DNA methylation analysis of paediatric low-grade astrocytomas identifies a tumour-specific hypomethylation signature in pilocytic astrocytomas

Differentially methylated CpG sites identified between supratentorial pilocytic astrocytomas and cerebral cortex controls. 1_ MethLAB analysis identified 90,249 CpG sites that are significantly differentially methylated in supratentorial pilocytic astrocytomas, diffuse astrocytomas, glial component of the cerebral cortex, neuronal component of the cerebral cortex, adult cerebral cortex and foetal cerebral cortex (Benjamini-Hochberg corrected p-value <0.05). The adult cerebral cortex controls (including the glial and neuronal components) were taken from [Guintivano et al, Epigenetics 8:290-302, 2013]. The number of differentially methylated sites (averaged beta values with a difference of δβ ≥ 0.3, Benjamini-Hochberg corrected p-value <0.05) identified in tumour and all controls was 382 CpG sites for supratentorial pilocytic astrocytomas. 2_ CpG sites hypermethylated and 3_ hypomethylated in pilocytic astrocytomas compared to controls. 4_ Expression analysis for the genes that show differentially methylated CpG sites. Highlighted genes show ≤ 2 fold change in expression compared to controls. (XLSX 37842 kb)

本数据集鉴定了幕上毛细胞型星形细胞瘤与大脑皮层对照组之间的差异甲基化CpG位点（CpG site）。1. MethLAB分析共鉴定出90249个CpG位点，这些位点在幕上毛细胞型星形细胞瘤、弥漫性星形细胞瘤、大脑皮层胶质组分、大脑皮层神经元组分、成人大脑皮层及胎儿大脑皮层中呈现显著差异甲基化（Benjamini-Hochberg校正P值<0.05）。其中成人大脑皮层对照组（包含胶质组分与神经元组分）的数据取自Guintivano等人2013年发表于《Epigenetics》第8卷第290-302页的研究。在肿瘤样本与所有对照组的比较中，针对幕上毛细胞型星形细胞瘤鉴定出的差异甲基化CpG位点共计382个，筛选标准为平均β值差异δβ≥0.3且Benjamini-Hochberg校正P值<0.05。2. 与对照组相比，毛细胞型星形细胞瘤中呈高甲基化的CpG位点；3. 与对照组相比，毛细胞型星形细胞瘤中呈低甲基化的CpG位点；4. 针对携带差异甲基化CpG位点的基因开展表达分析，其中经高亮标注的基因相较于对照组的表达折叠变化倍数≤2。（附件为XLSX格式文件，大小37842 KB）