Waha Anke, Güntner Stefanie, Huang Tim Hui-Ming, Yan Pearlly S, Arslan Bülent, Pietsch Torsten, Wiestler Otmar D, Waha Andreas
Department of Neuropathology, University of Bonn Medical Center, Bonn, Germany.
Neoplasia. 2005 Mar;7(3):193-9. doi: 10.1593/neo.04490.
In a microarray-based methylation analysis of astrocytomas [World Health Organization (WHO) grade II], we identified a CpG island within the first exon of the protocadherin-gamma subfamily A11 (PCDH-gamma-A11) gene that showed hypermethylation compared to normal brain tissue. Bisulfite sequencing and combined bisulfite restriction analysis (COBRA) was performed to screen low- and high-grade astrocytomas for the methylation status of this CpG island. Hypermethylation was detected in 30 of 34 (88%) astrocytomas (WHO grades II and III), 20 of 23 (87%) glioblastomas (WHO grade IV), and 8 of 8 (100%) glioma cell lines. There was a highly significant correlation (P = .00028) between PCDH-gamma-A11 hypermethylation and decreased transcription as determined by competitive reverse transcription polymerase chain reaction in WHO grades II and III astrocytomas. After treatment of glioma cell lines with a demethylating agent, transcription of PCDH-gamma-A11 was restored. In summary, we have identified PCDH-gamma-A11 as a new target silenced epigenetically in astrocytic gliomas. The inactivation of this cell-cell contact molecule might be involved in the invasive growth of astrocytoma cells into normal brain parenchyma.
在一项基于微阵列的星形细胞瘤（世界卫生组织（WHO）二级）甲基化分析中，我们在原钙黏蛋白-γ亚家族A11（PCDH-γ-A11）基因的第一个外显子内鉴定出一个CpG岛，与正常脑组织相比，该岛呈现高甲基化。进行了亚硫酸氢盐测序和联合亚硫酸氢盐限制性分析（COBRA），以筛查低级别和高级别星形细胞瘤中该CpG岛的甲基化状态。在34例星形细胞瘤（WHO二级和三级）中的30例（88%）、23例胶质母细胞瘤（WHO四级）中的20例（87%）以及8株胶质瘤细胞系中的8株（100%）检测到高甲基化。在WHO二级和三级星形细胞瘤中，通过竞争性逆转录聚合酶链反应测定，PCDH-γ-A11高甲基化与转录减少之间存在高度显著的相关性（P = 0.00028）。用去甲基化剂处理胶质瘤细胞系后，PCDH-γ-A11的转录得以恢复。总之，我们已将PCDH-γ-A11鉴定为星形细胞胶质瘤中一个新的表观遗传沉默靶点。这种细胞间接触分子的失活可能参与星形细胞瘤细胞向正常脑实质的侵袭性生长。
