Institute of Human Genetics, Johannes Gutenberg University, 55101 Mainz, Germany.
Mol Hum Reprod. 2010 Sep;16(9):704-13. doi: 10.1093/molehr/gap107. Epub 2009 Dec 9.
To study possible effects of assisted reproductive technologies (ART) on epigenetic reprogramming, we have analyzed the DNA methylation levels of differentially methylated regions (DMRs) of seven imprinted genes (H19, MEG3, LIT1, MEST, NESP55, PEG3 and SNRPN) as well as the promoter regions of the pluripotency gene NANOG and the tumor suppressor gene APC in chorionic villus samples (CVS) of 42 spontaneous miscarriages and stillbirths after ART and 29 abortions/stillbirths after spontaneous conception. We did not find an increased rate of faulty methylation patterns after ART, but significant and trend differences (ROC curve analysis, Wilcoxon test) in the methylation levels of LIT1 (P = 0.006) and H19 (P = 0.085) between ART and non-ART samples. With the possible exception of NANOG, we did not observe a gestational age effect on the methylation levels of the studied genes. The frequency of extreme methylation values in PEG3 and APC was markedly higher than in the other studied genes, indicating an increased susceptibility of some genes to epigenetic alterations. Most methylation abnormalities in CVS represented either hypermethylated DMRs of paternally and maternally imprinted genes or hypomethylated promoters of non-imprinted genes. The observed methylation abnormalities (mosaicism) are consistent with methylation reprogramming defects during early embryogenesis.
为了研究辅助生殖技术（ART）对表观遗传重编程的可能影响，我们分析了 42 例 ART 后自然流产和死胎及 29 例自然受孕后流产/死胎绒毛组织中差异甲基化区域（DMR）的七个印迹基因（H19、MEG3、LIT1、MEST、NESP55、PEG3 和 SNRPN）以及多能基因 NANOG 和肿瘤抑制基因 APC 的启动子区域的 DNA 甲基化水平。我们没有发现 ART 后错误甲基化模式的发生率增加，但在 LIT1（P=0.006）和 H19（P=0.085）的甲基化水平上，ART 和非-ART 样本之间存在显著且呈趋势性差异（ROC 曲线分析，Wilcoxon 检验）。除了 NANOG，我们没有观察到研究基因的甲基化水平与孕龄之间的影响。PEG3 和 APC 中极端甲基化值的频率明显高于其他研究基因，表明一些基因对表观遗传改变的敏感性增加。CVS 中大多数甲基化异常表现为父系和母系印迹基因的高甲基化 DMR 或非印迹基因的低甲基化启动子。观察到的甲基化异常（镶嵌现象）与早期胚胎发生过程中的甲基化重编程缺陷一致。
