Methylation status of imprinting centers for H19/IGF2 and SNURF/SNRPN in primate embryonic stem cells
Methylation status of imprinting centers for H19/IGF2 and SNURF/SNRPN in primate embryonic stem cells
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DOI：
10.1634/stemcells.2006-0120
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发表时间：
2007-03-01
期刊：
影响因子：
5.2
通讯作者：
Wolf, Don
中科院分区：
文献类型：
--
作者：
Mitalipov, Shoukhrat;Clepper, Lisa;Wolf, Don
胚胎干细胞（ESCs）具有分化为多种体细胞和组织的能力，有望成为治疗人类疾病的细胞和组织替代方法。然而，长期的体外培养和操作的胚胎干细胞可能会产生不利影响，其表观遗传的完整性，包括印记。我们最近报道了IGF 2和H19在几个恒河猴ESC系中的异常双等位基因表达，而SNRPN和NDN通常是印迹的，主要由父本等位基因表达。与人类肿瘤发生相关的IGF 2和H19的失调可能是由于印迹中心（H19上游的IQ）等位基因特异性甲基化模式的不适当维持所致。为了测试这种可能性，我们通过基因组亚硫酸氢盐测序对几种猴ESC系进行了甲基化分析。我们研究了IGF 2/H19 IC内含有CTCF-6结合位点的CpG岛的甲基化谱。此外，检查了称为Prader-Willi综合征IC的SNURF/SNRPN启动子/外显子1内IC的甲基化状态。我们的研究结果表明，在所有分析的ESC系中，IGF 2/H19 IC异常甲基化，而SNURF/SNRPN IC甲基化差异，与单等位基因表达一致。
Embryonic stem cells (ESCs) bold promise for cell and tissue replacement approaches to treating human diseases based on their capacity to differentiate into a wide variety of somatic cells and tissues. However, long-term in vitro culture and manipulations of ESCs may adversely affect their epigenetic integrity, including imprinting. We have recently reported aberrant biallelic expression of IGF2 and H19 in several rhesus monkey ESC lines, whereas SNRPN and NDN were normally imprinted and expressed predominantly from the paternal allele. The dysregulation of IGF2 and H19 that is associated with tumorigenesis in humans may result from improper maintenance of allele-specific methylation patterns at an imprinting center (IQ upstream of H19. To test this possibility, we performed methylation analysis of several monkey ESC lines by genomic bisulfite sequencing. We investigated methylation profiles of CpG islands within the IGF2/H19 IC harboring the CTCF-6 binding site. In addition, the methylation status of the IC within the promoter/exon 1 of SNURF/SNRPN known as the Prader-Willi syndrome IC was examined. Our results demonstrate abnormal hypermethylation within the IGF2/H19 IC in all analyzed ESC lines, whereas the SNURF/SNRPN IC was differentially methylated, consistent with monoallelic expression.