An upstream insulator regulates DLK1 imprinting in AML
An upstream insulator regulates DLK1 imprinting in AML
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DOI：
10.1182/blood-2009-03-212746
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发表时间：
2010-03-18
期刊：
影响因子：
20.3
通讯作者：
Minden, Mark D.
中科院分区：
文献类型：
--
作者：
Khoury, Haytham;Suarez-Saiz, Fernando;Minden, Mark D.
DLK1是位于14号染色体上的一个印记基因。利用信息性编码的单核苷酸多态性，我们发现DLK1在正常骨髓中的表达是单等位基因，而在高表达DLK1的急性髓系白血病(AML)中有76%(61%)是双等位基因。对7个胞嘧啶-磷酸-鸟苷富集区(DLK1上游或其内的3个，推测的基因间差异甲基化区域和MEG3上游或其内的3个区域)的定量甲基化分析显示，双等位基因DLK1的表达与DLK1上游18kb的胞嘧啶-磷酸-鸟苷富集区的高甲基化密切相关。该区域的等位基因特异性甲基化分析显示，在正常骨髓和单等位基因DLK1 AML中存在差异甲基化的等位基因，而在双等位基因表达的AML中，这两个等位基因的甲基化增加。此外，染色质免疫沉淀分析表明，在单等位基因表达的样本中，CCTC结合因子与该区域结合，但在双等位基因表达样本中不结合。综上所述，我们的数据表明，位于DLK1上游18kb的绝缘子在调节DLK1印记方面发挥着重要作用。(血。2010；115：2260-2263)
DLK1 is an imprinted gene on chromosome 14. Using informative coding single nucleotide polymorphisms, we found DLK1 expression to be monoallelic in normal bone marrow, whereas it was biallelic in 76% of acute myeloid leukemia (AML) overexpressing DLK1 (61% of all AML). Quantitative methylation analysis of 7 cytosine-phosphate-guanosine-rich areas (3 upstream of or within DLK1, the putative intergenic-differentially methylated region and 3 upstream of or within MEG3) revealed a strong association between biallelic DLK1 expression and hypermethylation of a cytosine-phosphate-guanosine-rich region 18 kb upstream of DLK1. Allele-specific methylation analysis of this region revealed the alleles to be differentially methylated in normal bone marrow and monoallelic DLK1 AML, whereas there was increased methylation of both alleles in AML with biallelic expression. Moreover, chromatin immunoprecipitation analysis revealed that CCTC-binding factor binds to this region in monoallelic but not biallelic expression samples. Taken together, our data indicate that an insulator located 18 kb upstream of DLK1 plays an important role in regulating DLK1 imprinting. (Blood. 2010;115:2260-2263)