Recent studies have revealed an unexpected role of DNA methylation at promoter regions in transcription activation. However, whether DNA methylation at enhancer regions activates gene expression and influences cellular functions remains to be determined. In this study, by employing the transcription factor krUppel-like factor 4 (KLF4) that binds to methylated CpGs (mCpGs), we investigated the molecular outcomes of the recruitment of KLF4 to mCpGs at enhancer regions in human glioblastoma cells. First, by integrating KLF4 ChIP-seq, whole-genome bisulfite sequence, and H3K27ac ChIP-seq datasets, we found 1,299 highly methylated (beta > 0.5) KLF4 binding sites, three-quarters of which were located at putative enhancer regions, including gene bodies and intergenic regions. In the meantime, by proteomics, we identified 16 proteins as putative targets upregulated by KLF4-mCpG binding at enhancer regions. By chromosome conformation capture (3C) analysis, we demonstrated that KLF4 bound to methylated CpGs at the enhancer regions of the B-cell lymphocyte kinase (BLK) and Lim domain only protein 7 (LMO7) genes, and activated their expression via 3D chromatin loop formation with their promoter regions. Expression of mutant KLF4, which lacks KLF4 ability to bind methylated DNA, or removal of DNA methylation in enhancer regions by a DNA methyltransferase inhibitor abolished chromatin loop formation and gene expression, suggesting the essential role of DNA methylation in enhancer-promoter interactions. Finally, we performed functional assays and showed that BLK was involved in glioblastoma cell migration. Together, our study established the concept that DNA methylation at enhancer regions interacts with transcription factors to activate gene expression and influence cellular functions.
基金:
Walther Cancer Foundation; NIH [R01NS091165, EY024580, EY023188, GM111514, R33CA186790, U54 HG006434, U24 CA160036, T32 GM007445]; Ford Foundation
第一作者单位:[1]Hugo W Moser Res Inst Kennedy Krieger, Baltimore, MD 21205 USA[2]Johns Hopkins Univ, Johns Hopkins Sch Med, Dept Pharmacol & Mol Sci, Baltimore, MD USA
通讯作者:
通讯机构:[1]Hugo W Moser Res Inst Kennedy Krieger, Baltimore, MD 21205 USA[3]Johns Hopkins Univ, Dept Neurol, Johns Hopkins Sch Med, Baltimore, MD 21218 USA[9]Indiana Univ Sch Med, Dept Med & Mol Genet, Indianapolis, IN 46202 USA[10]Indiana Univ Sch Med, Ctr Computat Biol & Bioinformat, Indianapolis, IN 46202 USA
推荐引用方式(GB/T 7714):
Oyinlade Olutobi,Wei Shuang,Kammers Kai,et al.Analysis of KLF4 regulated genes in cancer cells reveals a role of DNA methylation in promoter-enhancer interactions[J].EPIGENETICS.2018,13(7):751-768.doi:10.1080/15592294.2018.1504592.
APA:
Oyinlade, Olutobi,Wei, Shuang,Kammers, Kai,Liu, Sheng,Wang, Shuyan...&Xia, Shuli.(2018).Analysis of KLF4 regulated genes in cancer cells reveals a role of DNA methylation in promoter-enhancer interactions.EPIGENETICS,13,(7)
MLA:
Oyinlade, Olutobi,et al."Analysis of KLF4 regulated genes in cancer cells reveals a role of DNA methylation in promoter-enhancer interactions".EPIGENETICS 13..7(2018):751-768