Department Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, Stuttgart, Germany.
Methods Mol Biol. 2024;2842:3-20. doi: 10.1007/978-1-0716-4051-7_1.
The introduction of CRISPR/Cas systems has resulted in a strong impulse for the field of gene-targeted epigenome/epigenetic reprogramming (EpiEditing), where EpiEditors consisting of a DNA binding part for targeting and an enzymatic part for rewriting of chromatin modifications are applied in cells to alter chromatin modifications at targeted genome loci in a directed manner. Pioneering studies preceding this era indicated causal relationships of chromatin marks instructing gene expression. The accumulating evidence of chromatin reprogramming of a given genomic locus resulting in gene expression changes opened the field for mainstream applications of this technology in basic and clinical research. The growing knowledge on chromatin biology and application of EpiEditing tools, however, also revealed a lack of predictability of the efficiency of EpiEditing in some cases. In this perspective, the dependence of critical parameters such as specificity, effectivity, and sustainability of EpiEditing on experimental settings and conditions including the expression levels and expression times of the EpiEditors, their chromatin binding affinity and specificity, and the crosstalk between EpiEditors and cellular epigenome modifiers are discussed. These considerations highlight the intimate connection between the outcome of epigenome reprogramming and the details of the technical approaches toward EpiEditing, which are the main topic of this volume of Methods in Molecular Biology. Once established in a fully functional "plug-and-play" mode, EpiEditing will allow to better understand gene expression control and to translate such knowledge into therapeutic tools. These expectations are beginning to be met as shown by various in vivo EpiEditing applications published in recent years, several companies aiming to exploit the therapeutic power of EpiEditing and the first clinical trial initiated.
CRISPR/Cas 系统的引入为基因靶向表观基因组/表观遗传重编程（EpiEditing）领域带来了强大的推动力，在该领域中，EpiEditors 由靶向的 DNA 结合部分和用于重写染色质修饰的酶部分组成，应用于细胞中以定向改变靶向基因组位点的染色质修饰。在此之前的开创性研究表明，染色质标记指示基因表达的因果关系。给定基因组位点的染色质重编程导致基因表达变化的累积证据为该技术在基础和临床研究中的主流应用开辟了道路。然而，随着对染色质生物学的不断深入了解以及 EpiEditing 工具的应用，人们也发现，在某些情况下，EpiEditing 的效率缺乏可预测性。从这个角度来看，EpiEditing 的关键参数（特异性、有效性和可持续性）取决于实验设置和条件，包括 EpiEditors 的表达水平和表达时间、它们与染色质的结合亲和力和特异性，以及 EpiEditors 与细胞表观基因组修饰物之间的串扰。这些考虑因素强调了表观基因组重编程的结果与 EpiEditing 技术方法的细节之间的密切联系，这是本卷《分子生物学方法》的主要主题。一旦以完全功能性的“即插即用”模式建立，EpiEditing 将能够更好地理解基因表达控制，并将这些知识转化为治疗工具。近年来发表的各种体内 EpiEditing 应用表明，这些期望正在得到满足，一些公司旨在利用 EpiEditing 的治疗力量，并且已经启动了第一个临床试验。
