Advances in CRISPR-Cas systems for epigenetics.

The CRISPR-Cas9 method has revolutionized the gene editing. Epigenetic changes, including DNA methylation, RNA modification, and changes in histone proteins, have been intensively studied and found to play a key role in the pathogenesis of human diseases. CRISPR-While the utility of DNA and chromatin modifications, known as epigenetics, is well understood, the functional significance of various alterations of RNA nucleotides has recently gained attention. Recent advancements in improving CRISPR-based epigenetic modifications has resulted in the availability of a powerful source that can selectively modify DNA, allowing for the maintenance of epigenetic memory over several cell divisions. Accurate identification of DNA methylation at specific locations is crucial for the prompt detection of cancer and other diseases, as DNA methylation is strongly correlated to the onset as well as the advancement of such conditions. Genetic or epigenetic perturbations can disrupt the regulation of imprinted genes, resulting in the development of diseases. When histone code editors and DNA de-/ methyltransferases are coupled with catalytically inactive Cas9 (dCas9), and CRISPRa and CRISPRi, they demonstrate excellent efficacy in editing the epigenome of eukaryotic cells. Advancing and optimizing the extracellular delivery platform can, hence, further facilitate the manipulation of CRISPR-Cas9 gene editing technique in upcoming clinical studies. The current chapter focuses on how the CRISP/ Cas9 system provides an avenue for the epigenetic modifications and its employability for human benefit.