Clinical translation of epigenome editing technologies.

CRISPR/Cas-based epigenome editing technologies hold great promise for identifying novel therapeutic targets, improving gene and cell therapies, and directly addressing the underlying issues in many diseases, all while minimizing risks of genotoxicity often associated with conventional genome editing. Exciting recent advances in CRISPR/Cas-based epigenome editing technologies have drastically enhanced the ability to precisely control the timing, levels, and durations of endogenous gene expression and reprogram epigenetic states in human cells. As a result, epigenome editing is now poised to unlock new biomedical discoveries and treatments for diseases driven by transcriptional and epigenetic dysregulation as well as those stemming from aberrantly repetitive genomic regions or complex genomic arrangements that are difficult to target using conventional genome editing. Additionally, the power of epigenome editors is generating new strategies to control cell fate and function, which has direct and important implications for cell therapies and regenerative medicines. Here, as the first wave of CRISPR/Cas-based epigenome editors move into clinical trials, we cover recent advances as the field looks to address pressing hurdles facing widespread clinical deployment of epigenome editing technologies including delivery, performance, and safety. For instance, the discovery of compact Cas chassis, engineering efforts to reduce effector sizes for efficient delivery, and campaigns to tailor the targeting discrimination of epigenome editors are rapidly progressing, as is research into the development of new effector domains with high specificity, robust performance, and a lack of immunogenicity and cytotoxicity. This exciting progress is quickly moving the community closer to fulfilling the promise of CRISPR/Cas-based epigenome editing as a powerful class of platform technologies for biological discoveries, biotechnological innovations, and medicines.