Ubiquitous Chromatin-opening Elements (UCOEs): Applications in biomanufacturing and gene therapy

Ubiquitous Chromatin-opening Elements (UCOEs) are defined by their ability to consistently confer stable, site of integration-independent transgene expression that is proportional to copy number, including from within regions of heterochromatin such as centromeres. UCOEs structurally consist of methylation-free CpG islands encompassing single or dual divergently-transcribed housekeeping gene promoters. Since their discovery in 1999, UCOEs and their sub-fragments have found applications in areas of biotechnology requiring stable, reproducible, and high levels of gene expression. This review recounts the discovery of UCOEs and examines their current and future applications in protein therapeutic biomanufacturing and gene therapy.