Novel, synthetic gene editing technology for gene knock-ins without DNA cleavage

点击翻译按钮获取中文摘要

Recent advances in the field of genome editing have moved us closer to the dream of repairing defective genes in human patients. Over the last 20 years, successive dynasties of programmable nuclease technologies have been applied to this problem. From zinc-finger nucleases, through TALENs to CRISPR--Cas- nucleases there has been a trend towards increasing flexibility of such systems. Several of the systems have been adapted to use alternative effector moieties to the nucleases embedded in the first versions of these systems, allowing target cell modification via better tolerated and more controllable changes to chromosomal DNA.What is missing however, is a flexible and effective method for introducing new genetic material at a defined locus of a genome without creating double-strand (ds) breaks. Such ds breaks are lethal if not rapidly repaired, and they are also recognized as a threat to genome integrity and hence can easily trigger programmed cell death in target cells.Pencil Biosciences has created, and is developing, a fully-synthetic genome modulation system (ApGet) and seeks funding to adapt the system to deliver highly-efficient knock-in of donor DNA sequences at key target sites. The ApGet system is small in size (~0.7 kb), modular and non-CRISPR in composition. It is capable of recruiting diverse effector proteins to specific sites in the host genome by means of RNA-guides.Pencil plans to replace some of ApGet's components with others allowing knock-ins via a fundamentally different mechanism that does not induce a dsDNA break. The aim is to recruit donor DNA to target sites of interest in order to deliver safe, well-tolerated and highly efficient knock-in edits for gene repair and the generation of engineered cell therapies.In the long term gene editing may make a significant contribution to reducing the burden of genetic diseases, which in the UK alone affect more than 3 million people. Many of these diseases would be best treated with a 'one and done' treatment involving a knock-in-mediated replacement of the defective section of an allele.