The past and presence of gene targeting: from chemicals and DNA via proteins to RNA

• Published in: Philosophical transactions of the Royal Society of London. Series B. Biological sciences 2018-06, Vol.373 (1748), p.20170077-20170077
• Main Authors: Geel, T. M., Ruiters, M. H. J., Cool, R. H., Halby, L., Voshart, D. C., Andrade Ruiz, L., Niezen-Koning, K. E., Arimondo, P. B., Rots, M. G.
• Format: Article
• Language: English
• Subjects: Chemicals; Clinical trials; CRISPR; Crispr/dcas; Deoxyribonucleic acid; DNA; DNA - chemistry; DNA damage; Fusion protein; Gene Targeting; Genome Editing; Genomes; Human health and pathology; Humans; Life Sciences; Loci; Medical research; Modulators; Mutation; Nuclease; Oligonucleotides; Polyamides; Proteins; Review; Ribonucleic acid; RNA; RNA - chemistry; Scientists; Tales (transcription Activator-Like Effectors); Transcription; Zfps (zinc Finger Proteins); Zinc; Zinc finger proteins
• ISSN: 0962-8436; 1471-2970
• DOI: 10.1098/rstb.2017.0077

The ability to target DNA specifically at any given position within the genome allows many intriguing possibilities and has inspired scientists for decades. Early gene-targeting efforts exploited chemicals or DNA oligonucleotides to interfere with the DNA at a given location in order to inactivate a gene or to correct mutations. We here describe an example towards correcting a genetic mutation underlying Pompe's disease using a nucleotide-fused nuclease (TFO-MunI). In addition to the promise of gene correction, scientists soon realized that genes could be inactivated or even re-activated without inducing potentially harmful DNA damage by targeting transcriptional modulators to a particular gene. However, it proved difficult to fuse protein effector domains to the first generation of programmable DNA-binding agents. The engineering of gene-targeting proteins (zinc finger proteins (ZFPs), transcription activator-like effectors (TALEs)) circumvented this problem. The disadvantage of protein-based gene targeting is that a fusion protein needs to be engineered for every locus. The recent introduction of CRISPR/Cas offers a flexible approach to target a (fusion) protein to the locus of interest using cheap designer RNA molecules. Many research groups now exploit this platform and the first human clinical trials have been initiated: CRISPR/Cas has kicked off a new era of gene targeting and is revolutionizing biomedical sciences. This article is part of a discussion meeting issue ‘Frontiers in epigenetic chemical biology’.