[Applications of ZFN, TALEN and CRISPR/Cas9 techniques in disease modeling and gene therapy]

Precise and effective modification of complex genomes at the predicted loci has long been an important goal for scientists. However, conventional techniques for manipulating genomes in diverse organisms and cells have lagged behind the rapid advance in genomic studies. Such genome engineering tools have featured low efficiency and off-targeting. The newly developed custom-designed nucleases, zinc finger nucleases (ZFN), transcription activator-like effector nucleases (TALEN) and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system have conferred genome modification with ease of customization, flexibility and high efficiency, which may impact biological research and studies on pathogenesis of human diseases. These novel techniques can edit the genomic DNA with high efficiency and specificity in a rich variety of organisms and cell types including the induced pluripotent stem cells (iPSCs), which has conferred them with the potential for revealing the pathogenesis and treatment of many human diseases. This review has briefly introduced the mechanisms of ZFN, TALENs and CRISPR/Cas9 system, and compared the efficiency and specificity of such approaches. In addition, the application of ZFN, TALENs and CRISPR/Cas9 mediated genome modification for human disease modeling and gene therapy was also discussed.