Recent advances in stem cells and gene editing: Drug discovery and therapeutics

The recently introduced genome editing technology has had a remarkable impact on genetic medicine. Zinc finger nucleases, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeat (CRISPR)/Cas nucleases are the three major platforms used for priming of stem cells or correction of mutated genes. Among these nucleases, CRISPR/Cas is the most easily applicable. Various CRISPR/Cas variants such as base editors, prime editors, mad7 nucleases, RESCUE, REPAIR, digenome sequencing, and SHERLOCK are being developed and considered as a promising tool for gene therapy and drug discovery. These advances in the CRISPR/Cas platform have enabled the correction of gene mutations from DNA to RNA level and validation of the safety of genome editing performance at a very precise level by allowing the detection of one base-pair mismatch. These promising alternatives of the CRISPR/Cas system can benefit millions of patients with intractable diseases. Although the therapeutic effects of stem cells have been confirmed in a wide range of disease models, their safety still remains an issue. Hence, scientists are concentrating on generating functionally improved stem cells by using programmable nucleases such as CRISPR. Therefore, in this chapter, we have summarized the applicable options of the CRISPR/Cas platforms by weighing their advantages and limitations in drug discovery and gene therapy.