Drug Inducible CRISPR/Cas Systems

Abstract

Clustered, regularly interspaced, short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) systems have been employed as a powerful versatile technology for programmable gene editing, transcriptional modulation, epigenetic modulation, and genome labeling, etc. Yet better control of their activity is important to accomplish greater precision and to reduce undesired outcomes such as off-target events. The use of small molecules to control CRISPR/Cas activity represents a promising direction. Here, we provide an updated review on multiple drug inducible CRISPR/Cas systems and discuss their distinct properties. We arbitrarily divided the emerging drug inducible CRISPR/Cas systems into two categories based on whether at transcription or protein level does chemical control occurs. The first category includes Tet-On/Off system and Cre-dependent system. The second category includes chemically induced proximity systems, intein splicing system, 4-Hydroxytamoxifen-Estrogen Receptor based nuclear localization systems, allosterically regulated Cas9 system, and destabilizing domain mediated protein degradation systems. Finally, the advantages and limitations of each system were summarized.

Genome Editing for CNS Disorders

“…Transient expression strategies have been mainly developed for CRISPR/Cas-based tools either through the delivery of RNPs or ON/OFF expression systems. These include self-inactivation systems (Merienne et al, 2017;Li et al, 2018) and the use of drug inducible promoters, such as the doxycycline (dox)-induced Tet or the Tamoxifendependent Cre promoters (Zhang et al, 2019). However, the optimization of self-inactivation kinetics and the requirement of additional molecules to regulate promoters will delay the translation of these strategies to the clinic.…”

Development of a Tet-On inducible expression system for the anhydrobiotic cell line, Pv11

“…The establishment of a Tet-On inducible expression system in Pv11 cells could accelerate the clarification of the molecular mechanisms underlying anhydrobiosis in this cell type and more generally. For example, the Tet-On expression system has been used for inducible gene knockdown or knockout [36][37][38][39][40], thereby providing valuable insights into specific gene functions. Such tightly regulated loss-of-function experiments will be helpful in examining whether or not a gene contributes to anhydrobiosis in Pv11 cells.…”

Application of CRISPR/Cas9 to human-induced pluripotent stem cells: from gene editing to drug discovery

“…Just after the spread of the reprogramming technology, getting a disease model through the employment of hiPSCs has been used to test several candidate drugs for different pathologies. This expedites the process leading to the clinical application of a particular compound, especially if it has been previously approved for the treatment of other diseases, improving the identification of possible targets and drugs, but also optimizing the selection and stratification of trial participants [11]. However, hiPSCs constitute a successful method when they have to reproduce monogenic diseases, while they may still have limitations in cases of sporadic disorders, where the environmental factors could contribute to the onset of a de novo mutation [9,12].…”

“…This can be considered one of the most powerful and versatile technology both for gene editing and transcriptional control but also for epigenetic modulation. Its assembling with hiPSCs is having important implications for scientific research [11].…”