AsianScientist (Sep. 16, 2016) – Researchers in Singapore have developed a protein that can alter DNA in living cells with much higher precision than current methods. Details have been published in Nature Chemical Biology.
The ability to alter DNA accurately through gene editing will open more doors in the development of personalized medicine for diseases that have unmet therapeutic needs. Examples of such diseases include Huntington’s disease, muscular dystrophy, and blood disorders like sickle cell anemia.
According to study lead Assistant Professor Tan Meng How of Nanyang Technological University and the Genome Institute of Singapore, DNA is like an ‘instruction manual’ that tells living cells how to behave. Gene editing enables us to rewrite the instructions in this manual and gain control over what the cells are supposed to do.
To ensure that DNA is precisely altered, the activity of the Cas protein must be tightly regulated. The new protein, named iCas, can be easily controlled by an external chemical input and thus solves some of the problems with CRISPR-Cas, the existing gold standard for DNA altering. For example, existing Cas enzymes may sometimes alter unintended places in the DNA that result in dire consequences. With iCas, users now have the ability to control enzyme activity and thus minimize unintended DNA modifications in the cell.
The chemical that switches the iCas protein on or off is tamoxifen, a drug commonly used to treat and prevent breast cancer. In the study, iCas was found to outperform other chemical-inducible CRISPR-Cas technologies with a much faster response time and an ability to be switched on and off repeatedly, which may be useful in research or applications that demand precise control of DNA editing.
The article can be found at: Liu et al. (2016) A Chemical-Inducible CRISPR–Cas9 System for Rapid Control of Genome Editing.
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Source: Nanyang Technological University & A*STAR; Photo: Shutterstock.
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