Safety and CRISPR

by Lauren Johnstone




CRISPR technology uses Cas proteins, most commonly Cas9, found in bacteria bound to specific RNA molecules in gene editing. CRISPR is already commonly used in scientific research and there is food available which has been genetically modified using CRISPR. The hope is that this technology could also be used in Medicine in treating and preventing disease. However, there are some concerns about the safety and the ethics of the use of CRISPR.

Researchers have been investigating the safety of the technology. The results from the first phase clinical trial of a CRISPR cancer treatment were recently published in ‘Science’. The results of the trial were promising regarding the safety of the technology. The trial involved removing the immune cells of three patients with tumours with the same protein. CRISPR was used to delete genes from these immune cells and a virus was used to add a gene to the T-cells to ensure they targeted the specific protein found on all three of the patients’ tumours. The cells were infused back into the patients.  

The main concerns about the safety of using CRISPR in this trial were the possibility that CRISPR would cause unintentional changes to the genome that could result in cancerous cells and that the CRISPR protein used for the gene editing may trigger an immune reaction. However, there were no signs of the cells turning cancerous or any immune reaction and the patients experienced no severe side effects.


There has also been research into genetically altering cells so that they self-destruct in the presence of CRISPR. As many people have fears about the uncontrolled spread of genetic mutations in the wild, this could potentially be useful in helping prevent this. Engineering human cells so that they are CRISPR-proof is also important to the safety of the technology if CRISPR is to be more widely used in Medicine. At Harvard University a team engineered human cells to produce guide RNA that would target LINE-1 DNA sequences. They also gave the cells a gene for the Cas9 protein with a regulatory sequence that meant it could only become active in the presence of doxycycline. When these cells were added to a dish containing the antibiotic 99.9% of them died within nine days. The hope is that this mechanism could be used in gene therapies, much like the CRISPR cancer trial in the US, to shut the therapy down if any problems are encountered. Though there are already other methods to manage the safety of CRISPR the team from Harvard believe that theirs is better.

There is still more research and development taking place using CRISPR which hopefully will reveal more about the technology and its safety.
  
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