New CRISPR/Cas9 technique corrects cystic fibrosis in cultured human stem cells

Researchers from the group of Hans Clevers (Hubrecht Institute) corrected mutations that cause cystic fibrosis in cultured human stem cells. In collaboration with the UMC Utrecht and Oncode Institute, they used a technique called prime editing to replace the 'faulty' piece of DNA with a healthy piece.

Cystic fibrosis (CF) is one of the most prevalent genetic diseases worldwide and has grave consequences for the patient. The mucus in the lungs, throat and intestines is sticky and thick, which causes blockages in organs.

The researchers succeeded in correcting the mutations that cause CF in human intestinal organoids. These organoids, also called mini-organs, are tiny 3-D structures that mimic the intestinal function of patients with CF. They were previously developed by the same research group from stem cells of patients with CF and stored in a biobank in Utrecht.

Now that the researchers showed that the mutations that cause CF can be safely corrected, applications in the clinic come one step closer. "New variants of CRISPR/Cas9, such as prime editing, can safely correct mutations without causing damage in other regions of the DNA. This will hopefully enable us to cure or even prevent genetic diseases in the future."

But before that, some challenges still lie ahead for the researchers. The technique for example still needs to be adapted for safe use in humans. "But this is a great step towards successfully applying prime editing in the clinic," Geurts concludes.