In light of the biotechnological breakthrough of the genomic editor CRISPR, researchers at the Stanford University School of Medicine led by Mark Kay discover a safer and longer-lasting approach – one that allows scientists to replace faulty or disease-causing genes with working copies, in hopes of treating genetic diseases – and has shown promise in curing hemophilia in mice.
This technique differs from that of the previously developed genomic editor in that it doesn’t require the endonuclease co-delivery enzyme to cleave the recipient’s DNA at specific locations. This new approach is also promoterless gene targeting as it doesn’t rely on the co-insertion of promoters (“on” switches) to activate the new gene’s expression. These reduces the chances of adverse effects, including cancer and DNA damages.
The new genomic editing tool enabled hemophiliac mice to produce a missing clotting factor, thereby curing the mice. The functional copies of clotting factor genes were successfully inserted near the albumin gene using the viral vector adeno-associated virus (AAV) though homologous recombination. The insertion, although accomplished in only about 1 percent of liver cells, made sufficient clotting factors for therapy.
With such therapeutic effects and with further clinical trials, it seems promising that the new approach will allow for treatment of all kinds of genetic disorders.