In a study conducted bythe Salk Institute researchers, a new technique was discovered which allows for the insertion of new genes into a precise DNA location of non-dividing adult cells. This can be applied to cells of the eye, brain, pancreas, or heart, enabling endless possibilities for treatments of disease related to these areas. Previously, researchers used techniques such as the CRISPR-Cas 9 system which modify DNA in dividing cells. The new technique is remarkable because it can do just that, but ten times more efficiently, as well as modify non-dividing cells which has never been done before.
The actual experiment leading up to the discovery featured the targeting of NHEJ, a DNA-repair cellular pathway which routinely repairs DNA breaks by rejoining the original strand ends. The Salk research team used the CRISPR-Cas9 system to optimize theNHEJ machinery alongside a custom insertion package made up of a nucleic acid cocktail they created, homologous-independent targeted integration (HITI). An inert virus was used to deliver HITI’s package of genetic instruction to neurons derived from human embryonic stem cells. The team then successfully delivered the construct to brains of adult mice because they suspected HITI could work on non-dividing cells.
To test whether HITI could work for gene-replacement therapy, the team tested the technique on 3-week old rats with retinitis pigmentosa, an inherited retinal degeneration condition that also causes blindness in humans. Five weeks later these rats were able to respond to light and passed several tests indicating healing to their retinal cells. These results encourage the team to improve the delivery efficiency of the HITI construct as well as adapt the technique to other genome engineering systems.
This is a such a cool article. Everyone’s understanding before this new technique is that the best way to combat diseases is to focus on stem cells and other dividing cells. Now we can modify pre-existing adult cells which are the real problems. It is remarkable how efficient and precise this technique is. I am excited to see what other discoveries this will make with this new technology because the possibilities and opportunities so very promising.