In 2015, the pioneering technique in genetic editing CRISPR-Cas9 became the one chosen as Beakthrough of the year by the prestigious Science magazine, a category that annually selects the most innovative prodigies in the field of science.
And so much so, since the (journalistically) known as the genetic ‘cutter’ allows the possibility of adding, modifying or (in this case) eliminating a problematic gene, such as the one that predisposes to developing a certain disease, with the promise for the individual to develop in a healthy way.
Until now, the CRISPR technique had been used in animal models and in human cells in vitro , with promising results; For example, in 2017 the ability of gene editing to reverse Huntington’s disease in mice was shown. Now, for the first time, this technique has been applied to humans: a person with a genetic condition that causes blindness (Leber congenital amaurosis 10 or LCA10), who has received CRISPR-Cas9 gene therapy administered directly into their body.
As published in the journal Nature , the treatment is part of a landmark clinical trial, aimed at evaluating the ability of CRISPR-Cas9 gene editing techniques to eliminate the mutations that cause this rare condition. There is currently no treatment available for the disease, which is the leading cause of childhood blindness.
Previous CRISPR-Cas9 clinical trials had been limited to using the genome-editing technique of cells already removed from the body, to reintegrate genetic material into the body; hence the thrill of the recent essay.
How does CRISPR-Cas9 work in the body?
Unlike previous techniques, this time, components of the gene-editing system, encoded in the genome of a virus, were injected directly into the eye, near light-sensitive cells, called photoreceptors.
Specifically, gene editing was used to eliminate a mutation in the CEP290 gene that is responsible for the type of blindness LCA10.
Mutations in CEP290 turn off photoreceptors in the retina , but the cells are still present and alive in people with LCA10. The hope is that, after the application of CRISPR, these cells can be reactivated.
The researchers are hopeful: “This is one of the few diseases in which we believe that the patient’s condition could really be improved thanks to this technique.”
A giant leap
For now, the use of CRISPR-Cas9 for the first time in the human body is a significant leap, considering that we came from treating cells in vitro . For Fyodor Urnov, who studies genome editing at the University of California, Berkeley: ” This achievement is akin to spaceflight versus everyday plane travel . Mind you, the technical challenges and inherent safety concerns are much greater.” .
Pioneers before CRISPR
However, this is not the first time gene editing has been attempted in the body – an older gene editing system, called zinc finger nucleases, was administered directly to humans in 2018. The technique consisted of applying a healthy copy of the affected gene to a specific location in the genome of liver cells. Although it appears to be a safe technique, it has not yet been shown to be effective: early results suggest that there is little it can do to alleviate symptoms of the disease it was intended to reverse, Hunter syndrome.
Article reference:
doi: 10.1038 / d41586-020-00655-8
