A new modified CRISPR-Cas9 technology has just been created by scientists in order to eliminate the need to cut DNA during treatment.
A group of researchers from the Salk Institute for Biological Studies in San Diego, California introduced a modified CRISPR-Cas9 technology that will enable them to activate genes without creating breaks in the DNA. According to reports, this breakthrough discovery could potentially boost the usage of CRISPR in treating human diseases.
For years, CRISPR-Cas9 has been considered as one of the most controversial breakthroughs in the field of medicine. While being lauded for its potential benefits in treating genetically inherited diseases, it also received an equal amount of criticism and opposition from skeptics.#CRISPRtechnology has been modified by researchers to avoid creating breaks in #DNA strands of living organisms!Click To Tweet
“Although many studies have demonstrated that CRISPR-Cas9 can be applied as a powerful tool for gene therapy, there are growing concerns regarding unwanted mutations generated by the double-strand breaks through this technology,” Salk’s Gene Expression Laboratory professor and senior author of the new paper Juan Carlos Izpisua Belmonte said.
The concern for live human application is apparently driven by the fact that the treatment works by permanently altering the genetic composition of the subject. However, the Salk researchers allegedly found a solution to solve this major hurdle being faced by the said gene-targeting technology today.
“We were able to get around that concern,” Izpisua Belmonte further added.
The Modified CRISPR-Cas9 Technology
In a paper published by the researchers in the journal Cell, they suggested a new approach to treat common human diseases. Instead of creating so-called double-strand breaks (DSBs) to remove and replace targeted genomes, they used a modified CRISPR-Cas9 technology that just turns genes on and off.
The researchers used a dead form of Cas9 (dCas9) which could still target specific places in the genome but can no longer cut the DNA. Instead, the dCas9 was coupled with transcriptional activation domains or molecular switches that turn on targeted genes.
However, the resulting protein from combining dCas9 with activator switches is too bulky to fit into adeno-associated viruses (AAVs), the vehicle commonly used to deliver the therapies to living organisms. As a solution, the team combined the Cas9/dCas9 with different activator switches to find a combination that would work even if the proteins were not fused together.
The researchers put the combination in two separate AAVs, loading one virus with both Cas9 and dCas9 and the other with the molecular switches and the guide RNA that will find and target the right gene. The process worked.
“The components all work together in the organism to influence endogenous genes,” Hsin-Kai (Ken) Liao, a staff researcher in the Izpisua Belmonte lab and co-first author of the new paper, said.
The team tested the method using mouse models of acute kidney disease, type 1 diabetes, and muscular dystrophy. For each condition, they optimized their modified CRISPR-Cas9 technology to boost the expression of an endogenous gene that could potentially reverse disease symptoms.
The therapy worked as per results. For instance, the researchers claimed that they were able to boost the activity of genes that could generate insulin-producing cells for the mouse model of type 1 diabetes.
“We were very excited when we saw the results in mice,” adds Fumiyuki Hatanaka, a research associate in the lab and co-first author of the paper. “We can induce gene activation and at the same time see physiological changes.”
Right now, the researchers are already working on improving their method not just to treat a broader range of human diseases but also to rejuvenate specific organs, reverse aging process and all related conditions.