The researchers from Peking University have developed a new gene-editing technique that they say could have profound effects on the treatment of certain diseases.
The scientists believe that it is a CRISPR alternate for fighting human diseases. They call it LEAPER. According to a research paper published on Monday in the journal Nature Biotechnology, this new tech, LEAPER, which stands for “leveraging endogenous ADAR for programmable editing of RNA,” is said to prevent several of the drawbacks of CRISPR– Cas13.
Similar to Cas13, LEAPER aims strands of RNA– molecules in cells that like DNA carry hereditary information, but also is a significant player in its replication. The technique uses engineered strands of RNA which employ another type of enzyme, ADAR, to exchange one compound found in RNA for another. This, in turn, avoids some of the problems of existing gene-editing techniques, which include immune responses and unwanted side-effects. According to the researchers, this technique is efficient, rarely misses its targets, and can be used on several different cell types.
“There are clear prospects for using this new technology in disease treatment,” said Zhou Zhuo of Peking University’s School of Life Sciences, one of the lead authors of the paper. He noted that LEAPER has the ability to precisely switch adenosine — one of the molecules that make up RNA — for one which is similar to another molecule called guanosine. That is important because almost half of the known hereditary disorders can be corrected by swapping adenosine and guanosine, Zhou told Caixin Global.
The technique has proved effective for Hurler Syndrome — a rare and devastating genetic disorder. When tested on cells taken from people with the same disease, it showed good results suggesting at its potential use in gene therapy. “[The scientists] show that in human Hurler syndrome skin cells they can correct sufficient amounts of the mutated form of RNA to restore the defective enzyme activity that causes this disease,” informed professor Ernst Wolvetang, a geneticist from the University of Queensland in Australia who was not involved in the research.
The technique seems to have “substantial potential,” and is a breakthrough toward the treatment of genetic diseases.
Dr. Wolvetang, who leads a team at the Australian Institute for Bioengineering and Nanotechnology, said the way LEAPER technology works means it might not be effective on some types of cells, and that it didn’t eliminate unwanted genetic changes. He added that the technique has not been tested on animals yet. But he said LEAPER was plainer than existing gene-editing techniques because it uses only a single component — an arRNA — while the CRISPR-Cas method uses both a Cas-enzyme and guide RNA. For this reason, it is “more easily deliverable, and less likely to result in unwanted cellular immune responses.”
Many Chinese researchers have repeatedly claimed to provide alternate to CRISPR techniques. Previously, a paper in Natural journal was published about a different pair of genetic scissors known as NgAgo, which was initially publicized as an alternative to CRISPR. However, the paper was later withdrawn after several failed attempts to replicate its findings.
Research in gene editing has invited a lot of criticism especially after a Shenzhen based scientist He Jiankui announced in November that he had used CRISPR technology to edit the genomes of 2 girls who were born the previous month.
This led the Chinese government to introduce a draft regulation in May, specifying that those who manipulate genes in embryos or human adults will be held legally responsible for the effects of their work.