A method of editing DNA CRISPR/Cas9 is considered one of the most important discoveries in modern genetics. However, the large potential of the technology hides a monstrous side effects. Figure it out, scientists were allowed extensive analysis of the results of editing the genome of mice and humans. The conclusions of the study, the researchers shared in the journal Nature Biotechnology.
Scientists from the Sanger Institute (UK) found that the use of CRISPR/Cas9 to edit the cells of humans and animals often leads to extensive unwanted mutations.
“This is the first systematic evaluation of the unintended consequences of using the method of editing DNA CRISPR/Cas9 therapeutically important cells”, — commented the results of the study by the British geneticist Alan Bradley.
“We found that changes in DNA using this method was seriously underestimated as a result of past research.”
However, this is not the first time when scientists are sounding the alarm about potential dangers of using CRISPR technology.
In may last year, a team of scientists from Columbia University have indicated that CRISPR/Cas9 makes a lot of changes in the DNA outside the desired area. Although confirm the results of this study at that time failed, other scientists also got evidence that the CRISPR system causes more side effects than previously thought.
To assess the implications of the use of CRISPR technology in a new study by Bradley and his team used it for the stem cells of mice and epithelial cells of the human retina. It turned out that the system is causing massive genetic restructuring, including deletions (loss of sections of chromosomes) that affects a few thousand base pairs, located away from that area, which is directly edited using CRISPR. Such mutations are capable of irreversibly damaging important genes, which will be deadly for patients who may be such a gene therapy.
“Realizing the extent of genetic rearrangements, we began to systematically study, considering the different genes and different therapeutically important lines. We found that in all of them the effect persists,” says graduate student Michael Kosicki.
While scientists say that the danger is not only that these mutations can be dangerous, but in the fact that damage in the genome are not detected by standard methods of DNA genotyping.
In the worst case in the treatment of a person using the method for genome editing CRISPR/Cas9 can damage important genes, causing health catastrophic harm.
“In clinical practice is the edit of billions of cells. A mutation creating the likelihood that one or more of the edited cells will be affected. Such damage can lead to the start of the process of cancer development,” say the authors.
“It is important that the use of this technology for gene therapy approached with caution. And also carefully studied the possible negative effects,” concluded Bradley.