More and more countries are abandoning the integrity of human embryos and conducting research in the field of genetic manipulation. The first scientific works from the USA and China appeared, during which modified human embryos were created. "Lenta.ru" understands whether these experiments will be useful, how they threaten humanity and why they were banned.
On August 2, 2017, the journal Nature published an article that revealed the details of the first experiment in US history that posed a serious challenge to the champions of ethics and morality. Scientists at the University of Oregon Health and Science have used CRISPR technology to alter the DNA of human embryos. Previously, such manipulations in America were considered unacceptable, and in some places in the world, including in Russia, they are still prohibited. In doing so, the researchers were guided by a noble goal: to correct the genetic effect that causes the death of young people, most often athletes.
The MYBPC3 mutation causes hypertrophic cardiomyopathy, a hereditary heart defect that affects one in five hundred people. It is characterized by a violation of the location of muscle fibers in the myocardium, which leads to its hypertrophy. Most often, the disease manifests itself at a young or middle age. His cunning lies in the fact that about a third of patients do not complain about anything, and the only symptom is sudden death.
Although hypertrophic cardiomyopathy can be caused by a variety of mutations, the most common cause is MYBPC3. Scientists decided to test a method that will prevent the transmission of the defective gene from parents to children. If only one parent has a heterozygous mutation, 50 percent of children will be new carriers of the defective gene. Researchers tried to change this by fixing MYBPC3 in embryos so that they are potentially suitable for transfer to the uterus and further development.
CRISPR-Cas9 is a molecular system that allows you to cut out certain regions from DNA, which are then replaced by others. It consists of two main components: the protein "scissors" Cas9 and a primer in the form of a special molecule called guide RNA. The latter attaches to the desired section of DNA and tells Cas9 where to cut. The cell then activates mechanisms that "repair" the cut by inserting a new strand of DNA into that location. Using this technology, scientists obtained embryos in which not only the MYBPC3 was removed, but the normal nucleotide sequence was inserted in its place. At the same time, the researchers did not find mutations in the modified embryos that could become a side effect of the use of the CRISPR system.
Photo: Yorgos Nikas / SPL
One of the strict conditions of the experiment is the destruction of the resulting embryos. They were only allowed to develop for a few days. The US government does not permit research that could produce a genetically modified child. This is justified by the fact that the technology is not sufficiently developed to ensure the safety and health of people whose genome was manipulated. Biotechnological methods, including the CRISPR system, do not work with perfect accuracy and can lead to unwanted changes.
This is one of the reasons why the work of Chinese researchers was criticized - they were the pioneers in the field of genetic modification of human embryos in 2015. Although the leading specialist Junjiu Huang took non-viable embryos for experiments, he said, he failed to convince the scientific community of the correctness of his actions. Of 86 embryos, only four retained the necessary changes, and CRISPR often missed the mark by editing the genome in unplanned areas. In addition, the journals Nature and Science refused to accept his work for publication due to ethical concerns associated with the modification of human embryos.
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Then Edward Lanphier, president of Sangamo Biosciences, which specializes in editing DNA in adult cells, said that such research should be suspended and a broad discussion should be held about the possibility of experiments with human embryos. He called the Chinese experiment a failure. Junjiu Huang disagreed with the point of view of the Western scientific community and continued to work on improving his method.
Photo: L. Souci / BSIP / SPL
Francis Collins, director of the US National Institutes of Health (NIH), said that he and his colleagues find it unacceptable to edit embryonic DNA, even for scientific purposes, and the NIH does not intend to allocate any funds for such research.
Two years later, scientists from Oregon achieved the same as the Chinese researcher, but they could not check whether the embryos would turn into healthy children. In the current situation, the clinical application of this method is a matter for the distant future. The problem is that the existing US legislation allows experiments with human embryos only with funding from non-governmental and private organizations. Congress refuses to allocate budget money for such research, which greatly inhibits the development of this area.
The situation around biotechnology and gene modification is complicated by the attitude of some influential people and government organizations to this direction. For example, the US National Intelligence Agency issued an annual bulletin in 2016 that included genome editing tools in the weapons of mass destruction section. This is a sign of growing concern about the rapid development of technology, which has been spurred by the use of CRISPR systems.
Photo: Paul Sancya / AP
At the same time, this winter, the US National Academy of Sciences released a report arguing that scientists should be able to edit genes in human embryos for research purposes. This is not about raising ideal people, as shown in the movie "Gattaca". First of all, it is necessary to clarify in detail how the development of the embryo occurs, what role and at what stage of embryogenesis individual genes play in this process. Treatment of severe hereditary diseases is also allowed in the absence of other reasonable alternatives. Naturally, all this must be carried out under strict control and with public approval.
The proposed recommendations are relevant only if the ban on the creation of genetically modified people is still lifted. This will only be possible if a consensus is reached on the safety of this technology. Now, public concern is only growing. In this, a great role is played by the lack of understanding of what scientists are actually doing. However, the very fact that the study was conducted by scientists from Oregon gives hope that this problem will be solved.
As for other countries, in February 2016, the UK government allowed researchers to conduct experiments to edit the genomes of human embryos. The ultimate goal of scientists is to solve the problem of miscarriages. Experts want to determine the genes that are most active in the first days of the fetus's life, when the embryo forms cells - the basis of the future placenta.
In Russia, the situation is much more complicated. It is eloquently illustrated by the fact that since January 1, 2017 in our country it is forbidden to create human embryos for the production of a biomedical cell product, as well as the use of biomaterial obtained by interrupting (or disrupting) the development of a human embryo for the development, production and use of biomedical cellular products. There is no talk of a serious discussion of the possibility of genetic modification of human embryos.
Alexander Enikeev