New gene-editing techniques offer hope for treating single-gene diseases such as cystic fibrosis and Duchenne muscular dystrophy. However, I would not be surprised if it turns out that somewhere in the world genome editing is used illegally in athletes doping – said the geneticist Prof. Bowie Gulick.
A scientist from the University of Warsaw’s Faculty of Biology spoke about human genetic modifications during a lecture during the Science Festival in Warsaw.
The collective imagination associated with human genetic modification emerged when the CRISPR-CAS9 method was developed 10 years ago, which enables precise DNA editing – down to a single nucleotide – of DNA letters. This method is also simpler and cheaper than traditional genetic engineering methods. In addition, it is easier to adapt to experiments on different species.
a. Gulick noted that if you edit the genome of multicellular organisms, it can be done in two different types of cells: embryonic or somatic. Germ Cell Editing: The stem or germ line (i.e. egg or sperm cells) means that the change made can be passed on to the next generation and will be present in the offspring cells. “These methods are already widely used as a research tool – for example in the study of laboratory animals” – concluded the professor. Gulik.
However, the researcher mentioned an exception – the infamous experiment conducted by He Jiankui. This Chinese researcher announced in 2018 (not through a peer-reviewed scientific publication) that girls whose genomes had been edited using the CRISPR-CAS9 method had given birth. Jiankui boasted that he had altered one of the genes in the twin fetuses. As a result, the children will be immune to the HIV that their father has contracted. a. Gulick criticized this experience. First of all, Jiankui did not get approval from the Bioethics Committee for the experiment – the experiment was illegal, so the scientist was imprisoned (he had to finish his sentence this year). Second, modifying this gene was not necessary to protect the children from infection – it would be enough to clear the father’s sperm before IVF. And third, subsequent genetic studies showed that the girls did not really have a real guarantee of immunity to the virus. “So it was not only an unethical and unnecessary experiment, but also an unsuccessful one” – summed up the professor. Gulik.
When it comes to modifying cells that will be passed on to offspring, scientists around the world instead agree that it should not be done – the ban was suspended in 2019 – a call to refrain from modifying the genetic lines of the human genome signed by several geneticists.
a. Gulick describes that laboratories around the world are conducting research that involves modifying genes in human embryonic stem cells. “The barrier that must not be crossed, however, is the implantation of such an embryo in the woman’s body and leads to pregnancy” – said the scientist.
However, fetal genome editing does not mark the end of the genome editing process. CRISPR-CaS9 technology also makes it possible to modify genes in living somatic cells — the building blocks of the body — whose DNA is not passed on to their offspring.
However, the researcher points out, some tissues will be easier to modify than others: Thus, for example, muscle cells may be “corrected” by injection. And respiratory cells – in the “observed” ways in viruses. However, not all tissues are yet available for gene editing techniques. The researcher pointed out that “the cells of the central nervous system are not easily accessible.”
What diseases are genome editing used to treat patients? a. Gulick mentioned that these are cystic fibrosis and Duchenne muscular dystrophy.
Duchenne muscular dystrophy destroys muscle due to mutations in the gene that encodes a specific muscle-related protein, dystrophin. “It is a very long protein made of many repeats” – explained the geneticist. Mutations can cause the body to produce such a protein, but it is shorter and does not do its job well. So the researchers figured out how to alter the function of the faulty gene and bypass the mutation that shortens the protein. a. Gulick added that the US Food and Drug Administration has given the green light in recent weeks to use gene editing to treat this disease.
The geneticist added that other cells that would be relatively easy to modify would be those that could be grown outside the vivo, so they could be kept alive outside the body – such as skin or blood cells. These cells can be taken from the patient’s body, fitted with protein tools to edit the genome, check the quality of the changes made, multiply them, and then introduce the cells into the body. The risk of rejection of such repaired and “transplanted” cells will be much lower than in the case of a normal transplant, since the donor and recipient are the same patient.
The lecturer said there had already been a case of treating a person with skin ulcers using gene-editing methods. Work has also been advanced in the treatment of genetic blood diseases such as sickle cell anemia and thalassemia. In addition, there are also ideas about how to combat HIV by modifying patients’ bone marrow cells.
Another hope is to modify immune cells – lymphocytes – that can also grow and multiply outside the body. One promising treatment is anti-tumor therapy using modified T cells, which detect hostile cells with the help of receptor proteins. The proteins encoded in T lymphocytes can be modified in such a way that they target specific cells – such as cancer cells. “There are already cases of cancer that are treated in this way” – said the professor. Gulik.
The researcher asked the Science in Poland portal if genome editing could actually be used somewhere in the world in sports doping, and he replied: “I haven’t heard of it, but I wouldn’t be surprised if that was.” He gave the example that gene modification can, for example, increase the production of erythropoietin – to improve respiratory efficiency in endurance sports. Such steroids can be detected only if, as a result of this intervention, the production of erythropoietin in the body exceeds acceptable standards. “In terms of professional sports – it will not surprise me much” – assessed the researcher. He added that he expected unethical activities related to human genome editing in sports and not in scientific laboratories.
PAP – Science in Poland, Ludwika Tomala
“Internet Geek. Food Enthusiast. Thinker. Beer Practitioner. Bacon Specialist. Music Addict. Traveler.”