CRISPR/Cas9 and Human Gene Editing: What Does the Future Hold?

CRISPR/Cas9 technology is leading to revolutionary advances in medicine, realizing the promise of human gene editing. However, due to ethical concerns and regulatory difficulties, there is also a risk of overuse of the technology and social problems.

 

In July 2018, news broke that scientists in China had edited a human embryo. Human gene editing, which has been taboo, considered the realm of the gods, and only seen in movies and novels, had actually happened. Of course, the experiment used a fertilized egg that was unable to develop normally due to a congenital genetic defect, so a complete individual could not be created, but it was remarkable because it showed that this is no longer technically impossible. However, human genetic modification is not a new concept, having been discussed in the scientific community and in science fiction for decades. Nevertheless, it is only now, thanks to the discovery of an amazing tool called CRISPR/Cas9, that this has happened. But what is CRISPR/Cas9, and how does it allow us to do such an incredible thing as edit human genes, and how should we deal with this tool and the changes it will bring?
While the possibility of human gene editing has only recently been realized, gene editing in other organisms has been possible for a long time. In particular, gene editing in microorganisms such as E. coli and yeast has been widely used in real life since it became possible in the 1970s. An example of this is the mass production of insulin using E. coli, which has revolutionized the treatment of diabetes by making it possible to produce insulin in large quantities, which previously could only be extracted in small amounts from cows or pigs. This was thanks to a protein called restriction enzymes found in E. coli. Restriction enzymes are DNA-cutting enzymes that allow us to cut where we want in the DNA, so we can either cut out a section of DNA and remove its function, or we can create synthetic DNA that contains the function we need and splices it together to produce the substance we need.
However, the same restriction enzymes that were useful for editing genes in microbes were not useful for editing genes in mammals like humans, because the human genome (the entire genome, including all genes) is much larger than a microbial genome, and the restriction enzymes would cut unintended genes. This ability to cut exactly what is needed is called specificity, and the larger the genome of the organism being edited, the greater the importance of specificity. However, CRISPR/Cas9, which was discovered in bacteria, is like a restriction enzyme in that it cuts DNA, but it has a much higher level of specificity, which means it can effectively edit the human genome. The high specificity wasn’t the only advantage of CRISPR/Cas9. In addition to reducing the creation of transgenic mice from more than 10 steps to one, CRISPR/Cas9 has also revolutionized the time-consuming and laborious experimental methods, dramatically reducing the cost and time required for gene editing. This has revolutionized our society and industry.
A lot of science and capital has been poured into the development and commercialization of CRISPR/Cas9, resulting in numerous patents and new ventures. Of particular interest to us is the advances in medicine that have resulted. One of the strengths of CRISPR/Cas9 is that it can edit the genes of fully grown individuals, meaning that it can be used to correct diseases that are caused by genetic defects, even in full-grown adults. As such, CRISPR/Cas9 has the potential to revolutionize medicine.
However, there is also the possibility that CRISPR/Cas9’s endless possibilities could pose threats that we cannot predict. We have yet to see an ethical consensus on human gene editing. The evolution of ethics has not kept pace with the evolution of technology. Worse, even if there were an ethical consensus and institutional regulations in place, there is no way to enforce them. CRISPR/Cas9 has the advantage of being incredibly easy to use for its power. This means that anyone can use it, even if they don’t have a well-equipped lab. This makes it very difficult to regulate the use of CRISPR/Cas9. Furthermore, there are signs of a breakdown in research ethics. The July study was the first of its kind in China, where research ethics standards are much more lax than in other countries. This is even more concerning because it could lead to a situation where ethical standards are ignored in order to secure competitiveness in research. In addition, there are many difficulties ahead of us, such as the reduction of human genetic diversity due to indiscriminate gene editing and the creation of new social classes based on genes. Therefore, in order to solve these problems, we need to discuss and debate not only among scientists but also among the entire society, including politics and society. This means that science is no longer just for scientists.
The most important thing is for the general public to keep up with the changes in the scientific community. This is because accurate scientific knowledge is indispensable when it comes to building social consensus. Not only do people need to be educated on how to do science, but scientists need to constantly think about how to effectively communicate their work to the public. In turn, legislators, ethicists, and others who shape social institutions must work to ensure that the evolution of institutions and ethics keeps pace with the evolution of technology.
As we’ve seen, CRISPR/Cas9 will be an enormous technological advance. However, there is an equally great threat lurking behind it. Throughout history, humanity has faced many threats from technological advancements, and we’ve survived them, sometimes wisely, sometimes not so wisely. CRISPR/Cas9 will bring about social change on par with the Industrial Revolution. In order for humanity to navigate this massive change wisely, it will require not only scientists, but society as a whole to think about and work together to solve these problems.