Last week, Nature Biotechnology published a report voicing thoughts from leading researchers, ethicists and business leaders from across the world on the genetic engineering of human cells using the latest gene-editing technology, the CRISPR-Cas9 system. Given the speed at which publications are appearing that showcase the technology’s potential, is science at a point where international discourse is now required to decide how the technology may be used? A similar conference was held back in 1975, the Asilomar Conference on Recombinant DNA, where leaders in the field gathered to discuss the potential challenges of biotechnology, the effects of which remain in decent standing today. In the Nature report, experts spoke of the “unparalleled potential for modifying human and nonhuman genomes,” to treat genetic conditions in humans and to “reshape the biosphere.”
CRISPRs (clustered regularly interspaced short palindromic repeats), pronounced “crispers”, are considered a breakthrough. They are small segments of prokaryotic DNA (bacteria and archaea) containing short, repeated sequences. Since 2013, the CRISPR-Cas9 system has been used to alter the genomes of a number of species. What appears to make the system so attractive to researchers is its ease, high efficiency and versatility. In other words, it may be applied to almost anything, which is why researchers appear so eager to capitalise on these advantages. Ultimately, most research facilities aim to develop a library of CRISPRs that may be used to target any sequence in an organism’s genome.
When asked if the current advances in gene editing meant that germline engineering is inevitable, some of the responses were:
Annelien Bredenoord, an Associate Professor of Medical Ethics at UMC Utrecht in the Netherlands: “I prefer [to stay away from] the word ‘inevitable’, because in the end it [may] be a consequence of human decision-making. I am inclined to say that inheritable genetic modification is on the horizon, [however] perhaps the first application of germ-line modification [might] involve [something other than] gene editing techniques by mitochondrial gene transfer.”
Katrine Bosley, CEO of Avila Therapeutics and voted one of the ‘Top 10 Women in Biotech’: “I have confidence we [may] address it carefully and thoughtfully, the fact that this dialogue is emerging so early in the life of this technology shows that the scientific community sees the implications and… the importance of broadening the dialogue beyond the people working in the field and indeed beyond scientists and clinicians.”
The panel was also interviewed about the societal effects of using CRISPR to edit the human genome:
Luigi Naldini, Professor of Cell and Tissue Biology at the San Raffaele Scientific Institute and President of the European Society of Gene and Cell Therapy: “The main current societal [challenge] is … an exaggerated but potentially pervasive view that gene editing technologies [might] lead to science-fiction scenarios in which humans are bred upon design leading to a whole array of unanticipated effects… which may inhibit their full exploitation for… more fruitful applications in somatic gene therapy, biotechnology and biomedical research.”
Recent reports have established its potential for treating inherited conditions and have evidenced that it might even be used to cure HIV and cancer. Some scientists also claim that the technology might be capable of increasing the global food supply and overcoming world hunger.
In April 2015, researchers in China used human embryos to show that CRISPR may be used to cure beta thalassemia, publishing their results in Protein & Cell. When an author of the paper was asked about CRISPR’s clinical readiness, the response was in agreement with most experts featured in Nature’s report, and it too encourages wider deliberation: “If you want to do it in normal embryos, you need to be close to 100%… That’s why we [halted]. We still think it’s too [young].”
There may remain a great deal to be understood about CRISPR before it may be used in the clinic, including its safety and the use of human germ cells in labs. There are still individuals in the medical field working on predicting the off-target side effects of using such a system on human embryos. Intriguingly though, new research may bring new questions and reveal areas with the greatest potential for research and eventually bring the technology into the clinic where it might be used safely to treat many genetic conditions.
How might germline engineering of human cells be used for scientific research?