Jennifer Kraliz—McMaster University Honours Biology 2023
This past fall, biochemist Dr. Jennifer Doudna and microbiologist Dr. Emmanuelle Charpentier were awarded the Nobel Prize in Chemistry 2020 for their development of CRISPR/Cas9 gene editing technology (1). Charpentier and Doudna’s discovery has significantly progressed genome editing and has redefined the life sciences, unlocking new research avenues and an abundance of potential for further biotechnology and healthcare advancements (1). Achieved through several different technologies, genome editing allows scientists to alter the DNA of organisms, which leads to phenotypic changes, such as in hair colour or disease susceptibility (2). The first of these technologies were invented in the late 1900s, essentially acting like scissors, cutting the organism’s DNA in certain places so that scientists can detach, add, or replace DNA segments (2). This procedure was drastically advanced in 2009 with the invention of the CRISPR method, making genome editing easier, cheaper, and faster than ever before (2).
Consisting of guide RNA and the DNA-cutting enzyme Cas9, the CRISPR (Clustered Regularly Interspaced Short Palindromic) tool was adapted from an immune defense against viruses observed in bacteria (3). With it, scientists can inactivate genes, add in new segments of DNA, and even edit single nucleotide bases (3). Due to the universal and foundational position DNA holds, genome editing tools have countless applications across many fields of the life sciences.
Gene therapy for humans, however, is arguably one of the most remarkable. CRISPR/Cas9 and other genome editing technologies have great potential to treat diseases with genomic bases, such as cystic fibrosis (2). Research on CRISPR-based cancer treatment exploded after the first U.S. trial tested it in 2019, and deemed it feasible (3). As full of potential CRISPR is, it is extremely important to remember its novelty, and therefore its imperfection. CRISPR is undoubtedly fascinating and influential, but it is far from being an errorless method of genome editing (2). In using the CRISPR method, there is risk of altering off-target DNA and mosaicism, which could have unpredictable, detrimental effects on the individual’s phenotype (4). The concerns surrounding the CRISPR/Cas9 technology and other technologies alike do not end there. The effects of germline therapies, which edit the genes of reproductive cells, are passed down from generation to generation. This raises concerns about interference with human evolution (2). Furthermore, it has also been proposed that germline editing could produce hierarchical classes or divisions among people, delineated by the quality of their engineered genome (4). Another potential aspect of genome editing that could cause further harm and alienation is its cost and accessibility. What if gene therapies are expensive and only accessible to the wealthy? This could worsen the health gap between the rich and the poor (2). Many believe that genome editing used to treat diseases could very easily lead to people using it for enhancement or non-health related purposes (4). Beliefs on what is considered a disease or an impairment to one’s health are not universal. How will genetic enhancement be managed by policy and regulation (4)? Who will make the decisions concerning this regulation? How will political agendas and religious beliefs affect the outcome of these decisions?
In summary, genome editing technology is a powerful tool, and many fear it landing in the wrong hands. Current bioethical discourse on the issue often includes a comparison of gene editing technology to selective human reproduction, calling it a “renewal of eugenics” (5). Whether or not the potential benefits of genome editing technology outweighs its potential harm is an extremely difficult quandary to navigate. Many assert that restricting research and development in human genome editing is unethical because it completely eliminates any chance of a positive impact.Whatever one’s stance on the issue may be, it is undeniable that genome editing and CRISPR technology has opened a door for humankind that cannot be closed.
- The Nobel Prize in Chemistry 2020 [Internet]. NobelPrize.org. [cited 2021 Feb 19].Available from: https://www.nobelprize.org/prizes/chemistry/2020/popular-information/
- What is genome editing? [Internet]. Genome.gov. [cited 2021 Feb 19]. Available from:https://www.genome.gov/about-genomics/policy-issues/what-is-Genome-Editing
- How CRISPR Is Changing Cancer Research and Treatment – National Cancer Institute [Internet]. 2020 [cited 2021 Feb 19]. Available from: https://www.cancer.gov/news-events/cancer-currents-blog/2020/crispr-cancer-research-treat ment
- What are the Ethical Concerns of Genome Editing? [Internet]. Genome.gov. [cited 2021 Feb 19]. Available from: https://www.genome.gov/about-genomics/policy-issues/Genome-Editing/ethical-concerns
- Ranisch R. ‘Eugenics is Back’? Historic References in Current Discussions of Germline Gene Editing. Nanoethics. 2019 Dec 1;13(3):209–22.