Complex Made Simple

Gene editing: Great for medicine but ethical issues arise

Genome editing allows scientists to alter the DNA in an organism, whether through adding, subtracting, or changing the genetic code at a specific location

One way of using gene editing is to identify and deactivate genes that are causing diseases The World Anti-Doping Agency recently placed gene editing on their list of prohibited practices The Global genome editing market is expected to reach $8.7 billion by 2026

Genome editing allows scientists to alter the DNA in an organism, whether through adding, subtracting, or changing the genetic code at a specific location. There are many methods for editing DNA, but the most commonly mentioned are CRISPR-Cas9 and TALENs.

CRISPRs are repeated sequences of DNA interspersed with unique sequences of spacers. CRISPRs are naturally occurring, used by bacteria and archaea to fight off pathogens by slicing up the intruder’s genetic material and adding these slices to its own genome as a sort of “library”.

Since the pathogens’ genes become a part of the bacterium’s genes, the bacteria can “remember” the pathogen and better fight it in the future.

Molecular biologists use CRISPR to study relationships between genes and how living things look and function. In medicine, this technology gives hope for creating new treatments to cure diseases that are currently incurable.

One way of using gene editing is to identify and deactivate genes that are causing diseases. That includes genes that increase the risk of a disease, or normal genes that, when mutated or dysfunctional, cause genetic diseases.

The immune system, however, can also interfere with gene editing and disturb treatment.

TALENs is another method being used for efficient gene editing. Xanthomonas genus bacteria wreak havoc on plants, injecting a protein called TAL that can shut down a plant’s genes. This protein might be bad for plants, but for scientists, it’s opened up the world of gene editing even more. TAL is made up of sections that can identify certain DNA nucleotides, and tinkering with these sections allows scientists to locate genes they want to edit.

Is CRISPR flawed?

A recent study has flagged a new safety signal that could potentially hurt the drug developers focused on CRISPR–Cas9 gene editing.

The condition known as chromothripsis has the potential to cause cancer eventually, according to the study conducted by St. Jude Children’s Research Hospital, the Dana–Farber Cancer Institute, and Harvard Medical School.

When double-strand DNA breaks during CRISPR editing, there could be chromothripsis, a condition that results from the shattering of individual chromosomes and the haphazard rearrangement of genetic material subsequently.

According to an article published in Nature Biotechnology, none of the companies advancing the CRISPR-based therapies have considered the issue.

Is gene editing even ethical?

During the Olympics, the physiological prowess of elite athletes is clear, whether it’s the long-limbed volleyball players or the muscular weightlifters. Unsurprisingly, physiological advantages vary by sport, but there’s a number of genetic advantages that can arise.

Lance Armstrong even without performance-enhancing drugs, still had a genetically powerful build for cycling: he has a higher maximum oxygen consumption than the average person and this is associated with genetics.

Michael Phelps, the most decorated Olympian of all time, naturally produces half the lactic acid of other Olympic swimmers. When we perform high-energy activities, the body switches from generating energy aerobically (with oxygen) to generating energy anaerobically (without oxygen). During this process, the body breaks down a substance called pyruvate into lactic acid. This lactic acid tires out muscles, leaving them with that all-too-familiar burning sensation when you exercise. Since Phelps doesn’t have as much lactic acid, he’s able to recover from high-intensity activity quickly.

Could we create designer elite athletes using genome editing?

The US National Academy of Sciences and National Academy of Medicine have hosted an interdisciplinary committee to outline the regulatory standards and ethics of human gene modification. The very first of these regulations was that genome editing can occur if it is restricted to preventing the transmission of a serious disease or condition.

The World Anti-Doping Agency recently placed gene editing on their list of prohibited practices and substances. There’s just one problem: It’s extremely difficult to determine if someone has modified their genome.  

In theory, we could genetically engineer children to grow into “better” athletes: a runner with stronger leg muscles, a taller volleyball or basketball player, an archer with pinpoint vision.   

Moderna gets a jump on gene editing

Moderna has found a direction to volley their mountain of COVID-19 vaccine cash: gene editing.

Executives revealed during a second-quarter earnings call recently that Moderna is ready to expand its horizons with external technologies or products.  

Moderna’s pulled in billions with its COVID-19 vaccine. The shot, which the company now aims to market as Spikevax, is expected to bring in about $20 billion this year, based on existing orders.

Stéphane Bancel

Moderna is interested in new opportunities in nucleic acid technologies, gene therapy, gene editing and mRNA, CEO Stéphane Bancel said during the conference call.

Most likely, Moderna will start with hematopoietic stem cells, which is the company’s bread-and-butter delivery method. Other companies working on gene editing include CRISPR Therapeutics, Precision Biosciences, Beam Therapeutics, and Sangamo Therapeutics.

Gene editing applications

The Global genome editing market is expected to reach $8.7 billion by 2026, according to Reportlinker.com.

Genome editing finds application in a large number of areas, such as mutation, therapeutics, and agriculture biotechnology. The rise in the number of chronic and infectious diseases is likely to expand the scope of genome editing in the coming years.