CRISPR Gene-Editor Explained: Upgrades, Applications, Concerns

Anya Wilkinson, Writer

A New Tool Revolutionizing Medical Treatment

When first unveiled as a functional technology in 2012, Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR) was a major source of conversation in the scientific community. A new tool for editing genes and DNA that was cheaper, more accurate, and hypereffective? The tool was an innovative breakthrough in the medical field and in genomics, the study of the human genome. CRISPR has continued to make strides and to save lives to this day, yet scientists are still attempting to figure out how to grow its capabilities.

CRISPR began as a bacteria’s self-defense against bacteriophages, or viruses that target bacteria. An article from the National Institutes of Health (NIH) summarizes the process as follows:
“The bacteria capture snippets of DNA from invading viruses and use them to create DNA segments known as CRISPR arrays… If the viruses attack again, the bacteria produce[s] RNA segments from the CRISPR arrays to target the viruses’ DNA. The bacteria then use Cas9 [a CRISPR-associated enzyme]…  to cut the DNA,…  [disabling] the virus.” (NIH, 2019).
Scientists have been able to apply CRISPR to a multitude of scientific fields. Recently, an experimental trial with CRISPR was conducted on patients with sickle cell anemia, a single-point mutation on one specific gene. So far, symptoms of the disease have “vanished” in multiple subjects and scientists “hope the effects will last,” (Kolata, 2019).

Drawbacks As a Tool
While CRISPR is a valuable tool that can be harnessed to cut out harmful DNA, viruses, or mutated genes, it lacks the ability to replace those genes with healthy or functional ones. Researchers have tried to develop these abilities, but couldn’t figure out how to until a pair of scientists at the Broad Institute made a breakthrough in 2018.

Getting An Upgrade?

The scientific community had little clue how to expand the capabilities of CRISPR until Columbia student Andrew Anzalone collaborated with David Liu, a chemist at the Broad Institute. Together, they are working to develop a system entitled “prime editing,” which can change the DNA by additions, deletions, rearrangements, etc., “without severing the DNA double helix,” (Molteni, 2019). This breakthrough could greatly increase the aid of CRISPR, as according to Liu the technology would be able to “correct around 89 per cent of the mutations that cause heritable human diseases.” So far, the technology has only been tested in lab cultures, but this new side to CRISPR could be very significant.

Applications For the Present and Future

Currently, CRISPR is focused on medical treatments and technologies, in addition to other experiments as the scientific community continues to test its range of abilities. In addition to the tests being done to treat or cure sickle cell disease, CRISPR has also “[altered] mosquitoes so they can’t spread malaria, [and edited] tomatoes so they are more flavorful,” according Knvul Sheikh, New York Times. In a recent study, a team of scientists used the “CRISPR associated enzyme called Cas-9 to eliminate a species of Salmonella,” (Sheikh, 2019).

In the future, some predict CRISPR may be used regularly to treat strains of the flu or as a regular antibiotic. Instead of normal antibiotics that can destroy healthy bacteria, CRISPR could be programmed “to kill only specific pathogenic bacteria and leave … our healthy microbes [alone],” says Dr. Luciano Marraffini, a microbiologist at Rockefeller University (Sheikh, 2019). This is in the testing stages and has yet to be tested on living subjects. Additionally, with its successful trials in possibly eliminating sickle cell disease, there are hopes for curing similar single-point gene mutations. The new ability to replace faulty DNA with healthy material may be key in curing multifactorial or complicated genetic disabilities, such as Huntington’s disease or cystic fibrosis. However, this technology could also become problematic.

 Public Concerns

Due to the extensive range of CRISPR, many people have concerns about invasive properties. “I think it’s a really dangerous technology… though there isn’t one piece of technology that wouldn’t be abused these days… people are going to try to edit their babies genes to look like a certain ideal,” says interviewee Taj Wilkinson. When asked if CRISPR would not just be a medical-focused technology, Wilkinson said that people would probably be willing to pay a lot to “fix [their] baby” if they knew the baby’s genes would be faulty (which can already be seen from processes like amniocentesis, where a chart of a fetus’s genes is drawn up from amniotic fluid). Responses on social media are controversial, with mixed positive and negative reactions to the technology. According to Chemistry World, public approval on Twitter dipped greatly “in February 2019, when biohackers encoded malware into a strand of DNA,” although that incident wasn’t directly related to CRISPR. The technology can appear daunting, because to many, your genes are unchangeable. A popular expression, “It’s in my genes,” is used to show a part of one’s personality is constant or wouldn’t change. Now with the advent of CRISPR, that idiom and much more is called into question.