It’s that time of the year again when the freshmen are learning about CRISPR in their biology classes. Let’s be honest for a second - most of us who are learning or have learned about this innovation are more focused on getting that good grade on that quiz or test. Thus, we fail to comprehend the true significance of this advancement, which is helping humanity achieve perfection. We can save people with incurable illnesses, bring back extinct species, and allow our own species to evolve even further. Our existing technology has already allowed us to begin achieving these aforementioned goals. With new developments in CRISPR technology, we are successfully able to remove simple genetic illnesses like sickle cell anemia and are on the brink of bringing back the wooly mammoth.
CRISPR is a natural process that has long functioned as a bacterial immune system, acting as a defense mechanism for unicellular bacteria and archaea from invading viruses. Two components are used in this naturally occurring process. The first is short snippets of repetitive DNA sequences conveniently named CRISPRs. The second is CAS-9 proteins which separate the DNA when required. When viruses invade the bacteria, CAS-9 proteins cut out a certain section of the virus’s DNA and stitch it into the bacteria’s DNA. The foreign DNA sequence is then copied into short pieces of RNA. While RNA has thousands of purposes in different kinds of cells, in the case of CRISPR, it binds to free CAS-9 protein and acts like a scout. If the virus were to ever invade the bacteria again, the free-floating CAS-9 protein will quickly recognize it and swiftly destroy it before it creates another infection. In 2012, scientists discovered how to hijack CRISPR and use this process for the benefit of humanity. By creating a custom “guide” RNA to match the gene they want to edit and attaching it to the CAS-9 protein, they are able to direct the CAS-9 protein to the DNA molecule and snip off the target gene. While DNA is being destroyed during the procedure, no harm comes toward the patient. The cells are able to rebuild the damaged DNA through nuclease proteins.
Scientists are using such guide RNAs to direct CAS-9 to faulty genes, such as the one that causes sickle cell anemia. Sickle cell anemia is an inherited disease that affects the shape of red blood cells; while healthy red blood cells are round and flexible, most of the cells affected by this disease are often sickle-shaped (as the name suggests) and rigid. This abnormality causes our blood circulation to reduce drastically and creates blockages with the rigid cells. If not treated, this can cause strokes, paralysis, and vision issues. Curing sickle cell disease is one of the first objectives of CRISPR scientists because the disease is caused by the mutation of only one specific gene; HBB (Hemoglobin-Beta). If scientists are able to use CRISPR to fix this one mutation with almost a hundred percent accuracy everytime, they could advance to more complex illnesses caused by a multitude of genes (cancer). The entire CRISPR process starts with “intense chemotherapy” in order to cleanse the patient’s bone marrow that is responsible for making the faulty blood cells. After injecting the CRISPR based treatment in their blood, the patients wait for about a month until a satisfactory amount of healthy cells are produced. The patients are extremely immunocompromised after this process as their body is still adjusting to losing so many familiar sickle-cells during the chemotherapy, and gaining so many unfamiliar healthy cells during the actual treatment. While this procedure is excruciating on the patient and the hospital giving this meticulous treatment, it provides many with a new chance at living life to its fullest. According to an interview with Jimi Olaghere, a sickle cell patient, conducted by the NY Times, CRISPR therapy helped him tremendously. Jimi Olaghere is a man whose life is dictated by this illness: so much in fact, a job in e-commerce was the only viable career-path for him as it allowed him to stay at home and rest. “Every day, [he] used to be bedridden” by his condition. But after being one of the first sickle cell patients to undergo CRISPR trials, he was able to rid the disease. ““It feels like a miracle,” he says.
The wooly mammoth was an elephant species that roamed the Earth until about 10,000 years ago. Characterized by its lengthy fur, vigorous tusks, and intimidating presence in early ecosystems, the wooly mammoth was crucial in transforming our world’s terrain. A new startup company named Colossal hopes to bring back this cousin of the elephant to prevent climate change. With their enormous and powerful feet, they can stomp on the wet tundras and turn them into dry grasslands; such grasslands would consume more carbon dioxide and reflect more sunlight, maintaining the permafrost. The goal of this project is not to create a perfect copy of the species, but rather use CRISPR to give the offspring specific mammoth characteristics (physical and behavioral). Using Asian elephant embryos, Colossal scientists are making elephant-mammoth hybrids (mammophants). As CRISPR technology is advancing by the day, the company projects that “mammophants” will be roaming the Earth once again by 2027 (just 4 years)! Of course, this does not mean that scientists will bring back every species that has gone extinct. Not only do we lack the resources to rebirth thousands of stable organisms, our simple world simply lacks the space to hold so much life. We are “playing god” with this kind of project, scientists say.
CRISPR, along with the rest of bioinformatics and genetic engineering, holds the key to our species' future. With this technology, the impossible becomes possible. Who would have ever thought of the possibility of curing cancer or bringing back entire species of extinct organisms by the next 20 years in 2010? The future is progressing faster than we anticipated.
Image Citation:
Anselm, Viktoria. “File:CRISPR-Cas9 Mode of Action.png.” Wikimedia Commons, 18 Dec. 2015, https://commons.wikimedia.org/wiki/File:CRISPR-Cas9_mode_of_action.png.