What is CRISPR technology? How has it changed the medical world? How could CRISPR technology help us find a cure for cancer? We explore all this and more.
What is CRISPR?
CRISPR (pronounced “crisper”) refers to a special segment of DNA characterized by repeated sequences of nucleotides, interspersed with spacers. CRISPR is an acronym that stands for:
CRISPR-Cas9 is an associated enzyme that works like a pair of scissors on a molecular level, cutting other strands of DNA.
Scientists created CRISPR technology by adapting the immune responses of bacteria and other microorganisms. These organisms use RNA derived from CRISPR to prevent viral attacks by effectively cutting up and destroying the DNA of the invading virus. By transferring these components to more complex organisms, scientists have created a way of successfully manipulating genes, or editing DNA.
Who discovered CRISPR?
Rodolphe Barrangou and his team from Danisco, a food testing company, discovered the potential of CRIPSR in 2007. Their studies relied on Streptococcus thermophilus, a species of bacteria commonly found in yogurt, as a model. Barrangou observed that following a viral attack on the bacteria, new spacers appeared in CRISPR. He discovered that the DNA sequence of the spacers was identical to DNA strings found in the genome of the virus. Barrangou established that CRISPR effectively edited bacteria cells by introducing DNA strings it extracted from the virus. This had the beneficial effect of making the bacteria resistant to future attack by the same virus.
What is the potential of CRISPR technology?
CRISPR technology has enabled scientists to modify cells faster and more efficiently than ever before. Many diseases occur at a cellular level. The ability to safely and effectively edit mutated cells has the potential to revolutionize medicine.
CRISPR technology has drastically reduced the time and cost involved in genome editing. This has already had a huge impact in terms of research, facilitating an explosion of scientific studies. Though CRISPR technology is still in the developmental stages and is as yet unlicensed for use on the general public, the results so far have been encouraging.
What diseases could CRISPR technology treat?
Many illnesses are caused by gene mutations. The ability to edit those mutations out of existence with CRISPR technology is tantalizing, for obvious reasons. Though there are still many unknowns and we are really just at the start in terms of developing CRISPR technology, this relatively new technique has the potential to address a wide range of notoriously difficult-to-treat diseases, including:
Beta-thalassemia is a hereditary blood disorder that affects red blood cells and their ability to deliver vital oxygen throughout the body. Clinical trials are currently underway in Europe involving the use of CRISPR technology to harvest hematopoietic stem cells (immature cells that can develop into a range of different blood cells) and induce them to manufacture fetal hemoglobin.
Fetal hemoglobin is much more effective at binding with oxygen than adult hemoglobin. Though FDA approval has been withheld pending further evidence of the treatment’s safety and efficacy, there is hope that through the implementation of CRISPR technology we could one day successfully cure a wide range of blood disorders, including sickle cell anemia and hemophilia.
Huntington’s disease is a neurogenerative condition caused by a hereditary gene mutation. A US team of scientists is currently developing a version of CRISPR-Cas9 to effectively act as a self-destruct button for the Huntington’s-causing gene mutation.
Several forms of blindness are hereditary, including Leber’s congenital amaurosis, the most common cause of inherited childhood blindness. There is currently no cure for this disorder, but scientists are aware of the specific gene mutations that cause it. Trials are currently ongoing involving the treatment of the disease through CRISPR technology.
This genetic disorder causes the body to produce large amounts of thick, sticky mucus that can build up in the lungs, causing respiratory problems and infection. Though treatment of this disorder, which was once considered a fatal childhood illness, has improved drastically over the years, there is no known cure. The average life expectancy of a person who has cystic fibrosis is currently around 40 years.
Researchers have established that CRISPR technology may allow them to “fix” human lung cells affected by one of the main cystic fibrosis-causing mutations in the CFTR gene. Though scientists attribute the disease to numerous mutations, meaning that they will need to develop different CRISPR treatments to tackle each one, the potential for using gene editing to cure cystic fibrosis is huge.
The Hangzhou Cancer Hospital in China is running clinical trials to assess the effectiveness of CRISPR technology in editing the genes of people in the advanced stages of esophageal cancer. Cells are extracted from patients and edited via CRISPR technology to remove the gene that codes for a receptor that the tumor attaches to and uses to instruct the patient’s immune system not to attack. The edited cells are then reintroduced to the patient to attack the tumor at a cellular level. Meanwhile, in the US, planning is currently underway for CRISPR cancer trials.
Though only time will tell whether CRISPR can provide life-saving treatments for cancer, technological advancements are creating a great deal of excitement in the scientific world, with some researchers believing that we are edging ever closer to a cure.