CRISPR, a new biotechnological method of gene editing, stands for Clustered Regularly Interspaced Short Palindromic Repeats. Scientists discovered a while ago that bacteria fight off viruses by using an enzyme called Cas9 and what it does is it reorders certain genes in order to protect itself from bacteriophages and scientists recently figured out how Cas9 does this. Scientists have found a similar method in 2013 to turn the bacteria’s virus-fighting system into a new form of gene editing.This tool can easily change any gene in any plant or animal. The way it works is scientists start with RNA, and it finds the area of the DNA that needs to be cut.
The RNA tells Cas9 where the DNA needs to be cut. Cas9 then separates the DNA into single strands. Now the RNA can pair up with the part of the DNA that needs to be changed. Cas9 then cuts the DNA at that spot, making space in for whatever changes may be added. The DNA fragment is removed, modified, or replaced in order to achieve what was what sought out. Researchers can activate gene expression using modified versions of Cas9, instead of cutting the DNA. These techniques allow researchers to study the gene’s function.
Research also show that CRISPR-Cas9 can be used to target and modify “typos” between nitrogenous bases in the human genome to treat genetic disease (Saayman et al, 2015). This new biotech has stirred up a new set of ethical issues and concerns because of the possibility of enhancements in the human body, whether for aesthetics or for functionality. This CRISPR technique has the potential to enhance performance of athletes or increase intellectual capacity, nevertheless, there will be some ethical problems concerning people having a disadvantage over genetically modified people. Also another issue with a gene editing is that newly added enhancements can be transmitted to following generations, causing a change in the entire germline, but if it were a hereditary disease that was taken out then it would exeunt from that line and the following generations. CRISPR/Cas9 technique is in its developmental stage, and it may cause some unpredictable side effects that may be passed down the gene pool (E, 2016). Scientist from China in 2015 published a paper in a journal that was rejected due to ethical concerns because they altered the DNA of a human embryo. “The experiments resulted in changing only some of the genes, and had effects on other genes.The journal stated that the technique is not ready for clinical use” (Zhang, 2015).
Another ethical issue is who gets to patent CRISPR techniques, and since it’s inexpensive and arguably very easy to program Cas-9, who’s stopping one from editing their own germline in their basement. The medical applications for CRISPR/Cas-9 are almost indefinite and researchers have already used it to fix genetic diseases in animals, to combat viruses and to sterilize bugs. The cutting of certain genes can lead to mutations that may help them understand genetic diseases (Hsu, 2013). The biggest goal however is to use CRISPR/Cas-9 in human cells and disable certain genes that play a role in inherited diseases. Genome editing has the potential to cure diseases by disrupting and correcting the disease caused by a gene or mutation, and inserting new genes. CRISPR has already started to eradicate the mutation causing cystic fibrosis.
This system can introduce DNA in the germline of any organism and researchers have already made changes in the genes of plants by “improving crop quality or introducing disease resistance” (Ishii, 2015). “This phenomenon of pushing a genetic trait through a population is called gene drive and among other uses, gene drives could be used to control damaging invasive species, reverse pesticide and herbicide resistance in insects and weeds in agriculture or prevent the spread of disease. Using this possibility, researchers were able in the lab to spread genes in mosquitoes that prevented them from harboring malaria parasites and also to render female mosquitoes infertile” (E, 2016).
Researchers also used crisper for transplanting animal organs into people by eliminating retroviruses harmful to human recipients. “CRISPR/Cas 9 in combination with induced pluripotent stem cells may have the potential to enable the creation of human organs in labs, with the possibility of having an unlimited supply of organs not rejected by the immune system of human recipients” (Collins, 2015). CRISPR was initially sought out for the purpose of curing genetic diseases, and since the technique is still in its experimental stage, most research surrounding CRISPR will be focused on eradicating diseases since it has the potential to do so. Some diseases that have already being treated are liver disease, a rare genetic disease called transthyretin amyloidosis, as well as hepatitis B (Saayman, 2015). CRISPR has also been used to delete the single nucleotide responsible for sickle cell disease, and is able to disable the gene that causes Huntington’s disease in 65 percent of subjects’ brain cells.
Researchers have also used it to change bacteria to destroy its own antibiotic-resistant genetic sequence (Saayman, 2015). Steps towards treating muscular dystrophy have also been taken with slow but positive feedback. A disease that might finally be treated, if not eradicated, is HIV. Since it harbors in one’s own DNA sequence it won’t be difficult to program the Cas-9 enzyme to target the genes for this disease then eliminate it and steps have already been taken towards this goal. Mice with HIV have been tested on and the data gathered from those experiments show the HIV production rate had dropped an astounding amount (Hsu, 2015). These diseases were only eradicated from the small infected samples that were taken from the patients. This technique works mainly in theory concerning adults, since it’s difficult to change every cell’s DNA sequence, in the entire human body, but tests on human embryos have already happened been done and the data states that 72% of the mutated and diseased embryos have been cured with no side effects or other genetic mutations.
Though it will take some time till CRISPR can be used clinically, there are noticeable advancements towards the end goal of eradicating genetic disorders and diseases (Hsu, 2015). This test has been published in many articles in famous journals such as Nature, and this is one of the first test to not have any random side effects or mutations. A lab was also conducted on cells infected with Huntington’s disease and 95% of the samples were treated. The only downside with this is that it’s an RNA disease, and RNA regenerates constantly, so these treatments would be only temporary, thats why a new viral treatment which uses programmed Cas-9 enzymes is being produced, and what it does is it spreads throughout the body with the Cas-9 enzyme and the genetic information to code for the programmed Cas-9 to make it possible for the body to constantly produce these enzymes to keep RNA diseases at bay (Hsu, 2015). The future is looking brighter now that this biotechnological revolution, and in some cases a miracle, has been made. Getting a specific mutation from gene editing used to be very hard to accomplish since they were only limited to certain restriction enzymes that could only cut out specific DNA sequences. Now with CRISPR, it’s only a matter of having the education, the sample, and Cas-9 in order to accomplish whatever gene editing is wanted. This is becoming more evident that easy, low cost gene editing will become the new reality and the eventual norm.
Though this is still in it’s experimental form, the technological advances being made are in rapid succession. This CRISPR technique is amazing because it’s able to rid of genetic disorders but the main ethical issue is mainly about non-disorder or disease related alterations. There is nothing really stopping this forseen occurrence unless it becomes against the law or something, but most likely it won’t because after having the CRISPR technique perfected at eradicating genetic diseases, there will be further research at how to enhance the human body, for no other reason but to be better than normal.