CRISPR gene therapy has taken over by storm. This scientific breakthrough has revolutionized medicine. Simply put, CRISPR is an affordable way of editing DNA. This game-changer has opened up limitless possibilities for researchers to cure chronic diseases, for instance, Alzheimer’s disease, cancer and blindness. It does not just stop there; CRISPR has also established more sustainable ways for manufacturing chemicals and producing fuel. This will lead to an improvement in the quantity and quality of agricultural produce, which will allow feeding the growing global population with ease.
What is CRISPR Genome Editing?
To begin, CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. Unlike ever before, this groundbreaking technology allows scientists to edit and manipulate the DNA of any genome, with the genetic material of an organism.
Why Is CRISPR Gene Editing Beneficial?
Genome editing allows scientists to remove, add and alter genomes in any location. Over the years, several approaches to genome editing have developed, the most recent one is CRISPR-Cas9. Not only is this system more efficient than the previous ones, but it is also faster, more accurate and costs much less.
Who Developed CRISPR Technology?
CRISPR cannot be accredited to anyone scientist, as a lot of scientists had a part in revolutionizing it. Yoshizumi Ishino and his colleagues in Japan at Osaka University published the first gene sequence in 1987. However, during those simpler times, the data they stumbled across was incomprehensible and scientists were not fully able to decipher it. This research was further carried out by numerous other scientists, including Francisco Mojica, Jennifer Doudna and Feng Zhang.
Francisco Mojica, from the University of Alicante, located in Spain, was the first individual to propose CRISPR serves as a bacterial immune system, which shields the body against harmful viruses. This system comprises of genetic code repetition and the interruption of sequences with genetic code remnants from previous invaders. To recapitulate, the system is similar to genetic memory which allows cells to distinguish viruses and destroy them, if and when they return.
Though this theory was proposed a long time ago, it was not until 2012 when Doudna, Charpentier and their colleagues showcased the possibilities of CRISPR. Later in 2013, Zhang Lab revealed CRISPR method of engineering, which allows scientists to edit the genome in human and mouse cells. As time passes, new discoveries are being made for CRISPR.
How CRISPR-Cas9 Technology Works?
CRISPR is much simpler than it sounds. When a virus infects a microbial cell, the microbe deploys a CRISPR nuclease (Cas9), which guides the system to match DNA sequences. Cas9 binds itself to the DNA and cuts it off, which completely shuts down this specific gene. As CRISPR has progressed, more modified versions of Cas9 have developed, which allow researchers to study gene functionality by activating gene expression without cutting the DNA.
To simplify things, scientists are well aware that genetic mutations cause various ailments. This led to the thought of replacing these specific genes and preferably regressing it to its original state. To further put it into layman terms, Mr. Feng Zhang himself compares it to proofreading and editing a novel. The example he gave was, “Twinkle twinkle big star.” We all know it should be a little star, so how do you fix it? You can either go ahead and write “Twinkle twinkle star,” but that would not serve the same purpose and will not have the same meaning as intended. Another way is to write “Twinkle twinkle big little star,” however, this is ambiguous and leaves the reader feeling confused. The best way is to write precisely what you mean, would be “Twinkle twinkle little star.”
Hence to achieve this, scientists can give Cas9 a guide RNA to replace “big” with “little.” This enables Cas9 to take this search string and find a place where the mutation matches “big” within the DNA. Cas9 will then cut “big” and prepare a repair template to provide to the cell for the missing word, which will then replace the DNA break with the desired new repair sequence, which in this case is “little.”
Simply put, it works the same as any editing tool does. CRISPR is loosely used as an umbrella term to encompass CPF1 and Cas9, used strategically to edit specific DNA locations and target genetic code. CRISPR genetic editing gives researchers an edge as it allows them to modify genes within organisms and living cells permanently. In the foreseeable future, it may even be possible to manipulate and alter mutations within the human genome, which can potentially cure genetic ailments.
Why Is CRISPR Gene Editing Beneficial?
The benefits of CRISPR allow scientists to create animal models and cells in a short span that can be utilized by researchers to study more complicated diseases, for instance, cancer. Moreover, to ensure the maximum number of people can benefit from CRISPR genome editing technology, Feng Zhang and his team of experts have trained numerous researchers all around the globe in the use of CRISPR.
Is CRISPR Safe?
In a research published in the U.S. National Medicine, researchers demonstrated the safety of CRISPR, led by the University of Pennsylvania. The study was conducted on three individuals, out of which one was suffering from sarcoma, while the other two were suffering from multiple myeloma. This process involved the removal of T cells and it’s editing. Researchers deployed CRISPR to exchanged warhead cells with the removed T cells. These warhead cells contained a gene that directs cells to infected tumor cells.
At the start of December 2019, findings from the above study were presented at the American Society of Hematology in Orlando. All three patients were free of side effects. Which, previously in similar studies, would have resulted in patients experiencing seizures, low blood pressure and high fevers. Unfortunately, CRISPR did not, in any way, slow down the spread of cancer within the subjects. This study did, however, establish the safety of CRISPR.
Though numerous researches are taking place in the United States, London, China and all across the globe, utilizing CRISPR is a bit challenging. In certain viruses, it is impossible to decipher if, in fact, the gene editor has removed the unwanted edit. Although external editing enables researchers to ensure the right edits. However, it is not feasible for all diseases. Therefore, more in-depth research and clinical trials are required to determine how soon the U.S. government can adequately utilize this technology.