We have around 20-25000 genes that determine every characteristic that we possess as human beings. These characteristics can be as conspicuous as our height and weight. Our genetic code, or ‘Genome,’ is also responsible for underlying medical conditions like diabetes, sickle cell anemia, thalassemia, and other similar conditions.
Biotechnologists worldwide have been working on gene editing, which has the potential to revolutionize healthcare as we know it. Gene editing, simply put, is the process of altering or deleting a problematic genetic code in living organisms.
As a beginner, here are a few things you should know about gene editing:
1. The most accurate gene editing technique right now is CRISPR
CRISPR stands for ‘clustered regularly interspaced palindromic repeats.’ These DNA sequences are synthesized against specific DNA sequences that we need to alter or delete. Unveiled in 2012, CRISPR first located a problematic gene using a single synthetic guide RNA. It is aided by the Cas-9 protein, which acts as the molecular scissors to cut the faulty DNA out of the genome.
For CRISPR, we need a specifically designed single guide RNA, or sgRNA for short. These act as a code that helps synthesize a DNA segment. Selecting a carefully designed sgrna, like genscript sgrna, is integral for the success of the procedure. This sgRNA is synthesized in a temperature and pH-controlled environment that ensures maximum stability for lengthy periods of time.
Once the sgRNA is designed, it is introduced in the cells to locate the specific DNA sequence. Once the sequence is identified and located, the Cas-9 protein cuts the DNA sequence.
2. The technique is new, but the concept is not
Although the CRISPR Cas-9 system was introduced in 2012, the concept is not original. This phenomenon was first observed in bacteria, where this process occurs naturally.
Like every living being, bacteria also face attacks from viruses. The viruses that attack bacteria are called bacteriophages. They infect bacteria in the same way other viruses infect humans: by injecting their DNA into the host’s body.
Bacterial species have devised a system to protect themselves from bacteriophage attacks. It is similar to the vaccination system we have in place, by keeping a part of phage DNA in their cells for security. They keep short copies of the bacteriophages after their attack and integrate it into their genome as CRISPR.
CRISPR is the natural immune system of bacteria. It protects the bacteria against specific bacteriophages, so if it attacks a second time, the phage DNA is identified and destroyed.
This approach was studied extensively and later experimented with using synthetic sgRNA segments in other species. Although the success rate of CRISPR is 50-70%, higher than other gene editing techniques, it still requires extensive research for improvement.
3. It has different implications for different types of cells
Humans have two kinds of cells: somatic and germline cells. Somatic cells are responsible for building our body, including muscles, organs, and skin. Germline cells are reproductive cells.
CRISPR can be used to treat somatic as well as germline mutations. However, the implications of this process vary from cell to cell. CRISPR in somatic cells only lasts one generation. Although both cells contain DNA, somatic cells are not responsible for reproductive purposes. Hence, CRISPR mutation in somatic cells does not last several generations.
Germline cells, however, show a different story. As they are responsible for transmitting genetic characteristics to the next generation, germline mutations are also passed on from generation to generation.
4. Gene Editing can revolutionize healthcare
Gene editing, particularly CRISPR, is now an innovative technology in healthcare. New discoveries in healthcare are being made by using this technique. Scientists have harnessed CRISPR to study the cure of certain genetic diseases like sickle cell anemia and thalassemia. They locate the gene responsible for hereditary diseases in germline cells, target it, and remove it. Gene therapy also involves inserting a genetic sequence in the genome that represses the expression of the harmful gene.
Gene therapy is not the only application of CRISPR in healthcare. It can also treat HIV by inhibiting the replication machinery of this virus.
CRISPR also has potential in the pharmaceutical industry
As the research in CRISPR advanced, scientists discovered more ways to harness this technique in healthcare. The pharmaceutical industry also took full advantage of gene editing by creating drugs using genetically modified immune cells.
T-cells provide immunity to the body by repressing the disease characteristics after infection. Genetically modified T-cells are introduced into the body to treat HIV, which was thought to be a life-long disease.
CRISPR-modified stem cells also have the potential to cure terminal cancer. This, however, is still being researched. CRISPR and stem cell therapy are two ways to treat cancer. Combined, they can revolutionize oncology medicine.
5. Gene Editing is not exclusive to Human Genome
Living organisms that possess DNA can be genetically modified. This includes plants, insects, and other animals as well.
Genetically modified plants produce better yields, better taste, and protection against bugs and viruses. For this purpose, a specific gene is located and targeted using CRISPR. Once identified, the DNA sequence is modified to fit our purpose, which can range from experimental to better crop health. Genetically modified plants are then grown in a controlled environment. A few examples include flood-resistant rice and edible cotton seeds.
Not only plants but insects are also genetically modified. An example of this phenomenon is genetically modified mosquitoes to control and eliminate malaria. Mosquitoes are genetically modified to express the genes that inhibit malarial growth in them. These mosquitoes then pass on this characteristic to their offspring, controlling and ultimately eliminating malaria.
6. The moral implications of gene editing can limit its potential
Genetic modification techniques have the potential to revolutionize the world as we know it. While somatic cell modification is accepted, many communities are concerned regarding embryo modification and its ethical controversies.
Many countries, especially in Asia and Europe, have banned gene editing because the long-term effects of this are not yet understood. The International Society of Stem Cell Research released a guideline in 2016 that regulated gene editing practice, limiting it to research and clinical trials.
Gene editing is a cutting-edge technology. If used correctly, it can eradicate chronic and terminal diseases worldwide, becoming a huge part of the healthcare revolution. Pharmaceuticals and horticulture can also benefit from this technology, making history and breaking records. Keeping up with the advancements in gene editing can benefit us as scientists, researchers, entrepreneurs, or healthcare experts. With the progress in CRISPR research, we can expect remarkable things to unfold in the world of genetic modification.