Genes are the heredity units that pass the characteristics (physical and behavioral) from parents to their offspring. They define features such as height, eye color, ability to digest, style of conversation, our response to external threats, etc.
Additionally, our own real-world experiences, observations and learning come into play. So, our attitude and behavior is a combination of genetics and the external environment where we grew up (our surroundings, society, school, friends, teachers, etc.).
Every human being has an estimated 20,000 to 25,000 genes. Each gene is made of DNA (DeoxyriboNucleic Acid). DNA is made up of molecules called nucleotides. The order of the nitrogen bases adenine (A), thymine (T), guanine (G) and cytosine (C) determines DNA’s instructions. Adenine and guanine are purine (colorless crystalline compounds that have two rings), and thymine and cytosine are pyrimidines (colorless crystalline compounds that have one ring). Adenine pairs with thymine and guanine pairs with cytosine. An easy way to remember this is that Apples are on Trees and Cars go in Garages. These pairings come in different orders and combinations. This is called genetic coding.
This forms the basis of gene therapy. It is still an evolving field. In controlled laboratory conditions, various combinations of these sequences (coding) are tested for different medical conditions for possible cures and improvements.
Gene therapy can be used to treat diseases such as cancer, neurological disorders, inherited diseases, infectious diseases and cardiac diseases. For example, cancer is a result of a defective p53 gene. The p53 gene helps regulate cell growth. Cancer is a cell cycle disease, which is why a defective p53 gene results in cancer.
Did you know that cancer cells are technically immortal?
The earliest cases of gene therapy were used to help treat cancer. Gene therapy in cancer is used to introduce tumor suppressor genes, genes that induce apoptosis (death of cells), genes that inhibit tumor angiogenesis (development of new blood vessels) and genes that code for enzymes to induce active drugs.
Gene therapy is used for head and neck cancer, lung cancer, prostate cancer, renal cell cancer and colorectal cancer. Gene therapy vaccines are being developed to fight against cancers that are sensitive to immunotherapy. Some gene therapies are being used to fight against the defective p53 genes.
Gene therapy is also being used to fight against neurological disorders such as Parkinson’s, Alzheimer’s and motor neuron disease.
A serious side effect of gene therapy is sometimes the immune system attacks the therapeutic genes. Other side effects include therapeutic genes inserting themselves in incorrect places, which may cause cancer or a mutation. Side effects can be caused by an over-expression of the gene.
The hopes for gene therapy are that it will be safer — meaning that the side effects will be less likely to occur. There is also hope that gene therapy will be more efficient, developed (less likely for accidents) and that there will be more uses for it.
Gene therapy becomes powerful due to its potential ability to cure the most challenging diseases.
As gene therapy can potentially alter human behavior, there can be potential misuse. This ethical aspect is what some people are worried about.
With continued research and practical case studies, this field is going to contribute significantly to the betterment and well-being of human life.
Vaageesha Das is a 10th grader at Morgantown High School. Today’s information comes from: https://www.pharmaceutical-journal.com/files/rps-pjonline/pdf/cp200906_gene_applications-270.pdf; https://www.cell.com/current-biology/fulltext/S0960-9822(14)01279-2; https://www.asgct.org/education/gene-therapy-basics; https://ghr.nlm.nih.gov/primer/basics/gene; https://www.lexico.com/en/definition/purine; https://www.albert.io/blog/what-is-the-difference-between-purines-and-pyrimidines/
