Recombinant DNA and Insulin - Genetic Engineering in Action

By Michelle V.

Genetic Engineering has always sounded like some advanced technology in the distant future, one that results in human clones and hybrid organisms. We tend to see genetic engineering as a way to alter genes and create a new organism with different characteristics, mainly in agriculture through GMO corn and various other genetically modified vegetables. However, in our perception that genetic engineering is some faraway, “mad scientist-like” technology that happens in the industry, sometimes it is hard to believe that various medical innovations that have become extremely beneficial in today’s society are derived from genetic engineering methods. One great example is Recombinant DNA Technology and its role in insulin production.

Source: https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.genome.gov%2Fgenetics-glossary%2FRecombinant-DNA-Technology&psig=AOvVaw1pw-LkBUWCs1DzWflIhyHx&ust=1720294531401000&source=images&cd=vfe&opi=89978449&ved=0CBEQjRxqFwoTCMC58tXSkIcDFQAAAAAdAAAAABAE

First off, what is insulin? The human body needs to maintain certain internal conditions in order to function, mainly that of sugar levels in the blood after a meal. Insulin is a protein secreted by the pancreas in order to regulate blood glucose levels by allowing cells to uptake the sugar in the bloodstream. The insulin hormone binds with receptors on the surface of the bodily cells, signaling the cell to open channels allowing glucose to be transported out of the bloodstream and into the cell. This process is arguably one of the most important for bodily functions, as cells cannot undergo cellular respiration to produce energy for the body to move without its fuel, glucose. However, some bodies can lose their ability to produce or react to insulin in a widely known condition called diabetes, causing high blood glucose levels or hyperglycemia, as discussed in Insulin by Cleveland Clinic. So in order to intake sugar for energy, people with diabetes must obtain insulin from external sources. However, insulin hasn’t been around much longer than penicillin has. In fact, according to the article The History of a Wonderful Thing We Call Insulin by the American Diabetes Association, the first administration of insulin was in 1922 and its successful effects led to the widespread use of insulin afterwards. The discovery and production of insulin has allowed modern doctors to treat those with diabetes by administering shots of this protein, causing it to become one of the most important and beneficial medical innovations. But, how can this human protein be mass produced and distributed as an insulin treatment? The production of insulin requires a genetic engineering method called Recombinant DNA Technology.

Recombinant DNA Technology, to those who are unfamiliar with it, seems complicated, but when broken down into steps, it’s fairly simple. Firstly, breaking down the name makes it easy to understand; it’s the use of genetic technology to combine two different strands of DNA to make one strand with the desired characteristics of two organisms. The National Human Genome Research Institute, on their website, defines Recombinant DNA Technology as “using enzymes and various laboratory techniques to manipulate and isolate DNA segments of interest. This method can be used to combine (or splice) DNA from different species or to create genes with new functions”. In the production of insulin for people with type 1 diabetes, the gene responsible for insulin production is added to a vector or a segment of DNA that will be used to carry the gene into a host organism, usually the plasmid of a bacteria. A plasmid is a small ring of DNA that floats in the cytoplasm of a bacterial cell and is separate from the DNA in the nucleoid. In simpler terms, the insulin gene is “cut out” of human DNA using a tool called a restriction enzyme, which are enzyme that cuts DNA at specific sequences. The cut DNA is then inserted into the plasmid of bacteria using another enzyme called “DNA ligase”, which acts as a glue to put the DNA back together. The new “recombined” DNA is inserted into a bacteria and the new insulin gene allows the bacteria to make the insulin protein. This process is typically performed in a lab through bacterial transformation, when external plasmids enter a bacterial host through a tunnel-like structure called the pili according to the organization addgene. The bacteria produces the insulin and scientists will then “harvest” the insulin by separating the proteins from the bacteria and purifying the insulin so it can be administered safely to humans without bringing on infection or other health problems. 

Recombinant DNA Technology has changed the lives of various patients with diabetes by providing an effective treatment to supply them with what their bodies need to function. It shows that genetic engineering is not an aspect of Hollywood, simply a futuristic plotline for entertainment. Genetic engineering, though many don’t realize it, saves numerous lives in our modern-day society, something patients of the past were not fortunate enough to experience.