In this lesson we’ll review the basics of genetic engineering. Next we will go over three key examples of genetic engineering in medicine. We will learn about both the current and potential uses for genetic engineering as well.
Definition of Genetic Engineering
When you think of genetic engineering, you might be picturing test tubes full of naked humans, cloned for purposes of creating a vast disposable army. Although cloning is definitely part of genetic engineering, scientists are nowhere near using their skills for cloning armies of people, though you might recall that they did clone a sheep named Dolly in 1996. What scientists and doctors really focus on is using genetic engineering to cure deadly diseases, like Alzheimer’s disease, diabetes, and heart disease.Genetic engineering is the process of cutting and pasting DNA from different sources inside a cell. These cells can be part of a multicellular organism like a plant, or inside a single cell, like a bacterium. DNA is the blueprint for every cell and gives all the instructions for the cell’s job. Let’s look at some examples of how scientists use this technique to design treatments for diseases.
Insulin is a protein that regulates our blood sugar. People with type I diabetes don’t have enough insulin, so their blood sugar stays very high unless they inject it themselves. High blood sugar can damage our organs, like the kidney and cardiovascular system.Insulin is usually made by cells in our pancreas, but these cells are hard to grow in a lab.
Because of this, scientists decided to find an easier method to make insulin. They cut the DNA instructions for insulin out of pancreas cells and pasted it into bacterial cells. Bacteria grow very quickly in the lab.
These new bacteria produce insulin, which can be easily isolated and then given to patients. By using genetic engineering, scientists found a treatment for diabetes that could be made quickly and inexpensively.
You might have seen genetically modified organisms (GMOs) at the super market, or maybe you’ve seen signs advertising that there are not GMOs in that store, but I’m sure you’ve at least heard that GMOs are controversial. Lately, there has been a lot of hype about the potential dangers of genetically modified food. However, this fear is mostly unfounded.
GMO food sources have tons of benefits and are not harmful to our bodies at all. They’re broken down just like regular food.Right now, scientists are working on designing foods that contain vaccines. Vaccines create immunity, where our body recognizes a virus and is able to fight it off without us getting sick. Instead of getting injections, which can be tough to transport and administer to remote countries where disease is most prevalent, scientists want to put it into their food.One vaccine being studied is for hepatitis B. Hepatitis B is a virus that affects the liver.
Tobacco plants have been engineered to make part of the virus, which when consumed by mice, causes immunity to the virus, just like a vaccine.
Imagine a future where there are no wait lists for organ transplants. Patients with heart or kidney disease are able to have a tailor-made organ from their own tissue transplanted as soon as they need it. Currently, wait lists for organ transplants are very long and patients can wait years, and even die waiting for an organ that’s a match for their body.
Scientists are using a special type of cell, called a stem cell, to grow new organs and replace damaged tissue. Stem cells are cells that are basically a blank slate and can become any other type of cell. They can be found in both embryos and adults. Scientists take the stem cells, put in healthy, normal DNA, and then put them into patients to replace their cells that have defective DNA. Manipulating stem cells is probably one of the most recognizable forms of genetic engineering in medicine.For example, in Alzheimer’s disease, brain cells, or neurons, start to die off because of defective DNA. If doctors could grow new neurons from the patient’s stem cells, they could replace the dying cells in the brain with cells engineered to have normal DNA, curing the disease.
Currently, there is no cure for Alzheimer’s and people’s neurons slowly deteriorate over time, eventually making them unable to do even the most basic self-care.
Beyond these very tangible uses for stem cells in medicine, scientists are also using stem cells to find out more about diseases to develop drugs. Scientists can actually change a person’s body cells into a stem cell by using certain chemicals and changing the DNA that’s used inside the cell.
These are called induced pluripotent stem cells (iPSCs). They can use these cells to study diseases where getting cells from the patient is nearly impossible (like from the brain), which prevents them from understanding what causes certain diseases.For example, schizophrenia is a mental illness characterized by hallucinations and emotional problems. Although medications can be used as treatment, these people are sometimes unable to care for themselves or hold a job. Recently, scientists took skin cells from patients with schizophrenia.
They then engineered these cells back into iPSCs. From there, the scientists treated the iPSCs to change them into neurons, since stem cells can become any type of cell. Then, they looked at what was different about these neurons compared to normal neurons. Through this process, they could see what was missing in schizophrenic cells and start to design drugs to help make them healthy again. Without this process, obtaining schizophrenic neurons is nearly impossible, since it requires cutting into the brain of living patients.
And I don’t think any of us wants a scalpel cutting into our heads.
Genetic engineering is the process of cutting and pasting DNA from one organism into another. Scientists use this to create proteins, like insulin, or blood sugar, for diabetic patients by putting DNA for insulin in bacteria, which quickly make the protein.
Genetic engineering can also be used to incorporate medicine into food, such as vaccines, which create immunity, where our body recognizes a virus and is able to fight it off without us getting sick. Stem cells are a promising cure for many diseases, where blank cells can be changed into any other type of cell in the body and grown to replace damaged tissue. Research is also being performed using induced pluripotent stem cells (iPSCs) to learn more about certain diseases, like schizophrenia. This is a process in which scientists can actually change a person’s body cells into a stem cell by using certain chemicals and changing the DNA that’s used inside the cell.