In the early 1900s, scientists were beginning to debate on a crucial topic. What did species pass into the next generation to make them continue? The molecules that controlled it all were unknown at the time. The debate continued into the 1950s when experiments finally showed that DNA was the molecule of life. Just how DNA made everything from blue whales to bacteria was unlocked in the mid-1960s. Manipulating the code of life would begin in the ’70s and expand significantly from there.
The growth in understanding and controlling the code of life has been exponential. Countless articles, published across many scientific journals daily, tell the history and future of our planet. Manipulation of the code of life is becoming easier all the time. So, when you tell students that science can put spider web genes in a goat and make the goat’s milk produce spider silk, some will ask, “what else could we do”? All science begins with a question!
A recent article titled “Transgenic goats producing an improved version of cetuximab in milk” helps answer that fundamental question. Monoclonal antibodies have become a go-to medication for a variety of ailments. The antibodies can bind very specifically to about anything in our bodies and give us great control over cell behavior. These antibodies can stop your rheumatoid arthritis, cure your migraines, get rid of your psoriasis, and treat your cancer. They are currently being investigated as a potential cure for Covid-19 also. Unfortunately, they are costly and challenging to mass produce!
Goats can produce copious amounts of milk, so imagine genetically engineering a goat to make a drug, like a monoclonal antibody, in their milk. Then you extract the product from their milk with standard and inexpensive techniques. If you Google the title of the article above, you can read the entire paper for free. The article provides great detail on just how science genetically modifies a goat to make various substances in their milk and how they get that substance out.
Cetuximab is a monoclonal antibody that binds to epidermal growth factors helping to inhibit the growth of metastatic colorectal and head and neck cancers. Health.gov puts the cost of this drug at about $7,000 per month. Finding ways to reduce the cost of monoclonal antibodies is vital, and modifying goats to make it for us is one way to accomplish this.
Fetal goat cells are genetically modified in the lab to produce the desired monoclonal antibody within the milk-producing cells of the adult goat. The genetics of the engineered cells get double-checked to ensure the modification was correctly made. The modified nuclei of the fetal cells are then inserted into donor eggs and placed in a surrogate mother. If all goes as planned, out pops your edited baby goat about 150 days later. Once she starts making milk, she will produce about 10 grams of cetuximab for every 1 liter of milk. The team’s research showed that the edited goats produced a more effective version of cetuximab with a better safety profile.
Genetically engineered goats are not new. They were FDA approved in 2009 to make human antithrombin, an anticoagulant. This was the first drug made by genetically modified animals, imagine what tomorrow will bring.