Cancer cells and coronavirus infections are completely different. Thanks to mRNA (or messenger RNA) technology, however, there may eventually be many similarities in how modern medicine combats them.
“Remember, people expected that a successful COVID-19 vaccine using mRNA would provide protective immunity to about 50 percent of patients,” said Dr. Herbert Kim Lyerly, the George Bart Geller Distinguished Professor of Immunology at the School of Medicine of Duke University. “But the first two mRNA vaccines provided over 90% protection, which is a remarkable achievement.”
How do most vaccines work?
Most vaccines work by delivering either a dead or inactive version of a pathogen or a protein from that pathogen into the body. The body’s immune system cells recognize these key proteins in the vaccine and prepare the entire system to respond more quickly if it later encounters the pathogen for real.
How are mRNA vaccines different?
mRNA vaccines are fundamentally different from most vaccines. mRNA, which stands for messenger RNA, works with your DNA. Genes in DNA encode protein molecules, the “workhorses” of the cell, performing all the functions necessary for life. But to code for these proteins, DNA needs a messenger. Enter mRNA, which reads DNA and acts as a template to make proteins.
When lab-produced mRNA is injected into the body, it does the same thing. Specific proteins are produced and an immune response can be triggered.
“It’s an RNA nucleic acid that encodes a specific protein that’s encapsulated in something we like to call a lipid nanoparticle, which is actually a little bubble of fat,” said Dr. Zachary Hartman, associate professor of surgery at Duke Cancer Institute. “This nanoparticle can be injected into your body and it kind of teaches your body what to look for immunologically.”
According to an article published in 2021 c Naturethe use of mRNA in vaccines stems from a history of research that began in the late 1980s.
Predictable cancer mutations create an opportunity
Duke researchers sought to exploit the similarities between cancer and other pathogens that mutate over time.
People with a type of breast cancer known as HER2-positive are often treated with an antibody-based drug called Herceptin. The treatment is often initially successful, but then the cancer cells develop resistance to it and the drug stops working. This is similar to how bacteria develop resistance to antibiotics. Only in this case, cancer cells develop in a very predictable way. Specific mutations occur in specific genes.
Duke’s mRNA vaccine targets four of these known mutations. The researchers plan to test the vaccine in a small number of patients with advanced HER2-positive breast cancer. Each patient will receive the same vaccine because they are each expected to develop the same mutations.
“We will effectively vaccinate people against mutations that their cancer does not yet have,” Dr. Lyerley told the BBC Scientific focus magazine.
Then, when the mutated cancer cells appear, the patient’s immune system must be ready to detect and destroy them. If it works, the vaccine should prevent the cancer from developing resistance to Herceptin. This would allow a drug that initially works well to continue working, meaning doctors would never run out of treatment options.
Researchers already say that the mRNA vaccine, even if it proves successful in clinical trials, will not be enough to defeat cancer. The disease is too complicated.
However, the mRNA vaccine can be used in combination with other therapies, including surgery and chemotherapy, offering a chance not only to treat some cancers, but also to prevent them.
“We are getting to a point where we can start being proactive with cancer as well as reacting to it,“, he says Dr Samuel Godfrey, Senior Science Communications Manager at Cancer Research UK. “I think it’s phenomenally exciting.“