In a major development in cancer research, scientists at the University of Florida have created an experimental mRNA vaccine that stimulates the immune system to attack tumours. According to a study published in Nature Biomedical Engineering, the vaccine, when used alongside immune checkpoint inhibitors, produced a strong antitumor effect in mice.
The vaccine does not target specific cancer proteins. Instead, it activates the immune system in the same way it would respond to a virus. Researchers found that the vaccine increased the levels of a protein called PD-L1 within tumours, making them more sensitive to immunotherapy.
A new approach to cancer treatment
Dr. Elias Sayour, a paediatric oncologist at UF Health and the lead researcher, said this development could lead to a new form of cancer treatment that does not rely entirely on surgery, radiation, or chemotherapy. The research was supported by the National Institutes of Health and other leading institutions.
“This paper describes a very unexpected and exciting observation: that even a vaccine not specific to any particular tumor or virus – so long as it is an mRNA vaccine – could lead to tumor-specific effects,” said Sayour, who is also the principal investigator at the RNA Engineering Laboratory at UF’s Preston A. Wells Jr. Center for Brain Tumor Therapy.
Sayour added, “This finding is a proof of concept that these vaccines potentially could be commercialised as universal cancer vaccines to sensitise the immune system against a patient’s individual tumor.”
The research challenges the two current approaches in cancer-vaccine development: targeting common proteins found in cancer patients or customising a vaccine for each patient. This study suggests a third path that focuses on stimulating a broad immune response.
“This study suggests a third emerging paradigm,” said Duane Mitchell, MD, PhD, a co-author of the paper. “What we found is by using a vaccine designed not to target cancer specifically but rather to stimulate a strong immunologic response, we could elicit a very strong anticancer reaction. And so this has significant potential to be broadly used across cancer patients, even possibly leading us to an off-the-shelf cancer vaccine.”
Building on past research
Sayour has spent more than eight years developing mRNA-based cancer vaccines using lipid nanoparticles. These vaccines work by delivering messenger RNA (mRNA), a molecule that instructs cells to make specific proteins, into the body to prompt an immune reaction.
Last year, Sayour’s lab conducted a human trial using a personalised mRNA vaccine made from a patient’s own tumour cells. The treatment quickly activated the immune system to fight glioblastoma, a deadly brain cancer. The new study builds on that work by testing a generalised mRNA vaccine, not specific to any virus or cancer mutation.
The formulation of this new vaccine is similar to the technology used in COVID-19 vaccines but is designed to prompt a general immune response rather than target a specific protein like the COVID spike protein.
If the vaccine shows similar results in future human studies, it could lead to a universal tool in the fight against cancer.
