SIMPLIFIED: "Can mRNA Vaccines Help Treat Cancer?"

Link to original article:

https://www.cancer.gov/news-events/cancer-currents-blog/2022/mrna-vaccines-to-treat-cancer

Authors of original article: Edward Winstead

This image was taken from the original article: https://www.cancer.gov/news-events/cancer-currents-blog/2022/mrna-vaccines-to-treat-cancer

mRNA (Messenger RNA) is similar to a set of instructions. It tells cells how to make a specific protein through transcription and translation. Transcription is located inside the cell’s nucleus, and it helps the cell make a temporary, single-stranded copy of a specific gene from the DNA. This copy is the mRNA. Then, the mRNA leaves the nucleus and travels to the ribosome, the cell’s protein factory, located in the cytoplasm. The ribosome then reads the mRN sequence in groups of three letters (ex. AUG, UUU, CGC). Transfer RNA (tRNA) molecules act as delivery trucks. Each tRNA has a specific amino acid and a matching “anticodon” on the other. When the tRNA’s anticodon matches the mRNA codon, the ribosome links that amino acid to the growing chain. COVID vaccines used mRNA to help the body recognize the coronavirus. Cancer researchers use mRNA to help the immune system recognize cancer cells. 

Cancer cells often have unique mutations that create abnormal proteins. Scientists can identify these abnormal proteins and design an mRNA vaccine that can allow the immune system to pinpoint exactly what it is looking for. Once the immune system is able to pinpoint the proteins, it may be able to find and attack cancer cells more effectively. 

Because of the success of the COVID vaccines, it showed that mRNA technology can be developed and manufactured faster than many people expected.  Most cancer vaccines discussed in the article are treatment vaccines which means that they are given to people who already have cancer. The goal of the vaccine is to help the immune system fight existing tumors rather than prevent cancer from developing in the first place.

One of the major concerns while developing mRNA cancer vaccines is protecting the mRNA once it enters the body. The mRNA needs to be injected with proper protection because, if not, the immune system will see it as a foreign substance and destroy it before it can do its job. To address this problem, scientists package the mRN inside tiny fat particles called lipid nanoparticles that act like protective containers that safely deliver the genetic instruction into cells.  Researchers have found that slightly modifying the mRNA helps avoid detection by the immune system so that the vaccine works more effectively.

Scientists use these new discoveries to develop personalized mRNA cancer vaccines. These treatments are specifically designed for each patient depending on their unique genetic mutations that are found in their tumor. Once a tumor sample is collected, researchers identify abnormal proteins called neoantigens that are produced only by cancer cells. The vaccine is then created to help the immune system recognize these neoantigents and target the cancer tumors more precisely. 

In one study involving patients with advanced head and neck cancer, some participants were able to experience significant tumor shrinkage while others saw their tumor completely disappear with the treatment. Although the studies include a small number of patients, the results from the study show that personalized mRNA vaccines may be a powerful new form of cancer immunotherapy. There is still much research that still needs to be continued and improved to determine how these vaccines can be combined with other treatments to achieve even better outcomes for patients.