Can We Train the Immune System to Kill Cancer?

Cancer is the second highest cause of death around the world ^[1]. The fight against cancer is a very, very hard one. This is, in part, because cancer isn’t just one disease, but instead over 275 of them ^[1]. Cancer is the result of random mutations giving some cells individuality that pits the cell against the body. Genes mutate both naturally and as a result of carcinogens (like cigarette smoke), which changes how a cell functions ^[1]. Mutations happen all the time, and the immune system usually kills the cells. Cancer cells are defined by mutations that help them gain six major functions:

• Growing and dividing even without growth signals from the body
• Ignoring signals to “stop growing” from the body
• A limitless ability to divide into more cells
• Avoiding the immune system’s ability to kill them
• Convincing the body to build more blood vessels to supply nutrients
• The ability to spread to other parts of the body ^[2]

These mutations present problems; the cancerous cells will take resources and destroy or replace healthy cells and organs.

Fighting cancer is particularly hard because cancer cells are human cells; they’re us! This means that medications and treatments have a lot of difficulty attacking cancer cells specifically while leaving healthy cells intact. Headlines will often tout that a new medication “kills cancer,” but fail to explain if the medication kills only cancer. For example, lava has a 100% kill rate against cancer, but injecting lava into the body isn’t a very good idea ^{[study funded by Big Lava—just kidding]}. Many current treatments kill cancer cells more than healthy cells, and finding the balance is a real art ^[3]. Surgery, hyperthermia, radiation therapy, and photodynamic therapy are used to destroy (or remove) cancer cells from the body, while hopefully limiting the damage to the area around a cancerous growth (called a tumor) ^[3]. Chemotherapy affects the whole body, with the aim to kill hungry cancer cells while hopefully sparing healthy cells ^[3]. But what if we could arm the body with the tools to fight cancer itself?

Vaccines are awesome. A vaccine is really just a way to train our immune system to fight dangerous cells or particles ^[4]. The general idea is to make a dangerous thing less dangerous (but still identifiable) and introduce it to the immune system ^[4]. The exciting part is that this has potential for use with cancer ^[5]! Cancer cells might be human cells, but the genetic mutations make unique proteins that may be detectable by the immune system ^[5]. These unique proteins are called neoantigens, and are what may be targeted by a cancer vaccine ^[5].

Personalized cancer vaccines are an exciting area of intense clinical research. A personalized vaccine can teach the immune system how to fight cancer on its own, without damaging healthy cells ^[5]. The research into this field is immense, and the science behind it is incredible. The general idea of personal cancer vaccines is to compare healthy and cancerous cells, and find unique neoantigens in the tumor ^{[5, 6]}. The hard work is finding neoantigens that can be targeted, presenting them to the immune system, and overcoming the immunosuppressant nature of cancer ^[6]. When this is figured out, a team then makes copies of the neoantigens and injects them back into the body, causing the immune system to attack any remaining cancer cells and to be vigilant in looking for new ones ^[5]. These vaccines are highly specific, which should make them safer, and are getting cheaper to manufacture ^[5]. They have been shown to be quite effective in a range of cancers, including skin, lung, and now renal cell carcinoma (kidney cancer) ^[6]. It might be that the best way to fight over 275 different types of cancer is to actually fight 8 billion of them with personalized medicine.

Creative Director Benton Lowey-Ball, BS, BFA

References:

[1] Hassanpour, S. H., & Dehghani, M. (2017). Review of cancer from perspective of molecular. Journal of cancer research and practice, 4(4), 127-129. https://www.sciencedirect.com/science/article/pii/S2311300617300125

[2] Hanahan, D., & Weinberg, R. A. (2000). The hallmarks of cancer. Cell, 100(1), 57-70. https://doi.org/10.1016%2FS0092-8674%2800%2981683-9

[3] National Cancer Institute. (n.d.) Types of cancer treatment. U.S. Department of Health and Human Services, National Institutes of Health. [Website]. https://www.cancer.gov/about-cancer/treatment/types

[4] Iwasaki, A., & Omer, S. B. (2020). Why and how vaccines work. Cell, 183(2), 290-295.https://pmc.ncbi.nlm.nih.gov/articles/PMC7560117/

[5] Xie, N., Shen, G., Gao, W., Huang, Z., Huang, C., & Fu, L. (2023). Neoantigens: promising targets for cancer therapy. Signal transduction and targeted therapy, 8(1), 9. https://www.nature.com/articles/s41392-022-01270-x