Antimicrobial Peptides To Kill Cancer

Antimicrobial Peptides (AMPs) are small proteins made by organisms as part of their innate immune system. They kill invading bacteria, fungi, and viruses by ripping their cell membrane and interfere with the processes of the microbe. Given that they don’t target human cells or other animal cells, cancer cells seem immune to AMPs. Many studies show, however, that this is not the case.

Cancer cells are simply regular cells that have gone rogue. They usually arise from an imperfection in mitosis that causes them to act as an individual rather than as a part of the body. These mutants are usually killed by the body quickly but, by chance, some mutations let cells go undetected. Eventually, it leads to the blood vessels in the body being redirected to the cell as it multiplies. It hogs the body’s resources and this is what leads to a life-threatening tumor. Given that cancer cells gain these mutations while still remaining normal cells, it makes sense that AMPs wouldn’t harm them. However, similar to how cancer cells have variations based on their host animal, AMPs also have many forms based on their origin.

AMPs are molecules that float around in the body as part of the innate immune system, killing invaders without needing to dispatch the macrophages, dendritic cells and neutrophils that could potentially harm the body. Using reactions between the multiple peptides, they rip open the cell membrane of invading microbes and kill them. AMPs exist in every multicellular creature and in every part of them. Muscles, bones, organs, even venom and saliva, have AMPs. AMPs coming from different sources have different properties: plant AMPs are very heat resistant, bacterial AMPs can be used as food preservatives, and venom AMPs from honeybees can kill cancer cells.

Melittin is a protein assembled by 26 amino acids derived from honeybee venom. It is amphipathic, meaning they have both hydrophilic and hydrophobic parts, and has direct tumoricidal effects and immunomodulatory functions. Like other AMPs, melittin destroys the cell membrane and allows fluid and cytoplasm to leak out. It also harms and affects cancer cells. There are a couple issues with this, one of them being that it affects normal human cells, as is the nature of a venom. If it is applied directly to the tumor, it can remove it, but it cannot guarantee the tumor won’t come back or that the normal cells around the tumor will be unharmed. However, it has shown promising results against treatment resistant cancers and targeted versions for specific types of cancer have been made. Overall, AMPs could be how cancer is beaten in the future instead of traditional pills and syrups. 

References:

Zhang, H.-Q., Sun, C., Xu, N., & Liu, W. (2025). The current landscape of the antimicrobial peptide Melittin and its therapeutic potential. Retrieved from https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1326033/full  

Duffy, C., Sorolla, A., Wang, E., Golden, E., Woodward, E., Davern, K., … Blancafort, P. (2020). Honeybee Venom and Melittin suppress growth factor receptor activation in HER2-enriched and triple-negative breast cancer. Retrieved from https://www.nature.com/articles/s41698-020-00129-0 

Barashkova, A. S., & Rogozhin, E. A. (2020). Isolation of antimicrobial peptides from different plant sources: Does a general extraction method exist? - plant methods. Retrieved from https://plantmethods.biomedcentral.com/articles/10.1186/s13007-020-00687-1 

Yu, X., Jia, S., Yu, S., Chen, Y., Zhang, C., Chen, H., & Dai, Y. (2023). Recent advances in Melittin-based nanoparticles for antitumor treatment: From mechanisms to targeted delivery strategies - journal of nanobiotechnology. Retrieved from https://jnanobiotechnology.biomedcentral.com/articles/10.1186/s12951-023-02223-4 

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