An antimicrobial agent called Defensin kills tumor cells and shrinks tumor size in fruit flies, with help from a pathway that flags the cells for destruction. Antimicrobial peptides (AMPs) are small cationic molecules best known as mediators of the innate defence against microbial infection. The study providing the first evidence in live animals that antimicrobial peptides (AMPs), which help protect against infection, also defend against cancer.
But also studies in animals and humans; the discovery could one day lead to new cancer treatment strategies. Using a Drosophila model of tumourigenesis; study demonstrating a role for the AMP Defensin in the control of tumour progression. that AMPs kill cancer cells grown in the laboratory, but the findings had not been confirmed in living creatures. But experiments showing that tumor-prone fruit flies produce more Defensin than their normal counterparts.
Antimicrobial peptides in humans
By using the fruit fly Drosophila melanogaster to investigate; whether the machinery that is best knowing for its role in the recognition and elimination of harmful microbes is also capable of recognizing malignant cells; in a living organism and eliminating them in a similar manner. Defensin recognizes tumor cells in the same way it recognizes harmful microbes.
The fly version of a protein called Tumour Necrosis Factor helps flag the tumor cells for destruction and makes the cells more sensitive to Defensin’s attack. As it does this by bringing a protein called phosphatidylserine to the surface of the tumor cells. Defensin then binds to phosphatidylserine-rich areas on the tumor cells and kills them. Defensin binds tumour cells in PS-enriched areas, provoking cell death and tumour regression.
Altogether, our results provide the first in vivo demonstration; for a role of an endogenous AMP as an anti-cancer agent, as well as a mechanism; that explains tumour cell sensitivity to the action of AMPs. While in vitro and ex vivo evidence suggest AMPs’ capacity to kill cancer cells; in vivo demonstration of an anti-tumour role of endogenous AMPs is lacking
However, the study results reveal an anti-tumor role for Defensin in flies; and provides insights on the molecular mechanisms that make tumors sensitive to the killing action of AMPs. significant translational potential for cancer research in mammalian models; as it raises the possibility that human AMPs could have anti-tumor effects similar to those of Defensin in flies. If future work confirms this, natural AMPs or chemically designing analogs might be used in anti-cancer therapeutics.