Nutritionists and other health experts will all tell you the same thing: eating fish can be very good for your health. However, did you know that even a salmon plague can treat cancer? It may sound ridiculous, but this is what some researchers are suggesting after the discovery of toxins in fish bacteria that can stop tumor growth in its tracks.

Redmouth disease is a bacteria-borne illness that ravages salmon and trout populations across six major continents (excluding Antarctica) every year. The prevalence and impact of the disease varies by region, but because it is heavily dependent on water quality, poorly-managed fish farms often suffer losses on a plague-like scale. And this should be no surprise. The pathogen behind this disease, Yersinia ruckeri, is a relative of the bubonic plague - a disease infamous for its ability to quickly and efficiently cull populations in unsanitary environments.

However, the same mechanism that makes redmouth disease so deadly for fish could also make it a novel weapon in the battle against cancer. According to a study recently published in the journal Nature Communications, Y. ruckeri traditionally attacks cells by injecting them with a specialized enzyme called Afp18. (Scroll to read on...)

By observing it in action, researchers from the BIOSS Centre for Biological Signalling Studies in Germany determined that Afp18 acts as a toxin after finding its way into the cells of fish embryos. It turns out that Afp18 is uniquely capable of deactivating a switch protein called RhoA, which is responsible for building up and breaking down of actin filaments. These filaments are essential for cell division, which mean they are also essential for the spreading of tumor metastases in the body.

Now, after seeing the toxin wreak its havoc in the embryos of zebra fish, the researchers suspect that Afp18 could likewise attack and kill harmful cancers. However, how exactly they will keep the toxin on target and isolated - away from a patient's healthy cells - remains to be seen.

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